Early radiographic failure of reverse total shoulder arthroplasty with structural bone graft for glenoid bone loss.

Abstract

Structural glenoid bone grafting in reverse total shoulder arthroplasty (RSA) has previously been reported to have good functional outcomes and low complication rates. We have observed different complication rates and hypothesized that baseplate fixation and severity of deformity may be predictors of early failure. We retrospectively identified 44 patients who underwent RSA with structural bone grafting for glenoid bone defects. All patients had preoperative and postoperative (Grashey and axillary) radiographs at a minimum of 1 year after surgery and within 3 months of surgery for evaluation of implant and graft positioning. Clinical data and outcome scores were collected at the same intervals. There were 61% females and 39% males, with an average age of 74 ± 8 years at the time of surgery. The median final radiographic follow-up was 20 months, with 37 primary RSA and 7 revision RSA. Graft resorption was found in 11 of 44 patients (25%), and radiographic failure was found in 11 of 44 patients (25%) at a median of 8 months (range 3-51 months). Forward elevation, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) scores all significantly improved postoperatively (P < .0001). Radiographic baseplate failure was associated with graft resorption (P = .002), more retroversion correction (P = .02), and worse SANE scores at final follow-up (P = .01). RSA with structural bone graft improved range of motion and function, but there was a larger than previously reported baseplate loosening rate. This early radiographic loosening appeared to be associated with graft resorption, retroversion correction, and worse outcome scores.