Pain Relief Survivorship: A Comparison of Exactech Equinoxe Anatomic and Reverse Total Shoulder Arthroplasty for Primary Osteoarthritis.

Background: Pain-relief plays a major deterministic role when assessing postoperative patient satisfaction; however, whether anatomic total shoulder arthroplasty (aTSA) or reverse total shoulder arthroplasty (rTSA) provides the most durable pain-relief has not been studied. The purpose of this study was to evaluate the durability of pain-relief after aTSA compared to rTSA in patients undergoing surgery for rotator cuff-intact glenohumeral osteoarthritis (RCI-GHOA).

Methods: A retrospective review of a multicenter shoulder arthroplasty database (Exactech Equinoxe) was performed. We included 1,848 aTSAs and 1,464 rTSAs performed for RCI-GHOA between 2007 and 2023. Pain after surgery was assessed postoperatively at 3-months, 6-months, and yearly thereafter. Average postoperative pain on a daily basis and pain at worst were compared between aTSA and rTSA up to 8-years postoperatively. Kaplan-Meier survivorship analysis for pain-relief maintenance was performed to compare the maintenance of clinically-relevant pain-relief defined as pain scores that achieved the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS). Maintenance of favorable patient satisfaction over time was also evaluated. Multivariable cox regression was performed to determine whether the type of prosthesis (aTSA vs. rTSA) was independently associated with pain recurrence.

Results: Maintenance of achievement of the MCID and SCB for both daily pain and pain at worst as well as favorable patient satisfaction was similar between aTSAs and rTSAs. However, aTSA had longer maintenance of average daily pain below the PASS compared to rTSA (P=.024). This was confirmed on multivariable cox regression analysis which found that rTSAs had a 34% greater likelihood of recurrence of postoperative average daily pain exceeding the PASS (VAS rating 1/10) compared to aTSAs.

Conclusion: Patients that undergo either aTSA or rTSA for RCI-GHOA and achieve initial pain-relief postoperatively can expect to maintain their clinically-relevant pain improvement at similar rates up to 8-years postoperatively. However, recurrence of low levels of daily pain was significantly higher after rTSA.