Rotator Cuff and Impingement Lesions




Historical Perspective


A description of rotator cuff pathology is found in the earliest surgical text, the Edwin Smith Papyrus (ca. 1500 bce ). Subsequently, throughout ancient and modern history, multiple authors around the globe have spilled various quantities of ink about the rotator cuff, its disease, and its nonoperative and operative treatment. The first modern case report and illustration of a rotator cuff tear was penned by Monro in 1788 in his treatise, A Description of all the Bursae Mucosae of the Human Body . John Gregory Smith reported the first cases series of seven rotator cuff tears in a letter to the editor of the London Medical Gazette, and Muller described a rotator cuff repair in 1889. However, it was the publication of Ernest Amory Codman’s landmark book, The Shoulder, in 1934 that ushered the rotator cuff, its pathology, and its treatment into mainstream medical discourse and consciousness. Codman was a Boston general surgeon who dedicated a tremendous amount of his energy, talent, skill, and clinical practice to the study of the shoulder and its maladies. The foundation of contemporary care of rotator cuff disease—and arguably the care of surgical patients in general—can be traced to the principles described in this book. Although Codman’s book and the works of other authors have shed light on the subject, many questions regarding the care of the rotator cuff remain, and nowhere is this more relevant than in the rotator cuff of the athlete.


The years following the publication of Codman’s book saw a rapid proliferation of active study of the shoulder by authors such as Harrison McLaughlin, Carter Rowe, and Charles Neer. The pioneering work of Charles Neer set the stage for the contemporary discussion and debate of how to best care for the rotator cuff, in athletes or otherwise. Neer expanded on the concept of outlet impingement first elucidated by Meyer in 1937. Neer vigorously investigated subacromial outlet impingement and argued that impingement was the basis of a spectrum of disease, encompassing most disorders involving the rotator cuff.


Neer proposed three stages of impingement. Initially, in stage I, there is inflammation and edema within the cuff. This is followed by the fibrosis and tendinitis seen in stage II. Finally, there is partial or complete tearing of the rotator cuff in stage III. Neer eventually came to argue that a vast majority, if not all, lesions of the rotator cuff were due to subacromial impingement. This argument generated vigorous and vocal opposition from other surgeons who argued that the etiology of rotator cuff disease is more degenerative in nature. The debate of extrinsic impingement versus intrinsic degeneration as the etiology of rotator cuff tears continues to this day. In reality, rotator cuff tears are likely the result of a multifactorial combination of these two sources.


The medical history of care of the athlete’s shoulder follows a parallel course to that of the care of the shoulder in general. Based on Neer’s groundbreaking work on impingement and acromioplasty, many surgeons have applied the principles that Neer had elucidated to degenerative lesions of the shoulder to the treatment of maladies unique to the athlete’s shoulder. However, as was the case with cuff lesions in general, clinical experience ultimately revealed that the scope of the problems facing the athlete’s shoulder was more complex than simple extrinsic impingement. The extremes of range of motion and the dynamic loads placed on an overhead athlete’s shoulder are unique and unparalleled. The complex biomechanical activity of elite throwing predisposes the thrower’s shoulder to multiple pathologic derangements in shoulder structure and function, such as scapular dyskinesis, posterior capsular contracture, anterior microinstability, internal impingement, and even classic outlet impingement. In a symptomatic throwing athlete, identifying the specific etiology of the problem is a complex endeavor that demands a mastery of the anatomy and biomechanics of the shoulder, as well as a sound clinical evaluation, to make a correct diagnosis and recommend the correct treatment.




Pertinent Anatomy


The glenohumeral joint is the most mobile in the body, allowing for precise positioning of the hand in space. The glenohumeral joint also acts as a fulcrum for the upper extremity, absorbing the majority of forces in sports that require propulsive action. Vitally linked to these motions in terms of precision, propulsion, and stability is the rotator cuff. The cuff is composed of the confluent tendons of the supraspinatus, infraspinatus, subscapularis, and teres minor muscles, which originate from the anterior and posterior faces of the scapula and insert as a composite onto the greater and lesser tuberosities of the humerus. The cuff envelops and blends with the glenohumeral capsule on all sides except at the redundant inferior pouch.


The tendon of the long head of the biceps is intimately associated with the rotator cuff and has been called the “fifth tendon” of the cuff. The biceps tendon originates at the supraglenoid tubercle and traverses the glenohumeral joint as an intraarticular but extrasynovial structure. The biceps passes deep to the interval between the supraspinatus and subscapularis (the “rotator interval”) and exits the joint in the intertubercular sulcus, which is bounded by the coracohumeral ligament superiorly and the confluence of the superior tendinous slip of the subscapularis and superior glenohumeral ligament inferiorly. These ligaments, along with the tendinous slip of the subscapularis, form a pulley for the biceps tendon as it enters the intertubercular groove. The groove has a variable shape and depth, and the bony anatomy of the supratubercular region has been implicated in degenerative lesions of the biceps tendon. Distal to its articular portion, the biceps is held in the intertubercular groove by the transverse humeral ligament.


The rotator interval is an anatomic space defined by the inferior edge of the supraspinatus tendon and the superior edge of the subscapularis tendon. The superficial roof of the rotator interval is the coracohumeral (CH) ligament and the floor of the interval is the superior glenohumeral ligament (SGHL). This interval is occupied by the biceps tendon as it enters the shoulder joint, with the CH ligament and SGHL forming a pulley for the biceps tendon ( Fig. 52-1 ). The rotator interval functions, biomechanically, as a suspensory structure for the humeral head. Lesions of the rotator interval have been recognized as an important pathology in the genesis of shoulder pain.




FIGURE 52-1


A, Anterior cuff structures with biceps tendon entering the rotator interval. B, Arthroscopic view from within the glenohumeral joint. The biceps tendon is seen entering the joint.


The vascular supply of the biceps and rotator cuff has been studied extensively. Anatomic studies have demonstrated that the vascular supply of the rotator cuff comes from six branches of the axillary artery, with the largest contributions arising from the suprascapular and the anterior and posterior humeral circumflex arteries. Previous belief held that there is an area of relatively poor vascularity known as the “critical zone.” This area lies within the supraspinatus tendon immediately proximal to its insertion onto the greater tuberosity, where most degenerative changes and degenerative rotator cuff tearing begin. However, recent intraoperative Doppler flowmetry studies failed to show a critical zone of decreased vascularity in normal supraspinatus tendons, although there is a demonstrated decrease in overall tendon vascularity with increasing age. The biceps tendon also demonstrates an area of hypovascularity in its intra-articular portion related to tension or pressure from the humeral head when the tendon is in the anatomic position. With arm abduction, these areas demonstrate complete vascular filling.


Superficial to the rotator cuff is the deltoid and coracoacromial (CA) arch. The acromion is an extension of the spine of the scapula and has a variable shape and slope that form the posterolateral bony roof of the arch. The acromion serves as the origin of the deltoid laterally and articulates with the clavicle anteriorly and medially, its undersurface creating a finite space for the rotator cuff tendons superior to the humeral head. The CA ligament extends from the outer edge of the coracoid and widens to insert on the anteromedial aspect and undersurface of the acromion. The CA ligament encompasses the anterior extent of the CA arch and, with the anteroinferior edge of the acromion and the coracoid process, is implicated in classical extrinsic impingement of the rotator cuff. Some authors have suggested that the shape and slope of the acromion may be related to extrinsic rotator cuff pathology. However, whether the variability in acromial shape is the result or the cause of the underlying cuff degeneration remains controversial ( Fig. 52-2 ).




FIGURE 52-2


Variability in acromial morphology. Lateral views of a normal acromion ( A ) and a more hooked acromion associated with impingement ( B ).


Deep to the CA arch lies the subacromial bursa. It is a filmy synovium-lined sac that attaches at its base to the greater tuberosity with its roof fixed to the undersurface of the acromion and CA ligament. The remaining superior and inferior surfaces of the bursa articulate loosely with the deltoid and rotator cuff, respectively. The roof and base of the bursa are separated by a thin interface of synovial fluid that allows relatively frictionless motion between the cuff and the overlying deltoid and CA arch.




Relevant Biomechanics


The biomechanics of the athlete’s shoulder involve a complex interaction between several “joints,” including the scapulothoracic, glenohumeral, acromioclavicular and sternoclavicular articulations. The most relevant to this topic are the scapulothoracic and glenohumeral articulations. Matsen’s concept of the “humeroscapular articulation” is useful for understanding the CA arch with regard to normal shoulder motion and abnormal shoulder impingement. In this model, the shoulder is seen as two concentric articulations. In the inner articulation, the humeral head articulates with the glenoid. In the outer articulation, the proximal humerus articulates with the CA arch. Motion of the CA arch and biomechanics of the rotator cuff, however, are part and parcel with the scapula. This concept emphasizes the importance of the scapulothoracic articulation in the athlete’s shoulder.


Rotator Cuff Function


Because the glenohumeral joint lacks inherent bony stability, it relies heavily on both static and dynamic soft tissue stabilizers for its stability and function. The muscles of the rotator cuff contribute to glenohumeral motion. But much more importantly, they help maintain a stable fulcrum at the glenohumeral joint around which the other muscles of the shoulder girdle can effectively act on the humerus.


Although previously believed to initiate abduction, the supraspinatus is currently considered to function primarily as a stabilizer of the glenohumeral joint. Its orientation 70 degrees from the plane of the glenoid means it provides a compressive force driving together the humeral head and the glenoid cavity ( Fig. 52-3 ). By maintaining the articular congruity through concavity compression, a stable fulcrum is created for the more powerful muscles of the shoulder girdle. The powerful deltoid, for example, requires this stability at the glenohumeral joint to function effectively. Without the stabilizing, synergistic action of the supraspinatus the humeral head would displace superiorly as the deltoid contracts, resulting in impingement of the rotator cuff between the humeral head and the undersurface of the acromion.




FIGURE 52-3


Angle of pull of the supraspinatus with a direct line of force ( solid arrow ) and the compressive component of the force ( dashed arrow ).


By virtue of their orientation, the action of the infraspinatus and teres minor muscles is external rotation of the arm and depression of the humeral head, with the infraspinatus being the primary depressor. The subscapularis muscle also depresses the humeral head and acts as an internal rotator of the arm. The infraspinatus and subscapularis act as a “force couple,” stabilizing the glenohumeral joint, especially during eccentric contraction and overhead activity. The rotator cuff provides stability through eccentric contraction, whereas the large superficial muscles around the glenohumeral joint (such as the deltoid, trapezius, latissimus dorsi, and pectoralis major) provide the propulsion for movements of the shoulder by their powerful concentric contractions.


With concentric muscular contraction producing motion in one direction, there is a concomitant eccentric muscular contraction on the opposite side of the joint that produces stability. These eccentric contractions are provided by the muscles of the rotator cuff and point to their essential role in shoulder stability. For example, with external rotation of the arm, the infraspinatus contracts concentrically while the subscapularis shows significant electromyographic (EMG) activity as it contracts eccentrically. In this case, the infraspinatus produces the propulsive power on one side of the joint while the subscapularis produces a counteracting, stabilizing force on the opposite side of the joint. This balance is biomechanically important for fine-tuning the movements in the athlete’s shoulder.


Biceps


The long head of the biceps, long thought of as a humeral head depressor, is most likely a passive player during most shoulder motions ( Fig. 52-4 ). Yamaguchi and colleagues used electromyography to assess the activity of the long head of the biceps with shoulder-related activity. They controlled elbow function with the use of a brace that locked the elbow at 100 degrees of flexion and neutral forearm rotation. With elbow motion thus eliminated, they demonstrated that the long head of the biceps is essentially inactive during shoulder-related activities in normal shoulders. Furthermore, they showed that the presence of a rotator cuff tear results in the same lack of activity. Rodosky et al. demonstrated in an in vitro cadaveric model that the long head of the biceps may passively contribute to anterior stability of the glenohumeral joint in the abducted and externally rotated position by increasing the resistance of the shoulder to torsional forces. More recent studies have shown a complex interaction between the shoulder and the elbow, including the biceps tendon. Loading of the biceps tendon and changes in elbow position lead to changes in shoulder motion and shoulder muscle recruitment.




FIGURE 52-4


By virtue of its location, the biceps tendon can resist superior translation of the humeral head in situations in which normal restraints have failed.


Static Stabilizers


The static structures of the shoulder, such as the glenohumeral ligaments and labrum, are important for stability but also may be implicated in the internal impingement phenomenon. For example, tight posterior structures cause greater anterior translation of the humeral head with forward elevation and may contribute to secondary impingement. Similarly, anterior laxity and subluxation may result in compromise of the available subacromial space leading to classical outlet impingement, or may result in increased hyperangulation of the humeral head in the abduction/external rotation position, leading to posterosuperior glenoid or “internal” impingement.


Scapular Lag


Biomechanically, the scapula plays an intimate role in shoulder function. It is the origin of the rotator cuff musculature as well as the deltoid and acts as a base for the motions of the glenohumeral joint. Many pathologic situations such as impingement and various instabilities result in subtle winging through dysfunction of the scapula as it moves on the chest wall, termed scapular dyskinesia . Fatigue of the scapular rotators on the chest wall leads to inability of the scapula to rotate properly and prevents the acromion from getting out of the way when the arm is elevated. This situation, termed scapular lag, may result in secondary impingement. Recent work related to treatment of patients with scapular dyskinesia has shown improvement in the biomechanics of the rotator cuff, acromial humeral distance, and impingement-related symptoms with improved scapular stabilization, emphasizing the importance of the scapulothoracic articulation, specifically the scapula-stabilizing musculature, regarding rotator cuff function and subacromial impingement.




History


A thoughtful, concise history and physical examination remain the most important components in establishing the diagnosis in an athlete with shoulder symptoms. Treating an athlete’s shoulder can be significantly complex; imaging studies, examination under anesthesia (EUA), and arthroscopy can sometimes be used to help clarify the clinical picture. Such studies, however, should only be a supplement to a good history and physical exam.


The history can begin by questioning the athlete. What bothers you about your shoulder? How did it start bothering you? When did it start? Do you have pain? Does your shoulder feel unstable? Is there a history of trauma? What specific activities exacerbate the pain or exacerbate the difficulties with your shoulder? If the shoulder is painful during a throwing motion or other type of athletic motion, at what phase of the motion does the pain occur? What specific modalities or activities alleviate or exacerbate what is bothering you? Is there a history of previous shoulder surgery? These questions, coupled with a standard medical history, can help point the surgeon toward the diagnosis.




Physical Examination


Because shoulder pathology in the athlete can be complex, the specific physical exam tests that may elicit these symptoms can be specific and quite subtle, even when positive. As such, it is not useful to apply the “shotgun” approach to diagnosis, in which every test described for the shoulder is performed on every shoulder. The differential-directed approach, as in the history-taking part of the examination, helps direct the physical exam toward the tests that will either confirm or refute the tentative diagnosis. The physical examination should nonetheless be organized and thorough.


At the start of the physical exam, an initial impression is taken regarding the athlete’s age, overall health, and level of specific distress related to the shoulder problem. Inspection, palpation, range of motion, strength testing, and neurologic and vascular stability assessment constitute an orderly sequence.


Inspection considers symmetry (taking into account that pitchers and tennis players may have unilateral drooping of the dominant shoulder) or deformities such as old acromioclavicular injuries and muscle wasting, which is most often located in the infraspinatus fossa with a rotator cuff tear ( Fig. 52-5 ). A proximally ruptured biceps tendon shows the characteristic bulging distally with muscle contraction ( Fig. 52-6 ).




FIGURE 52-5


A patient with prominent infraspinatus wasting in the right shoulder.



FIGURE 52-6


A patient with a ruptured long head of the biceps tendon in the right arm with ecchymosis and a “Popeye” deformity.


The location and degree of tenderness found on palpation often provide a reliable physical sign leading to an accurate diagnosis. Tenderness in the bicipital groove (2 to 5 cm distal to the anterior acromion and midway between the axilla and the lateral deltoid with the arm in the anatomic position) is a reliable sign of bicipital tendonitis ( Fig. 52-7 ). Tenderness in this region with palpation and passive external rotation of the arm (rolling the bicipital groove under the examiner’s fingers) is another reliable sign of bicipital pathology. The supraspinatus insertion (Codman’s point) is palpated through the deltoid just distal to the anterolateral border of the acromion with the shoulder extended and internally rotated ( Fig. 52-8 ). Maximal tenderness over the acromioclavicular joint may also indicate specific pathology. Range of motion should be documented. A true discrepancy between active and passive ranges of motion is suggestive of a rotator cuff tear. However, in the athlete, superior strength and flexibility can mask these findings. Many athletes, such as swimmers and gymnasts, may have developed what appears to be a supranormal range of motion compared with the general population. On the other hand, the overhead throwing athlete may have side-to-side range of motion differences with increased external rotation and decreased internal rotation in their throwing arm compared with the contralateral side. However, the total arc of motion is typically the same on both sides, albeit shifted. This decreased internal rotation is believed to be an adaptive mechanism in athletes engaging in overhead throwing, possibly due to hyperangulation of the humerus with relative stretching of the anterior capsular structures and relative tightening of the posterior capsular structures. This may be a contributing factor in rotator cuff overuse syndromes through excessive obligatory anterior translation and secondary impingement. When evaluating shoulder range of motion, stressing the shoulder at the extremes of motion can also provide clues to pathology in the shoulder.




FIGURE 52-7


A, A patient with underlying acromion, acromioclavicular joint, coracoid, and coracoacromial ligaments drawn on the skin. B, Examination of the biceps tendon by palpation.



FIGURE 52-8


Palpation of Codman’s point.


Active and passive range of motion should be documented in all planes. This includes elevation in the scapular plane and external rotation with the arm at the side, which can be recorded in degrees. It is also important, especially in athletes, to document external rotation (particularly passively) in the 90-degree abducted position in the coronal plane. This position represents a more functional measure of external rotation. Internal rotation can be recorded as the most cephalad vertebral level obtainable by the “hitchhiking thumb” or index finger ( Fig. 52-9 ).




FIGURE 52-9


A through D, Active range of motion is tested for absolute range as well as symmetry.


Strength is considered along with range of motion. Although assessment of strength is part of the neurologic examination, it is particularly important in athletes with rotator cuff pathology. Objective weakness beyond that which can be attributed to pain or a neurologic deficit is a highly specific sign of rotator cuff deficiency. The remainder of the neurologic examination helps rule out pathology such as a cervical root, brachial plexus, or peripheral nerve lesion.


The assessment of shoulder stability is quite important because rotator cuff signs and symptoms are often a secondary manifestation of an underlying problem of stability. It has been suggested in high-profile throwing athletes that shoulder pain is due to instability related to anterior subluxation with secondary impingement until proven otherwise. Stability is assessed by translating the humeral head in the glenoid fossa anteriorly, posteriorly, and inferiorly (the load-and-shift and sulcus tests, respectively) with the arm in varying degrees of abduction and rotation ( Fig. 52-10 ). The presence of an anterior apprehension sign is also important and can represent either anterior instability or pain from internal impingement. This test is performed by passively placing the arm in increasing degrees of abduction and external rotation ( Fig. 52-11 ). The relocation test (Jobe’s relocation test) is a variation of the apprehension sign ( Fig. 52-12 ). The arm is placed in the abducted/externally rotated position until pain or apprehension is elicited. The same maneuver is then repeated but with a posteriorly directed force on the arm. Relief of pain or apprehension with improved external rotation is indicative of internal impingement or anterior subluxation, respectively.




FIGURE 52-10


A, Shoulder stability can be assessed with the load-and-shift test performed with the patient sitting. B, The load-and-shift test performed with the patient supine. C, Sulcus test.



FIGURE 52-11


Apprehension test performed with the patient supine. This can elicit apprehension and pain.



FIGURE 52-12


Relocation test with a posteriorly directed force. This can relieve symptoms from the apprehension test.


Examination of the regional vascular supply is necessary as a baseline and also to evaluate for conditions such as thoracic outlet syndrome.


Finally, a number of special tests should be considered. The signs of impingement are characteristic of rotator cuff tendinitis and tears. These include a painful arc of abduction between 60 and 120 degrees, pain on forced forward flexion in which the greater tuberosity is forced against the anterior acromion (Neer’s sign), and pain on forcible internal rotation of the 90-degree forward flexed arm (Hawkins’ sign, or the impingement reinforcement test) ( Figs. 52-13 and 52-14 ). The latter maneuver causes impingement against the CA ligament. Biceps tendon involvement is demonstrated by Speed’s test, in which pain is reproduced on resisted forward elevation of the humerus against an extended elbow ( Fig. 52-15 ). Yergason’s test is performed with the elbow flexed to 90 degrees and the forearm pronated. The examiner grasps the wrist and resists active supination by the patient. Pain in the area of the bicipital groove is suggestive of pathology in the long head of the biceps ( Fig. 52-16 ). The active compression test (O’Brien’s test, with resisted elevation and the arm at 90 degrees of forward flexion and 10 to 15 degrees of adduction) may also be positive with pathology of the long head of the biceps without a superior labral-anterior posterior (SLAP) lesion.




FIGURE 52-13


Neer’s sign suggests classic impingement when this maneuver elicits pain.



FIGURE 52-14


Hawkins’ sign.



FIGURE 52-15


Speed’s test.



FIGURE 52-16


Yergason’s test.


Biceps tendon instability (medial subluxation or dislocation) can be determined by passively abducting the shoulder to 80 to 90 degrees and eliciting a palpable snap in the region of the bicipital groove with internal and external rotation. This is a rare presentation as an isolated entity and usually indicates a lesion to the superior fibers of the subscapularis tendon and/or the SGHL.


The history and physical examination lead to an appropriate diagnosis. As previously stated, in athletes the main differential diagnosis is between instability and primary rotator cuff pathology. Shoulder pain in the athlete can create a vicious cycle, with an overlap between shoulder instability and/or laxity and rotator cuff and biceps tendinitis and/or impingement. Whether instability causes tendinitis or tendinitis causes instability remains unclear.


Impingement Test


This test, as described by Neer, involves injection of local anesthetic into the subacromial region after a positive Neer’s sign. The injection is performed under sterile conditions with insertion of the needle from the anterior, lateral, or posterior direction into the subacromial space. After the injection, impingement signs should be sought as previously described. Subjective relief or significant diminution of the previously present painful with impingement testing demonstrates impingement to be at least a component of the patient’s underlying problem. Nevertheless, it should be emphasized that this is a nonspecific test and can be misleading since it may be positive in those with primary impingement as well as those with secondary impingement due to instability.


Although not strictly an impingement test, injection of local anesthetic into the acromioclavicular joint or the bicipital groove can supply additional information about the source of the pain. Subacromial anesthetic can mask or minimize the symptoms from these two areas. The clinical examination is critical in guiding the selections and order of the injection sites.




Imaging


Diagnostic imaging for rotator cuff lesions has advanced significantly in recent years. The most commonly used methods to evaluate the cuff are detailed here.


Plain Radiographs


Standard plain radiographs should include an anteroposterior film at right angles to the scapular plane, a lateral film in the scapular plane with the beam tilted 10 degrees to evaluate acromial shape and slope, and an axillary view. Plain radiographs of the typical athlete with a rotator cuff complaint are most often normal. The characteristic changes of advanced rotator cuff disease include sclerosis and cystic changes in the greater tuberosity and osteophyte formation on the acromion. This has been described as acetabularization of the acromion and femoralization of the proximal humerus. There can be a more pronounced notch between the greater tuberosity and the articular surface, changes in the shape of the acromion and, in the presence of a massive rotator cuff tear, a narrowed acromiohumeral distance of less than 6 mm can be seen. There may be osteophyte formation on the inferior surface of the acromioclavicular joint as part of chronic rotator cuff disease. Although plain radiographs are often normal, they are nonetheless invaluable because they help rule out other conditions that may present with shoulder pain, such as glenohumeral arthritis, calcific tendinitis, or even neoplasm, conditions that would not typically be considered first in the athlete.


Plain radiographs can also be used to evaluate the bicipital groove. A shallow groove may indicate a very rare biceps tendon instability problem. Osteophytes around the groove may be implicated in pathologic degenerative conditions of the biceps.


Arthrography


Single- or double-contrast arthrography was once considered the gold standard for determining the presence of a full-thickness rotator cuff tear before the advent of magnetic resonance imaging (MRI). Arthrography is now most commonly used in combination with other imaging modalities (such as computed tomography or MRI) to make subtle lesions of the cuff and glenohumeral joint more conspicuous.


Ultrasonography


Diagnostic ultrasound is a noninvasive form of examination of the rotator cuff. It allows comparison with the contralateral side and can provide good anatomic detail. It has a reported 91% sensitivity and specificity, with a 100% positive predictive value when it shows nonvisualization or focal thinning. It has also been reported to be useful in diagnosing bicipital pathology and is helpful in patients who have previously undergone a rotator cuff repair. However, the results are related to the operator’s experience, and the technique has inherent limitations because of the surrounding bony anatomy.


Magnetic Resonance Imaging


MRI has become the gold standard for the investigation of rotator cuff pathology, with sensitivity and specificity exceeding 90% in most current series ( Fig. 52-17 ). MRI can demonstrate the size, location, and characteristics of the cuff pathology—and whether full thickness, partial thickness, or intratendinous. There are drawbacks to MRI, however. Patients are occasionally unable to tolerate the exam because of claustrophobia or inability to remain still for the period necessary to obtain a useful scan. The presence of metallic implants may interfere with image acquisition, and other implants such as pacemakers or recently placed vascular clips may preclude MRI evaluation. The addition of intraarticular contrast may help augment MRI and may be of particular benefit in the identification of partial cuff tears and labral lesions in the athletic population.




FIGURE 52-17


Coronal magnetic resonance image of a supraspinatus tear.




Decision-Making Principles


The key principle in treating the athlete with a shoulder problem is the judicious correlation of a patient’s history, physical examination, imaging studies, and, if necessary, intraoperative findings to make an accurate diagnosis of the etiology of the patient’s complaint. When an accurate diagnosis has been made, the surgeon and patient can have an informed discussion of treatment options and determine the most effective way to help the patient achieve his/her goals.


First and most important in the management of any athlete with a rotator cuff, impingement, or biceps problem is establishing the correct diagnosis. We place strong emphasis on a careful history, thorough physical examination, plain radiographs, and the judicious use of diagnostic injections. Further investigation (usually in the form of MRI) is reserved for athletes with an atypical presentation, those who are older, those with a significant traumatic episode, and those in whom a lesion requiring surgery is suspected.


The diagnosis and treatment of the rotator cuff or biceps injury is based on the etiology, as outlined below. The type of management used follows from the etiologic classification. Of note, the focus of treatment is nonoperative in the great majority of individuals.


Acute Trauma


Patients with acute traumatic episodes resulting in a strain of these musculotendinous units require rest until the symptoms have subsided and then a rehabilitation program involving a gradually increasing regimen of stretching and strengthening. Immobilization should be avoided. Antiinflammatory agents are sometimes helpful in this situation. The prognosis is good, and an early return to sport is possible depending on the severity of the injury. In an older individual (>40 years) acute trauma is more likely to result in a disruption of the rotator cuff. This should be initially treated with rest to allow sufficient healing to take place followed by range-of-motion and strengthening exercises. Persistent pain or weakness requires further investigation. Surgical repair should be considered early (within 2 months) to minimize the long-term effects of such an injury.


Primary Impingement


Patients with primary impingement more commonly present at an older age. This diagnosis implies an anatomic narrowing of the subacromial space. Nonoperative management is attempted, but with failure of nonoperative treatment we advocate surgical decompression earlier than in someone with secondary impingement.


Instability and Secondary Impingement


Patients with associated instability are treated nonoperatively, especially if multidirectional instability is diagnosed. The emphasis is on strengthening the cuff after symptoms have subsided. Only after nonoperative management has been attempted for a prolonged period and failed is surgical management pursued. This usually is in the form of stabilization (arthroscopic or open).


Anterior subluxation causing secondary impingement and pain can produce both a diagnostic and a therapeutic challenge. In such cases prolonged nonoperative measures are appropriate. If surgery is considered, the choice of anterior stabilization (arthroscopic or open), subacromial decompression, or a combined procedure remains unclear. We use the physical examination, EUA, and arthroscopic evaluation to determine the most appropriate course of action and typically perform all technical procedures (both stabilization and decompression) arthroscopically.


Internal Impingement


Patients with internal impingement undergo similar nonoperative treatment. Extremes of abduction/external rotation are restricted until symptoms resolve. A program emphasizing deltoid, rotator cuff, and scapular stabilizer exercises is begun with a gradual return to throwing. Intraarticular cortisone injections are used on a selected basis to reduce pain in the early stages. Caution should be exercised in the management of these athletes because this can be a very difficult entity to treat. Surgical management is indicated with refractory symptoms and an adequate trial of rehabilitation. Again, the physical examination, EUA, and arthroscopic evaluation help in the identification and treatment of any subtle but pathologic associated anterior laxity.


Overuse Problems


Overuse problems should be treated extensively with nonoperative methods. Surgery is recommended in chronic situations in which nonoperative management has failed or when the problem has progressed to the point of a cuff tear.


Combined Etiologies


In athletes, multiple underlying pathologies can often coexist. Which lesion is primarily responsible for the patient’s symptoms is not always clear, and there is no guarantee that addressing one lesion or even all the lesions will be curative. Such cases can be very difficult to treat. A nonoperative approach is prudent until the specific components can be determined and the treatment is modified accordingly.




Treatment Options


In the majority of athletes, treatment of a rotator cuff or biceps tendon problem is nonoperative. Three important items to be considered are the etiology of the condition, as previously discussed; the sport and level of performance; and the severity of the problem.


Types of Treatment


Treatment options can be divided into three general categories: (1) preventive, (2) nonoperative, and (3) operative.


Preventive Treatment


When dealing with athletes, the paramount concern to the sports medicine physician, surgeon, trainer, therapist, or coach should be prevention of injury. Prevention is of particular importance in relation to the shoulder, in which the majority of injuries are related to overuse. Intense training and practice may be detrimental to the athlete when poor technique or improper training methods are used. The underlying principle of prevention is applied common sense. A musculotendinous unit is capable of resisting only as much as it has been prepared to resist. A 50-year-old athlete who plays 2 hours of doubles tennis once per week cannot expect his shoulder to suddenly tolerate the 12 hours required in a 2-day weekend tournament. The same logic can be applied to the college- or professional-level pitcher who arrives in training camp with little or no off-season training. The basis of prevention is preparation. This involves overall body conditioning, flexibility, strengthening, and careful attention to technique while recognizing the stresses that both training and competition present.


The influence of shoulder flexibility has been demonstrated in swimmers. Published reports have demonstrated a clear correlation between anterior shoulder inflexibility and shoulder pain. It follows that stretching is an important preventive measure. The particular goal in stretching is to try to maintain internal rotation and adduction ( Fig. 52-18 ). It is not necessarily the intention to normalize internal rotation compared with the opposite side. The intention is to avoid posterior capsular contractures and maladaptive loss of internal rotation and adduction. Stretching is as important in older athletes, in whom the potential for stiffness is greater.


Feb 25, 2019 | Posted by in SPORT MEDICINE | Comments Off on Rotator Cuff and Impingement Lesions
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