Shoulder function and pain level after revision of failed reverse shoulder replacement to hemiarthroplasty

BACKGROUND: The reverse total shoulder replacement has become a popular treatment option for cuff tear arthropathy and other shoulder conditions requiring arthroplasty in the setting of a deficient rotator cuff. Despite a revision rate of as much as 10%, to date, there are few reports of reverse replacement conversion to hemiarthroplasty, and none specifically examining shoulder function. MATERIALS AND METHODS: Six patients with a reverse replacement that was dislocated, infected or loose were revised an average of 9.2 months after the reverse replacement. Two of the three patients that were dislocated also had a known deep infection. Patients with known infection were treated with explant of the reverse prosthesis and conversion to a preformed antibiotic spacer hemiarthroplasty. In three cases with gross loosening of the glenosphere without infection, treatment was performed with removal of glenosphere only, bone grafting of glenoid with allograft and conversion of humeral stem to hemiarthroplasty. Patients were evaluated with outcome scores and physical examination an average of 26.5 months after removal of the reverse prosthesis. RESULTS: The average range of motion postoperatively was forward elevation 42.5 degrees and external rotation 1.7 degrees. The VAS pain score was 2.42 (range 0–6); simple shoulder test was 3.17 (range 1–5); and ASES score was 52.1 ± 8.5. There were no reoperations to date, and five patients had anterosuperior escape. CONCLUSIONS: Safe removal of a reverse replacement and conversion to hemicement spacer or hemiarthroplasty can provide pain relief in those patients with a dislocated or infected reverse replacement. However, the shoulder will likely have very poor function and anterosuperior escape postoperatively. Further studies are needed to determine the optimal treatment for the failed reverse shoulder replacement. LEVEL OF EVIDENCE: Therapeutic Level IV.