A 51-year-old male with past medical history of HTN, DM presents with right shoulder pain. He states he tripped off the curb and landed on his right shoulder. On exam, there are no palpable deformities, but patient has limited abduction of shoulder and tenderness on palpation of anterior shoulder. An X-ray is obtained and shown below. What’s the diagnosis?
Answer: Acromioclavicular (AC) joint separation
- AC joint is composed of the acromion process and clavicle and supported by AC ligament, coracoclavicular ligament
- Mechanism of injury is fall directly on shoulder or FOOSH
- AC joint injuries range from sprain of ligaments to complete rupture of all supporting ligaments and complete separation of clavicle and acromion
- Type I: normal X-ray, due to sprain of ligaments
- Type II (X-ray above): widened AC joint, clavicle is displaced <50%, due to rupture of AC ligaments
- Type III: clavicle displaced >50%, due to rupture of AC ligaments and coracoclavicular ligaments
- Type IV: clavicle is dislocated posteriorly
- Type V: clavicle displaced >200% superiorly
- Type VI: clavicle dislocated inferiorly
- Treatment
- Sling immobilization and physical therapy for types I – III
- Surgical repair for types IV – VI
References:
Bjoernsen, Lars Petter, and Alexander Ebinger.. “Shoulder and Humerus Injuries.” Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e Eds. Judith E. Tintinalli, et al. New York, NY: McGraw-Hill, 2016