Acromioclavicular Joint Injuries
AC joint injuries are among the most common injuries encountered in athletes. Classic history for injury is direct trauma to the anterior or superior shoulder, such as with a fall, with most of the force directed against the acromion during shoulder adduction.
On physical examination, edema and tenderness can be noted over the AC joint, sometimes with visible deformity. Pain is elicited with forced adduction of the shoulder or resisted shoulder elevation.
Classification of Injury: AC joint injuries are classified by the extent of dislocation and damage to the ligamentous structures of the joint, in particular the acromioclavicular and coracoclavicular ligaments. Diagnosis is by physical examination with comparison of both shoulders; plain AP films are useful in excluding fractures of the clavicle, coracoid, or acromion.
Type I: Sprain of the acromioclavicular ligament without anatomic disruption.
Type II: Disruption of the acromioclavicular ligament with sprained but intact coracoclavicular ligaments and less than 25% superior diplacement of the clavicle.
Type III: Complete disruption of both ligaments and greater than 25% superior displacement of the clavicle.
Type IV: Complete disruption of both ligaments with posterior displacement of the clavicle into or through the trapezius muscle.
Type V: Complete disruption of both ligaments and the attachments of the deltoid and trapezius muscles along with major separation of the clavicle and the acromion.
Type VI: Similar to Type V, with inferior displacement of the clavicle below the acromion or the coracoid.
Management: Varies according to the degree of injury.
Types I-II: Nonoperative management. Rest, ice, analgesics, and cessation of strenuous activity until patient has painless full range of motion. A sling (Kenny-Howard) can be applied in Type II injuries for 2 weeks, with delayed return to full activity up to 6-8 weeks.
Type III: Optimal management is controversial. It has been suggested that operative management should be reserved for patients with >2 cm displacement, baseball pitchers/high-level athletes, patients with open injuries, and patients with brachial plexopathy. Conservative management consists of use of a sling for 4 weeks, followed by gentle mobilization and PT. Patient can return to strenuous activity within 3 months only if patient has a stable joint with painless full ROM. Return to contact sports can be allowed within 3-5 months of the injury.
Types IV-VI: Refer to orthopedic surgeon for operative repair. Type VI injuries can sometimes require resection of the distal clavicle to enable proper reduction.
D. Suh 10/31/00