A 17-year-old girl is brought to the emergency department due to severe right shoulder pain. She was playing basketball when her shoulder popped out of place. Her coach placed her arm in a sling, gave her an ice pack, and drove her to the emergency department. The patient has no numbness or tingling in the arm. She takes no medications. Vital signs are normal. On examination, the range of motion in the right shoulder is limited, with anterior and lateral tenderness to palpation. The neurovascular examination is normal. X-ray of the right shoulder is shown in the exhibit. The condition is treated successfully without complications. This patient is at greatest risk for which of the following conditions?
Acute glenohumeral dislocation | |
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This patient has an anterior glenohumeral dislocation, confirmed on x-ray showing inferomedial displacement of the humeral head in relation to the coracoid process and glenoid. Shoulder dislocation is common in basketball and similar sports in which the arm is subject to forceful contact while abducted overhead. Patients who experience shoulder dislocation are often at increased risk for recurrent dislocation due to labral tears (ie, Bankart lesion), ligamentous laxity due to overuse, and underlying multidirectional joint instability (MDI).
MDI is excessive, symptomatic laxity of the joint capsule in >1 direction. It typically becomes symptomatic in young (age <40), athletically active individuals, often in the setting of repetitive microtrauma or participation in sports requiring lifting the arms over the head. In addition to overt joint dislocation, patients may report looseness or weakness in the shoulder, especially in certain positions.
(Choice A) Avascular necrosis may occur secondary to acute shoulder dislocation associated with a proximal humerus fracture that disrupts blood flow to the humeral head. It is not a common complication of isolated dislocation.
(Choice B) Axillary artery thrombosis secondary to anterior dislocation is rare. It typically presents with reduced distal pulses; this patient's pulses are normal, and the dislocation has been reduced.
(Choice C) Myositis ossificans is characterized by ectopic bone formation within a muscle after an injury (eg, fracture, quadriceps contusion). It is relatively uncommon in the upper extremity and rare following dislocation.
(Choices D and F) Osteomyelitis can occur due to contamination of an open fracture fragment or contiguous extension from a local wound. Similarly, septic arthritis can be caused by traumatic contamination by a penetrating wound. These infections are not seen in shoulder dislocation in which the overlying skin barrier is intact.
Educational objective:
Patients who experience shoulder dislocation are often at increased risk for recurrent dislocation due to labral tears (ie, Bankart lesion), ligamentous laxity due to overuse, and underlying multidirectional joint instability (ie, excessive, symptomatic, and involuntary laxity of the joint capsule in >1 direction).