Evaluation and management of glenohumeral arthritis





Overview


Glenohumeral arthritis may be defined as a condition in which the normal articular surfaces of the humeral head and glenoid are compromised by degeneration, inflammation, or injury. Many different philosophies, surgical approaches, and implants are used to manage glenohumeral arthritis. The body of knowledge surrounding the evaluation and management of shoulder arthritis has shown tremendous growth over the past several decades. This chapter presents updated information regarding current trends in anatomic and reverse shoulder arthroplasty with a focus on evidence-based outcomes and value-based care. The end result is a comprehensive resource describing in detail the past, present, and future of the evaluation and management of glenohumeral arthritis.


Relevant anatomy and biomehcanics


The normal articular surfaces of the glenohumeral joint are concentric, smooth, and securely bonded to the underlying bone. The two essential functions of these articular surfaces are (1) to distribute the joint reaction force across the broadest possible articular contact area throughout the range of shoulder motion and (2) to optimize stability without compromising motion. Even with the translation of the humeral head that occurs at the extremes of motion, the glenoid fossa, with its thick peripheral articular cartilage and labrum, still maintains full surface contact with it for optimal load transfer ( Fig. 60.1 ). The unique design of the glenohumeral joint allows a great range of motion with a large humeral head ( Fig. 60.2 ) and a small glenoid socket ( Fig. 60.3 ). This potentially unstable anatomy is stabilized by the action of the rotator cuff, which compresses the humeral articular surface into the glenoid concavity—a mechanism referred to as concavity compression ( Fig. 60.4 ). , This is similar to the stabilization of a golf ball on a small golf tee by the compressive force of gravity. When there is a sufficient concavity in the glenoid fossa, the concavity compression mechanism can provide glenohumeral stability even if the supraspinatus is deficient ( Fig. 60.5 ). However, if the glenoid concavity is compromised, the humeral head is no longer stabilized ( Fig. 60.6 ).




Fig. 60.1


Cadaver dissection of the glenoid, biceps tendon insertion, and associated glenohumeral ligaments. This dissection demonstrates the anterior glenohumeral ligaments. Note the relationship of the anterior inferior (I) and the anterior middle (M) glenohumeral ligaments to the anterior rim of the glenoid.



Fig. 60.2


The smooth articular surface of the humeral head surrounded by the insertion of the tendons of the rotator cuff, with the long head of the biceps entering the bicipital groove at top center.



Fig. 60.3


The relatively smaller surface area of the glenoid socket allows a large range of humeral motion before contact occurs between the humeral tuberosities and the glenoid rim (arrows) .



Fig. 60.4


Compression into the glenoid concavity. The rotator cuff compresses the humeral articular convexity into the glenoid concavity, as shown by the arrows .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:85.)



Fig. 60.5


Intact glenoid concavity. If the glenoid concavity is intact, the compressive action of the subscapularis and infraspinatus can stabilize the humeral head in the center of the glenoid socket against the upward pull of the deltoid, even in the absence of the supraspinatus (red dotted lines) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:263.)



Fig. 60.6


Loss of centering. A loss of both the rotator cuff and the superior glenoid concavity (dotted line) allows the destabilized humeral head to move upward rather than abduct on deltoid contraction.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:263.)


In the arthritic glenohumeral joint, the smooth, concentric joint surfaces are lost because of damage to the articular cartilage and the underlying bone ( Figs. 60.7 and 60.8 ). There are numerous types of pathophysiology that can result in an arthritic glenohumeral joint. This chapter discusses important differences among the different types of arthritis, but a brief overview is provided here. Degenerative joint disease (also known as osteoarthritis or osteoarthrosis) is a common type of glenohumeral arthritis in which the articular cartilage fails from heavy use, cumulative minor traumatic episodes, underlying structural defects in the joint, anomalies in cartilage composition, or a combination of these factors. Capsulorrhaphy arthropathy is one of the most common forms of glenohumeral arthritis in younger patients; it is a complication of a prior repair for glenohumeral instability with some combination of (1) overtightening of the anterior capsule that causes posterior humeral subluxation and/or (2) prominent suture anchors, staples, screws, or transferred coracoid bone that cause excoriation of the humeral articular cartilage. , In rheumatoid and other types of inflammatory arthritis the cartilage of the humeral head and glenoid is uniformly destroyed by an autoimmune reaction, with characteristic periarticular osteopenia, marginal erosions, and minimal osteophyte formation. Chondrolysis is an iatrogenic condition in which the glenohumeral articular cartilage is destroyed, most commonly due to the toxic effects of local anesthetics infused by a pain pump after arthroscopic surgery, particularly after procedures involving the use of glenoid suture anchors in young individuals. In avascular necrosis the bone supporting the humeral articular cartilage collapses, often because of corticosteroid use, alcoholism, or prior trauma. In posttraumatic arthritis the anatomy of the glenohumeral joint is distorted due to a prior fracture with malunion or nonunion. Rotator cuff tear arthropathy is the combination of an irreparable rotator cuff defect and glenohumeral arthritis, which may lead to anterosuperior escape and pseudoparalysis. Neurotropic arthropathy arises in association with syringomyelia, diabetes, or other causes of joint denervation; the joint and subchondral bone are destroyed due to the loss of the trophic and protective effects of their nerve supply.




Fig. 60.7


The arthritic head devoid of articular cartilage and surrounded by osteophytes.



Fig. 60.8


An arthritic glenoid with loss of cartilage on the posterior 75% of the surface (to the right of the image).


Clinical evaluation


Patients suspected of having glenohumeral arthritis should be evaluated with a history, a physical examination, and standardized plain radiographs. In the great majority of cases this basic evaluation is sufficient to establish the diagnosis and treatment plan. ,


History


Chief complaint


Patients with symptomatic glenohumeral arthritis often complain of pain, stiffness, crepitation on movement, loss of function, difficulty sleeping, and discomfort with changes in barometric pressure. Glenohumeral arthritic pain is commonly felt over the posterior aspect of the glenohumeral joint in contrast to pain from cervical radiculopathy that is commonly felt in the area of the trapezius. It is important to document the circumstances surrounding the onset of the problem, its pattern of progression over time, and its response to prior medical and surgical treatment.


The use of standardized patient-reported outcome measures (PROMs) is an effective way to get a snapshot of the condition of the shoulder at the time of initial presentation and during follow-up evaluation. The routine use of these measures allows for the ability to track improvement in the individual patient and outcomes of cohorts of patients that facilitates our ability to improve outcomes. In my practice all patients are asked to complete PROMs specific for the shoulder as well as an assessment of global health.


The Simple Shoulder Test (SST) ( Box 60.1 ) , is a practical, efficient, sensitive, and extensively validated tool based on the chief complaints of patients presenting with shoulder arthritis. The major functional deficits for the common types of glenohumeral arthritis include difficulty with sleeping comfortably on the affected side, washing the back of the opposite shoulder, placing eight pounds on a shelf, and throwing overhand ( Fig. 60.9 ; Table 60.1 ).



BOX 60.1

Simple Shoulder Test





  • Is your shoulder comfortable with your arm at rest by your side?



  • Does your shoulder allow you to sleep comfortably?



  • Can you reach the small of your back to tuck in your shirt with your hand?



  • Can you place your hand behind your head with the elbow straight out to the side?



  • Can you place a coin on a shelf at the level of your shoulder without bending your elbow?



  • Can you lift 1 lb (a full pint container) to the level of your shoulder without bending your elbow?



  • Can you lift 8 lb (a full gallon container) to the level of the top of your head without bending your elbow?



  • Can you carry 20 lb (a bag of potatoes) at your side with the affected extremity?



  • Do you think you can toss a softball underhand 10 yards with the affected extremity?



  • Do you think you can throw a softball overhand 20 yards with the affected extremity?



  • Can you wash the back of your opposite shoulder with the affected extremity?



  • Does your shoulder allow you to work full time at your regular job?





Fig. 60.9


Percentage of 3128 patients with primary degenerative joint disease of the shoulder able to perform each of the 12 functions of the Simple Shoulder Test.


TABLE 60.1

Percentage of Patients Able to Perform Functions of the Simple Shoulder Test at the Time of Initial Evaluation, According to Type of Glenohumeral Arthritis












































































































Function DJD SDJD RA CTA CA AVN
Sleep comfortably 12 13 18 8 0 29
Arm comfortable at side 67 36 61 33 65 79
Wash back of shoulder 13 20 13 0 18 7
Hand behind head 35 38 26 21 35 50
Tuck in shirt 32 33 39 38 29 50
8 lb on shelf 19 16 3 0 18 7
1 lb on shelf 54 36 26 21 53 50
Coin on shelf 59 44 29 29 53 64
Throw overhand 7 9 3 4 0 0
Do usual work 39 44 21 17 41 21
Throw underhand 53 44 13 42 29 21
Carry 20 lb 62 62 21 33 41 29

AVN, Avascular necrosis; CA, capsulorrhaphy arthropathy; CTA, cuff tear arthropathy; DJD, degenerative joint disease; RA, rheumatoid arthritis; SDJD, secondary degenerative joint disease.


As a patient-reported assessment, SST serves as the baseline for documenting the presenting status of the shoulder and tracking its response to treatment over time, and it removes concern over variability related to different observers. Importantly, this assessment tool does not require the patient to return to the office, but rather can be submitted by mail, email, or online. Without any substantial investment of time or money, this practical method allows surgeons to establish for themselves the time to recovery and the duration of the functional benefit of different procedures and share these results with prospective patients. Perhaps even more importantly, monitoring changes in SST after surgery enables the surgeon to identify individual arthroplasty procedures that were not successful in restoring comfort and function for the patient, and to learn from these “with a view to preventing similar failures in the future,” as recommended by Codman. ,


The second important PROM is a self-assessment tool that evaluates global health. An example of this is the Short Form-36 Health Survey (SF-36), which enables patients to document their overall health status. , , The SF-36 scales of emotional role function, mental health, and social function are more closely correlated with pain and functional impairment than the “objective” measures of the severity of the disease. , , , For patients with osteoarthritis presenting for shoulder arthroplasty, the SF-36 scores are inversely correlated with the number of comorbidities. The greatest compromise in the self-assessed overall health status of patients with glenohumeral arthritis is found in the SF-36 domains of physical role function and overall comfort ( Table 60.2 ). For patients with primary or secondary degenerative joint disease or cuff tear arthropathy (CTA), scores for the other SF-36 parameters (such as vitality and overall health) are relatively close to those of population-based age- and sex-matched controls. In contrast, the health status of patients with rheumatoid arthritis, capsulorrhaphy arthropathy, or avascular necrosis is poorer than that of controls of the same age and sex. , The overall well-being of the patient, including preoperative physical function, general health, social function, and mental health, has been shown to be strongly correlated with the quality of the outcome after shoulder arthroplasty. , The recognition of the importance of the overall condition of the patient in influencing the outcome of treatment recalls the quote often attributed to Sir William Osler: “It is much more important to know what sort of a patient has the disease than what sort of a disease the patient has.” SF-36 provides a convenient and standardized way of knowing “what sort of a patient has the disease.”



TABLE 60.2

Self-Assessed Health Status of Patients, Revealed by the Short Form-36, According to the Type of Glenohumeral Arthritis












































































Parameter DJD SDJD RA CTA CA AVN
Physical role function 44 33 23 30 39 28
Comfort 54 47 34 39 40 47
Physical function 78 73 38 81 62 50
Emotional role function 83 76 58 100 64 40
Social function 84 73 63 81 71 62
Vitality 86 83 44 81 65 60
Mental health 92 90 87 97 76 84
General health 100 93 65 100 71 63

Data presented as the mean percentage of the value for an age- and sex-matched control population.

AVN , Avascular necrosis; CA , capsulorrhaphy arthropathy; CTA , cuff tear arthropathy; DJD , degenerative joint disease; RA , rheumatoid arthritis; SDJD , secondary degenerative joint disease.


I utilize an SF-12, which has fewer questions than the SF-36 but maintains the accuracy for physical and mental health domains. I also collect visual analog scale responses for pain and function of the shoulder, which are simple but effective tools for longitudinal evaluation of patient progression through treatment.


Medical history


When taking the patient’s history, the surgeon attempts to elicit all factors that may influence the patient’s situation and recovery from surgery, such as use of nicotine, alcohol, and narcotics; complications of prior surgeries and anesthetics; medical comorbidities; depression; the patient’s living situation; social and family support; the relationship of the shoulder condition to work; and insurance coverage for surgical and postoperative care. Shoulder arthroplasty is an elective procedure which allows time to optimize medical comorbidities. Modifiable risk factors in shoulder arthroplasty include pain medication control, respiratory health (including obstructive sleep apnea), diabetic control, blood pressure, cardiac health, and urinary function. Patients are encouraged to actively participate in optimizing their surgical and postoperative care with the help of their medical providers. The use of a preoperative checklist ( Box 60.2 ) and open communication with the patient’s other medical providers are effective strategies in engaging patients in this process.



BOX 60.2

Checklist for Patients Considering Shoulder Joint Replacement


Habits





  • ____ Engage in 3 hours of aerobic exercise per week unless your primary care physician deems it unsafe.



  • ____ Avoid smoking or use of any nicotine-containing products for 3 months prior to surgery.



  • ____ Avoid any narcotic medications stronger than hydrocodone for 3 months prior to surgery. If heavier narcotics have been used, detoxification under physician supervision is recommended 3 months before the surgery.



  • ____ For 3 months before surgery, restrict alcohol consumption to one drink per day.



Planning





  • ____ Formulate a plan for postoperative care well in advance of surgery, recognizing that the shoulder may be less useful than it was before for a period of weeks or longer after surgery. Understand the limitations on activities after surgery, such as restrictions on driving (usually for 6 weeks after surgery), as well as the need for someone to be with you for days or weeks after the procedure. Identify the possible need for a temporary stay at a skilled nursing facility and secure the funding for this stay well in advance of the procedure.



  • ____ Identify a primary care physician who will manage your nonsurgical concerns and medications after surgery. If you live at a distance from your surgeon, identify a physician locally who will be available to check the wound and obtain follow-up radiographs as necessary.



  • ____ Understand and plan for the rehabilitation program after surgery as well as the plan for follow-up with the surgeon. Ask your surgeon if a local therapist will be needed after this procedure; if so, identify one before surgery.



Physical and emotional health





  • ____ Obtain a current dental evaluation. Optimize dental hygiene, including gum care. The mouth can be a source of bacteria leading to infection. Dental concerns need to be tended to at least 4 weeks before surgery.



  • ____ Identify any skin lesions anywhere on the body, especially on the arm that will undergo surgery. These need to be completely healed at least 2 weeks before surgery. Be particularly careful to check the skin in the armpit and under the breasts.



  • ____ Ensure that any infections are completely resolved and antibiotics discontinued at least 6 weeks prior to surgery.



  • ____ Optimize control of health conditions, such as sleep apnea, anxiety, depression, diabetes, hypertension, heart conditions, and urinary tract function.



Communication with the surgical team





  • ____ Discuss the surgeon’s personal experience with the problem and the procedure, along with possible risks, alternatives, and anticipated outcomes.



  • ____ Notify the team if prior experience suggests that it will be difficult to establish an intravenous (IV) line for surgery, that it has been difficult for an anesthesiologist to establish an airway, or if you have had any problems with prior anesthetics, the control of pain, excessive bleeding, or blood clots.



  • ____ Let the surgical team know if any family member or blood relative ever had a serious problem with anesthesia; if they did, what was the problem?



  • ____ Discuss with the surgeon any heart conditions, strokes, kidney disease, liver disease, lung disease, bleeding tendencies, prior surgical complications, reactions to anesthetics, or seizures. Do you have a pacemaker?



  • ____ Document and communicate all medical allergies, especially allergies to antibiotics and latex.



  • ____ Could you be pregnant? If so, we would recommend that you have a pregnancy test performed before coming for surgery, and, if you are pregnant, that you not undergo elective surgery until after delivery.



  • ____ Compile and share with your surgeon a complete list of all prescription and over-the-counter medications you are taking.



  • ____ Recognize that antiinflammatory medications, blood thinners (e.g., aspirin, ibuprofen, Advil, warfarin, Coumadin, or Plavix), fish oil, omega-3 fatty acids, and some herbal supplements can increase the risk of bleeding and their use may need to be modified well in advance of surgery. If you are taking drugs to prevent blood clotting, you should consult with your cardiologist and the preanesthesia clinic or your surgeon at least 10 days in advance to obtain instructions regarding when these medications need to be stopped or modified.



  • ____ Identify and discuss with your surgeon any legal issues regarding the shoulder problem well in advance of surgery.



  • ____ Verify insurance coverage well in advance of surgery. This is especially important for patients from a different state than the one where the surgery will be performed, for those for whom an extended care facility may be needed after surgery, and for patients making Workers’ Compensation insurance claims.




Physical examination


The first and possibly the most important part of the physical examination is a general assessment of the overall person. This includes evaluation of the mental, nutritional, and social status of the patient. Many factors can influence outcome of treatment for glenohumeral arthritis, and the surgeon should consider these aspects of the overall person in determining the appropriate treatment plan. Some factors to consider are as follows. Is the individual happy or depressed, healthy or chronically ill, fit or frail, well-nourished or malnourished, actively engaged or passive? Who accompanied the patient to the visit: spouse, friend, caregiver, caseworker, or lawyer? Does the patient smell of cigarettes or alcohol, or have pinpoint pupils suggestive of narcotic use? Does the patient use a cane or crutch and, if so, in which hand? Is the patient steady or unsteady on his or her feet? Can the patient get up on the examination table unassisted? Does he or she use the involved arm to slip off a coat or to talk or shake hands?


The examination of the shoulder should include an assessment of the cervical spine. Examination of the neck may reveal evidence of cervical spondylopathy that may be contributing to the patient’s symptoms, or restriction of the range of neck motion that would require special attention at the time of surgery. In patients with rheumatoid arthritis it is important to determine neck stability as well as the patient’s ability to open the mouth to a degree that would allow anesthetic intubation.


Inspection of the shoulder requires it to be exposed by appropriate disrobing so that the examiner can evaluate the health of the skin over the shoulder, including the presence of previous incisions, rashes, acne, vascular changes, or open wounds. Inspection also includes evaluation of the vascular and lymphatic circulation of the limb, muscle atrophy, swelling, deformity or signs of inflammation, or deep infection.


After the inspection, it is useful to start the physical examination with a “no-touch” opening: “Can you show me the movements that are the biggest problem for you?” These patient-identified limitations allow initial consideration about which treatment may be of benefit. Next, ask the patient to demonstrate ability to actively abduct, flex, and rotate the shoulder as well as reach across the body and up the back, first with the normal shoulder and then with the symptomatic one. In a patient-friendly way this provides an initial broad assessment of the function of the shoulder and the degree of discomfort associated with motion. After asking permission to physically examine the shoulder, palpate it, seeking evidence of effusion, tenderness, or glenohumeral instability, as well as subacromial, glenohumeral, scapulothoracic crepitance, or rotator cuff and subscapularis defects ( Figs. 60.10–60.12 ).




Fig. 60.10


Palpation of cuff defects. Defects in the tendinous cuff can often be palpated through the overlying skin and deltoid.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:283.)



Fig. 60.11


Palpation of supraspinatus defects. The accessibility of the supraspinatus tendon for palpation can be enhanced by extending the arm.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:283.)



Fig. 60.12


A defect in the superior subscapularis tendon insertion may be palpable at the anterior shoulder.


Then proceed with the formal evaluation of shoulder mobility, including the assessment of forward elevation ( Fig. 60.13 ), abduction ( Fig. 60.14 ), external rotation at the side ( Fig. 60.15 ), external rotation in abduction ( Fig. 60.16 ), internal rotation up the back ( Fig. 60.17 ), internal rotation in abduction ( Fig. 60.18 ), and cross-body adduction ( Fig. 60.19 ). These tests evaluate the range of motion of the humerus relative to the thorax. A more specific assessment of the range of glenohumeral motion can be obtained if the examiner uses one hand to stabilize the scapula while establishing flexion and extension and internal and external rotation of the humerus, relative to the scapula, with the other hand. It is useful to show the patient and family members the contrast between the motion of the affected shoulder and that of the contralateral normal or less affected shoulder.




Fig. 60.13


Limited humeral forward elevation relative to the thorax.



Fig. 60.14


Limited humeral abduction.



Fig. 60.15


Limited humeral external rotation with the arm adducted at the side.



Fig. 60.16


Limited humeral external rotation with the arm in the 90-degree abducted position.



Fig. 60.17


Limited humeral internal rotation behind the back as measured by the level of the thumb position relative to the level of spine.



Fig. 60.18


Limited humeral internal rotation with the arm in the 90-degree abducted position.



Fig. 60.19


Limited cross-body adduction as measured by the distance between the elbow antecubital crease and the opposite shoulder.


Although most arthritic shoulders develop stiffness and contractures, it is possible for some to have instability. Shoulders with degenerative joint disease or capsulorrhaphy arthropathy may demonstrate posterior humeral translation as the arm is raised in the plane of the scapula ( Fig. 60.20 ) or when it is actively moved from 90 degrees of abduction to 90 degrees of flexion ( Fig. 60.21 ). Shoulders with anterior glenoid deficiency may demonstrate anterior instability as the arm is moved from flexion to extension. Shoulders with cuff deficiency may demonstrate upward displacement of the humeral head with active contraction of the deltoid, referred to as “anterosuperior escape” ( Figs. 60.22–60.25 ). Shoulders with distorted bony anatomy, cuff deficiency, or deltoid deficiency may have inferior instability.




Fig. 60.20


Posterior humeral head subluxation as the arm moves from adduction at the side (A) to abduction in the scapular plane (B), referred to as “scaption.”



Fig. 60.21


Posterior humeral head subluxation (red arrow) as the arm actively moves from 90 degrees of abduction (A) to 90 degrees of flexion (B).



Fig. 60.22


Anterosuperior escape.



Fig. 60.23


Rotator cuff tear arthropathy with anterior instability.



Fig. 60.24


Rotator cuff tear arthropathy with severe acromial erosion that predisposes to acromial fracture.



Fig. 60.25


In shoulders with rotator cuff deficiency the humeral head demonstrates superior displacement with active contraction of the deltoid (bottom left) . If the coracoacromial arch is also impaired, anterior displacement from beneath the acromion may occur, referred to as “anterosuperior escape” (bottom right) .


Shoulder strength is examined by manually assessing the isometric force that the patient can generate with the anterior, lateral, and posterior deltoid, as well as with the supraspinatus ( Fig. 60.26 ), infraspinatus ( Fig. 60.27 ), and subscapularis ( Fig. 60.28 ) muscles. Examination of the function of suprascapular, long thoracic, axillary, musculocutaneous, median, radial, and ulnar nerves is important for both identifying possible neurologic contributions to the patient’s symptoms as well as establishing the integrity of these nerves before surgical intervention.




Fig. 60.26


The supraspinatus is tested by positioning the arm in 90 degrees of abduction in the plane of the scapula and in internal rotation; this puts the supraspinatus tendon on top of the humeral head. The patient holds this position while the examiner attempts to adduct the arm.



Fig. 60.27


The infraspinatus is tested by positioning the humerus with the elbow at the side and the forearm pointing straight ahead. The patient holds this position while the examiner attempts to push the arm into internal rotation.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:287.)



Fig. 60.28


The subscapularis is tested by having the patient press the hand in toward the stomach, keeping the elbow in the plane of the body. The patient holds this position while the examiner attempts to pull the hand away from the stomach (red dotted arrow) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:287.)


Radiographic evaluation


The purpose of imaging of the shoulder is to help establish the diagnosis, determine the severity of the pathoanatomy, assist in surgical planning, and enable the surgeon to illustrate the condition of the shoulder to the patient. Unless a specific research protocol is in place, the temptation to “overimage” should be resisted, obtaining only the scans or reconstructions that are necessary for the care of the patient ( Fig. 60.29 ). Standardized plain films are essential in the evaluation of patients with glenohumeral arthritis. Proper radiographic technique is as important to achieve the desired images to allow for the development of an appropriate treatment plan.




Fig. 60.29


Three-dimensional reconstructions can reveal fine details of the shoulder anatomy, but this additional information rarely changes the planning or conduct of the arthroplasty.


The first key view is the anteroposterior (AP) in the plane of the scapula taken so that the x-ray beam passes through the glenohumeral joint ( Fig. 60.30 ). This view shows the superoinferior position of the humeral head relative to the glenoid, the presence of osteophytes on the humeral head and glenoid, narrowing of the joint space, the degree of medial displacement of the humerus in relation to the lateral acromial line ( Fig. 60.31 ), the quality of the humeral and glenoid bone, the presence of loose bodies, and whether there is humeral head collapse or deformity.




Fig. 60.30


Anteroposterior radiograph in the plane of the scapula taken 30 degrees medial to the lateral of body’s sagittal plane such that the x-ray beam passes through the glenohumeral joint. It is most easily taken by positioning the patient’s scapula flat against the cassette (asterisk) and then passing the beam at right angles to the film, aiming at the coracoid process.



Fig. 60.31


(A) Normal humeral lateral offset with the greater tuberosity lateral to the lateral acromial line (red line) . (B) Loss of humeral lateral offset due to medial joint erosion in glenohumeral arthritis. (C) Improved humeral lateral offset following an anatomic total shoulder arthroplasty.


The second key view is the axillary view taken with the arm in the functional position of elevation in the plane of the scapula ( Fig. 60.32 ) and oriented so that both the spinoglenoid notch and the scapular neck are visible. This view shows a different perspective of the humeral anatomy, the amount of glenoid bone, the shape of the glenoid, its version in relation to the plane of the scapula, and the relationship of the humeral head to the glenoid fossa. This view can be referred to as the “truth view” because it demonstrates the glenohumeral relationships in the functional position of elevation. This is in contrast to computed tomography (CT) scans, , which have the disadvantage of being taken with the arm in the adducted position ( Fig. 60.33 ). Unfortunately, many “axillary views” are taken without standardization, making it impossible to determine the important features of the glenohumeral joint ( Fig. 60.34 ).




Fig. 60.32


Axillary view taken with the arm in the functional position of elevation in the plane of the scapula. This is referred to as the axillary “truth view.”



Fig. 60.33


Computed tomographic scan taken with the arm at the side.



Fig. 60.34


A nonstandardized axillary view from which it is difficult to determine the glenohumeral pathoanatomy.


When taken properly, the standardized AP and axillary views indicate the thickness of the cartilage space between the humerus and the glenoid, relative positions of the humeral head and the glenoid, presence of osteophytes ( Fig. 60.35 ), degree of osteopenia, and extent of bony deformity and erosion.




Fig. 60.35


(A) A large “goat’s beard” osteophyte shown on the anteroposterior view. (B) A medially eroded glenoid seen on the axillary view.


Since arthritis usually involves the central aspect of the humeral head ( Figs. 60.36 and 60.37 ; also see Fig. 60.7 ), joint space narrowing is most evident on the truth view as opposed to images made with the arm at the side. Of even greater importance is the ability of the axillary truth view to show posterior subluxation or “functional decentering” that is not evident in images taken with the arm at the side ( Figs. 60.38–60.44 ). , , The degree of posterior subluxation can be measured as (1) the position of the center of the humeral head in relation to the plane of the scapula ( Fig. 60.45 ), (2) the position of the center of the humeral head in relation to the glenoid face ( Fig. 60.46 ), or (3) the point of contact of the humeral articular surface on the glenoid articular surface ( Figs. 60.47 and 60.48 ). I prefer the last of these because this point of contact reflects the degree of centering of the net humeral joint reaction force on the glenoid (see Fig. 60.47 ). , Malcentering of this joint reaction force leads to posterior instability, posterior glenoid wear, and “rocking horse” loosening of prosthetic glenoid components. The standardized axillary view also enables the surgeon to see the shape of the glenoid surface. Four main surface types have been described : concentric wear (type A) (see Fig. 60.35 ; Fig. 60.49 ), eccentric posterior wear (type B) ( Fig. 60.50 ), dysplastic (type C) ( Fig. 60.51 ), and anterior (type D) ( Fig. 60.52 ). In practice there are so many intermediate types of glenoid pathoanatomy that rigorous categorization into a few distinct classes is difficult (see Fig. 60.50 and Figs. 60.52–60.58 ). An important aspect of glenoid pathology is the amount of the glenoid that is involved in the pathologic concavity, known as the “neoglenoid” ( Fig. 60.59 ). Finally, the standardized axillary view enables measurement of the degree of glenoid retroversion in relation to the body of the scapula ( Figs. 60.60 and 60.61 ). Thus, on the standardized axillary view, the surgeon can usually determine the major important characteristics of glenohumeral arthritic pathoanatomy: the amount of joint space narrowing, degree of retroversion, degree of posterior subluxation with the arm in a functional position, shape of the glenoid, percentage of the glenoid involved in the pathologic concavity, and angle of retroversion (see Figs. 60.45–60.47 , and 60.61 ). Because of their low cost and freedom from metal artifacts, standardized axillary views provide a practical and reliable way to document the postoperative anatomy sequentially over time and to compare it to the anatomy before surgery. , ,




Fig. 60.36


Secondary degenerative joint disease with a central humeral defect from contact with suture anchors. (A) Anteroposterior radiograph showing minimal joint space narrowing. (B) Axillary view showing minimal joint space narrowing. (C) Intraoperative image showing substantial central defect.



Fig. 60.37


The “Friar Tuck” pattern of central baldness commonly seen in primary degenerative joint disease, with remaining articular cartilage at the periphery. This central loss of articular cartilage is only evident on radiographic images taken with the arm in abduction, a position that places the bald spot in contact with the glenoid.



Fig. 60.38


Functional decentering revealed by the “truth view” that was managed with a ream and run arthroplasty using an anteriorly offset humeral component. (A) Anteroposterior radiograph showing degenerative changes. (B) Axillary view showing functional decentering of the humeral head on the glenoid. (C) Anteroposterior view showing reconstruction with the ream and run procedure. (D) Axillary view showing improved centering achieved with an anteriorly eccentric humeral head component.



Fig. 60.39


Functional decentering in the absence of substantial glenoid retroversion. (A) The anteroposterior view suggests minimal pathology. (B) The truth view shows decentering of the humeral head, as indicated by a posterior contact point of the humeral head on the glenoid face.



Fig. 60.40


The axillary truth view reveals pathology without computed tomography. (A) Anteroposterior view showing loss of glenohumeral joint space. (B) Axillary view showing severe posterior subluxation in a biconcave glenoid.



Fig. 60.41


Functional decentering. (A) Anteroposterior view showing an arthritic glenohumeral joint. (B) Axillary view showing posterior humeral head subluxation into a biconcave glenoid.



Fig. 60.42


Functional decentering. (A) Anteroposterior view showing an arthritic glenohumeral joint. (B) Axillary view showing posterior humeral head subluxation into a biconcave glenoid.



Fig. 60.43


Functional decentering. (A) Anteroposterior view showing an arthritic glenohumeral joint. (B) Axillary view showing posterior humeral head subluxation into a biconcave glenoid.



Fig. 60.44


Functional decentering. (A) Anteroposterior view showing an arthritic glenohumeral joint. (B) Axillary view showing posterior humeral head subluxation into a biconcave glenoid.



Fig. 60.45


Measure of humeral posterior subluxation as the distance (SD) from the humeral head center (HC) relative to the scapular plane (red dotted line) through the mid glenoid, that is, glenoid center (GC) , which is the point midway between the anterior (A) and posterior (P) glenoid rim. The humeral head center is determined from the best circle for the humeral head curvature (circular black dotted line) .



Fig. 60.46


Measure of humeral posterior subluxation as the distance (SD) from the humeral head center (HC) relative to the mid-glenoid axis (red line) . The glenoid plane (black line) is the line between the anterior (A) and posterior (P) glenoid rim. The glenoid center (GC) is the midpoint of the glenoid plane. The mid-glenoid axis (red line) is a line perpendicular to the glenoid plane through the GC. Posterior humeral subluxation is calculated as SD divided by the glenoid width (GW) .



Fig. 60.47


Measure of humeral posterior subluxation as determined by the point of contact of the humeral articular surface on the glenoid articular surface. The point of contact is characterized as the ratio of the distance from the anterior lip of the glenoid to the center of glenohumeral contact (red arrow) divided by the distance between the anterior and posterior lips of the glenoid (black arrow) .



Fig. 60.48


Measurements of the pathoanatomy of the arthritic glenohumeral joint. S is the axis of the scapular body. G is the line connecting the anterior and posterior lips of the glenoid. C is the distance between the anterior lip of the glenoid and the center of the contact area between the humeral head and the glenoid. The angle between G and S reflects the glenoid version. The ratio of C to G reflects the position of the center of contact point on the face of the glenoid; a centered contact point has a ratio of 0.5.



Fig. 60.49


Axillary view showing an A2 glenoid.



Fig. 60.50


Axillary view showing a major biconcavity with a relatively small amount of posterior subluxation.



Fig. 60.51


Glenoid dysplasia. (A) Anteroposterior radiograph showing glenoid deformity. (B) Magnetic resonance image showing failure of formation of the posterior glenoid bone.



Fig. 60.52


Axillary view showing a small biconcavity illustrating the high degree of variability in glenoid pathoanatomy.



Fig. 60.53


Axillary view of the “bad arthritic triad”: a biconcave glenoid, glenoid retroversion, and posterior subluxation of the humeral head on the glenoid.



Fig. 60.54


Axillary view of a mildly biconcave glenoid, with minimal glenoid retroversion but substantial posterior subluxation of the humeral head on the glenoid.



Fig. 60.55


Axillary view showing a small biconcavity illustrating the high degree of variability in glenoid pathoanatomy.



Fig. 60.56


Posterior subluxation with minimal glenoid biconcavity and mild retroversion.



Fig. 60.57


Axillary view showing a small biconcavity illustrating the high degree of variability in glenoid pathoanatomy.



Fig. 60.58


Various intermediate types of glenoid pathology depend on the extent of medial glenoid erosion, posterior humeral subluxation, biconcave glenoid morphology, and glenoid retroversion.



Fig. 60.59


An important aspect of glenoid pathology is the amount of glenoid fossa that is involved in the pathologic concavity, known as the “neoglenoid.”



Fig. 60.60


Degree of glenoid retroversion relative to the scapular plane. The glenoid plane (red line) is presented by the line through the anterior and posterior glenoid rim. The scapular plane (dotted line) is presented by the line parallel to the scapular body. Glenoid version is the angle between the scapular plane and the glenoid plane.



Fig. 60.61


(A) The important characteristics of glenohumeral pathoanatomy can be quantified on the standardized axillary view. (B) Glenoid version is the angle between the axis of the scapular body (S) and the line connecting the anterior and posterior lips of the glenoid (G) . (C) The degree of centering is indicated by the ratio between the distance between the anterior lip and the point of glenohumeral contact (C) and the distance between anterior and posterior lips of the glenoid (G) . A well-centered articulation has a ratio of 0.5.


A third view, the templating view, is obtained when humeral arthroplasty is being considered. This view is an AP view of the humerus taken with the arm in 30 degrees of external rotation relative to the x-ray beam, with a magnification marker added ( Fig. 60.62 ). This view places the humeral neck in maximal profile and allows the comparison of potential humeral prostheses with the proximal humeral anatomy ( Fig. 60.63 ). In templating, it is important to recognize that the humeral canal is not cylindrical; the mediolateral dimension is usually wider than the AP dimension and so the AP view may overestimate the size of the stem that will fit the diaphysis ( Fig. 60.64 ). The templating view is also useful for determining whether sufficient osteoporosis is present to merit special consideration at the time of arthroplasty ( Fig. 60.65 ).




Fig. 60.62


(A–B) The humeral templating view is obtained by having the flexed forearm externally rotated 30 degrees with respect to the x-ray beam. (C) The humeral templating view shows the humeral shaft with the humeral head and neck in maximal profile. A calibrated marker helps correct for magnification in templating.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:11.)



Fig. 60.63


Templating view. The templating view enables the surgeon to preview the procedure and estimate the required component size and fit.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:513.)



Fig. 60.64


The varying shape and orientation of the humeral canal cross sections from proximal to distal make it impossible to fit the endosteal surface with a defined shape of prosthetic body (left) . There is also wide variety between humeral medullary canals that are more cylindrical or more funnel-shaped (right) . A tapered stem would not fit well in a cylindrical canal, and a cylindrical stem would not fit well in a funnel-shaped canal.



Fig. 60.65


Impaction bone grafting for an osteopenic humerus. (A) Anteroposterior radiograph showing very thin bone. (B) Humeral prosthesis secured with impaction grafting without reaming to a press-fit, bone ingrowth, or cement.


Advanced imaging in shoulder arthritis


Due to the challenges in obtaining the appropriate radiographic views described in the previous section, many surgeons now utilize advanced imaging in the evaluation of patients with arthritis. In my practice, the diagnosis of arthritis is made using standard radiographs. Once the decision for shoulder replacement is made, I obtain a CT scan of the shoulder for preoperative planning. The use of CT scans provides greater understanding of the scapular, glenoid, and humeral anatomy and factors that may influence implant selection and placement. Currently, I use software that creates a three-dimensional (3D) model of the scapula from the CT scan and allows planning with implants in the 3D model of the glenoid. The use of this preoperative template intraoperatively helps to accurately position implants ( Figs. 60.66 and 60.67 ). These software platforms are now clinically available for most shoulder arthroplasty implant systems, and most are available at no cost. These software platforms also come with the option of obtaining patient-specific instrumentation for use in the operating room. The use of 3D planning software with a patient-specific guide does improve glenoid implant position compared to standard instrumentation in both clinical and cadaveric studies. , Despite the improved accuracy of implant position, there is still no evidence that demonstrates improved clinical outcomes when using these software platforms and patient-specific instruments. In my practice the use of this new technology is useful for unusual cases where the anatomy is distorted by congenital defect, injury, or surgery, and when there is concern about the amount of bone available for reconstruction. Surgeons with less experience may find the use of these software platforms and patient-specific instruments useful when performing shoulder arthroplasty.




Fig. 60.66


Image of 3D planning software for glenoid. The image allows for visualization of the glenoid in 3D (left panel) and 2D cuts in the coronal and axial planes (right panels) .



Fig. 60.67


Image of 3D plan for anatomic glenoid component for glenoid in Fig. 60.66 . The software allows for measurement of surface contact area (99%), version (−5 degrees), and inclination (10 degrees). The use of planning software allows surgeons to plan for implant position prior to surgery based on the patient’s anatomy.


Magnetic resonance imaging (MRI) is rarely needed in the evaluation of patients with shoulder arthritis. I can learn what I need to know about the status of the rotator cuff from physical examination, plain radiographs, and CT imaging, so shoulder MRIs are not needed unless indicated to exclude avascular necrosis or tumor. However, MRI of the cervical spine may be useful in evaluating patients suspected of having cervical radiculopathy, myelopathy, stenosis, or a syrinx.


Laboratory evaluation


Blood or joint fluid laboratory tests are not necessary in the assessment of the arthritic shoulder, but with two exceptions: cases of suspected inflammatory or septic arthritis (where tests, such as the rheumatoid factor, sedimentation rate, C-reactive protein, and antinuclear antigen may be useful) and suspected malnutrition (where tests, such as a complete blood count, hemoglobin A1C, metabolic chemistry panel, iron binding capacity, transferrin, albumin, and prealbumin may be useful in addition to assessment of the body mass index).


Disease characteristics


A number of diseases can destroy the glenohumeral joint surface. This section describes the characteristics of the most significant of these.


Degenerative joint disease


Degenerative joint disease is also known as osteoarthritis, osteoarthrosis, or wear-and-tear arthritis. The pathogenesis of this condition results from the age-related loss of the ability of articular cartilage to sustain itself against seemingly minor mechanical imbalances and years of use. Degenerative joint disease typically affects healthy and active individuals. The disease results in progressive loss of the glenoid cartilage and subchondral bone, typically in one of two patterns: concentric medial loss, which is more characteristic of female shoulders and shoulders with inflammatory arthritis; or eccentric posterior loss (with the articular cartilage often left intact anteriorly), which is more characteristic of male shoulders and shoulders with degenerative joint disease or capsulorrhaphy arthropathy ( Fig. 60.68 ). The concern with the eccentric wear pattern is that the diminished articular contact area results in increased force per unit area leading to increased posterior wear, which in turn results in even less contact area ( Fig. 60.69 ). The cartilage of the humeral head is eroded in a so-called “Friar Tuck” pattern: central baldness often surrounded by a rim of remaining cartilage and osteophytes (see Figs. 60.7 and 60.37 ). The bone underlying the joint surfaces is usually sclerotic, but degenerative cysts can occur in the humeral head or glenoid. When severe, glenoid cysts may jeopardize the fixation of prosthetic glenoid components ( Fig. 60.70 ).




Fig. 60.68


Degenerative arthritis. (A) Anteroposterior view in the plane of the scapula. (B) Axillary view showing posterior erosion typical of degenerative arthritis and capsulorrhaphy arthropathy. The humeral head is displaced posterior to the glenoid centerline (dotted line) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:425.)



Fig. 60.69


Contact pressure. Loss of the articular cartilage from the humeral head and glenoid results in the loss of the uniform distribution of the humeral joint reaction force over the face of the glenoid. (A) Normal load transfer. (B) Load transfer after cartilage loss results in a locally large joint pressure and a steep pressure gradient between the loaded and unloaded glenoid bone.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: WB Saunders; 2004:424.)



Fig. 60.70


Cyst formation within the glenoid may compromise glenoid component fixation, requiring the use of bone graft or cement. (A) Anteroposterior radiograph. (B) Computed tomographic scan.


In its early stages degenerative glenohumeral joint disease may be visible only on the truth view radiograph (see Fig. 60.38 ). Later, it is typical for osteophytes to surround the anterior, inferior, and posterior aspects of the humeral head and the inferior and posterior glenoid; as a result, the humeral and glenoid articular surfaces may take on a flattened configuration that blocks rotation ( Fig. 60.71 ). The commonly seen inferior humeral osteophyte is referred to as the “goat’s beard” (see Fig. 60.35 ; Fig. 60.72 ). Loose bodies are often found in the axillary or subscapularis recesses. The pathoanatomy of the arthritic glenoid may include medial erosion, posterior erosion, and retroversion along with varying degrees of posterior humeral subluxation (see Fig. 60.58 ). The triad of glenoid biconcavity, glenoid retroversion, and posterior humeral subluxation—the “bad arthritic triad”—is commonly found together in primary degenerative joint disease. , Progressive contracture of the anterior capsule limits external rotation and compounds the tendency of the humeral head to translate posteriorly ( Fig. 60.73 ). The common clinical course is one of slowly progressive loss of the ability to sleep and to use the shoulder for work and recreation due to shoulder pain and stiffness.




Fig. 60.71


Flattening of the humeral and glenoid articular surfaces. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.72


The commonly seen inferior humeral osteophyte is referred to as the “goat’s beard” osteophyte (red arrow) .



Fig. 60.73


(A) Normal capsular laxity allows unrestricted range of motion. (B) The capsule may be contracted in degenerative joint disease and must course over osteophytes. (C) As the joint approaches the limit of its range, the tension in the capsule and ligaments increases sharply, thereby limiting the range of rotation.


Young individuals are less likely to have primary glenohumeral osteoarthritis and more likely to have capsulorrhaphy arthropathy, secondary degenerative joint disease, or other more complex forms of arthritis, often a result of injury, prior surgery, glenoid dysplasia or systemic disease. This, along with their greater longevity and increased activity expectations, may help explain the diminished satisfaction and increased rate of arthroplasty complications for younger individuals after shoulder arthroplasty. A number of these important but less straightforward diagnoses are discussed later.


Secondary degenerative joint disease


In contrast to primary degenerative joint disease—that arises spontaneously without a specific cause—secondary degenerative joint disease develops when a prior injury or surgery affects the joint surface, precipitating its degeneration. The presentation and clinical course of each case of secondary arthritis depend on the underlying etiology.


Anchor arthropathy is a type of secondary degenerative joint disease in which the glenohumeral joint surfaces are destroyed by prominent suture anchors used for the repair of superior labral anterior to posterior lesions ( Fig. 60.74 ; see Fig. 60.36 ) or for Bankart repairs ( Figs. 60.75–60.77 ). In this condition the suture anchors excoriate the humeral joint surface, which then erodes the glenoid surface. In cases of anchor arthropathy—or with any prior glenohumeral surgery—it is important to be alert to the possibility of infection with Cutibacterium species ( Fig. 60.78 ).




Fig. 60.74


Anchor arthropathy. (A) Destruction of the central aspect of the humeral head. (B) The cause was prominent suture anchors.



Fig. 60.75


Anchor arthropathy. Metallic suture anchors can be seen in the joint on the anteroposterior (A) and axillary (B) view.



Fig. 60.76


Anchor arthropathy with excoriation of the articular surface of the humeral head by prominent suture anchors, with secondary loss of the glenoid and humeral articular cartilage. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.77


Anchor arthropathy caused by placement of suture anchors on the glenoid surfaces. (A) Anteroposterior view. (B) Axillary view. (C) Intraoperative image.



Fig. 60.78


Septic arthritis from Propionibacterium species after a labral repair, with loss of joint space. (A) Anteroposterior view. (B) Axillary view.


Posttraumatic arthropathy is a condition in which prior injury has damaged the joint surfaces or given rise to malunion with joint incongruity ( Fig. 60.79 ), instability, nonunions, and/or posttraumatic avascular necrosis ( Fig. 60.80 ), with or without problems related to fixation hardware ( Figs. 60.81–60.83 ).




Fig. 60.79


Traumatic arthritis with a loss of glenohumeral cartilage developed after malunion of a comminuted proximal humeral fracture. (A) Anteroposterior view in the plane of the scapula. (B) Axillary view.



Fig. 60.80


Traumatic arthritis with malunion and osteonecrosis of the head segment. (A) Radiograph showing collapse of the head segment and a slight malunion of the greater tuberosity relative to the shaft. (B) Radiograph showing the collapse of the humeral head segment, but with the tuberosities in reasonable positions on this view. Damage to the glenoid articular surface is underestimated on these projections. Proximal humeral prosthetic replacement or total shoulder arthroplasty might be needed as reconstructive surgery for such situations, depending on the extent of glenoid surface involvement.



Fig. 60.81


Posttraumatic arthritis with humeral head deformity and prominent intra-articular screws. (A) Anteroposterior view showing head deformity. (B) Axillary view showing head deformity with screw penetration.



Fig. 60.82


Subtuberous nonunion. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.83


Posttraumatic arthropathy with screws eroding the joint surfaces and the anterior glenoid bone. (A–B) Anteroposterior and axillary views with the hardware in place. (C–D) Anteroposterior and axillary views with the hardware removed.


Anterior or posterior dislocations may be followed by dislocation arthropathy ( Fig. 60.84 ). In unreduced dislocations the humeral head may be indented and worn ( Figs. 60.85 and 60.86 ). The cartilage of the joint surfaces may be replaced by scar tissue, or the subchondral bone may be so weakened by bone atrophy that it collapses after reduction, resulting in an incongruous joint surface ( Fig. 60.87 ).




Fig. 60.84


An elderly man had a 5- to 10-year history of progressively severe shoulder pain and limitation of motion. As an adolescent, he experienced recurrent dislocations of this shoulder; his current arthritis presumably developed subsequent to his recurrent instability.



Fig. 60.85


Arthroplasty for chronic shoulder dislocation. (A) Anteroposterior view showing anterior dislocation. (B) Axillary view showing posterior humeral and anterior glenoid bone loss. (C) Apical oblique view showing posterior humeral and anterior glenoid bone loss. (D) Computed tomography scan showing posterior humeral and anterior glenoid bone loss. (E) Anteroposterior view showing hemiarthroplasty after an iliac crest graft to the anterior glenoid. (F) Axillary view showing hemiarthroplasty after an iliac crest graft to the anterior glenoid.



Fig. 60.86


Chronic posterior shoulder dislocation in a 26-year-old man. The injury occurred approximately 1 year prior to obtaining the radiographs. A recent previous anterior approach to the shoulder was ineffective in reducing the dislocation. The shoulder was reduced during a second surgical procedure, but the cartilage of the humeral head was replaced with fibrous tissue. A proximal humeral prosthesis was placed as a part of the reconstructive procedure. (A) A 40-degree posterior oblique view illustrating the overlap between the humeral head and the glenoid. (B) Clearly illustrated are the posterior dislocation, the slight malunion between the head and shaft fragments, and evidence of fracturing of the lesser tuberosity and healing of this tuberosity to the shaft, although somewhat displaced from the humeral head segment.



Fig. 60.87


This young woman underwent open reduction of a posterior shoulder dislocation that had been unreduced for approximately 2 months. At the time of reduction, the cartilage surfaces were intact, but the humeral head was noted to be somewhat softened. A bone graft was added to the posterior aspect of the shoulder to substitute for an area of glenoid wear. Within the first month after open reduction, it was apparent on the anteroposterior and axillary view that because of its softness, the humeral head had collapsed and traumatic arthritis was developing. A proximal humeral prosthesis was subsequently placed. (A) Anteroposterior view. (B) Axillary view.


Shoulders with secondary degenerative joint disease often have complex pathology that can challenge surgical management. Each case presents its own particular combination of capsular contracture, scarring, malunion, nonunion, bone loss, bone fragility, nonanatomic location of neurovascular structures, and the presence of hardware from prior procedures.


Capsulorrhaphy arthropathy


Capsulorrhaphy arthropathy is a specific type of secondary degenerative joint disease in which deterioration of the joint surface is related to a prior repair for recurrent dislocations and is one of the most common causes of severe arthritis in individuals younger than 55 years. It may be caused by overtightening the anterior capsule; when external rotation is limited by a Putti-Platt repair ( Fig. 60.88 ), a Bankart repair, or a Bristow-Latarjet procedure, , , obligate posterior translation can force the humeral head out of its normal concentric relationship with the glenoid fossa ( Figs. 60.89 and 60.90 ). This chronic posterior humeral subluxation typically erodes the posterior glenoid, and major posterior bone deficiencies can result ( Figs. 60.91 and 60.92 ). Shoulder arthroplasty for capsulorrhaphy arthropathy is associated with high rates of revision surgery and unsatisfactory outcomes because of instability, subscapularis failure, glenoid component failure after total shoulder arthroplasty, and pain from glenoid arthrosis after hemiarthroplasty. , , The importance of these poor results is heightened as commonly the individuals affected are young.




Fig. 60.88


Putti-Platt repair consisting of shortening of the anterior capsule and subscapularis tendon, limiting humeral external rotation.



Fig. 60.89


Progressive contracture of the anterior capsule limits external rotation and leads to obligate posterior humeral translation, increased force on the posterior glenoid, and eventual posterior glenoid erosion.



Fig. 60.90


Axillary view of capsulorrhaphy arthropathy in which an excessively tight anterior capsular repair is forcing the head of the humerus posteriorly (arrow) . This effect is accentuated by forced external rotation. Note also the typical posterior glenoid erosion.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.91


Capsulorrhaphy arthropathy, that is, arthritis after a prior repair for anterior glenohumeral instability. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.92


Capsulorrhaphy arthropathy. (A) Anteroposterior view showing loss of joint space and hardware from a prior repair for anterior instability. (B) Axillary view showing glenoid retroversion, a biconcave glenoid, and posterior humeral subluxation.


Rheumatoid and other types of inflammatory arthritis


Rheumatoid arthritis is a systemic disease with highly variable clinical manifestations. It can appear to be isolated to the glenohumeral joints or it can affect most of the tissues in the body. In rheumatoid arthritis and many other types of inflammatory arthritis, the cartilage is characteristically destroyed evenly across all joint surfaces of both glenohumeral joints. The glenoid is eroded medially ( Fig. 60.93 ) rather than posteriorly, as in degenerative joint disease (see Fig. 60.68 ). The arthritic process erodes not only cartilage but also subchondral bone, rendering it osteopenic and at risk of fracture ( Fig. 60.94 ). Rheumatoid arthritis can be associated with major bone loss and rotator cuff deficiency, even in young individuals ( Fig. 60.95 ). When the onset of the disease occurs during youth, the joint volume may be small ( Fig. 60.96 ) and the humerus curved, with a thin medullary canal ( Fig. 60.97 ). The restoration of comfort and function to the rheumatoid glenohumeral joint is often complicated by concurrent involvement of the rotator cuff, , as well as the acromioclavicular, sternoclavicular, elbow, wrist, and hand articulations and the joints of the opposite upper extremity. , Arthritis in the lower extremities may demand the use of ambulatory aids and that in the upper extremities may demand wheelchair transfers. Even the skin of an individual with rheumatoid arthritis may be fragile and subject to compromised wound healing. The fragility of a patient with rheumatoid arthritis is often compounded by long-term use of steroids and other disease-modifying antirheumatologic medications. The physician should remain aware of the possible coexistence of joint infection as rheumatoid arthritis involves the immune system due to the patient often receiving immunosuppressive medication, and the clinical manifestations of this condition are similar to those of infectious arthritis. Methotrexate may also increase the risk of nerve dysfunction after shoulder arthroplasty.




Fig. 60.93


Inflammatory arthritis. Medial erosion (arrow) typical of inflammatory arthritis. The original contour of the glenoid is shown (dotted line) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:425.)



Fig. 60.94


A shoulder with rheumatoid arthritis. Sclerosis and osteophytes typical of osteoarthritis are absent. The bone is osteopenic with erosions at the margins of the articular surface. The humeral head is displaced upward, suggesting cuff deficiency, and the glenoid is eroded medially. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.95


A shoulder with findings of rheumatoid arthritis more advanced than those shown in Fig. 60.92 . (A) Anteroposterior view. (B) Axillary view.



Fig. 60.96


Severe medial erosion in rheumatoid arthritis. Note that the entire proximal humerus is medial to the lateral acromial line . Normally, the lateral acromial line passes through the lateral humeral articular surface.



Fig. 60.97


Lateral view of the humerus of a patient who experienced the onset of rheumatoid arthritis as a child. The radiograph shows a bend; this was included in the preoperative planning.


Because of the fragility of the skin and other soft tissues, osteopenia, and the severe bone erosion common with this condition, a patient with substantial involvement of rheumatoid arthritis or similar types of arthritis must be treated with extreme gentleness and thoughtfulness. Shoulder arthroplasty for rheumatoid arthritis has a high rate of glenoid component loosening and rotator cuff failure. , , , Patients with rheumatoid arthritis characteristically have substantially lower self-assessed vitality and overall physical function than do those with other causes of glenohumeral arthritis. The compromised general health and strength of patients with rheumatoid arthritis must be considered in planning their surgical and postoperative management. Special preoperative evaluation and intraoperative care should be directed at the potentially tenuous stability of the cervical spine.


Cuff tear arthropathy


CTA is a compound degenerative condition of the shoulder that involves tendon, cartilage, and bone. , In this condition, chronic, massive rotator cuff defects are associated with loss of the humeral articular cartilage and superior displacement of the humeral head so that it articulates with the undersurface of the coracoacromial arch. The humeral head becomes “femoralized” by rounding off of the tuberosities, whereas the coracoacromial arch and upper glenoid fossa become “acetabularized” when the humerus sculpts a concentric concavity from these structures ( Figs. 60.98–60.108 ).




Fig. 60.98


Cuff tear arthropathy. In cuff tear arthropathy the shoulder takes on a form similar to that of the hip: the greater tuberosity becomes eroded such that the proximal humerus is “femoralized” ( dotted lines on the humerus), and the coracoacromial arch and upper glenoid erosion results in their “acetabularization” ( dotted lines on the upper glenoid).



Fig. 60.99


Rotator cuff tear arthropathy (CTA) treated with a CTA prosthesis. (A) Preoperative anteroposterior radiograph showing superior displacement of the humeral head that has resulted in contact with the acromion as well as the loss of humeral and glenoid articular cartilage and a secondary superior glenoid concavity. The proximal humerus has been “femoralized” and the coracoacromial arch and upper glenoid have been “acetabularized.” (B) Preoperative axillary radiograph showing medial but not posterior erosion of the glenoid. (C) Intraoperative photo showing measurement of the humeral diameter of curvature. (D) Intraoperative photo showing preservation of the clavipectoral fascia coming off the coracoacromial ligament (the “CA+”) to enhance anterosuperior stability. (E) Postoperative anteroposterior view after implantation of the CTA prosthesis. Note the congruent fit of the prosthesis in the socket. (F) Postoperative axillary view after implantation of the CTA prosthesis.



Fig. 60.100


Rotator cuff tear arthropathy with acetabularization of the coracoacromial arch and upper glenoid.



Fig. 60.101


Rotator cuff tear arthropathy with femoralization of the proximal humerus and acetabularization of the coracoacromial arch and upper glenoid.



Fig. 60.102


Cuff Tear Arthropathy.

Superior medial erosion (dotted red line) typical of cuff tear arthropathy.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures . Philadelphia: Saunders; 2004:426.)



Fig. 60.103


Acromial traction spur. (A) Normal position. (B) As the humeral head moves upward, the coracoacromial arch becomes progressively loaded. (C) The result is a traction spur in the coracoacromial ligament. Because it lies within the substance of the ligament, this spur does not encroach on the rotator cuff, even though it might look impressive on the radiograph. (D) Rotator cuff tear arthroplasty.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures . Philadelphia: Saunders; 2004:280.)



Fig. 60.104


The boutonnière deformity, in which the subscapularis and infraspinatus tendons slide below the center of the humeral head.

(Modified from Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.105


Erosion of the superior glenoid concavity ( dotted line and horizontal arrow ) compromises the concavity compression stability mechanism and allows upward translation of the humeral head (vertical arrow) when the deltoid contracts.

(Modified from Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.106


Hemiarthroplasty with a laterally extended cuff tear arthropathy (CTA) head. (A) CTA prosthesis. (B) The installed prosthesis.



Fig. 60.107


Rationale for a laterally extended cuff tear arthropathy (CTA) head. (A) Abduction and external rotation are limited due to painful impingement against the uncovered greater tuberosity. Impingement is indicated by the dashed red lines radiating up and to the left. (B) The laterally extended CTA head allows a greater arc of motion in abduction and greater external rotation by coverage of the greater tuberosity.



Fig. 60.108


Rotator cuff tear arthropathy. The humeral head is displaced superiorly and medially, eroding into the acromion and upper glenoid. The thinning of the acromion will predispose it to fracture at the time of or after arthroplasty.


In CTA the glenohumeral joint is deprived of several of its major stabilizing factors: the normal cuff muscle force vector compressing the humeral head into the glenoid (see Fig. 60.5 ); the superior lip of the glenoid concavity, which is typically worn away by chronic superior subluxation (see Fig. 60.6 ); and the cuff tendon that is normally interposed between the humeral head and the coracoacromial arch ( Fig. 60.109 ). The superior displacement of the humeral head slackens the deltoid, weakening its ability to flex or abduct the shoulder ( Fig. 60.110 ). As the condition progresses, the coracoacromial arch may become compromised, allowing anterosuperior escape ( Fig. 60.111 ). Prior acromioplasty and section of the coracoacromial ligament further compromise glenohumeral stability and contribute to anterosuperior escape ( Figs. 60.112 and 60.113 ). These consequences of loss of integrity of the coracoacromial arch are reminders of the need to preserve the integrity of the acromion and coracoacromial ligament in all shoulder procedures.




Fig. 60.109


The cuff tendon interposed between the humeral head and the coracoacromial arch stabilizes the head against superiorly directed loads. The graph shows the mean superior humeral displacement (relative to the scapula) as a function of the superior humeral load, comparing displacements under four conditions: intact specimens, after venting the joint to air, after cutting (but not excising) the cuff tendon, and after excising the superior cuff tendon. Note the markedly increased superior displacement after excision of the cuff tendon.



Fig. 60.110


Superior displacement of the humeral head slackens the deltoid so that its ability to flex or abduct the shoulder is weakened.



Fig. 60.111


Patient with long-standing cuff tear arthropathy with anterosuperior escape of the humeral head when active elevation is attempted.



Fig. 60.112


(A) Normal shoulder. (B) Cuff-deficient shoulder with an intact coracoacromial arch. If the coracoacromial arch remains intact (i.e., not damaged by acromioplasty or coracoacromial arch section), the arch may provide secondary stabilization for the humeral head against the upward pull of the deltoid.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:264.)



Fig. 60.113


Anterosuperior escape of the humeral head. Resection of the coracoacromial ligament and anterior acromioplasty can allow the humeral head of the cuff-deficient shoulder to escape anterosuperiorly.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:265.)


CTA provides several challenges for the surgeon. In the absence of an intact rotator cuff, total shoulder arthroplasty has been shown to have an early failure rate from glenoid loosening through the so called “rocking horse” phenomenon ( Fig. 60.114 ). Standard hemiarthroplasty may provide only partial pain relief and partial improvement in function. , , Currently, the surgical management of CTA commonly involves either a CTA prosthesis (see Fig. 60.107 ) or a reverse total shoulder arthroplasty ( Fig. 60.115 ).




Fig. 60.114


Total shoulder arthroplasty in the absence of an intact rotator cuff has been shown to result in early glenoid loosening by the “rocking horse” mechanism of the superior migrated humeral component on the superior glenoid component.



Fig. 60.115


In the cuff-deficient shoulder with a compromised coracoacromial arch and subsequent functional anterosuperior escape, the reverse ball-and-socket prosthesis helps provide glenohumeral stability by retensioning the deltoid and moving the center of rotation medially.


Several systems for the classification of the pathoanatomy of CTA have been proposed as guides to treatment. , , , However, the following factors have been found to be even more critical than radiographic classification in determining the treatment: (1) the stability of the humeral head beneath the coracoacromial arch (i.e., the presence or absence of anterosuperior escape) ( Figs. 60.116 and 60.117 ; see also Figs. 60.111 and 60.113 ); (2) the amount of active elevation provided by the deltoid (i.e., the presence or absence of pseudoparalysis, defined as the inability to actively raise the arm to 90 degrees despite a good passive range of motion); (3) the strength of the residual internal and external rotator musculature; (4) the amount and quality of glenoid, humeral, and acromial bone stock available for surgical reconstruction ( Fig. 60.118 ); (5) the patient’s fall risk, which is a particular concern in individuals with Parkinson disease or other problems of balance; (6) the patient’s dependency on the upper extremities for mobility; and (7) the patient’s activity expectations.




Fig. 60.116


Hemiarthroplasty with cuff tear arthropathy. The head component is stable beneath the intact coracoacromial arch.



Fig. 60.117


Anteroposterior radiographs, static and dynamic with fluoroscopy. (A) Superior displacement with the arm resting at the side. (B) Superior dislocation with the arm under resisted abduction.



Fig. 60.118


Typical radiograph of a progressive cuff tear arthropathy. It shows superior migration of the head with secondary superior glenoid erosion.


Avascular necrosis


Nontraumatic or primary avascular necrosis of the humeral head may be idiopathic or may be associated with systemic steroids, trauma, dysbaric conditions, renal or other organ transplantation, or systemic illnesses with vasculitis. Other implicated conditions include alcoholism, sickle cell disease, hyperuricemia, Gaucher disease, pancreatitis, familial hyperlipidemia, and lymphoma. , Avascular necrosis has also been reported as a result of section of the anterior humeral circumflex artery in open instability surgery.


Avascular necrosis of the humeral head may be seen on plain radiographs or MRI before collapse of the joint surface occurs ( Figs. 60.119–60.122 ). Often, a fracture superocentrally through the abnormal subchondral bone is noted ( Fig. 60.123 ). Subsequently, collapse of the subchondral bone can occur, putting the glenoid articular surface at risk for secondary erosion ( Fig. 60.124 ). In end-stage avascular necrosis the irregular humeral head destroys glenoid articular cartilage, resulting in glenohumeral joint disease ( Fig. 60.125 ).




Fig. 60.119


Early avascular necrosis revealed as sclerosis of the superior medial aspect of the humeral head. The humeral head has not collapsed.



Fig. 60.120


Magnetic resonance imaging findings of early avascular necrosis, shown on a sagittal T2-weighted image.



Fig. 60.121


Magnetic resonance imaging findings of early avascular necrosis, shown on a coronal T1-weighted image.



Fig. 60.122


Magnetic resonance imaging findings of early avascular necrosis, shown on a coronal T2-weighted image.



Fig. 60.123


Early collapse of the humeral head in avascular necrosis.



Fig. 60.124


Avascular necrosis with humeral head collapse and secondary destruction of the glenoid articular surface. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.125


Bilateral avascular necrosis with collapse of the humeral articular surface. (A and C) Anteroposterior views. (B and D) Axillary views.


Core decompression may be of benefit early in the course of the disease. When the process involves only the humeral head, a humeral hemiarthroplasty is considered, but when the glenoid is involved, a glenohumeral arthroplasty may be needed ( Fig. 60.126 ). ,




Fig. 60.126


Avascular necrosis with collapse of the humeral head and secondary glenohumeral arthritis. (A) Anteroposterior view. (B) Axillary view.


Glenohumeral chondrolysis


Glenohumeral chondrolysis is a condition the etiology of which unfortunately was formerly referred to as being “speculative,” , but is now clearly recognized as being most commonly caused by the intra-articular infusion of local anesthetics using a “pain pump.” This condition is particularly a risk after arthroscopic procedures in which suture anchors are placed in the glenoid. Chondrolysis has also been associated with radiofrequency or laser procedures within the joint. , The diagnosis is made from a history of pain pump use, the postoperative onset of pain and stiffness, and radiographs showing loss of the joint space without osteophytes ( Figs. 60.127 and 60.128 ). This iatrogenic condition primarily affects young individuals, often leaving them without options other than arthroplasty; even with arthroplasty the prognosis for the recovery of comfort and function is poor. The condition can largely be prevented by avoiding the use of pain pumps and heat energy, which are not necessary for the treatment of shoulder disorders.




Fig. 60.127


Chondrolysis in the right shoulder of a 22-year-old man resulting from the intra-articular infusion of local anesthetics with a pain pump. There was a complete loss of articular cartilage but without the osteophytes or sclerosis typical of osteoarthritis. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.128


Chondrolysis in the left shoulder of a 24-year-old woman resulting from the intra-articular infusion of local anesthetics with a pain pump. There was a complete loss of articular cartilage but without the osteophytes or sclerosis typical of osteoarthritis. (A) Anteroposterior view. (B) Axillary view.


Other types of arthritis


Neurotropic (Charcot) arthropathy


Neurotropic (Charcot) arthropathy arises in association with syringomyelia, diabetes, or other causes of joint denervation. The joint and subchondral bone are destroyed because of the loss of the trophic and protective effects of its nerve supply. The individual may have experienced cervical spine trauma in the past, or there may be unrecognized syringomyelia. , Other causes include diabetes, leprosy, syphilis, and chronic alcoholism, and it has been suggested that injection of corticosteroids might accelerate the development of this condition. The Charcot joint is characterized by functional limitation and pain, despite the denervation. There is usually significant bone destruction and osseous debris about the joint area ( Figs. 60.129 and 60.130 ). A useful mnemonic for the characteristic features of Charcot arthropathy is given by the three D’s: d enervation, d estruction, and d ebris. This condition can resemble infectious arthritis. The longevity of an arthroplasty performed for Charcot arthropathy may be jeopardized by the lack of a protective nerve supply.




Fig. 60.129


Occasionally, neuropathic arthritis can be confused with more common forms of glenohumeral arthritis. (A) Fragmentation of the proximal end of the humerus with bone debris scattered throughout the joint region. (B) Bone fragmentation is shown, but in addition, there is a predominantly sclerotic response associated with neuropathic arthritis. The underlying condition in both this patient and the one shown in Fig. 60.126 was syringomyelia of the cervical portion of the spinal cord.



Fig. 60.130


Shoulder with Charcot arthropathy characterized by massive bone destruction. (A) Anteroposterior view. (B) Axillary view.


Radiation arthropathy


Radiation, especially for the treatment of breast cancer, can cause a number of shoulder problems: brachial plexopathy, osteonecrosis, secondary malignant bone tumors, and fibrous scarring. Glenohumeral cartilage and subchondral bone are occasionally affected by these changes and can require treatment by prosthetic arthroplasty ( Fig. 60.131 ). A lack of normal soft tissue suppleness, scars from prior surgery, or lymphedema may complicate surgical management.




Fig. 60.131


Cartilage loss, alteration in the shape of subchondral bone with segmental collapse, and a change in bone texture secondary to irradiation performed as part of treatment for breast cancer. Symptoms were quite significant in this elderly woman and were relieved effectively by total shoulder arthroplasty.


Septic arthritis


Septic arthritis of the shoulder may arise from bacteria in the patient’s dermis, from hematogenous spread from a remote infection, from injections into the joint, or from surgery on the joint itself. Patients with reduced immunologic defenses—from chronic systemic disease , or from immunosuppressive medications—are particularly at risk. Radiographs may show bone destruction and instability ( Figs. 60.132–60.134 ). Treatment must be directed at resolving the infection before considering arthroplasty for the management of the resulting arthritis.




Fig. 60.132


Septic arthropathy characterized by loss of the joint surface, marginal erosions around the humeral articular surface, rotator cuff destruction, and superior migration of the humerus.



Fig. 60.133


Complete loss of articular cartilage after a coracoid transfer for instability. The shoulder showed multiple positive cultures for Propionibacterium species at revision surgery.



Fig. 60.134


Septic arthritis due to Propionibacterium species after internal fixation of a proximal humeral fracture. (A) An internal fixation removed because of the concern for screw penetration into the joint. (B) Progressive destruction of the articular surface leading to shoulder hemiarthroplasty, at which time cultures were positive for Propionibacterium species.


Neoplastic joint destruction


Neoplastic joint destruction may present insidiously and is often characterized by nonmechanical pain. , Alternatively, tumors may present acutely as a pathologic fracture. The diagnosis will depend on knowledge of the patient’s general health; high-quality plain radiographs; and possibly additional imaging modes, such as tomography, CT, bone scanning, or MRI. Identification of the primary lesion in metastatic disease is desirable, but sometimes biopsy of the shoulder lesion is the most direct route when making a diagnosis ( Fig. 60.135 ).




Fig. 60.135


An upper-middle-aged woman with gradual onset of shoulder pain and reduction in movement. The shoulder was more painful with use but was also painful at rest. She had no known systemic illness. (A) Involvement of the glenohumeral joint is shown, with some collapse of the humeral head articular surface. More importantly, this radiograph shows destruction of the bone of the glenoid. (B) Computed tomographic image showing the bone destruction quite well. A biopsy revealed metastatic thyroid carcinoma.


Miscellaneous arthropathies


Miscellaneous arthropathies include crystalline arthritis (such as calcium pyrophosphate deposition disease or hydroxyapatite deposition disease), dialysis arthropathy, hemophilic arthropathy, hemochromatosis, , synovial chondrometaplasia, alkaptonuria, gouty arthropathy, acromegalic arthropathy, spondyloarthropathy, Milwaukee shoulder, rapidly destructive articular disease ( Fig. 60.136 ), , amyloid arthropathy, pseudogout, primary hyperparathyroid arthropathy, psoriatic arthropathy, ulcerative colitis, Crohn disease, Reiter syndrome, pigmented villonodular synovitis, and Lyme arthritis.




Fig. 60.136


Rapid-onset glenohumeral arthritis. (A) Anteroposterior view showing findings typical of a chronic cuff tear. (B) Axillary view showing slight joint space narrowing. (C) Anteroposterior view taken 10 months later with no intercurrent injury or evidence of infection. (D) Axillary view. (E) Intraoperative image showing destruction of the humeral head.


Treatment


Communication


Treatment should begin with a dialogue between the surgeon and the patient regarding the diagnosis; the probable natural history of the condition, if untreated; and the potential risks and benefits of the different treatment options. The likely outcomes are discussed in light of the patient’s expectations and the surgeon’s personal experience in treating the patient’s condition. A partnership is formed with the common goal of improving the patient’s quality of life with the least invasive intervention. Because glenohumeral arthritis is usually insidious in onset and chronic in duration, there is ample opportunity to try nonoperative management. A period of nonoperative treatment offers the patient and surgeon the opportunity to get to know each other better and gives the patient time to learn some of the exercises that will be a part of the postoperative rehabilitation should surgery be elected. Patients may have difficulty recalling the nature of these discussions; thus my practice is to provide illustrated handouts ( Fig. 60.137 )




Fig. 60.137


Educational handouts are useful for informing patients about their disease, the treatment alternatives, and the risks of the different options.


Nonoperative treatment


Activity modification and fitness


Most patients with glenohumeral arthritis wish to continue their activities of daily living, work, and recreation, but continued full participation in these activities may lead to aggravation of the arthritis symptoms. As a general principle, work that involves pushing heavy loads or impact loading as well as recreational activities, such as wood chopping or bench pressing, may hasten the progression of the disease process and symptoms. Eliminating these activities through vocational and recreational modification may lessen the symptoms and extend the survival of the natural joint. Occupational therapy may help effect changes in the workplace, as well as suggesting adaptive changes in the home. Modification of sports activity may also be helpful; for example, rowing, swimming, paddling, and two-handed tennis strokes may be better tolerated than handball, martial arts, and vigorous bench pressing. Activities that are disallowed after a surgical reconstruction should be disallowed before surgery to observe the effect on the patient’s symptoms. Another important aspect of nonoperative management is optimizing the overall fitness of the patient through regular aerobic exercise; withdrawing from nicotine, alcohol, and narcotics; a healthy diet; and achieving a body mass index less than 25. Improved fitness can improve the feeling of well-being and optimism as well as the safety of surgical intervention, should that become necessary.


Exercises


Glenohumeral joint arthritis is commonly accompanied by stiffness related to contracture and adhesions involving the glenohumeral capsule, the cuff muscles, and the nonarticular humeroscapular motion interface. Disuse or tendon failure can result in weakness of the deltoid and cuff muscles. Instability patterns can also complicate glenohumeral roughness, such as the posterior subluxation characteristic of degenerative joint disease and capsulorrhaphy arthropathy, or the superior subluxation characteristic of CTA.


The mechanics of the shoulder may often be improved by a physician-directed program of gentle range-of-motion and strengthening exercises ( Figs. 60.138–60.148 ). Stretching exercises are performed slowly with a full 2-minute hold, allowing time for the muscles to relax and for the tight capsule to be plastically deformed. One of my patients used his electric toothbrush to time his stretches. It is important that vigorous torque and force not be applied in an attempt to regain mobility because of the possibility of causing obligate translation and accelerated wear (see Fig. 60.73 ; Fig. 60.149 ). Strengthening exercises must also be gentle, with the resistance limited to a level that allows at least 20 comfortable repetitions. Activities that apply gentle repetitive traction to the joint, such as the pulley ( Fig. 60.150 ), swimming, latissimus pulls ( Fig. 60.151 ), and rowing ( Fig. 60.152 ), seem to be particularly well tolerated. When forward elevation is weak, gentle progression of the supine press ( Fig. 60.153 ) can be helpful in improving active shoulder motion, even with what seems to be pseudoparalysis. When posterior stability is compromised, gentle external rotator strengthening may help restore the centering of the humeral head ( Fig. 60.154 ).




Fig. 60.138


Stretching in overhead reach, with the opposite arm assisting the movement in place of the therapist.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.139


Stretching in overhead reach with progressive forward leaning used to apply gentle force to the arm.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.140


Stretching in external rotation with the opposite hand used in place of the therapist.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.141


Stretching in external rotation by turning the body away from a fixed object to apply a gentle stretching force.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.142


Stretching in internal rotation with a towel used to apply a gentle stretching force.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.143


Stretching in cross body reach with the opposite arm serving in place of the therapist.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.144


Internal rotation can be strengthened with (A) isometrics, (B) rubber tubing, or (C) free weights.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.145


External rotation strengthening with (A) isometrics, (B) rubber tubing, or (C) free weights.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.146


In the press plus the arm is pushed upward until the shoulder blade is lifted off the table or bed.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.147


In the shoulder shrug exercise the tip of the shoulder is lifted toward the ear while the elbow is held straight.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.148


Sleeper stretch. A gentle internal rotation force is applied to the arm abducted to 90 degrees.



Fig. 60.149


Forceful torque causes obligate translation leading to accelerated glenoid wear.



Fig. 60.150


Door pulley. If the opposite arm is weak or painful, a pulley is useful in helping the arm in elevation.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:549.)



Fig. 60.151


The lateral pulldown is a useful rehabilitative exercise because it enables movement of the shoulder while a distraction force is applied.



Fig. 60.152


Rowing is a useful rehabilitative exercise because it enables movement of the shoulder while a distraction force is applied.



Fig. 60.153


Incremental press. Integrated forward elevation is developed through a series of exercises that can be progressed in small increments. (A) With the patient in the supine position, the two hands are placed close to each other on a light stick and both are pressed upward toward the ceiling. (B) The same exercise is repeated with the arms progressively farther apart. (C) The arm performs the supine press unassisted. Small amounts of weight are added to the hand until 2 lb can be pressed upward 20 times. (D) The patient’s back is elevated slightly while the weight is pressed vertically upward. The amount of elevation is increased when 2 lb can be pressed upward 20 times. (E) The progression is continued until the exercise can be performed with the back in a vertical position.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: WB Saunders; 2004:344.)



Fig. 60.154


External rotation strengthening helps center the posteriorly subluxed humeral head by increasing the anterior displacement force (green arrow) . Contraction of the infraspinatus causes a force (black arrow) tangential to the point of contact with the humeral head. The force vector can be resolved into an anterior displacement force on the humeral head (green arrow) and a compression force into the glenoid (blue arrow) .


Medication


In the management of most forms of arthritis, nonsteroidal antiinflammatory medication and mild analgesics may be useful adjuncts to the exercise program. However, even these relatively benign medications can have side effects and unwanted interactions with other medications; if they are taken for an extended period, monitoring for allergic, gastrointestinal, hepatic, renal, cardiac, pulmonary, and hematopoietic side effects is important. Chondroitin sulfate and glucosamine have not been shown to have a significant effect on the symptoms or progression of shoulder arthritis.


The medical management of rheumatoid arthritis includes traditional disease-modifying drugs, including methotrexate, leflunomide, sulfasalazine, hydroxychloroquine, cyclosporine, azathioprine, D-penicillamine, and gold (oral or intramuscular). For patients who do not respond to this class of medications, rheumatologists may turn to biologic response modifying agents. These drugs are engineered proteins designed to inhibit specific components of the immune system that fuel the inflammation in rheumatoid arthritis. They include tocilizumab (Actemra), certolizumab pegol (Cimzia), etanercept (Enbrel), adalimumab (Humira), anakinra (Kineret), abatacept (Orencia), infliximab (Remicade), rituximab (Rituxan), and golimumab (Simponi). Both classes of drugs may affect the safety of surgical interventions, reducing healing time and increasing the risk of neurologic complications and infection; consultation is therefore recommended to determine the recommended time for preoperative dosage modification or discontinuance ( Table 60.3 ). ,



TABLE 60.3

Immunomodulating Medications and Recommendation for Discontinuation Prior to Total Shoulder Arthroplasty

Based on 2016 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Anti-rheumatic Medication in Patients with Rheumatic Diseases Undergoing Elective Total Hip or Total Knee Arthroplasty. From Goodman S, Springer B, Sing J, et al. Do immunomodulatory disease-modifying medications (e.g., methotrexate or antitumor necrosis factor (anti-TNF) agents) need to be withheld preoperatively to reduce the risk for subsequent surgical site infection/periprosthetic joint infection (SSI/PJI)? Proceedings of the Second International Consensus Meeting on Musculoskeletal Infection. International Consensus Group LLC . 2018:38–40.































































































































DMARDs: CONTINUE these medications through surgery.
Dosing Interval Continue/Withhold
Methotrexate Weekly Continue
Sulfasalazine Once or twice daily Continue
Hydroxychloroquine Once or twice daily Continue
Leflunomide (Arava) Daily Continue
Doxycycline Daily Continue
BIOLOGICS: STOP these medications prior to surgery and RESUME at a minimum of 14 days after surgery in the absence wound healing problems, surgical site infection, or systemic infection.
Dosing Interval Schedule Surgery (Relative to Last Schedule Surgery at the End of the Dosing Cycle)
Adalimumab (Humira) Every 2 weeks Week 3
Etanercept (Enbrel) Weekly or twice weekly Week 2
Golimumab (Simponi) Every 4 weeks (SQ) or every 8 weeks (IV) Week 5 Week 9
Infliximab (Remicade) Every 4, 6, or 8 weeks Week 5, 7 or 9
Abatacept (Orencia) Monthly (IV) or weekly (SQ) Week 5Week 2
Rituximab (Rituxan) 2 doses 2 weeks apart every 4–6 months Month 7
Tocilizumab (Actemra) Every week (SQ) or every 4 weeks (IV) Week 3 Week 5
Anakinra (Kineret) Daily Day 2
Secukinumab (Cosentyx) Every 4 weeks Week 5
Ustekinumab (Stelara) Every 12 weeks Week 13
Belimumab (Benlysta) Every 4 weeks Week 5
Tofacitinib (Xeljanz): STOP this medication 7 days prior to surgery. Daily or twice daily 7 days after last dose
SEVERE SLE-SPECIFIC MEDICATIONS: CONTINUE these medications in the perioperative period.
Dosing Interval Continue/Withhold
Mycophenolate Twice daily Continue
Azathioprine Daily or twice daily Continue
Cyclosporine Twice daily Continue
Tacrolimus Twice daily (IV and PO) Continue
NONSEVERE SLE: DISCONTINUE these medications in the perioperative period.
Dosing Interval Continue/Withhold
Mycophenolate Twice daily Withhold
Azathioprine Daily or twice daily Withhold
Cyclosporine Twice daily Withhold
Tacrolimus Twice daily (IV and PO) Continue

Dosing intervals obtained from prescribing information provided online by pharmaceutical companies.

DMARDs , Disease-modifying antirheumatologic medications; IV, intravenous; PO, oral; SLE, systemic lupus erythematosus; SQ, subcutaneous.


Injections


Although injections of steroids or viscosupplementation have been used in pursuit of the temporary relief of symptoms, the evidence in support of their use is weak at best. , I generally avoid them because of the risk of cartilage damage and allergic reactions as well as the possibility of introducing bacteria into the joint. , ,


Surgical treatment


Surgery should be considered for patients with refractory and functionally significant glenohumeral arthritis who are well informed, well motivated, cooperative, sufficiently healthy, and socially supported. Surgical reconstruction offers the potential to optimize soft tissue balance and muscle mechanics as well as the smoothness, size, and shape of the joint surfaces. It should be emphasized that surgery does not “fix” the problem; rather, it provides a basis for the patient to improve the comfort and function of their shoulder through a concerted rehabilitation effort. Although prosthetic arthroplasty is the primary surgical option to be considered when major pain and functional loss result from glenohumeral arthritis, other surgical alternatives may be useful in selected cases.


Arthroscopic


Considerations.


Patients sometimes ask, “Why can’t you just use an arthroscope to clean the arthritis out of my shoulder?” We know, however, that because glenohumeral arthritis is a condition in which articular cartilage is lost, the arthritis cannot be “cleaned out.” In most cases simply removing the osteophytes will not improve shoulder comfort and function unless the osteophytes are clearly restricting the range of motion and the joint surfaces are functional. Aspects of glenohumeral arthritis that could potentially be addressed arthroscopically include loose body removal ( Fig. 60.155 ), the release of capsular contracture, and resection of synovitis in cases of inflammatory arthropathy refractory to medical management. Beneficial results have been reported from arthroscopic debridement for glenohumeral arthritis without or with microfracture and without or with glenoid recontouring. However, rigorous evaluation of the outcome is complicated by the inconsistent inclusion of procedures, such as surgery on the subacromial space, acromioclavicular joint, or biceps tendon. It can be concluded from the published results for arthroscopic treatment that this can be successful in early instances of the disease before substantial destruction of the joint has occurred or for osteochondral lesions that are localized. , , Because such mildly involved shoulders may also improve with nonoperative management, it is important to determine the value of arthroscopic management using carefully controlled studies. The outcome of arthroscopic debridement is worse for shoulders with involvement of the joint surfaces of both the glenoid and the humerus, that is, true glenohumeral arthritis. , A recent systematic review found that there was insufficient evidence to support the routine use of arthroscopic debridement for glenohumeral arthritis. Another concluded that isolated arthroscopic debridement and capsular release did not provide sufficient benefit to justify its use in most patients. Microfracture appears to be of little benefit except for small localized defects in either the humeral or the glenoid joint surface. , It is important to note that arthroscopic surgery is still surgery, carrying costs and risks. A carefully controlled trial found that arthroscopic surgery for arthritis of the knee was no more effective than sham surgery (which, by the way, resulted in significant clinical improvement, illustrating the need for surgical controls).




Fig. 60.155


Loose body delivered by palpation from the subscapularis recess.


Open


Debridement and capsular release.


In a small number of cases of early arthritis—especially where there is substantial limitation of motion with relatively preserved joint surfaces—a debridement and capsular release may be considered for patients who wish to avoid a prosthetic arthroplasty, although it should be recognized that subsequent surgery may well be needed. This procedure is performed through the same skin incision as would be used for a joint replacement ( Fig. 60.156 ). The shoulder is approached through a subscapularis tenotomy ( Fig. 60.157 ), and adhesions in the humeroscapular motion interface are released ( Fig. 60.158 ). The subscapularis is released from the glenoid along with the attached subjacent anterior capsule ( Figs. 60.159–60.162 ) to allow a good range of passive motion ( Fig. 60.163 ). If there is a tendency for posterior instability, the capsular release is limited to the anterior aspect of the glenoid ( Fig. 60.164 ). Loose bodies, osteophytes, and interfering soft tissue are removed. The joint is thoroughly irrigated and gently manipulated to achieve the maximum possible range of passive motion, and the subscapularis is securely repaired ( Fig. 60.165 ). After surgery, a range of assisted motion exercises are immediately implemented. As with arthroscopic debridement, data on the effectiveness of this procedure are limited. I use it sparingly in cases of relatively early arthritis, especially in capsulorrhaphy arthropathy, where the anterior soft tissues have previously been tightened in the treatment of anterior instability (see Fig. 60.89 ). ,




Fig. 60.156


Incision.

The skin incision for the extended deltopectoral approach (dashed line) uses the mid-clavicle, the tip of the coracoid process, and the deltoid tuberosity of the midhumerus as landmarks. It is important that the incision avoid the axillary crease; otherwise, painful scarring might result.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:515.)



Fig. 60.157


Subscapularis tenotomy approach. The subscapularis tendon is divided medial to its insertion on the lesser tuberosity.



Fig. 60.158


Nerve-to-nerve release. All scar tissue in the humeroscapular motion interface (arrows) is released medially from the axillary nerve as it crosses the subscapularis, then under the coracoid, under the coracoacromial ligament, under the acromion, and finally under the deltoid to the axillary nerve posteriorly as it exits the quadrilateral space.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:517.)



Fig. 60.159


Releasing the coracohumeral ligament. The coracohumeral ligament is released from the base of the coracoid process, allowing unrestricted gliding of the supraspinatus as well as the subscapularis.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:519.)



Fig. 60.160


Releasing the subscapularis. (A) The subscapularis is often tethered to the coracoid and glenoid via the capsule, limiting its excursion (arrow) . (B) The subscapularis is released circumferentially (red arrow) , freeing it from the coracoid, the anterior glenohumeral capsule, the axillary nerve, and the coracoid muscles, allowing increased excursion (black arrow) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:519.)



Fig. 60.161


A 360-degree capsular release. (A) The glenoid here is concentrically worn and the shoulder is tight. (B) An extralabral release is therefore performed 360 degrees around the perimeter of the glenoid (red dashed line) .



Fig. 60.162


Posterior capsular release. If the posterior capsule is tight, it can be released under direct vision by rotating the inferior aspect of the retractor away from the glenoid and gently internally rotating the humerus.



Fig. 60.163


The 40-50-60 rule for appropriate soft tissue tensioning is as follows: at least 40 degrees external rotation with a reapproximated subscapularis tendon (left) , 50% posterior subluxation on the posterior drawer test (middle) , and 60 degrees of internal rotation of the 90-degree abducted arm (right) .



Fig. 60.164


(A) The preoperative axillary view shows posterior subluxation of the humeral head and posterior glenoid wear. (B) The extralabral release (red dashed line) then includes only the anterior capsule. (C) If the posterior instability is substantial, the release (red dashed line) stops at the inferior glenohumeral ligament.



Fig. 60.165


Anatomic repair of the subscapularis tendon should allow at least 40 degrees of external rotation.


Synovectomy.


The management of rheumatoid arthritis has been substantially improved through the use of disease-modifying agents (e.g., Plaquenil, cyclosporine, methotrexate, Cytoxan, Imuran, and Azulfidine) and biologics (e.g., Enbrel, Humira, Orencia, Remicade, and Rituxan). Before the availability of these medications, synovectomy and other nonprosthetic options were commonly used to remove inflammatory tissue from the glenohumeral joint. *


* References , , , , , .

Currently, synovectomy is used primarily to manage refractory synovitis and bursitis in the absence of major joint surface damage ( Fig. 60.166 ). ,


Fig. 60.166


The shoulder of a young man with rheumatoid arthritis and primary rheumatoid involvement of the subacromial-subdeltoid bursa. The rotator cuff was intact, and the glenohumeral joint had minimal involvement with rheumatoid synovitis. The patient had a full, minimally painful range of motion in the shoulder, with excellent shoulder strength. The hypertrophic bursitis did not respond to medical management, and the bursa was surgically excised.


Resection.


Before prostheses were available, resection of the humeral head was used to manage arthritis and severe fractures. , In general, comfort and function after resection arthroplasty are poor and so its current use is primarily for refractory infection or for failed arthroplasty without other means of reconstruction ( Figs. 60.167–60.169 ).




Fig. 60.167


A shoulder with resection of the total shoulder humeral and glenoid components because of refractory infection. (A) Anteroposterior view. (B) Axillary view.



Fig. 60.168


Resection for a failed arthroplasty.



Fig. 60.169


A proximal humeral prosthetic replacement had previously been placed in an elderly woman with multiple-joint osteoarthritis. (A) Her total knee arthroplasty became infected, and the infection spread to the proximal humeral prosthetic replacement. The shoulder region was brawny and erythematous, with a draining sinus on the anterolateral aspect of the arm. The region was debrided and the prosthesis and cement removed. (B) Radiographic appearance of the joint after delayed primary closure. At follow-up, the patient had only mild pain, and the shoulder was stable because of fibrosis. She had active abduction of 65 degrees and external rotation of 10 degrees.


Arthrodesis


Considerations.


Glenohumeral arthrodesis is usually reserved for attempts at salvaging septic arthritis or complex deficiencies of the joint surface associated with permanent loss of the cuff and deltoid. , , The best candidates for this procedure are shoulders that meet the following criteria: (1) permanent and severe weakness because of loss of cuff and deltoid function; (2) good scapular motors (e.g., trapezius, levator scapulae, pectoralis, serratus anterior, and rhomboids); and (3) sufficient residual glenoid and humeral bone stock to enable the fusion. Patients considering this procedure should have a strong motivation to succeed, minimal complaints of pain, and a good understanding of the following: (1) the potential complications of a shoulder fusion (including fracture of the humerus below the fusion); (2) the resultant limitation of internal and external rotation; and (3) the possible need for a second procedure to add bone graft to augment the fixation if the fusion does not “take” on the first attempt.


In the past, surgeons recommended fusing the shoulder in positions of abduction and flexion with the aim of optimizing function. , , However, such positions can be associated with substantial discomfort, largely related to the need to “wing” the scapula when the humerus is adducted to the resting position. To establish the limitations of function after shoulder fusion, we studied 12 shoulders that had undergone glenohumeral arthrodesis at least 2 years before the time of study. , The mean humerothoracic elevation in the plus 90-degree (anterior sagittal) plane was 47 degrees, the mean elevation in the minus 90-degree (posterior sagittal) plane was 22 degrees, the mean humerothoracic external rotation was 9 degrees, and the mean internal rotation was 46 degrees. These ranges of motion were similar to the scapulothoracic motion measured in normal subjects. Only one patient could reach his hair without bending the neck forward, five could reach their perineum, six could reach their back pocket, seven could reach the opposite axilla, and ten could reach their side pocket. We conducted a second study of normal in vivo shoulder kinematics to predict the functions that would be allowed by various positions of glenohumeral arthrodesis. This indicated that activities of daily living could best be performed if the joint was fused in 15 degrees of flexion, 15 degrees of abduction, and 45 degrees of internal rotation. This low angle of elevation and relatively high degree of internal rotation facilitated sitting comfortably on a chair; lying flat in bed; and reaching the face, the opposite axilla, and the perineum. Thus my preferred position is the “15, 15, 45” combination described above, a position that minimizes protrusion of the shoulder blade posteriorly into the chair or bed when the arm is at the side. This position has the additional advantages of being easy to determine at surgery and needing only a sling for postoperative immobilization rather than a cast or brace. It is most important to avoid fusing the shoulder in neutral or external rotation because this position precludes reaching the mouth or perineum.


Many techniques have been described for shoulder arthrodesis. *


* References , , , , , , , .

When possible, my preferred method is an intra-articular fusion that preserves the deltoid, most of the rotator cuff, and most of the bone of the glenohumeral joint, allowing the potential for later conversion to a reverse shoulder arthroplasty. If necessary for stability, however, a neutralization plate can be contoured over the scapular spine and down the humerus, but this risks denervating the anterior and part of the lateral deltoid. A vascularized fibular graft has been recommended when there is bone deficiency.


Technique.


The patient is placed in the beach chair position with the scapula in the prepared field and the arm draped free. The operative approach is through an anterior deltopectoral incision, with superior extension of the incision if plate fixation is used. I have used a low anterior axillary incision when cosmesis is a concern and intra-articular fusion is planned.


Any residual articular cartilage on the humerus or glenoid is curetted down to raw subchondral bone, as removing the subchondral bone weakens the construct and makes solid glenohumeral compression more difficult to achieve ( Figs. 60.170 and 60.171 ). The supraspinatus tendon is resected from between the humeral head and the acromion, and the undersurface of the acromion is stripped down to raw bone ( Fig. 60.172 ). The soft tissues are lifted from the anterior glenoid neck so that the subscapularis fossa can be palpated ( Fig. 60.173 ).




Fig. 60.170


Humeral head curettage. The articular cartilage is removed from the head of the humerus without sacrificing subchondral bone. Access to the joint surface is achieved by external rotation.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:236.)



Fig. 60.171


Glenoid curettage. The articular cartilage of the glenoid is removed with a curette without compromising the subchondral bone.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:237.)



Fig. 60.172


Acromion curettage. The periosteum of the acromial undersurface is curetted without compromising the cortical bone.



Fig. 60.173


Identifying the subscapularis fossa. The anterior aspect of the glenoid neck is palpated. This area will be the target for the compression screws.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:239.)


The humeral head is centered in the glenoid with the arm in 15 degrees of abduction, 15 degrees of flexion, and 45 degrees of internal rotation ( Fig. 60.174 ). It is temporarily fixed with three long 3.2-mm drill bits; these should exit the neck of the scapula anteriorly approximately 2 cm medial to the glenoid lip, where their tips can be palpated and controlled ( Figs. 60.175 and 60.176 ). When used in this manner, the known length of the drill bits can serve as depth gauges to determine the length of screws needed. The position of the arm is checked by making sure that the hand can reach the mouth, the anterior perineum, and the contralateral axilla. The 3.2-mm drill bits are sequentially replaced by fully threaded 6.5-mm cancellous screws with washers ( Figs. 60.177 and 60.178 ). Because the humeral head is softer than the glenoid, compression can usually be achieved without formally lagging the screw or needing to use a smooth shank.




Fig. 60.174


For many patients, the most comfortable position of fusion is that of 0 degrees of flexion, 0 degrees of abduction, and 60 degrees of internal rotation. This position allows the scapula to sit in its normal position on the chest wall while the arm is at the side.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:239.)



Fig. 60.175


While the humeral head is held reduced in the glenoid fossa in its proper position, a drill bit is passed through a stab incision then through the deltoid, the proximal humerus, and the glenoid, before exiting anteriorly from the neck.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:240.)



Fig. 60.176


Subsequent drill placement. Two additional drill bits are placed parallel to the first, equally spaced across the glenohumeral joint. The position and orientation of the humerus in relation to the glenoid is checked again.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:241.)



Fig. 60.177


Screw placement. The drill bits are sequentially replaced with 6.0-mm fully threaded cancellous screws with washers.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:242.)



Fig. 60.178


Screw length. Each screw should just penetrate the subscapularis fossa at the base of the glenoid neck.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:243.)


An iliac crest bone autograft is fashioned to fit between the humeral head and the acromion; it rests in the position normally occupied by the supraspinatus tendon ( Figs. 60.179–60.181 ). Interposition of the iliac crest graft maximizes humeroscapular contact by preserving the normal concave-convex glenohumeral relationships while allowing stabilizing contact between the head, the graft, and the acromion. If the humeral head is moved upward to make contact with the acromion without a graft, the glenohumeral contact area for fusion gets reduced. The graft is held in position by another screw placed from the acromion through the graft and out through the anteromedial aspect of the humeral neck ( Figs. 60.182 and 60.183 ). Additional bone graft is added around the fusion area to optimize healing.




Fig. 60.179


Acromiohumeral (AH) distance. After the supraspinatus tendon has been resected, the distance between the humeral head and the acromion is measured.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:243.)



Fig. 60.180


Graft harvest. A segment of graft measuring 20 × 20 × 8 mm is harvested from the iliac crest.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:244.)



Fig. 60.181


Graft placement. The graft is placed between the humeral head and the acromion in the area normally occupied by the supraspinatus tendon. This graft increases the quality of the fixation while helping maintain the position of the humeral head in the glenoid concavity.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:245.)



Fig. 60.182


Graft fixation. A fourth screw is passed through the acromion, the graft, and out the firm bone at the humeral neck.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:247.)



Fig. 60.183


Cancellous grafting. Cancellous bone graft is added across the area of glenohumeral arthrodesis.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:247.)


Depending on the circumstances, a neutralization plate (usually an 8- to 12-hole dynamic compression plate or pelvic reconstruction plate) may be used ( Fig. 60.184 ). If so, several points need to be emphasized. The plate needs a bend of about 90 degrees at the acromion and often an internal rotation twist of about 45 degrees to fit on the anterior of the humerus. The strongest fixation for the plate on the scapula is obtained by a screw down the base of the spine of the scapula just medial to the spinoglenoid notch. The arm is protected in a sling until the fusion is clinically and radiographically healed. When the fusion is solid, function and comfort can be enhanced by strengthening the periscapular musculature.




Fig. 60.184


Glenohumeral and acromiohumeral arthrodesis performed using a contoured iliac crest bone graft inserted between the acromion and the humeral head. The arthrodesis is stabilized securely with the following components: three washered, fully threaded cancellous humeroglenoid screws; one fully threaded cancellous screw through the acromion, graft, and humeral head; and a contoured reconstruction plate.


Complications of shoulder arthrodesis include nonunion, infection, malposition, prominence of the internal fixation plates, and fracture. Nonunion can be treated by freshening the arthrodesis site, repeat fixation, and bone grafting. It can sometimes be difficult to be sure from radiographs whether or not the fusion is solid; in such cases a reexploration may be helpful in evaluating the completeness of the fusion and the security of the internal fixation. Infection is treated by incision, drainage, and antibiotics, attempting to maintain the hardware stabilizing the fusion. Malposition is most common in excessive flexion, abduction, or external rotation. It is often preferable to manage malposition by humeral osteotomy ( Fig. 60.185 ), rather than by taking down a solid fusion and attempting to reposition it. Care must be taken in removing prominent hardware unless the fusion is absolutely solid. Humeral shaft fracture is a particular risk because the fused shoulder lacks the normal shoulder’s ability to absorb load without damage.




Fig. 60.185


Subtuberous humeral osteotomy performed for a shoulder that was fused in excessive abduction, excessive flexion, and malrotation. (A) Internal fixation. (B) After internal fixation has been removed.


Arthroplasty


Considerations.


Under optimal circumstances, glenohumeral arthroplasty can be a powerful approach for reconstructing an arthritic shoulder. In considering the advisability of a shoulder arthroplasty and the selection of a specific procedure, it is important to consider the four P’s.



  • 1.

    Is the problem (diagnosis and associated aspects of the shoulder) one that can be well managed with arthroplasty? Are the essential bone, deltoid, cuff, nerve, and skin tissues in sufficiently good condition for a safe and effective arthroplasty? Is the severity of the problem typical of patients presenting for shoulder arthroplasty? ( Fig. 60.186 )




    Fig. 60.186


    Frequency distribution of the number of Simple Shoulder Test functions that a sample of patients was able to perform immediately prior to shoulder arthroplasty. We use this chart to help the patient consider the question, “When is my arthritic shoulder bad enough to justify a joint replacement?” As shown by this graph, the great majority of these patients were able to perform less than half of the 12 functions.


  • 2.

    Is the patient informed and in sufficiently good physical, social, and emotional health to succeed with the procedure and its postsurgical rehabilitation? Comorbidities, level of education, type of insurance, age, sex, and the patient’s overall well-being have all been shown to influence the outcome of the arthroplasty. , , ,


  • 3.

    Is the physician sufficiently experienced in shoulder reconstruction to optimize the chance of a good outcome? Many shoulder arthroplasties are performed by surgeons who perform only a small number of these cases each year, yet case volume has a strong influence on the outcome of the surgery. As we say, “The surgeon is the method,” and “Experience is the great teacher.”


  • 4.

    Is the procedure appropriate for the problem, patient, and physician? Among the variations of shoulder arthroplasty available, which is the best fit for the shoulder, the patient, and the surgeon?



Types of arthroplasty.


There are four basic types of shoulder arthroplasty: the humeral hemiarthroplasty, the ream and run arthroplasty (humeral hemiarthroplasty with a nonprosthetic glenoid arthroplasty), the anatomic total shoulder arthroplasty (humeral hemiarthroplasty with a prosthetic glenoid arthroplasty), and the reverse total shoulder arthroplasty.


Prosthetic humeral hemiarthroplasty is considered under the following circumstances: (1) when the glenoid articular surface is intact (as in avascular necrosis before collapse of the humeral head and before secondary destruction of the glenoid surface); (2) when there is insufficient joint volume or glenoid bone stock to allow for secure placement of a glenoid component; (3) in cases of rotator CTA when the humeral head is stabilized by an intact coracoacromial arch (see Fig. 60.112 ) and active elevation exceeds 90 degrees *


* References , , , , , .

; and (4) in cases where concern about infection discourages the use of a glenoid component. In glenohumeral arthritis—that is, when both the humeral and glenoid articular surfaces are involved—a hemiarthroplasty alone may be insufficient treatment. There are two types of humeral hemiarthroplasty implants: a humeral head prosthesis fixed with a stem inserted down the medullary canal of the humerus ( Fig. 60.187 ) and a partial or complete resurfacing prosthesis mounted on the retained biologic humeral head ( Fig. 60.188 ).


Fig. 60.187


Humeral head prosthesis fixed with a stem inserted down into the humeral medullary canal.



Fig. 60.188


Complete resurfacing head prosthesis mounted on the retained biologic humeral head.


Ream and run arthroplasty (humeral hemiarthroplasty with a nonprosthetic glenoid arthroplasty) is considered for the treatment of glenohumeral arthritis when the patient, after being informed, wishes to avoid the potential risks and activity restrictions associated with a prosthetic glenoid component. Initially there was interest in biologic resurfacing of the glenoid with capsule or cadaveric meniscus ( Fig. 60.189 ) as a way to avoid the risks of prosthetic glenoid component failure; however, recent experience with this approach has not been encouraging. The ream and run procedure is a glenohumeral arthroplasty in which a humeral hemiarthroplasty is combined with conservative reaming of the glenoid to a single concentric concavity without substantially modifying glenoid version and without the use of biologic interposition. , , Because the ream and run procedure modifies both the humeral and glenoid articular surfaces, it is a glenohumeral arthroplasty; this should not be confused with a hemiarthroplasty in which only the humeral side of the joint is addressed. It is referred to as a radically conservative procedure because it involves the removal of less glenoid bone than would be required for the insertion of a glenoid component.




Fig. 60.189


Biologic glenoid resurfacing with a knee meniscal allograft.


In the anatomic total shoulder arthroplasty , a humeral hemiarthroplasty is combined with a prosthetic glenoid component. The total shoulder arthroplasty is the most commonly used approach to glenohumeral arthritis when the rotator cuff is intact and when sufficient glenoid bone is available for fixation of the glenoid prosthesis. , ,


In the reverse total shoulder arthroplasty , the positions of the ball and socket are reversed from the anatomic arrangement. This type of prosthesis is used when the arthritic shoulder demonstrates instability that cannot be managed with an anatomic prosthesis or when there is insufficiency of the rotator cuff. Reverse total shoulder arthroplasty is traditionally used to manage CTA and anterosuperior escape (see Figs. 60.111–60.113 and 60.117 ). Expanding indications for reverse arthroplasty include shoulders with an irreparable rotator cuff and pseudoparalysis, meaning that the shoulder cannot be actively elevated to 90 degrees despite a good range of passive motion and intact deltoid function. Reverse arthroplasty is also used to manage comminuted proximal humeral fractures in the osteopenic bone of older individuals and failed anatomic arthroplasty with instability or pseudoparalysis ( Fig. 60.190 ). , ,




Fig. 60.190


Failed anatomic prosthesis for a fracture with pseudoparalysis. (A) Anteroposterior view showing superior placement of the humeral prosthesis, superior subluxation of the humeral head, and an absent greater tuberosity. (B) Because of the high position of the stem, the humeral prosthesis had to be removed at the time of conversion to a reverse total shoulder arthroplasty.


Mechanics of anatomic arthroplasty.


Four basic mechanical characteristics are essential to shoulder function: mobility, stability, strength, and smoothness. Commonly, each of these characteristics is compromised in an arthritic shoulder, and each can potentially be improved by shoulder arthroplasty. The approach to glenohumeral arthritis is guided by an understanding of these elements necessary for optimal shoulder mechanics. Although recreation of appropriate bone alignment may help with soft tissue balance and restoration of appropriate shoulder mechanics, restoration of glenohumeral mobility and stability is the priority rather than trying to recreate “normal anatomy.” Templating systems or patient-specific instrumentation systems based on a preconceived “normal” shoulder are not able to fully address the issues associated with shoulder arthritis. In performing glenohumeral reconstruction it is often necessary to modify the humeral head size, thickness, and eccentricity to achieve the desired joint mechanics while preserving glenoid and humeral bone stock. An understanding of glenohumeral mechanics and how to use soft tissue balancing techniques to restore glenohumeral mechanics during shoulder arthroplasty are essential to successful outcome. , , ,


Mobility.


The requisites for a normal range of glenohumeral motion include normal capsular laxity, appropriately sized and shaped concentric articular surfaces, and the absence of osteophytes or other unwanted sources of contact between the proximal humerus and the lateral scapula.


Capsular laxity.


In normal shoulders ample capsular laxity allows the full range of rotation at the glenohumeral joint. The glenohumeral capsule normally remains lax through most of the functional range of motion. , As the joint approaches the limit of its range, the tension in the capsule and its ligaments increases sharply, checking the range of motion ( Fig. 60.191 ). However, in most conditions that require shoulder arthroplasty, the capsule and ligaments are contracted; this prematurely limits the range of motion and increases the joint pressure at the limits of motion ( Fig. 60.192 ). The term “stuffing” has been used to refer to additional tightening of the capsule that results from the insertion of prosthetic components that take up more space than that afforded by the available joint volume ( Fig. 60.193 ). Unless capsular releases ( Figs. 60.194 and 60.195 ) sufficient to accommodate this additional volume have been performed, the joint becomes “overstuffed,” limiting joint motion ( Fig. 60.196 ), with greater torque (muscle force) required to move the arm ( Fig. 60.197 ). Cadaver studies have indicated that less than 10 mm of overstuffing can reduce normal capsular laxity by as much as 50% ( Fig. 60.198 ). Overstuffing also causes obligate translation of the humeral head on the glenoid, resulting in eccentric glenoid loading ( Table 60.4 ); for example, the compressive load increases and forced posterior translation occurs when external rotation is attempted against a tight anterior capsule, accounting for the pathology commonly seen in capsulorrhaphy arthropathy (see Fig. 60.90 ; Figs. 60.199 and 60.200 ).




Fig. 60.191


Range of humeroscapular elevation with no capsular tension. This global diagram represents data from a cadaver experiment in which the humerus was elevated in a variety of scapular planes and free axial rotation was allowed. Elevation was performed until the torque reached 500, 1000, and 1500 N/mm. The positions associated with these torques are indicated by the isobars (gray, red, and blue dashed lines) . The area within the 500 N/mm isobar indicates the range of positions in which there was effectively no tension in the capsuloligamentous structures. For further details, see .



Fig. 60.192


(A) Normal capsular laxity allows an unrestricted range of motion. (B) In degenerative joint disease the capsule may be contracted and has to course over osteophytes. (C) As the joint approaches the premature limit of its range, the tension in the capsule and ligaments increases sharply, increasing the joint pressure (red arrows) .



Fig. 60.193


Shoulder arthroplasty can tighten the capsule. (A) A degenerated and collapsed humeral head. (B) The head has been replaced by a relatively larger prosthesis with a glenoid component added to the surface of the glenoid bone. The prosthetic components take up a greater volume than the degenerated surfaces they replace and consequently stuff the joint.



Fig. 60.194


Release of the anterior capsule from the glenoid while the axillary nerve is protected. (A) Anteroposterior view showing incision of the inferior capsule while the axillary nerve (yellow) is retracted. (B) Lateral view showing release of the capsule from the anterior and inferior glenoid.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:520.)



Fig. 60.195


Posterior capsule release. If the posterior capsule is tight, it can be released under direct vision. The surgeon places the capsule under tension by rotating the inferior aspect of the retractor away from the glenoid (arrow) and gently internally rotating the humerus.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: WB Saunders; 2004:555.)



Fig. 60.196


Effect of joint stuffing on the range of motion. This graph compares four humeroscapular ranges of motion that could be achieved with an applied torque of 1500 N/mm for an anatomic joint (0 mm of joint stuffing), an anatomic humeral arthroplasty with a 4-mm-thick glenoid component (4 mm of overstuffing), and an arthroplasty with a 4-mm-thick glenoid and a 5-mm oversized humeral neck (a total of 9 mm of overstuffing). Note the sequential loss of range of motion as the degree of stuffing increases.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.197


The average torque necessary to achieve 60 degrees of elevation in the +90-degree scapular plane for an anatomic shoulder (0 mm of stuffing), an anatomic shoulder arthroplasty with 4 mm of glenoid stuffing, and an arthroplasty with 4 mm of glenoid and 5 mm of humeral overstuffing (a total of 9 mm of overstuffing). The required torque is almost three times higher for the joint overstuffed with 9 mm of component than for the anatomic joint.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)



Fig. 60.198


The effect of overstuffing on capsular laxity in eight cadaver shoulders (mean age, 73 ± 8.5 years). The intact shoulders (0 mm of stuffing) demonstrated 15 mm of translational laxity on the anterior drawer, posterior drawer, and sulcus tests. Overstuffing by 9 mm reduced this normal joint laxity by approximately 50% in all directions.

(From Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)


TABLE 60.4

Range of Angular Motion Before Onset of Obligate Translation
















Angular Motion Anatomic Shoulder Joint Overstuffed 9 mm
Elevation in the +90-degree scapular plane 60 degrees 30 degrees
External rotation of the arm elevated 50 degrees 60 degrees 32 degrees

Values represent the maximal elevation achieved with no more than 2 mm of obligate translation.



Fig. 60.199


Ligament shortening (red dotted lines) can cause increased joint pressure (short arrows) . If the capsule and ligaments on one side of the joint are shortened, applying torque against them (red arrow) can increase the compressive force (c) applied to the joint surface. This increased joint pressure can damage the joint surface. d , Displacing force; t , total force.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:40.)



Fig. 60.200


If the humerus is rotated beyond the point at which the ligaments become tight, the displacing force (P) can push the humeral head out of the glenoid center, a phenomenon known as “obligate translation.”

(Modified from Matsen FA III, Lippitt SB, Sidles JA, et al. Practical Evaluation and Management of the Shoulder. Philadelphia: WB Saunders; 1994.)


In total shoulder arthroplasty, the contribution of the components to joint stuffing can be estimated by adding the thickness of the glenoid component to the net added thickness of the humeral component (i.e., the difference between the amount of intra-articular humerus resected and the amount of humerus added) (see Fig. 60.193 ; Figs. 60.201–60.203 ). The amount of stuffing from the humeral component is also influenced by the position in which it is placed: a humeral stem inserted in varus will increase the stuffing of the joint when the arm is at the side ( Fig. 60.204 ). A component inserted in an excessively high position tightens the capsule in adduction ( Fig. 60.205 ) and in abduction ( Fig. 60.206 ). The incremental thickness of the glenoid is determined by the thickness of the component, as well as by the amount of reaming, the presence or absence of cement between the component and the bone, and the effect of bone grafts ( Fig. 60.207 ). The thickness of currently available glenoid components varies from 3 mm to more than 15 mm.




Fig. 60.201


Consequences of the amount of joint stuffing. (A) When the head component is too small, the cuff is slack at rest. (B) With a properly sized head component, there is appropriate tensioning of the rotator cuff. (C) Overstuffing the joint with a head component that is too large places excessive tension on the rotator cuff.



Fig. 60.202


Neck length. (A) Normal relationships. (B) A prosthesis with a collar and gap increases the total neck length.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:458.)



Fig. 60.203


Overstuffing. Excessive height of the humeral articular surface, from either a thick glenoid (A) or a large head (B), overstuffs the joint and places the rotator cuff under greater tension when the arm is in adduction.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:702.)



Fig. 60.204


Varus position of the humeral component can increase the distance between the greater tuberosity and the glenoid (W) , effectively overstuffing the joint.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:703.)



Fig. 60.205


Head height and adduction. (A) The ideal position. (B) Positioning the humeral prosthesis in an excessively superior position causes excessive tension in the superior cuff when the arm is in adduction (dotted lines) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:454.)



Fig. 60.206


Head height and abduction. (A) The ideal position. (B) Positioning the humeral prosthesis in an excessively superior position causes excessive tension in the inferior capsule when the arm is in abduction.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:455.)



Fig. 60.207


Glenoid thickness contributes to the relative stuffing of the joint. This is particularly an issue with some metal-backed components, where a minimum thickness of 3 to 4 mm of polyethylene is superimposed on a metal base. As a result, some components are up to 1.25 cm thick. Insertion of such a component can be predicted to reduce the range of rotation in each direction by about 28 degrees (12.5 mm of increased thickness is half a radian for an average humeral head of radius 25 mm; in degrees, half a radian is 0.5 × 360/2π, or 28 degrees). Thus the restoration of motion to an arthritic shoulder can require a combination of soft tissue releases and avoiding the insertion of a thick glenoid component.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:504.)


Overstuffing can be avoided by ensuring adequate capsular laxity at the time of surgery using the “40, 50, 60” rule of thumb to guide the selection of the prosthetic sizes: the arm should allow 40 degrees of external rotation at the side after the anterior structures have been approximated ( Fig. 60.208 ), the humeral head should translate approximately 50% of the width of the glenoid in the posterior drawer test ( Fig. 60.209 ), and the abducted arm should allow 60 degrees of internal rotation ( Fig. 60.210 ).




Fig. 60.208


The 40-50-60 rule for adequate capsular laxity to guide the selection of a prosthetic replacement. The arm should allow 40 degrees of external rotation at the side after the anterior structures have been approximated.



Fig. 60.209


The 40-50-60 rule for adequate capsular laxity to guide the selection of a prosthetic replacement. The humeral head component should translate approximately 50% of the glenoid width on the posterior drawer test.



Fig. 60.210


The 40-50-60 rule: internal rotation. There should be 60 degrees of internal rotation of the arm abducted to 90 degrees.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:480.)


If the humeral head translates posteriorly by more than 50%, three strategies may be considered individually or in combination: (1) selecting a humeral head component of greater diameter or thickness ( Fig. 60.211 ); (2) using an anteriorly eccentric head component ( Fig. 60.212 ); or (3) performing a rotator interval plication ( Fig. 60.213 ).




Fig. 60.211


(A) The humeral head translates further than 50% posteriorly. (B) A larger width head component may improve the balance of the reconstruction.



Fig. 60.212


(A) The humeral head translates further than 50% posteriorly. (B) An eccentric head component oriented anteriorly may improve the balance of the reconstruction.



Fig. 60.213


Rotator interval closure, anterior view. The rotator interval is closed using four braided No. 2 nonabsorbable sutures inserted with the knots buried.


Humeral articular surface.


A substantial, properly located humeral articular surface area allows a large unimpeded range of motion ( Fig. 60.214 ). Humeral articular surfaces that are nonspherical ( Figs. 60.215 and 60.216 ) or that comprise a reduced portion of the sphere ( Figs. 60.217–60.220 ) reduce the amount of range of motion that can take place with full surface contact at the glenohumeral joint ( Fig. 60.221 ). , , ,




Fig. 60.214


Normal spherical cap. Restoration of the entire area of the spherical cap maximizes the range of motion with full surface contact between the humeral head and glenoid.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:430.)



Fig. 60.215


Nonspherical humeral head prosthesis.



Fig. 60.216


“Rocking horse” glenoid loosening with a nonspherical humeral head.



Fig. 60.217


Spherical cap reduced by collar and gap between the head and collar of the prosthesis. A prosthesis with a collar and a gap sacrifices the height of the spherical cap and the range of motion with full surface contact.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:432.)



Fig. 60.218


Spherical cap reduced by chamfering. A chamfered humeral head prosthesis has a reduced height of the spherical cap and reduced range of motion with full surface contact.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:431.)



Fig. 60.219


A humeral component with an articular surface that encompasses only a small portion of the potential spherical articular surface can predispose the prosthesis to unwanted translation as well as unwanted contact between the prosthetic collar and the glenoid.



Fig. 60.220


A large collar and a small articular surface provide minimal humeral articular surface area. In addition, this prosthesis was placed too high.



Fig. 60.221


Motion-limiting abutment between the glenoid component and soft tissue or bone when the arm is externally rotated (arrow) .

(Modified from Ballmer FT, Lippitt SB, Romeo AA, et al. Total shoulder arthroplasty: some considerations related to glenoid surface contact. J Shoulder Elbow Surg. 1994;3:299–306.)


Glenoid articular surface.


The glenoid surface encompasses a relatively small portion of the articulating sphere when compared with the articular surface of the humerus. If the prosthetic joint surface area of the glenoid is large compared with that of the humerus, abutment of the prosthesis against the humeral neck or tuberosities can restrict joint motion ( Fig. 60.222 ).




Fig. 60.222


If the prosthetic glenoid joint surface area is large compared with that of the humerus, abutment of the prosthesis against the humeral neck or tuberosities can restrict joint motion.


Concentricity of the coracoacromial and glenohumeral spheres.


Two spheres are involved in glenohumeral motion: one represented by the articular surfaces of the humeral head and the glenoid, and the other by the proximal humeral convexity and the coracoacromial arch ( Figs. 60.223 and 60.224 ). The difference in the radius of these two spheres is made up by the height of the tuberosities and the thickness of the rotator cuff. For optimal shoulder kinematics, the centers of these spheres need to match.




Fig. 60.223


Concentric spheres. The center of the coracoacromial concavity is the center of the sphere that best fits the concave undersurface of the coracoacromial arch. r is the radius of the humeral articular surface and the glenoid articular surface with which it articulates; R is the radius of the proximal humeral convexity (the outer surface of the cuff and tuberosity) and the undersurface of the coracoacromial arch with which it articulates.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:413.)



Fig. 60.224


Proximal humeral convexity. The center of the proximal humeral convexity is the center of the sphere that circumscribes the cuff tendons and the tuberosity. The radius of the proximal humeral convexity (R) differs from the radius of the humeral head (r) by the thickness of the rotator cuff.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:415.)


Absence of unwanted bone contact.


Osteophytes predispose to unwanted contact between the humerus and the glenoid and can impair motion ( Figs. 60.225–60.227 ). Any blocking osteophytes must be completely resected at the time of joint reconstruction ( Figs. 60.228 and 60.229 ). A malunited greater tuberosity can also limit rotation ( Fig. 60.230 ).




Fig. 60.225


When the arm is adducted (black arrow) , humeral inferior osteophytes can abut the inferior glenoid (red arrow) , causing the glenohumeral joint to “open book” superiorly (red lines) .



Fig. 60.226


Blocking osteophytes. Humeral osteophytes can abut against the glenoid lip (red arrow) , limiting the range of rotation.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:47.)



Fig. 60.227


(A) Care should be taken to ensure that the posterior humeral head does not abut the posterior glenoid in external rotation (red arrow) . (B) This can cause the joint to “open book” anteriorly.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:585.)



Fig. 60.228


Posterior “open book.” (A) If the posterior nonarticular humerus abuts against the posterior corner of the glenoid, the joint will “open book” on external rotation (B).

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:579.)



Fig. 60.229


Inferior “open book.” (A) Bone extending beyond the curvature of the prosthetic humeral articular surface (arrow) . (B) This can abut the inferior glenoid when the arm is adducted (arrow) .

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:701.)



Fig. 60.230


Malunion of the greater tuberosity. Malunion with posterior displacement of the greater tuberosity allows the tuberosity to abut the glenoid on external rotation.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:701.)


Normally, 4 to 5 cm of excursion takes place at the upper aspect of the interface between the coracoid muscles and the subscapularis ( Figs. 60.231 and 60.232 ). Bursal hypertrophy, adhesions, or spot welds between the proximal aspect of the humerus and the cuff on the one hand and the deltoid and coracoacromial arch on the other can limit motion, even when the intra-articular aspect of the arthroplasty is perfectly balanced ( Fig. 60.233 ). Lysis of humeroscapular spot welds is an important early step in arthroplasty of the shoulder.




Fig. 60.231


Humeroscapular motion interface (dotted line) . The external surface of the rotator cuff articulates with the undersurface of the coracoacromial arch. This articulation is part of the humeroscapular motion interface. Smooth, unrestrained movement at this interface is required for normal shoulder function.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:412.)



Fig. 60.232


Humeroscapular motion interface. The humeroscapular motion interface is the set of gliding surfaces (arrows) between the proximal humerus covered by the rotator cuff tendons and the overlying structures attached to the scapula, including the deltoid, acromion, coracoacromial ligament, coracoid, and the tendons of the coracoid muscles. Approximately 4 cm of motion takes place at this interface in normal shoulder movement.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:413.)



Fig. 60.233


Spot welds. Adhesions from the external to the internal surface of the humeroscapular motion interface can restrict the range and smoothness of motion.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:45.)


Stability.


The primary mechanism for glenohumeral stability is “concavity compression,” described earlier (see Fig. 60.4 ). , Concavity compression is optimized by an ample humeral articular surface area, a stabilizing glenoid concavity, and muscular control of the net humeral joint reaction force such that it compresses the humeral articular surface into the glenoid concavity ( Fig. 60.234 ). This mechanism is commonly altered in osteoarthritis, with some degree of posterior humeral head subluxation present in most cases. ,




Fig. 60.234


Balanced net forces. The direction of the forces exerted by the scapulohumeral muscles (dashed arrows) is determined by their effective attachments to the scapula and humerus.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:488.)


Humeral articular surface area.


The function of the humeral articular surface is to apply the net humeral joint reaction force evenly across the glenoid throughout the normal range of glenohumeral motion. A prosthetic surface area that represents only a small part of the total sphere can predispose to instability in the same way that a Hill-Sachs defect does in traumatic instability by offering less contact area for joint surface contact (see Figs. 60.215 to 60.220 ; Fig. 60.235 ).




Fig. 60.235


Surface contact. (A) Full surface contact provides broadly distributed load transfer and maximal joint stability. (B and C) Without full surface contact, the humeral component can be translated in the direction of the empty part of the glenoid.

(From Matsen FA III, Lippitt SB. Shoulder Surgery: Principles and Procedures. Philadelphia: Saunders; 2004:433.)


The orientation of the humeral articular surface can be described in terms of the humeral head centerline, a line that passes through the center of the humeral joint surface and the center of the anatomic neck ( Fig. 60.236 ). This line usually makes a valgus angle of about 130 degrees with the humeral shaft, and it generally makes a retroversion angle of about 30 degrees with the plane of the humerus ( Figs. 60.237 and 60.238 ). In contrast to the situation with the femoral component in hip arthroplasty where rotational alignment is critical ( Fig. 60.239 ), changing the version of the humeral component has relatively little effect on the effective position of the articulating surface of the humerus. This is because in most situations the center of rotation of the spherical humeral articular surface is close to the center of rotation of the stem of the prosthesis in the diaphysis ( Fig. 60.240 ). Thus alteration of humeral version is relatively ineffective in managing glenohumeral instability.


Aug 21, 2021 | Posted by in ORTHOPEDIC | Comments Off on Evaluation and management of glenohumeral arthritis
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