Bilateral shoulder arthroplasty for rotator cuff intact glenohumeral osteoarthritis: anatomic versus reverse shoulder arthroplasty

Background

The objectives of this study are (1) to analyze outcomes in patients with rotator cuff intact glenohumeral osteoarthritis (GHOA) who have undergone primary anatomic total shoulder arthroplasty (TSA) and contralateral primary reverse total shoulder arthroplasty (RSA), or vice versa; (2) to determine if patients with bilateral GHOA have similar patterns of pathology between shoulders; and (3) to determine how radiographic anatomic reconstructions for both TSA and RSA impact patient-reported outcome measures (PROMs) and rates of revision.

Methods

The inclusion criteria were patients with bilateral rotator cuff intact GHOA who underwent primary TSA and subsequently contralateral primary RSA, or vice versa, between January 2004 and January 2023 with completed PROMs and at least 1 year of clinical follow-up from their most recent arthroplasty procedure.

Results

(1) There were no differences for American Shoulder and Elbow Surgeons score between TSA and RSA shoulders at any timepoint between preoperative and 24-month follow-up. Six (12.0%) TSA shoulders underwent revision during the follow-up period compared to 1 (2.0%) RSA shoulder (P = .050). (2) Both TSA and RSA shoulders demonstrated similar glenoid retroversion (P = .323), glenoid inclination (P = .718), and posterior humeral head subluxation (P = .262). (3) TSA shoulders with changes in the center of rotation (ΔCOR) ≤3 mm experienced a greater increase in changes in American Shoulder and Elbow Surgeons score than those with ΔCOR >3 mm at the 3-6–month follow-up (P = .023) and at final follow-up (P < .001). TSA reconstructions with ΔCOR ≤3 mm experienced a lower rate of revision (4.5% vs. 17.8%) (P = .300). There was no difference in any PROM at any timepoint among RSA reconstructions with ΔCOR ≤10 mm, 10-20 mm, or ≥20 mm.

Conclusion

When performed for the treatment of GHOA in patients with bilateral pathology, TSA and RSA yielded similar clinical outcomes. Patients with bilateral GHOA had similar patterns of pathology between shoulders in terms of retroversion, inclination, and posterior humeral head subluxation. The findings highlight the importance of achieving an anatomic reconstruction for TSA and suggest that while an anatomic reconstruction for RSA may be ideal, deviations from the anatomic center of rotation may be better tolerated for RSA than for TSA.