Rate of improvement following reverse shoulder arthroplasty: a comparison of primary and revision reverse shoulder arthroplasty

Abstract

Background

As the incidence of reverse shoulder arthroplasty (rTSA) increases, so do the expected revision rates. Despite this, little is known about postoperative recovery rates following revision rTSA. This study aimed to determine the rate of improvement for patients who underwent revision rTSA compared to patients who underwent primary rTSA.

Methods

A retrospective review of 476 patients who underwent rTSA by a single fellowship-trained shoulder surgeon was conducted. In this cohort, 386 patients underwent primary rTSA and 90 patients underwent revision rTSA. Demographics, range of motion, and outcome scores—including the Simple Shoulder Test, Constant–Murray Score, University of California at Los Angeles Shoulder Score, Shoulder Pain and Disability Index (SPADI), Shoulder Arthroplasty Smart score, and American Shoulder and Elbow Surgeons scores—were collected preoperatively and postoperatively for both cohorts. Outcome scores were collected at 6 weeks, 3 months, 6 months, 12 months, and 24 months. The rate of improvement in each outcome measure was quantified and compared between primary rTSA and revision rTSA, and final follow-up scores were compared between the two groups.

Results

A total of 476 patients (primary rTSA = 386 patients, revision rTSA = 90 patients) were included in the final analysis. Preoperatively, no baseline differences were observed in patient-reported outcome measures or functional scores between the revision and primary rTSA groups. Postoperatively, both groups demonstrated improvements in outcome scores from their preoperative assessments. When postoperative outcomes were evaluated over time, revision rTSA patients showed lower scores than the primary rTSA cohort as early as 3 months in SPADI (46.6 vs. 58.6; P = .03) and 6 months for forward elevation (126.3 vs. 141; P = .04). Between 12 and 24 months, analysis revealed no significant changes in improvement trends for both revision rTSA and primary rTSA groups (P > .05), indicating that recovery stabilizes after the first year. However, postoperative outcomes collected at final follow-up visit demonstrated that the revision rTSA cohort achieved less favorable results compared to the primary rTSA group. Specifically, the revision rTSA group did not achieve the same level of improvement in Simple Shoulder Test (6.8 vs. 9.2, d = 0.67, P < .01), University of California at Los Angeles (25.2 vs. 29.8, d = 0.60, P < .01), American Shoulder and Elbow Surgeons (62.6 vs. 77, d = 0.61, P = .01), SPADI (50 vs. 30.8, d = 0.60, P = .01), and Shoulder Arthroplasty Smart (63.2 vs. 71.8, d = 0.53, P = .02) as observed in the primary rTSA cohort.

Conclusion

Although revision rTSA shows an early recovery pace comparable to primary rTSA, it plateaus at lower absolute patient-reported outcome measure and range of motion values after 6 months. Surgeons should use these data to set realistic expectations for long-term functional recovery and pain relief during patient counseling and follow-up.