Brian C. Halpern and Osric S. King. Sternoclavicular Sprain/Subluxation/Dislocation...499

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1 45 Shoulder Injuries Brian C. Halpern and Osric S. King X/04/$0.00+$ by Richard B. Birrer Introduction General Epidemiology Anatomy History and Physical Examination Diagnostic Procedures Sternoclavicular Sprain/Subluxation/Dislocation Acromioclavicular Sprain/Subluxation/ Dislocation Glenohumeral Instability: Sprain/Subluxation/Dislocation Glenoid Labrum Tears Impingement Syndrome (Bursitis, Tendinosis, Supraspinatus Syndrome) Rotator Cuff Strain Calcific Tendinitis Adhesive Capsulitis (Frozen Shoulder) Scapulothoracic Problems (Bursitis, Winging) Biceps Tendon Problems (Tendinitis, Subluxation/Dislocation, Rupture) Thoracic Outlet Syndrome Clavicular Fractures Other Fractures Miscellaneous Shoulder Injuries Vascular Neural Other Summary References General References INTRODUCTION The diagnosis and management of shoulder injuries is often challenging to the examiner. Complaints are typically vague and nonspecific. In addition to isolated musculoskeletal pathology, the etiologies of shoulder symptoms can come from a variety of neurological, inflammatory, and cardiovascular conditions. Determining the cause and treatment relies equally on the history, mechanism of injury, and physical examination. Imaging studies that depend strongly on technique and quality can confirm the diagnosis and help guide management. GENERAL EPIDEMIOLOGY Most shoulder injuries involve the soft tissues (e.g., cartilage, muscle tendon unit) and occur in

2 494 Shoulder Injuries Figure 45.1 Ligamentous anatomy of the shoulder. the sedentary as well as athletic individual. Many shoulder injuries result directly from repetition as in throwing and racquet sports. Similar damage can result from nonathletic, overhead activities such as painting or ladder climbing. In throwing and racquet sports, shoulder problems can account for more than 50% of injuries (Level of Evidence B, nonquantitative systematic review). 1 Anterior shoulder problems in these athletes are usually secondary to biomechanical and fatigue related instability. Unless direct trauma is the etiology, most athletic shoulder problems involve the dominant extremity. In sedentary individuals, symptoms in the nondominant or inactive shoulder are not uncommon. In an older population nonmusculoskeletal sources of symptoms can include cardiac, neurologic, primary neoplastic, and metastatic disease, as well as degenerative changes in the glenohumeral joint and rotator cuff. Age-related changes, poor conditioning, over-training, and trauma have common injury features. Studies have shown that rotator cuff and deltoid muscle weakness can cause superior migration of the humerus. This impingement of the humeral head against the subacromial arch is the hallmark event that contributes to bursitis and deterioration of the rotator cuff and biceps tendons. Investigations have repeatedly demonstrated subacromial impingement, whether seen in sports or related to poor conditioning, as one of the most common mechanisms of pain (Level of Evidence B, nonquantitative systematic review). 2 ANATOMY The shoulder girdle comprises the sternoclavicular joint, acromioclavicular joint, glenohumeral joint, subacromial space, and scapulothoracic space. Movement about all of these articulations allows for the complexity of the throwing motion. Motion exceeds 180 in three planes, with approximately two thirds of the full elevation occurring at the glenohumeral joint (Level of Evidence B, nonquantitative systematic review). 3 The sternoclavicular joint supports the anteromedial clavicle, and the articulation is between the proximal clavicle and superolateral portion of the manubrium. The posterior capsule of the joint is much stronger than the anterior capsule, thus allowing more anterior dislocations. The acromion is the anterior extension of the scapula. It has been described as having three shapes. Type 3 acromion is hooked and has been found to cause or aggravate rotator cuff impingement (Level of Evidence B, nonquantitative systematic review). 4 The acromioclavicular joint is between the lateral end of the clavicle and medial surface of the acromion and is associated with an intraarticular meniscus that may be incomplete. The acromioclavicular ligament provides superior support, but the major stabilizing structures are the coracoclavicular ligaments (the conoid and trapezoid) (Figure 45.1). The glenohumeral joint is a synovial ball-andsocket joint in which one third of a spherical humeral head sits in the shallow glenoid process. To improve the containment of the humeral head,

3 History and Physical Examination 495 Figure 45.2 Rotator cuff muscles. the glenoid labrum attaches peripherally around the margin of the glenoid. Thickening of the capsule forms the glenohumeral ligaments: superior, middle, and inferior. They are folds in capsule unlike the distinct ligaments found elsewhere in the musculoskeletal system. The inferior glenohumeral ligament has the most important role in stabilizing the shoulder joint in abduction and external rotation. The four major muscles of the shoulder girdle constitute the rotator cuff: the subscapularis anteriorly, the supraspinatus, the infraspinatus, and the teres minor posteriorly (Figure 45.2). The posterior rotator cuff muscles are major contributors to abduction and external rotation of the humerus. The subacromial space (rotator cuff interval) lies between the subacromial arch and the rotator cuff. The supraspinatus and biceps tendon lie adjacent to each other in this area. This space allows free movement between the rotator cuff below and the coracoacromial ligament, acromion, and deltoid above, providing the wide functional mobility of the shoulder girdle. The critical area of clearance is between the coracoacromial arch and the greater tuberosity. 2 In addition to this anatomic factor, a suboptimal healing environment worsens the pathology present in this space. Vascular studies have demonstrated that the blood supply to the supraspinatus tendon, with the arm at the side in the abducted position, has an area of avascularity 1 cm in length. It extends proximally from the musculotendinous junction directly to the point of insertion of the tendon onto the greater tuberosity. Likewise, the intracapsular portion of the biceps tendon has a similar avascular zone as it passes over the head of the humerus (Figure 45.3). HISTORY AND PHYSICAL EXAMINATION A description of symptoms should include the quality of the pain, the location, where it radiates, and whether or not it is associated with any swelling or tenderness. Are the symptoms present or worsened with a particular motion? Is there any associated numbness and tingling, which could indicate a brachial plexus injury or an associated cervical spine problem? Can the patient Figure 45.3 Lateral view of the shoulder; the bicipital (biceps) tendon runs through the bicipital groove in the head of the humerus. Sports Injuries: The Upper Extremity

4 496 Shoulder Injuries recall a traumatic event that preceded the pain? A dull aching discomfort, often felt at night, corresponds with rotator cuff tears, whereas a stabbing, burning pain is more typical of a bursitis or a tendinosis. The location of the pain can be diagnostic. Pain over the acromioclavicular joint might suggest degenerative disease and, if associated with trauma, might indicate an acromioclavicular joint sprain. Pain deep in the shoulder may come from rotator cuff involvement, capsular inflammation, arthritic changes, or a glenoid labrum tear. 3 A popping or catching noise inside the joint can indicate a glenoid labrum tear or biceps subluxation. A history of shoulder instability (described as giving way, slipping, or popping out) suggests subluxation or dislocation of the glenohumeral joint. Dislocation is more commonly caused by a contact injury, whereas either contact or non-contact injuries in addition to congenital ligamentous laxity, anteriorly or posteriorly, can cause subluxation. If the stability of the shoulder is affected by either trauma or fatigue, such intraarticular structures as the labrum can be torn by traction from the biceps tendon or impingement between the humeral head and the glenoid cavity. These types of injuries occur in baseball and tennis and often result from a combination of acceleration deceleration forces and internal external rotational velocities of the humerus; therefore, it is essential to question the patient regarding what phase of the motion the symptoms occur. Complete the review with a good past medical history inquiring about gout, chondrocalcinosis, arthritis, diabetes, neurovascular and metabolic disorders, and neoplastic disease. The diagnosis is usually confirmed by the physical exam. Begin with an anterior inspection of both clavicles and acromioclavicular joints. The uninjured shoulder should always be examined as a normal comparison. Look for asymmetry, ecchymosis, swelling, and atrophy. Palpate the injured area last. Check the acromioclavicular joint for pain, crepitus, and motion. Test for the stability of the clavicle by pushing down on its distal third. Dislocation of this joint can occur in the anterior, posterior, or superior direction. Perform the cross-over test by placing the hand of the injured shoulder on the uninjured shoulder (Figure 45.4). If there is pain with this maneuver, an acromioclavicular joint injury probably exists. Next, inspect and palpate the posterior rotator cuff muscles. Also check the trapezius and latissimus dorsi muscles, which accentuate rotator cuff movement. A prominent scapular spine suggests Figure 45.4 Cross-over test; testing for a sprain of the acromioclavicular joint. posterior rotator cuff atrophy from a complete tear or suprascapular nerve injury. Have the patient push against a wall and note any winging of the scapula, signifying injury to the long thoracic nerve or serratus anterior muscle. Assess the patient s range of motion, beginning with abduction, which occurs with glenohumeral and scapulothoracic movement in a 2:1 ratio. For every 3 degrees of shoulder abduction, 2 degrees occur at the glenohumeral joint and 1 at the scapulothoracic joint. 3 Check internal and external rotation in the sitting and supine positions with varying degrees of abduction. Rotator cuff tears, loose bodies, cervical radiculopathy, adhesive capsulitis, and osteoarthritis tend to decrease the glenohumeral motion segment and enhance the scapulothoracic segment during active shoulder elevation. The patient appears to shrug the injured shoulder into abduction. Testing active and passive range of motion is important because it helps to distinguish a rotator cuff tear from adhesive capsulitis. Remember that conditioned overhand throwers consistently demonstrate increased external rotation of the dominant extremity. Injuries to the supraspinatus muscle are best assessed by instructing the patient to slowly abduct and smoothly lower the arm and by applying downward force to the forearm with the shoulder in 90 of abduction, 30 of forward flexion, and full internal rotation (drop arm test, supraspinatus stress test, empty can test) (Figure 45.5). Weakness, pain, or a limited range of motion can indicate injury to the supraspinatus muscle or suprascapular nerve. 3 To test for strength of the subscapularis muscle, have the patient internally rotate against resistance with

5 History and Physical Examination 497 Figure 45.5 Supraspinatus test; testing for strength of the supraspinatus and deltoid muscles. Figure 45.6 Testing for strength of the subscapularis muscle. maximum adduction of the arm and elbow flexion to 90 (Figure 45.6). External rotation against resistance with maximum adduction of the arm and the elbow flexed 90 tests the infraspinatus and teres minor muscles (Figure 45.7). 3 Impingement maneuvers tend to drive the greater tuberosity under the coracoacromial arch. Examples include the Hawkins test (Figure 45.8), which elicits pain by internal rotation of the humerus in the forward flexed position; the cross-over test; and the Neer impingement test, which utilizes extreme forward shoulder flexion with forearm pronation. As impingement progresses, refractory tendinosis, wearing of the supraspinatus and biceps tendon, and partial or complete thickness rotator cuff tears can occur. 2 A 10-cc injection of 1% lidocaine beneath the anterior acromion may demonstrate pain relief with repeated impingement maneuvers. The test helps to rule out cervical radicular etiologies but the maneuver does Figure 45.7 Testing for strength of the infraspinatus and teres minor muscles. Figure 45.8 Impingement test; testing for impingement against the coracoacromial arch. not distinguish among impingement, anterior humeral head subluxation, or other rotator cuff pathology as the source of pain. Instability testing is done with the patient standing, sitting, or supine. Slowly abduct the patient s shoulder with the elbow flexed to 90. Place your hand on the glenohumeral joint with the fingers palpating the humeral head posteriorly and the thumb anteriorly. With your other hand, support the patient s arm. Apply anterior-directed stress to the humeral head, levering it anteriorly (Figure 45.9). Repeat this maneuver at varying degrees of abduction, feeling for anterior subluxation. Place your thumb on the patient s humeral Sports Injuries: The Upper Extremity

6 498 Shoulder Injuries Figure 45.9 Figure Figure labral tear. Testing for anterior subluxation. Testing for posterior subluxation. Clunk test; testing for an anterior head, flex the arm forward, and direct a posterior stress (Figure 45.10). Feel for any posterior subluxation with your posteriorly placed fingers. Posterior laxity (up to 50%) is often a normal finding in a throwing athlete s shoulder. Multidirectional instability presents an often-overlooked source of shoulder pain, so the examiner should test for inferior instability as well. Apply traction downward on the arm in 0 of elbow flexion and shoulder adduction. The appearance of a sulcus between the humeral head and lateral acromion is noted as a positive sulcus sign and is significant for inferior instability. 3 Apprehension or pain (positive apprehension, instability, or quadrant test) suggests prior subluxation or dislocation, although the tests may be positive with a tear of the rotator cuff or glenoid labrum. A lesion of the glenoid labrum can be diagnosed by the clunk test or labral grind test. Place your hand posterior to the humeral head while the other hand rotates the humerus. Bring the arm into full overhead abduction with 90 of elbow flexion while providing an anterior force to the humeral head. The clunk test is positive when a clunk, pop, or grind is felt in the shoulder as the humerus comes into contact with the labral tear (Figure 45.11). The presence of a labral tear can also be tested with the active compression (O Brien s) test. The maneuver consists of having the patient s arm forward flexed to 90, adducted to 15, and maximally internally rotated. The patient is instructed to resist as the examiner applies a uniform downward force. The patient then maximally supinates the arm and the maneuver is repeated. The test is positive if pain is felt deep within the shoulder and improved when the forearm is in the maximally supinated position. (Figure 45.12). The long head of the biceps can be palpated in the bicipital groove while the patient is in the supine position. With the examiner s finger still in the bicipital groove, the subscapularis tendon can be palpated for tenderness by externally rotating the humerus. The supraspinatus tendon can be palpated for tenderness by internally rotating the humerus. The integrity of the biceps tendon can be further assessed with the following maneuvers: Speed s, straight-arm flexion, or bowling test Resisted forward flexion of the humerus with the forearm supinated and the elbow extended produces bicipital groove pain. Yergason s or supination test Supination and external rotation of the forearm

7 Diagnostic Procedures 499 against resistance with the elbow flexed at 90 produces bicipital groove pain. Ludington s or subluxation test Apprehension and pain follow passive shoulder abduction with bicipital groove pressure, alternating resisted rotation, and biceps contraction. Gilcrest s test Bicipital groove pain and possible subluxation follow external rotation of the shoulder and forearm supination with a light weight at 90 of shoulder abduction. All examinations must include a neurovascular assessment of the upper extremities. Brachial, radial, and ulnar pulses should be checked. The neurologic exam should include motor and sensory exams, deep tendon reflexes (biceps, C5; brachioradialis, C6; and triceps, C7), and a Spurling test. The latter is performed by lateral rotation of the cervical spine toward the painful shoulder and then applying axial compression. DIAGNOSTIC PROCEDURES X-rays of the shoulder should include an anteroposterior (AP) view in internal and external rotation (true AP view). An axillary or west point axillary view is included in cases of less severe shoulder trauma, as these projections more accurately evaluate the relationship of the glenoid and humeral head and bony anatomy. For more severe trauma, a true lateral or Y view is important (Level of Evidence B, nonquantitative systematic review). 5 Ultrasonography and magnetic resonance imaging (MRI) are highly accurate for rotator cuff tears. Computed tomography (CT) demonstrates subtle fractures of the glenoid rim and reactive bone changes about a subluxing or recurrently dislocating shoulder. CT arthrotomography visualizes the internal shoulder structures and is particularly useful in delineating labral lesions. An MRI can confirm rotator cuff and labral tears as well as provide evidence of shoulder subluxation and dislocation. STERNOCLAVICULAR SPRAIN/SUBLUXATION/ DISLOCATION I. Epidemiology The sternoclavicular joint is the only articulation between the upper extremity and axial skeleton yet has the least amount of bony stability of any joint in the body. Sternoclavicular injuries are rare and associated with trauma to the chest or shoulder. They are classified as anterior or posterior, A B Figure Maximum Int. rot. Active compression test. 10 adduction 90 flexion Maximum Ext. rot. 10 adduction 90 flexion determined by the anatomic position of the medial head of the clavicle in relation to the sternum (Level of Evidence C, nonquantitative systematic review). 6 Anterior dislocation is more common than posterior, and many dislocations are actually fractures through the physeal plate because the epiphysis at the medial end of the clavicle closes at approximately 23 to 25 years of age. II. Mechanism The mechanism of injury is an indirect force applied from the anterolateral or posterolateral aspect of the opposite or uninjured shoulder. This Sports Injuries: The Upper Extremity

8 500 Shoulder Injuries usually occurs when the athlete falls on the injured shoulder with additional forces applied through the opposite shoulder. Injury can also occur with a direct force to the anteromedial aspect of the clavicle, pushing the clavicle posteriorly behind the sternum into the mediastinum. Disruption of the pulmonary and vascular systems can occur. III. Anatomy Tearing of the capsule, intraarticular disc, and costoclavicular ligaments: Grade I All ligaments are intact and joint is stable. Grade II Partial disruption of the sternoclavicular and costoclavicular ligaments leads to subluxation of the sternoclavicular joint. Grade III Complete disruption of the sternoclavicular joints leads to anterior or posterior dislocation. IV. and V. Symptoms and Signs Grade I slight swelling and tenderness at the joint; no instability; mild to moderate pain, especially with arm movement Grade II (subluxation) increased pain and swelling; palpable anterior or posterior subluxation Grade III (dislocation) severe pain with range of motion (ROM) In Grade III, the patient supports the injured arm across the trunk with the normal arm. In the supine position, pain increases and the involved shoulder does not lie flat on the table. Note: In anterior dislocation, the medial end of the clavicle is visibly prominent anterior to the sternum. In a posterior dislocation, the medial end of the clavicle is palpable and displaced posteriorly. Venus congestion may be present in the neck or upper extremity. Breathing difficulties, shortness of breath, swallowing difficulties, subcutaneous emphysema, and ipsilateral pulselessness, swelling, and discoloration can occur. VI. Diagnostic Imaging Anteroposterior (AP) or posteroanterior (PA) x- ray views of the chest or sternoclavicular joint may suggest an abnormality as one clavicle appears displaced compared to the normal side. A 40 cephalic tilt view (Rockwood view) is recommended. CT scan or MRI can be used to evaluate anterior or posterior dislocation, fractures, great vessels, and trachea. VII. Special Studies Not applicable. VIII. Diagnosis Sternoclavicular. IX. Differential Diagnosis Fracture. X. Treatment (See Wirth and Rockwood; 7 Level of Evidence B, nonquantitative systematic review.) Initially: Use RICE (rest, ice, compression, elevation) plus analgesics (as needed) plus nonsteroidal anti-inflammatory drugs (NSAIDs) plus sling immobilization. Long-term: Grade I Wean patient from immobilization at 5 to 10 days with a gradual return to use of the arm. Grade II (subluxation) Reduction may be required; draw the shoulders back and hold them with a clavicle strap. Protection with a sling and/or clavicle strap for a period of 4 to 6 weeks is recommended. Grade III (dislocation) Anterior: Have the patient supine on the edge of the table with a sandbag between the shoulders. With the upper extremity at 90 of abduction and extension, apply traction in line with the clavicle. Use a post-reduction figure-eight dressing for 6 weeks. Operative repair is debatable. Posterior: Have the patient supine with a sandbag between the shoulders. Apply lateral traction to the abducted arm which is then gradually brought back into extension. Use a post-reduction figure-eight dressing for 6 weeks. Because of potential damage to the posterior structures, some physicians prefer operative repair. Either way, reduction should be performed with extreme care for the posterior vasculature. XI. Complications Injury to the pulmonary vessels, trachea, superior vena cava, esophagus, and other mediastinal structures, especially with posterior dislocations. Risk of traumatic arthritis and chronic joint instability.

9 Acromioclavicular Sprain/Subluxation 501 XII. Prevention None ACROMIOCLAVICULAR SPRAIN/SUBLUXATION/ DISLOCATION I. Epidemiology The acromioclavicular joint is commonly injured in contact sports and falls off bicycles. II. Mechanism The mechanism of injury is a direct fall or blow to the point of the shoulder at the lateral edge of the acromion. Indirect force from a fall on an outstretched arm or blow to the upper back can also cause injury to the joint. 3 III. Anatomy Acromioclavicular injuries are classified as grades I thru VI: Grade I acromioclavicular ligament and capsular stretching Grade II acromioclavicular ligament disruption with slight upward migration of the clavicle and tearing of the coracoclavicular ligaments Grade III acromioclavicular and coracoclavicular ligaments and intraarticular meniscus disruption; acromioclavicular joint dislocation with the clavicle displaced upward relative to the acromion (Figure 45.13) Grade III acromioclavicular dislo- Figure cation. Sports Injuries: The Upper Extremity Grade IV a grade III injury with the clavicle anatomically displaced upward and posterior into or through the trapezius Grade V Severe upward dislocation of the distal clavicle relative to the acromion with complete destruction of the acromioclavicular and coracoclavicular ligaments and disruption of the deltoid and trapezius muscle attachments to the clavicle; clavicle may pierce the muscle and even the skin in some cases Grade VI Inferior dislocation of the clavicle underneath the coracoid; injury to the underlying neurovascular structures likely IV. and V. Symptoms and Signs Grade I Swelling and tenderness over the acromioclavicular ligament with no instability of the distal clavicle. Patient performs the cross-over test with minimal or no pain. Grade II Snapping of the acromioclavicular (AC) joint on shoulder motion with swelling and tenderness over the acromioclavicular ligament and some lack of symmetry when compared to the normal side. Tenderness and slight instability of the distal clavicle with downward pressure are observed. The cross-over test is painful, yet the patient can resist pressure when the examiner pushes the elbow downward. Grades III to VI Swelling and marked tenderness over the acromioclavicular and coracoclavicular ligaments and marked asymmetry with high-riding clavicle. Marked instability of the distal clavicle is observed. The patient is unable to perform the cross-over test. VI. Diagnostic Imaging Anteroposterior and axial x-ray views can demonstrate widening of the AC joint and high-riding clavicle, and Alexander view demonstrates posterior clavicular dislocation: Grade I normal Grade II 1.3 cm coracoacromial separation Grades III to IV greater than 1.3-cm separation or >50% increase in the distance when compared to the uninjured side VII. Special Studies Not applicable.

10 502 Shoulder Injuries VIII. Diagnosis Acromioclavicular. IX. Differential Diagnosis Contusion, fracture, synovitis, osteoarthritis. X. Treatment (See Phillips et al., 8 Bethis et al., 9 and Larsen et al.; 10 Level of Evidence A, quantitative systematic review.) Initially: Use RICE plus analgesics as needed plus NSAIDs plus sling or shoulder immobilizer. Long-term: Grades I and II Wean out of immobilization as tolerated; use early physical therapy (ROM + PREs) for several weeks. Grade III Same as above followed by physical therapy for 6 to 8 weeks; surgery is occasionally indicated for the throwing arm of an athlete; however, in non-athletes, significant benefit from surgery is questionable. Grade IV The clavicle must be dislodged from the trapezius, usually with closed reduction, but occasionally operative intervention is required. XI. Complications Traumatic arthritis, persistent decreased range of motion and strength in addition to pain. XII. Prevention None. GLENOHUMERAL INSTABILITY: SPRAIN/SUBLUXATION/ DISLOCATION I. Epidemiology Instability and laxity are terms often applied to the shoulder. Laxity is the asymptomatic translation of the humeral head on the glenoid. It may be a normal variant and represent a necessary feature of the soft tissue about the shoulder required for glenohumeral rotation. Instability is the excessive translation of the humeral head on the glenoid occurring during active shoulder rotation in association with symptoms. It represents varying degrees of injuries to dynamic and static structures that function to contain the humeral head in the glenoid. Throwing and racquet sports can also produce anterior glenohumeral instability from repetitive stretching (Level of Evidence C, nonrandomized clinical trial). 11 A sprain occurs when there is sequential tearing of the glenohumeral ligaments and capsule with pain but no obvious displacement of the humeral head. Subluxation is the symptomatic increased humeral translation beyond that permitted by normal tissue laxity, but without complete separation of the articular surfaces. Dislocation is the complete separation of the articular surfaces of the glenoid and humeral head; 85% of dislocations detach the glenoid labrum (Bankart lesion). Without the protection of the labrum, recurrent subluxations and dislocations can potentially lead to ectopic bone formation evident on radiographic images. In dislocations, 95% are anterior and inferior. Posterior injuries are uncommon and pure superior and inferior injuries are very rare. II. Mechanism A. Acute Anterior: Most cases of dislocation are anterior. Major trauma is usually involved but the shoulder does not often dislocate as a result of a direct blow (Level of Evidence C, nonquantitative systematic review). 12 A combination of forces stresses the abducted extended and externally rotated arm, which applies leverage to the anterior capsule, glenohumeral ligaments, and rotator cuff. The humeral head is forced anteriorly and out of the glenoid fossa. The most common type of anterior dislocation is the subcoracoid dislocation in which the humeral head is anterior to the glenoid and inferior to the coracoid process. The head of the humerus is anterior and below the glenoid fossa in subglenoid dislocation. The head of the humerus lies medial to the coracoid process at the inferior border of the clavicle in subclavicular dislocation. Significant trauma is associated with an intrathoracic dislocation where the head of the humerus lies between the ribs and thoracic cage (Level of Evidence C, historical uncontrolled study). 13 Posterior: Can be caused by direct force such as a direct blow to the anterior aspect of the glenohumeral joint. A posterior dislocation can occur as a result of an indirect force such as a fall on an outstretched

11 Glenohumeral Instability 503 arm with the shoulder in internal rotation, adduction, and flexion. When blocking, as in football, a direct axial load applied to a flexed arm, adducted, and internally rotated may cause a posterior subluxation or dislocation of the humeral head. Seizure or electric shock can produce a muscular contraction forceful enough to cause posterior displacement of the humeral head (Level of Evidence C, historical uncontrolled study). 14 B. Chronic Glenohumeral translation is less than that detectable on physical examination as clinical subluxation but is sufficient enough to cause excessive edge loading or shearing stress to the labrum (Level of Evidence B, nonrandomized clinical trial). 15 The result is the failure of the humeral head containment during motions such as throwing. III. Anatomy A. Sprain sequential tearing of the glenohumeral ligaments and capsule B. Subluxation joint laxity causing more than 50% of the humeral head to passively translate over the glenoid rim without dislocation or causing the humeral head to actively translate more than 4 mm from the center of the glenoid C. Dislocation joint instability with the humeral head losing contact with the glenoid and lodging beside the joint; of anterior dislocations, 85% detach the glenoid labrum (Bankart lesion), potentially leading to ectopic bone formation with recurrent dislocations B. Chronic injury 9 less intense and less localized pain; sensation of instability or apprehension with overhead activities; history of previous dislocations and progressively less trauma needed to sublux or dislocate shoulder IV. and V. Symptoms and Signs A. Sprain Capsule is tender to palpation; no instability; positive apprehension and relocation test (see Figure 45.14). B. Subluxation Sensation of the shoulder popping out and back into place; Figure Apprehension test; testing for anterior stability. the pain present may be associated with paresthesias down the arm or a sensation of the arm going dead ; 9 patient resists placing shoulder in abduction and external rotation and extension. Capsule is tender with mild swelling; positive apprehension/relocation test. Brachial plexopathy commonly involves the axillary, musculocutaneous or suprascapular nerves. 13 C. Dislocation Anterior: Acute severe pain with loss of ROM and possible numbness or weakness present before or after reduction (Level of Evidence C, historical uncontrolled study). 16 Patient presents with arm slightly abducted and externally rotated and held firmly by the other arm; prominent acromion process and coracoid process may not be identified because of swelling. Shoulder assumes squared-off appearance with anterior shoulder fullness. Movement of the arm is painful and limited, especially with attempted adduction or internal rotation. Posterior: Arm is fixed in the adducted position and internally rotated; coracoid process is more obvious. On the dislocated side, the anterior aspect of the shoulder is flat; the posterior aspect of the shoulder is rounded and more pronounced than the normal shoulder. External rotation of the shoulder is blocked; severely limited abduction. Sports Injuries: The Upper Extremity

12 504 Shoulder Injuries VI. Diagnostic Imaging Pre-reduction (if possible) and post-reduction films reveal displacement of the humerus and associated avulsion fractures. Routine AP views in internal and external rotation in the chest plane, AP views in the scapular plane, and axillary lateral views are recommended for posterior dislocations. True lateral view of scapula and modified axillary lateral (west point) view are good for chip fractures of the anterior inferior glenoid rim and labral tears (Bankart lesion). The Hill Sachs view identifies posterior humeral head defects caused by compression of the head against the glenoid during subluxation. The Stryker notch view is a posterior view of the humeral head that helps check for a Hill Sachs lesion. Magnetic resonance imaging is recommended for detailed assessment of the entire shoulder but is highly equipment and technique dependent; if optimum resolution is available, it can be used to identify bone bruising, muscle atrophy, neurovascular structures, and the extent of rotator cuff and biceps tears. It can also evaluate intraarticular pathology, such as the presence of ganglion cysts, glenoid labrum tears, and articular cartilage damage (Level of Evidence C, nonquantitative systematic review). 17 Computed tomography is useful for evaluating bony details especially with complicated fractures. VII. Special Studies Not applicable. VIII. Diagnosis Glenohumeral. IX. Differential Diagnosis Fracture (avulsion, humerus), acromioclavicular joint sprain, glenoid labral tear or fracture, rotator cuff injury, atraumatic osteolysis of distal clavicle. X. Treatment (See Bottoni et al.; 18 Level of Evidence B, lower quality randomized controlled trial.) Initially: Use reduction, immobilization with a sling and swathe or shoulder immobilizer, RICE, NSAIDs, and analgesics as needed. For a sprain, wean patient from immobilization in 5 to 10 days; use of arm should return gradually. For subluxation, use a sling and swathe or shoulder immobilizer for 2 to 4 weeks, then initiate aggressive rehabilitation. For a dislocation, perform anterior reduction by gentle external rotation using the following methods (Figure 45.15): Kocher The patient lies supine with the elbow externally rotated and flexed to 90. Progressive traction is applied to the humerus followed by gentle adduction and internal rotation of the arm after the humeral head slips into the glenoid. Stimson With the patient lying prone on a table, attach a 5-pound weight with two half hitches to the wrist; gravity and the weight together tend to relocate the humerus. Allow 20 to 30 minutes; muscle relaxants and compression of the humeral head may be necessary. Milch The arm is externally rotated and abducted overhead while the humeral head is pushed back into place. Hippocratic, double sheet, or Rockwood method With the athlete supine, gentle steady traction is applied to the affected arm in 30 to 45 of abduction, and counter-traction is applied in the opposite direction by means of a sheet or swathe wrapped around the upper thorax. The foot should not be placed on the chest wall for counter-traction as it may slip into the axilla and damage the brachial plexus. The affected arm should be flexed in muscular individuals to relax the biceps tendon and a wrist lock technique used for maximum traction. Scapular rotation maneuver With the patient prone, longitudinal traction is placed on the flexed affected arm; the inferior angle of the ipsilateral scapula is rotated toward the spine so that the glenoid and humerus are aligned; a pillow under the athlete s chest facilitates the relocation. For posterior reduction, with the patient supine, apply traction to the adducted, internally rotated, flexed arm in the line of deformity, along with a gentle lifting and internal rotation of the humeral head back into the glenoid fossa; open reduction is indicated following 1 to 2 unsuccessful trials. Long-term: Immobilization for 3 to 6 weeks, depending on age and activity level, is recommended. The shoulder

13 Glenohumeral Instability 505 Figure Shoulder reduction techniques. spica in the neutral position is preferred by some for posterior dislocations. Range of motion and isometric strengthening should be started early, followed by a resistive strengthening program. An exercise program should emphasize both internal and external rotators as well as large scapular muscles. Surgery is indicated for persistent instability. XI. Complications The incidence of fractures rises with age; complications include compression fracture of the A C D humeral head (Hill Sachs lesion), fracture of the glenoid lip (anterior or posterior), fracture of the greater or lesser tuberosity, fracture of the acromion or coracoid, rotator cuff tear, nerve injury (axillary, brachial plexus, musculocutaneous), vascular damage. XII. Prevention Flexibility and strengthening exercises of internal rotator muscles will improve anterior instability, and a shoulder harness (e.g., Denison Duke Wyre shoulder vest, Simply Stable shoulder stabilizer) can be helpful. Sports Injuries: The Upper Extremity B

14 506 Shoulder Injuries GLENOID LABRUM TEARS I. Epidemiology Glenoid labrum tears may occur from repetitive shoulder motion or acute trauma. In the throwing athlete with repeated anterior shoulder subluxation, tears of the middle and inferior portion of the labrum may occur, leading to instability. Glenoid labrum tears may also result from anterior instability during the release phase of throwing, secondary to the long head of the biceps tendon pulling on the anterior labrum. Weightlifters may also develop glenoid labrum tears from repetitive bench pressing and overhead pressing. Most patients present with nonspecific shoulder pain associated with activity. Complicating the presentation is that the majority of lesions reported in the literature are associated with other shoulder disorders such as rotator cuff tears, acromioclavicular joint disorders, and instability (Level of Evidence C, nonquantitative systematic review). 20 In the largest review in the literature, out of 140 lesions, only 28% were isolated. The majority of glenoid labral tears occur from traction and compression injuries. 18 Sudden contraction of the biceps can occur with overhead athletes during the release phase of throwing. Compression injuries occur with forceful subluxation or dislocation of the humeral head over the fibrocartilaginous labrum. Tears of the glenoid labrum may also occur from acute trauma such as falling on an outstretched arm. Also, horizontal adduction and internal rotation during the acceleration phase of throwing can damage the labrum by applying a sheering stress across the labrum. 12 II. Mechanism Multidirectional instability (MDI) occurs on a background of generalized shoulder-capsule laxity which may be genetic (35%) (e.g., Ehlers Danlos syndrome) or environmental (previous trauma, 30%; overuse, 35%) (Level of Evidence C, nonquantitative systematic review). 19 The instability may be voluntary (patient consciously subluxates/dislocates joint) or involuntary. III. Anatomy The labrum is a triangular structure located around the periphery of the glenoid. It is composed of dense fibrous tissue rather than cartilage (Level of Evidence C, historical uncontrolled study) 21 and functions as a static stabilizer of the glenohumeral joint (Level of Evidence B and C, nonquantitative systematic review). 22,23 The average depth of the articular surface of the glenoid in the transverse plane is 2.5 mm. The labrum serves to deepen the A Intact biceps tendon attachment to the posterior labrum Posterior band of the inferior glenohumeral ligament Axillary pouch of the inferior glenohumeral ligament B Posterior band of the inferior glenohumeral ligament Axillary pouch of the inferiorglenohumeral ligament Long head of the biceps tendon Long head of the biceps tendon Intact biceps tendon attachment to the anterior labrum Frayed and degenerative superior labrum at the biceps labral complex Superior glenohumeral ligament Middle glenohumeral ligament Anterior band of inferior glenohumeral ligament Avulsion of the superior labrum and biceps anchor Superior glenohumeral ligament Middle glenohumeral ligament Anterior band of inferior glenohumeral ligament Figure Labrum injury types I and II. (From Stoller, D.W., MRI, Arthroscopy, and Surgical Anatomy of the Joints, Lippincott-Raven, Philadelphia, With permission.) glenoid by an additional 2.5 mm both anteriorly and posteriorly, adding to the static stability of the joint (Level of Evidence C, nonquantitative systematic review). 24 The glenoid labrum and biceps tendon are closely associated. The biceps tendon is attached to the superior portion of the labrum and often included in the classification of superior labrum tears. (Figure 45.16). Superior labral anterior-to-posterior (SLAP) lesions describe anatomic lesions of the superior glenoid labrum and biceps anchor. Glenoid labrum tears that occur in close proximity to the biceps, in the superior third of the labrum, can demonstrate symptoms similar to those of biceps tendon subluxation. IV. and V. Symptoms and Signs An audible or palpable clunk occurs as the tear flips in and out of the joint. In throwing athletes, more pain is sensed with release because of the deceleration effect of the biceps pulling on the torn labrum. With other tears, a sense of popping, clicking, or snapping in the joint is experienced during abduction and external rotation (e.g.,

15 Impingement Syndrome 507 cocking phase). Anterior humeral joint tenderness and pain with abduction and external rotation are observed. The labral clunk test is positive, the active compression (O Brien) test is positive, and the biceps load test is positive (Figure 45.17). Pain and instability are often insidious and bilateral. Apprehension tests are present in all directions, the sulcus sign is positive, and increased humeral joint play is present. VI. Diagnostic Imaging Standard x-rays often demonstrate Hill Sachs and Bankart lesions. An injury involving the labrum only will appear normal; if the glenoid is involved, a fracture (bony Bankart lesion) may be present. Magnetic resonance imaging provides excellent evaluation of labral injuries (Level of Evidence B, lower quality randomized controlled trial). 25 Especially with a dedicated extremity coil, a good correlation with surgical findings has been found. Ultrasonography also has a promising role in the evaluation of the glenoid labrum, particularly in excluding tears when the labrum appears normal on sonography (Level of Evidence B, lower quality randomized controlled trial). 26 VII. Special Studies None indicated. VIII. Diagnosis Glenoid lateral tear. IX. Differential Diagnosis Instability, rotator cuff tear, impingement. X. Treatment Of patients with MDI secondary to ligamentous laxity, 50 to 70% respond to prolonged conservative rehabilitation (6 to 12 months). MDI secondary to trauma often requires surgical correction. Voluntary MDI secondary to psychological problems is often resistant to all forms of intervention. Initially: Use conservative management with RICE and NSAIDs with sling immobilization. Long-term: Recommend a program of flexibility and muscle strengthening exercises, specifically for the posterior rotator cuff muscles (as demonstrated in Figure 45.18). If symptoms do not resolve, these injuries require definitive treatment through arthroscopic surgery. Figure Biceps load test. XI. Complications Disability secondary to arthritis. XII. Prevention Proper throwing mechanics; progressive training and conditioning. IMPINGEMENT SYNDROME (BURSITIS, TENDINOSIS, SUPRASPINATUS SYNDROME) I. Epidemiology Impingement syndrome is the most common softtissue injury of the shoulder due to repetitive use of the arms above the horizontal plane, such as in throwing and racquet sports, swimming (40 to 60% of swimmer s shoulder), weightlifting, and javelin (Level of Evidence C, nonquantitative systematic review). 20,27 29 Inflexibility, fatigue, and mechanical and technique errors are risk factors. II. Mechanism With repetitive microtrauma from throwing, stroking, and serving, a dynamic imbalance occurs between the external (rotator cuff muscles) and internal (pectoralis and latissimus dorsi muscles) rotators. This allows the humeral head and its rotator cuff attachments to migrate proximally and impinge the undersurface of the acromion and the coracoacromial ligament. Symptoms can also be caused by direct trauma to the acromion and or chronic irritation under the coracoacromial arch due to a hooked (type 3) acromion or subacromial osteophyte. III. Anatomy The rotator muscle group consists of the supraspinatus, infraspinatus, subscapularis, and teres minor muscles. Recurrent inflammation of Sports Injuries: The Upper Extremity

16 508 Shoulder Injuries (A) Shoulder shrug with scapular abduction. (C) Strengthening the middle portion of the deltoid muscle by abduction exercises. (E) Shoulder position for strengthening the external rotators. Figure Muscle strengthening exercises for the shoulder. (B) Strengthening the anterior portion of the deltoid muscle by forward-flexion exercises. (D) Strengthening the supraspinatus muscle by internally rotating and abducting the humerus. (F) Strengthening exercise for the posterior portion of the deltoid muscle and the rotator cuff.

17 Impingement Syndrome 509 (G) Strengthening the shoulder depressor, horizontal adductor, and internal rotator muscles. (I) French curl exercise for strengthening the triceps muscle. (K) External rotation flexibility exercises performed with the shoulder abducted from 90 to full abduction. FIGURE (Continued) (H) Modified push-up. (J) Biceps or elbow curl for strengthening the biceps muscle. (L) Stretching exercise for the posterior shoulder structures. Sports Injuries: The Upper Extremity

18 510 Shoulder Injuries the rotator cuff, especially the avascular area of the supraspinatus tendon, the long biceps tendon, and the subacromial bursa, leads to impingement. 25 IV. and V. Symptoms and Signs Initially, discomfort may be minimal and present deep within the shoulder during activity with no obvious loss of strength. Symptoms progress to significant pain that is frequently worse at night and with overhead movements. Pain-free range of motion is restricted, with a painful arc of abduction 70 to 120 (i.e., positive impingement sign). In the worse stage, the patient may experience constant pain with any motion. Also observed are point tenderness over the greater tuberosity and anterior acromion (coracoacromial ligament), tenderness over the biceps tendon proximally in the bicipital groove, pain with supraspinatus testing, positive straight-arm raising test, resisted forward flexion of the humerus with the forearm supinated and the elbow extended (i.e., Speed s test), positive resisted supination forearm test (i.e., Yergason s sign), and weakness of rotator cuff and biceps. Atrophy may be present over the supraspinatus. VI. Diagnostic Imaging X-rays tend to be supportive but not diagnostic; they may reveal sclerosis and osteophyte formation on the anterior inferior acromion, an enlarged or hooked (type 3) acromion, and diminished distance ( 5 mm) between the acromion and proximal humeral head. 2,14 Magnetic resonance imaging demonstrates excellent visualization of partial and full cuff tears, inflammation of the subacromial bursa and supraspinatus tendon, and tears of the capsule and subscapularis. 15 Ultrasound is good for cuff tears and abnormal cuff mechanics. Arthrogram may reveal dye leakage superiorly through the defect and outside the confines of the rotator cuff, usually adjacent to the undersurface of the acromion. Sensitivity decreases with partial tears and complete tears that have sealed. VII. Special Studies Local anesthetic injection of subacromial space improves shoulder pain and range of motion. VIII. Diagnosis Impingement syndrome. IX. Differential Diagnosis Acute traumatic bursitis, subluxating shoulder, arthritis of AC or glenohumeral joint, cervical disc, adhesive capsulitis, suprascapular nerve injury, glenoid labrum tear, thoracic outlet syndrome, atraumatic osteolysis of the distal clavicle. X. Treatment Initially: Use RICE, NSAIDs, and analgesics as needed. Total rest may be necessary if the patient experiences pain that is sufficiently disabling to affect performance during and after activities. Long-term: Implement injection therapy with steroid and local anesthesia into subacromial bursa (not recommended for young athletes) (Level of Evidence B, lower quality randomized controlled trial; Level of Evidence A, randomized controlled trial) 30,31 Physical therapy improves range of motion as well as rotator cuff and scapular stabilizer muscle strength. Modalities such as electric stimulation and ultrasound may help with symptoms but do not necessarily improve healing (Level of Evidence A, lower quality randomized controlled trial). 32 Surgical decompression (open vs. arthroscopy) of subacromial space, acromioplasty, and coracoacromial ligament resection should be considered for patients who fail conservative management (Level of Evidence C, nonquantitative review; Level of Evidence A, randomized controlled trial). 33,34 XI. Complications Rotator cuff arthropathy or tears, adhesive capsulitis, decreased arm/shoulder function and strength. XII. Prevention Flexibility and strength training of the rotator group (Level of Evidence A, randomized controlled trial) 35 Improved biomechanics for swimming (avoidance of hand paddles and sprints, increased body roll, and alternation of breathing sides), weightlifting (avoidance of overhead training such as bench and military presses), pitching (slower opening up turning body toward home plate well ahead of the throwing shoulder)