Low acromial insufficiency fracture rate in reverse shoulder arthroplasty with distal clavicle excision.

Background: This study investigated the rate of acromial insufficiency fractures (AIF) in patients undergoing reverse shoulder arthroplasty (RSA) with concomitant distal clavicle excision (DCE).

Methods: Patients who underwent primary RSA with DCE by a single surgeon from 2010 to 2021 were identified. Exclusion criteria included revision RSA, RSA for fracture, or cases utilizing an augmented baseplate or bone graft. AIF was defined as a radiographically proven acromion or scapular spine fracture. Pain without an identifiable fracture on imaging was defined as an acromial insufficiency reaction. Patient demographics, implant information, and radiograph measurements were compared between patients with and without acromial pathology.

Results: One hundred and seventy-five patients were included. Mean age was 72.8 years, and 67% of patients were female. There were 3/174 acromial insufficiency fractures (1.7%). AIF occurred at a mean of 9.3 months after surgery. Twelve patients had insufficiency reactions (6.9%). Patients with acromial pathology were more likely to be female (p = .003) and have a diagnosis of osteoporosis (p = .047) and inflammatory arthritis (p = .049). There was no significant difference between groups in terms of other factors.

Conclusion: The AIF rate in patients who underwent RSA with DCE was 1.7%. These findings suggest that DCE in the setting of RSA may have a protective role against AIF.