Grammont Award 2018: Scapular fractures in reverse shoulder arthroplasty (Grammont style): prevalence, functional, and radiographic results with minimum 5-year follow-up.

BACKGROUND:
Scapular fractures after reverse shoulder arthroplasty (RSA) are an increasingly reported complication. Information is missing regarding midterm to long-term follow-up consequences. The aim of this study was to determine the rate of scapular fracture (acromial base and spine) after Grammont-style RSA and to report functional and radiographic results of patients with a minimum 5-year follow-up.

MATERIALS AND METHODS:
We retrospectively reviewed 1953 Grammont-style RSAs in 1745 patients in a multicenter study. Of these, 953 patients (1035 RSAs) had minimum 5-year follow-up for functional and radiographic assessment (anteroposterior and scapular Y views.

RESULTS:
Twenty-six patients (1.3%) had sustained a scapular fracture; of these, 19 (10 acromial base and 9 spine fractures) had minimum 5-year follow-up and were reviewed at a mean follow-up of 97 months. Three patients (15.8%) were diagnosed at the last follow-up after an undiagnosed fracture. There were 3 traumatic cases (15.8%) and 13 (68.4%) without antecedent trauma. These 16 patients underwent nonoperative treatment. The fracture was healed in 8 (4 acromion and 4 spine). The average active forward elevation was 109° (range, 50°-170°), and the Constant score was 47.0 points (range, 8-81 points).

CONCLUSIONS:
Scapular fractures after Grammont-style RSAs are rare (1.3%) but remain a concern. These fractures occur mainly in the early postoperative 6 months. Immobilization with an abduction splint frequently resulted in nonunion or malunion. Final functional outcomes are poor regardless of acromial or spine fracture compared with primary RSA without fracture.