Conversion to hemiarthroplasty as a salvage procedure for failed reverse shoulder arthroplasty.

BACKGROUND: Optimal treatment of a failed reverse shoulder arthroplasty (RSA) is unclear. In the case of poor glenoid bone stock, retaining a RSA may be infeasible. We report our experience with conversions to hemiarthroplasty.
METHODS: Within 7 years, 16 patients underwent conversion to hemiarthroplasty after failed RSA. All patients had insufficient bone stock for reimplantation of another RSA. Standard radiographs and Constant, Shoulder Pain and Disability Index, and the 11-item version of the Disabilities of the Arm, Shoulder and Hand scores were assessed preoperatively and up to a minimum of 24 months after surgery. Postoperative superior migration and complications were also documented.
RESULTS: Glenoid loosening was the primary reason for RSA failure in 11 patients. Three required revision surgery because of infection. Postoperative functional outcome was generally poor at the latest follow-up, with mean Constant, Shoulder Pain and Disability Index, and 11-item version of the Disabilities of the Arm, Shoulder and Hand scores of 25, 37, and 63 points, respectively. Baseline pain also did not improve. Medialization progressed beyond the coracoid in 6 patients, and complete anterosuperior escape was reported in 3 patients. Three postoperative complications were recorded by the final follow-up, including 2 periprosthetic humeral fractures treated conservatively and 1 patient with painful humeral component medialization leading to resection arthroplasty.
CONCLUSION: With excessive bone stock loss, hemiarthroplasty remains an option, despite the associated risks of uncertain pain relief and poor functional outcome. This technique offers a lower likelihood of undertaking further surgical interventions within the short-term to midterm postoperative period. Nevertheless, resection arthroplasty may still be considered another valuable solution.