Complications of shoulder arthroplasty for osteoarthritis with posterior glenoid wear.

BACKGROUND Anatomical total shoulder arthroplasty (TSA) for glenohumeral osteoarthritis (OA) and severe posterior glenoid wear may entail early postoperative complications (recurrence of posterior subluxation, glenoid loosening). To avoid these mechanical problems, reverse shoulder arthroplasty (RSA) has recently been proposed, mainly for its intrinsic stability. Our purpose was to present the results of TSA and RSA in glenohumeral OA with posterior glenoid wear of at least 20°. HYPOTHESIS By virtue of its constrained design, RSA could prevent recurrence of posterior subluxation and limit the occurrence of mechanical complications. MATERIALS AND METHODS A consecutive series of 23 patients (27 shoulders) were treated for glenohumeral OA with total shoulder prostheses: 19 TSAs and 8 RSAs. Mean age was 70 years (range, 47-85 years), mean retroversion angle 28° (20°-50°) and mean subluxation index 74% (57-89%). Constant Score, Subjective Shoulder Value (SSV), QuickDASH and Simple Shoulder Test (SST) were measured, and radiological examinations were performed at a mean follow-up of 52 months (24-95 months). RESULTS TSA and RSA patients respectively displayed Constant Scores of 65 and 65, SSV of 79% and 74%, QuickDASH of 16 and 27, and SST of 88 and 78. Two patients underwent surgical revision of TSA because of glenoid loosening; 52% of TSA patients presented complete radiolucent lines and 11% recurrence of posterior subluxation. CONCLUSION Complications are frequently observed after shoulder arthroplasty for OA with severe glenoid retroversion. RSA could be an alternative to TSA for selected patients, independently of rotator cuff status. Studies on RSA in this specific indication with longer follow-up are now needed. LEVEL OF EVIDENCE Level IV; retrospective case series.