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 ).
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.
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. ,
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 ).
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?
|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|
|Do usual work||39||44||21||17||41||21|
|Carry 20 lb||62||62||21||33||41||29|
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.”
|Physical role function||44||33||23||30||39||28|
|Emotional role function||83||76||58||100||64||40|
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.
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.
____ 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.
____ 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.
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 ).
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.
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.
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.
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.
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.
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 ).
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.
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. , ,
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 ).
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.
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.
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).
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 ).
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.
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 ).
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 ).
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 ).
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 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.
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.
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 ).
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.
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 ).
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.
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 ).
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 ). ,
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.
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.
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.
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.
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 ).
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.
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 )
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.
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 ).
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 ). ,
|DMARDs: CONTINUE these medications through surgery.|
|Sulfasalazine||Once or twice daily||Continue|
|Hydroxychloroquine||Once or twice 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.|
|Azathioprine||Daily or twice daily||Continue|
|Tacrolimus||Twice daily (IV and PO)||Continue|
|NONSEVERE SLE: DISCONTINUE these medications in the perioperative period.|
|Azathioprine||Daily or twice daily||Withhold|
|Tacrolimus||Twice daily (IV and PO)||Continue|
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. , ,
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.
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).
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 ). ,
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 ). ,
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 ).
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.
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 ).
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.
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.
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.
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.
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.
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 )
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. , , ,
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.”
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 ).
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.
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 ). , ,
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. , , ,
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.
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 ).
|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|
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.
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 ).
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 ).
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 ). , , ,
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 ).
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.
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 ).
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.
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. ,
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 ).
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.