Clinical and radiographical outcomes of scapular spine fractures after reverse shoulder arthroplasty treated with double plating and autologous bone graft.

Abstract

Scapular spine fractures (SSFs) are a challenging complication after reverse total shoulder arthroplasty (rTSA) leading to persisting pain, loss of function, and instability. So far there is no established uniform surgical procedure for successful treatment. Single-center consecutive cohort study of 25 surgically treated SSFs after rTSA between 2016 and 2021. Retrospective analysis regarding demographic data, implant specification, radiographic scans, and clinical analysis of all SSFs treated with a standardized fixation technique using a double plate augmented with an iliac crest autograft. Clinical analysis included range of motion, level of pain, and activities of daily living. Radiologic analysis included preoperative fracture classification and postoperative assessment of fracture union. For the 25 SSF cases, the median patient age was 80 years and 91% were female. 80% (20/25) were insufficiency fractures. Fifteen (68%) were posterior-medial fractures, with 1 Seebauer type IIB, 10 type IIIA, and 4 type IIIB fractures. Ten patients (45%) showed signs of delayed union on the preoperative CT scan, and 3 patients (14%) presented with dislocation of the prosthesis. Regarding risk factors, 8 patients (32%) had osteoporosis, 5 (20%) inflammatory arthritis, 3 (12%) Parkinson, and 7 (28%) had undergone revision arthroplasty. After osteosynthesis, clinical function improved significantly (active abduction from 47° preoperatively to 82° postoperatively [P = .009], active forward flexion from 52° to 82° [P = .015], and active external rotation from 16° to 28° [P = .242]) with a mean follow-up of 18 months (range 2-52 months). Radiologic follow-up showed fracture union in 57% of the cases. Seventy-five percent of the cases with preoperative delayed union healed postoperatively. Dislocated arthroplasties were revised simultaneously with fixation of the SSF and showed no signs of recurrent instability postoperatively. Complications included 5 iliac crest fractures (23%) and 1 scapular spine fracture medial to the plate; further, 2 patients had soft tissue irritation by the plate resulting in hardware removal. Double-plate fixation with autologous iliac crest augmentation of SSF after rTSA supports fracture consolidation, restores joint stability, and improves clinical function significantly.