Patients Undergoing Total Shoulder Arthroplasty on the Dominant Extremity Attain Greater Postoperative ROM.

BACKGROUND: Total shoulder arthroplasty (TSA) provides excellent functional outcomes and pain relief in appropriately selected patients. Although it is known to affect other shoulder conditions, the role of hand dominance after TSA has not been reported, to our knowledge. QUESTIONS/PURPOSES: We asked: (1) Does TSA of the dominant arm result in greater postoperative ROM compared with TSA of the nondominant arm? (2) Does hand dominance affect validated outcome scores after TSA?
METHODS: We performed a review of all patients who underwent primary TSAs between 2008 and 2011 with a minimum of 12 months followup. During that time, one surgeon performed 156 primary TSAs. One hundred twenty-seven patients met the minimum followup requirement for this analysis (81%), whereas 29 (19%) were lost to followup. Seven patients were excluded for surgical indications other than glenohumeral osteoarthritis. A total of 58 patients underwent TSA of the dominant upper extremity and 62 underwent TSA of the nondominant upper extremity. Patient demographics, preoperative and postoperative ROM, and preoperative and postoperative outcome scores, were collected from the medical records. Student's t-tests and chi-square tests were used for analysis. Demographics and preoperative ROM did not differ between patients undergoing TSA on the dominant or the nondominant upper extremity.
RESULTS: Dominant-arm TSAs showed greater postoperative forward elevation and external rotation. Postoperative active forward elevation in the dominant group was 151° versus 141° in the nondominant group (mean difference, 10°; 95% CI, 1°-18°; p = 0.033). Postoperative active external rotation was 61° in the dominant group, versus 51° in the nondominant group (mean difference, 10°; 95% CI, 5°-15°; p < 0.001). Active internal rotation did not differ (dominant, 52°, nondominant, 50°; mean difference, 2°; 95% CI, -3° to 7°; p = 0.419). There were no differences in postoperative VAS (dominant, 0.9, nondominant, 1.4; mean difference, 0.5; 95% CI, -0.1 to 1.1; p = 0.129), simple shoulder test (dominant, 9.8, nondominant, 9.2; mean difference, 0.5; 95% CI, -0.5 to 1.5; p = 0.278), and American Shoulder and Elbow Surgeons scores (dominant, 84, nondominant, 80; mean difference, 4; 95% CI, -2 to 10; p = 0.211).
CONCLUSIONS: Patients who underwent TSA of their dominant upper extremity had greater postoperative active forward elevation and active external rotation compared with patients who had TSA of their nondominant upper extremity. This average difference of 10° active forward elevation and active external rotation could be useful for preoperative and postoperative counseling of patients. Regardless of hand dominance, similar functional outcomes were achieved. LEVEL OF EVIDENCE: Level III, therapeutic study.