Review Question - QID 217991

This patient has a Type II acromioclavicular (AC) joint injury. A Type II AC joint injury is characterized as: AC ligament torn, CC ligament sprain, horizontal AC instability

An AC joint injury, otherwise known as a shoulder separation, is a traumatic injury to the AC joint with disruption of the acromioclavicular ligaments and/or coracoclavicular (CC) ligaments. Diagnosis is made with bilateral focused shoulder radiographs to assess for AC and CC interval widening. Treatment is immobilization or surgical reconstruction depending on patient activity levels, degree of separation and degree of ligament injury. Generally speaking, initial treatment in low-grade acromioclavicular injuries (Rockwood type I and II) is typically nonoperative, consisting of brief immobilization, ice, rest, and physical therapy. Rockwood type III injuries remains controversial. High-grade injuries (Rockwood type IV, V, and VI) are more often managed surgically.

Beitzel et al. performed a systematic review of patients treated for AC joint dislocations. They reported that there is a lack of evidence to support treatment options for patients with AC joint dislocations. They concluded that although there is a general consensus for nonoperative treatment of Rockwood type I and II lesions, initial nonsurgical treatment of type III lesions, and operative intervention for Rockwood type IV to VI lesions, further research is needed to determine if differences exist regarding early versus delayed surgical intervention and anatomic versus nonanatomic surgical techniques in the treatment of patients with AC joint dislocations.

Chang et al. performed a meta-analysis comparing outcomes between operative and nonoperative management of high-grade AC joint dislocations. They reported that no clinical difference in functional outcome scores were detected between operative and nonoperative management of high-grade AC joint dislocations. They concluded that patients in the nonoperative cohort had a more rapid return to work, but were associated with a poorer cosmetic outcome.

Deans et al. reviewed the relevant literature surrounding AC joint injuries particularly pertaining to overhead athletes. They reported that low-grade injuries (Rockwood types I & II) are typically treated non-operatively while high-grade injuries (types IV, V, and VI) are considered unstable and often require operative intervention. Type III AC separations remain the most controversial and challenging as no clear treatment algorithm has been established. They concluded that operative indications and techniques are still evolving, and more research is needed specifically surrounding overhead athletes.

Illustration A depicts the Rockwood classification for AC injuries

Incorrect Answers:
Answer 1: A Type I AC joint injury is characterized as: AC ligament sprain, CC ligament sprain, no AC instability
Answer 2: A Type II AC joint injury will display AC joint horizontal instability
Answer 4: A Type IIIA AC injury is characterized as: AC ligament torn, CC ligament torn, vertical instability with no horizontal AC instability
Answer 5: A Type IIIB AC joint injury is characterized as: AC ligament torn, CC ligament torn, vertical and horizontal AC instability