Simultaneous versus Staged Bilateral Shoulder Replacement: A Matched Cohort Study

The safety and value of performing simultaneous bilateral shoulder arthroplasty (SimBA) remain unclear. In this retrospective single-center matched-cohort study, we investigated the safety and clinical outcomes after simultaneous versus staged bilateral shoulder arthroplasty. All patients that underwent simultaneous bilateral shoulder arthroplasty for glenohumeral osteoarthritis, cuff tear arthropathy, avascular necrosis, or rheumatoid arthritis were included. Demographics, complications, length of stay, and outcomes were collected from the medical record. Patients were matched by age, gender, American Society of Anesthesiologists (ASA) score, and type of shoulder arthroplasty (hemi [HA], anatomic [aTSA], or reverse [rTSA]) to 32 patients (64 shoulders) who underwent staged bilateral arthroplasty (StaBA). All surgeries in both groups were performed by a single surgeon between 2007 and 2020. Complications, reoperation rate, range of motion (ROM), Constant score, and Subjective Shoulder Value (SSV) were compared between the matched cohorts. Alpha was set at 0.05. Sixteen SimBA patients (32 shoulders) and 32 StaBA patients (64 shoulders) were included. Implant distribution was identical between cohorts: 50% bilateral aTSA, 31% bilateral rTSA, 13% bilateral HA, and 6% mixed aTSA/rTSA. All patients were younger than 80 years old, had ASA scores &#x2264; 2, and had good social support.The mean follow-up was 25 months (range 24-36 months) in the SimBA group and 36 months (range 24-94 months) in the StaBA group. No patients in either group experienced surgical or medical complications, dislocations, periprosthetic infections, transfusions, or 90-day readmissions. Total length of stay was significantly shorter in the SimBA group (3.4 vs 7.5 days, p<0.001). At final follow-up, ROM, outcomes, and satisfaction were equivalent between groups (SSV 82 vs. 83, p=0.297), and all SimBA patients reported that they would undergo the procedure again and recommend it to others. In carefully selected patients (age &#x2264;80 years, ASA &#x2264;2, with no social issues), simultaneous bilateral shoulder arthroplasty reduces total length of stay and achieves equivalent outcomes, satisfaction, and complication and reoperation rates compared to staged surgery. The choice between one- and two-stage bilateral shoulder replacement should be made collaboratively among the surgeon, anesthesiologist, and an informed, medically appropriate patient.