The anatomy of the shoulder (Figures 20-1 and 20-2) is complex because of the unconstrained nature of the joint, which allows an arc of motion greater than any other joint in the body. The shoulder is stabilized by both bony and soft tissue restraints (Table 20-1). The glenoid forms a small cup, which minimally constrains and stabilizes the humeral head (Figure 20-3). The glenoid labrum, a fibrocartilage lip, adds to the depth and width of the glenoid and is commonly injured in shoulder dislocations and in biceps tendon attachment injuries. The superior, middle, and inferior glenohumeral ligaments stabilize the shoulder through different arcs of motion, and are commonly injured along with the labrum in both adult and younger athletes.1
The rotator cuff (Figures 20-4 and 20-5) provides secondary and dynamic stability to the shoulder, as do the periscapular muscles, which aid in stabilizing the shoulder and position it in space. There is some debate as to whether the biceps and its long head provide significant dynamic shoulder stability or not, but the biceps tendon and associated muscles are commonly injured in association with other patterns of shoulder injury. Although significant portion of shoulder motion is caused by the motion of the shoulder girdle itself, the scapula, the acromioclavicular (AC) joint, clavicle and the sternoclavicular (SC) joint, all contribute to the scapulothoracic and shoulder motion, and this needs to be addressed in detail when considering shoulder injuries. Basic movements of the shoulder are depicted and described in Figure 20-6.
Injuries resulting from acute macrotrauma to the shoulder, scapulothoarcic region and proximal arm in the young athlete are listed in Table 20-2. Although sport-related acute injuries to the shoulder and arm are most common in contact—collision sports, such injuries also occur in noncontact throwing sports and weight lifting and similar activities.
Proximal humeral physis
Medial clavicular physis
Lateral clavicular physis
Proximal biceps brachii strains
Pectoralis major strains
Glenoid labrum avulsions
The history should ascertain the mechanism of injury. The athlete with acute shoulder area injury will present with localized pain that is exacerbated by movements. There will be localized tenderness and characteristic deformity depending upon the nature of the injury. Because of the pain, the movements are restricted. The shoulder area is examined based on the methods described under the “Physical Examination” section below. Abnormal findings are further described under specific injuries.
Always examine the neck and cervical spine in a patient with shoulder and arm symptoms. Neurovascular examination of the entire upper limb should be an integral part of assessing shoulder complex and arm symptoms.
Observe the patient from front, back, and side and systematically note abnormal findings including sternoclavicular joint, the clavicle, acromioclavicular joint, the shoulder, and the scapulothoracic area. Note any swelling, skin break, apparent deformity, asymmetry compared with the uninjured side, and muscle atrophy. A step-off at AC Joint is seen in severe AC joint disruption. Note scapular winging at rest and on performing wall push-up.
Palpate all areas systematically for tenderness and crepitus.
Assess active and passive shoulder and scapulothoracic movements. Observe the quality and form of the movements from front, side, and behind. Note the scapulothoracic motion. Assess strength by testing movements against manual resistance.
Hawkins-Kennedy sign. With the athlete standing or sitting on the examination table the arm is forward flexed to 90 degree and forcibly rotated internally. Pain is elicited in injury of the supraspinatus tendon as it impinges against the anterior surface of the coracoacromion ligament and coracoid process.
Supraspinatus test. With the athlete standing or sitting on the examination table the shoulder is abducted to 90 degree, internally rotated (thumbs down) and moved forward to approximately 30 degree. Downward manual resistance is applied while the athlete attempts to hold this position. Pain or weakness is indicative of supraspinatus strain. The test may also be positive in case of suprascapular neuropathy.
Drop arm test. The examiner assists the athlete to bring the shoulder to a position of 90-degree abduction (A). Then the athlete is asked to slowly lower the arm to the side (B). In case of rotator cuff tear, pain is elicited as the athlete is lowering the arm or the arm drops suddenly to the side because of weakness.
Yergason test. With the arm by the side, the elbow held at 90 degree, and forearm pronated (A), the athlete is asked to supinate the forearm and flex the elbow against manual resistance, while the examiner is palpating the biceps tendon over the bicipital groove with his other hand (B). Pain and tenderness is elicited in case of biceps tendnitis. Biceps tendon may also be felt to subluxate from the bicipital groove.
Jobe relocation test. With the athlete supine and shoulder at the edge of the table the arm is abducted and shoulder gently rotated externally. In case of anterior instability the athlete will feel pain (or a sense of apprehension) during external rotation. At this point a posteriorly directed stress is applied to proximal arm with relief of the pain or apprehension.
Load and shift test. With the athlete seated resting arms by the side and palms resting on her thighs (thumbs posterior) the examiner from behind the athlete stabilizes the shoulder with one hand and grasps the head of the humerus with her other hand. The examiner then gently moves the head of the humerus in anterior direction and notes the amount of translation. A relative increase in the movement of the head of the humerus is associated with anterior instability.
O’Brien sign. The athlete’s shoulder is held in 90 degree of forward flexion, 10 degree of horizontal adduction, and full internal rotation. The examiner applies downward manual resistance to distal forearm while the athlete attempts to hold the position. Pain is elicited in case of glenoid labral tears.
Anterior slide test. The athlete is sitting resting her hands on the waist. From behind the athlete, the examiner stabilizes the shoulder with one hand and with the other hand over the elbow applies anteroposterior force. In case of a tear of the glenoid labrum a pop or crack is felt as the head of the humerus slides over the labrum.
Scapular retraction test. From behind the athlete the examiner stabilizes the medial border of the scapula as the athlete elevates the arm. A positive test is indicated by relief of rotator cuff impingement pain and suggests a role of the periscapular muscles in the pathophysiology and rehabilitation of the impingement syndrome.
Plain films of the shoulder are indicated to assess the presence and nature of fractures and dislocations. Specific views may be needed for certain injuries as discussed in the subsequent sections. For assessment of soft tissue injuries such as musculotendinous tears, MRI is the study of choice. MR arthrogram may be indicated in the assessment of glenoid labral tears.2,3 Radiographic findings for specific injuries are described under individual conditions.
Immediate treatment depends upon the nature of the injury. In general, in case of fracture with or without neurovascular involvement, the shoulder and arm should be splinted and immobilized in a sling and the athlete should be sent to the emergency department for definitive evaluation and orthopedic consultation as appropriate. Indications for orthopedic consultation are listed in Box 20-1.
Injuries that Need Orthopedic Consultation
Superior labral anterior posterior tears with persistent pain and disability
Full thickness acute rotator cuff tears
Displaced fracture of proximal humerus
Type 3, 4, and 5 acromioclavicular joint sprains
Significantly displaced clavicle shaft fractures
Posterior dislocation of the sternoclavicular joint
Complete rupture or avulsion of proximal biceps brachii
Complete tears of the pectoralis muscle
Scapula fractures that are open, displaced, and involving glenoid or neck
Fractures of the acromion
Fractures of the distal clavicle (lateral to the coracoclavicular ligaments)
Any open fracture
Any injury associated with neurovascular compromise
Acute Glenohumeral Dislocation
In a shoulder dislocation the humeral head is at some point completely translated outside the glenoid, and will usually require a reduction to replace the head into the glenoid. Anterior dislocations, in which the humerus is usually dislocated anterior and inferior to the glenoid, are by far the most common.
Shoulder dislocations in general are rare in children. In the athletic setting shoulder dislocations occur in adolescents most often near the time of skeletal maturity, mostly in collision sports. Up to 40% of all primary shoulder dislocations occur in patients younger than 22 years of age, and the overall incidence of shoulder dislocation is as high as 7% in youth hockey.1,4
The mechanism for anterior dislocations is an anteriorly directed force placed on an abducted and externally rotated shoulder, as in being blocked while attempting a throw or similar mechanism. Anterior dislocation can also result from a fall on the externally rotated abducted outstretched arm.
With the more common anterior dislocation the athlete will present acutely on the field or on the sideline with pain, a prominent humeral head anteriorly, with the arm in external rotation, and will not want to move the shoulder. Palpate brachial artery. Test sensation to touch and pin prick over the arm. Loss of sensation over the lateral aspect of the shoulder over the deltoid indicates axillary nerve injury.