Outcomes of anatomic total shoulder arthroplasty revised to reverse shoulder arthroplasty in patients with contained central glenoid bone defects

Background

The purpose of this study is to present the outcomes of patients with failed total shoulder arthroplasty (TSA) who were treated by conversion to reverse shoulder arthroplasty (RSA).

Methods

This retrospective cohort study investigates patients who underwent single-stage revision from TSA to RSA by one of three fellowship-trained orthopedic surgeons between 2012 and 2020. Patients with central bone defects in the glenoid were included, whereas those with uncontained peripheral or combined glenoid defects or with infections requiring a 2-stage revision were excluded. The glenoid baseplate size and use of bone graft augmentation were recorded. A minimum 2-year postsurgical follow-up was required to participate in the outcome evaluations. Primary outcome measures were shoulder pain on the visual analog scale and active shoulder forward flexion and abduction, while secondary outcome measures included patient satisfaction, procedure complications, and reoperations. The Wilcoxon signed rank exact test was used to compare preoperative and postoperative clinical data.

Results

Data from 18 shoulders in 16 patients, average age 74 years, were analyzed. The standard 28-mm-sized baseplate with longer and wider central peg was implanted in 12 of 18 reconstructions. Bone graft augmentation of the glenoid was required in 4 of 6 cases when the 25-mm mini baseplate was used. Clinical evaluation of 13 patients (15 shoulders) with an average of 5 (range, 2-10) years after surgery showed statistically significant improvements in median visual analog scale shoulder pain score decreasing from 7 to 0 (P < .001), median active shoulder forward flexion increasing from 90° to 140° (P < .001), and median active shoulder abduction increasing from 60° to 125° (P < .001). In 14 of 15 cases, the patient was satisfied with the outcome. There were minor complications in 2 cases (13%), but there were no major complications or reoperations.

Conclusion

In patients with symptomatic TSA from component failure, shoulder instability, or rotator cuff insufficiency, single-stage revision to RSA for those with contained glenoid bone defects is a reliable salvage option to reduce shoulder pain and improve shoulder motion. At a mean 5-year follow-up, we observed 100% implant survival in 15 cases.