Scapular Fractures after Reverse Shoulder Arthroplasty

Abstract

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.