Scapular Fractures after Reverse Shoulder Arthroplasty

With the increased use of reverse shoulder arthroplasty, the complication of postoperative scapular fracture is increasingly recognized. The incidence is variable and dependent on a combination of factors including patient age, sex, bone mineral density, diagnosis of inflammatory arthritis, acromial thickness, and implant-related factors. Acromial stress reactions are a clinical diagnosis based on a history and physical examination. These are treated successfully with 4 to 6 weeks of immobilization. Acromial stress fractures are visible on imaging studies and are classified based on anatomic location by the classification systems of Crosby and Levy. In approximately 20% of fractures, a CT scan is necessary to make the diagnosis. Treatment is typically nonsurgical that leads to a high rate of nonunion or symptomatic malunion. Scapular spine fractures (type III) can be treated with either nonsurgical or surgical management; however, obtaining fracture union is challenging, and the outcomes are typically inferior to that of type I and II fractures. Although the nonsurgical and surgical treatment of acromial stress fractures improves the clinical outcomes from the patient's preoperative state, the outcomes of a control group undergoing reverse shoulder arthroplasty without fracture are better. The exception to this is oftentimes the displaced and angulated type III fracture.