Nonoperative management of glenoid baseplate failure in reverse shoulder arthroplasty

Background

Glenoid baseplate failure in reverse total shoulder arthroplasty (RSA) remains a challenging problem. Nonoperative management may be an option in certain patients. The purpose of this study was to evaluate outcomes following nonoperative management of glenoid baseplate failure after RSA.

Methods

Utilizing a single-institution database, a retrospective review was performed to identify patients from 2010 to 2019 who sustained glenoid baseplate failures after RSA and were treated nonoperatively. The exclusion criteria included revision surgery and presence of active infection. Included patients had a minimum 2-year clinical and radiographic follow-up. Chart review captured patient demographics, surgical indications, and techniques. Radiographs were reviewed to determine the etiology of baseplate failure and other implant complications. Glenosphere inclination angle was measured on true anteroposterior radiographs immediately postoperatively and after baseplate failure.

Results

Eighteen patients had glenoid baseplate failures treated nonoperatively during the study period. Five patients were deceased, leaving 13 patients who were available for clinical follow-up. Twelve (92%) patients were successfully contacted. The mean age was 77 years, body mass index was 28, and 8 out of 12 were female. The mean Charlson Comorbidity Index score was 4.1. The mean preoperative American Shoulder and Elbow Surgeons (ASES) score was 43.0, and visual analog scale (VAS) pain was 6.3. At a mean 5.7-year follow-up, patients had an ASES score of 49.2, VAS pain of 4.3, single assessment numeric evaluation of 49%, and 50% of patients were satisfied with their outcome. The preoperative and final follow-up ASES and VAS scores were similar. The average time from index surgery to baseplate failure was 19 months. Of the eighteen identified patients, 16 (89%) failures resulted in increased baseplate superior tilt (7 with concomitant broken baseplate screws). For these 16 patients, the mean glenosphere inclination angle after failure (131°) was significantly greater than the initial inclination angle (100°), P = .03. The other 2 failures resulted in increased baseplate anteversion. 8 out of 18 (44%) patients had bone grafting at the time of surgery. When comparing dissatisfied and satisfied patients, there were no specific patient characteristics or radiographic parameters that were associated with satisfaction.

Conclusion

Nonoperative management of glenoid baseplate failure yields modest patient-reported outcomes, with 50% patient satisfaction at mid-term follow-up. The mortality rate in this cohort of patients was almost 30%. Therefore, in select patients, nonoperative treatment of RSA baseplate failure may be a reasonable option.