Factors associated with poor outcomes for female patients undergoing total shoulder arthroplasty

Numerous studies have demonstrated gender disparities in outcomes following total shoulder arthroplasty (TSA), with female patients typically having inferior outcomes. However, the current literature has yet to elucidate exactly why female patients have inferior outcomes. The aim of this study was to determine demographic and clinical differences between women with better and worse outcomes following TSA.

All female patients undergoing primary anatomic (aTSA) or reverse TSA (rTSA) between March 1, 2016, and January 1, 2022, with a 2-year post-operative Single Assessment Numeric Evaluation (SANE) score from a single tertiary institution were included in the study. Female patients were stratified by achievement of patient acceptable symptom state (PASS) for the SANE score (75%) at 2 years post-operatively, and compared based on demographic factors, surgical indication, pre-operative range of motion, and post-operative outcome scores (visual analog scale [VAS] pain, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] function score, ASES total score, and satisfaction), using both univariate and multivariate regression.

There were 409 women identified who underwent aTSA or rTSA during the study period; of these, 264 patients (64.5%) achieved PASS (SANE score >75) and 145 patients (35.4%) did not achieve PASS. The patients who achieved PASS had significantly superior outcome scores compared with those who did not achieve PASS (VAS pain: 4.1 ± 5.9 vs. 19.8 ± 23.4; ASES function 41.9 ± 6.9 vs. 30.8 ± 10.1; ASES total 89.8 ± 8.0 vs. 70.9 ± 18.5; satisfaction 97.2 ± 4.8 vs. 66.3 ± 32.7; all P < .001). Reverse TSA (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.23-0.65; P < .001) and prior ipsilateral shoulder surgery (OR 0.53, 95% CI 0.32-0.87; P = .013) were negatively associated with achieving PASS in female patients at 2 years post-operatively. Conversely, never smoking (OR 1.8, 95% CI 1.12-2.91, relative to current smoker; P = .016) was positively associated with achieving PASS. The ability to perform the tasks of combing hair (γ = 0.808, P < .001), reach up to a high shelf (γ = 0.737, P < .001), and perform usual work (γ = 0.715, P < .001) post-operatively were most predictive of PASS achievement at 2 years post-operatively.

Smoking, previous shoulder surgery, and rTSA were found to independently associate with inferior outcomes in female patients following TSA, and thus these factors should be factored in patient counseling and decision making. Female patients are most satisfied following TSA if they can perform activities that require shoulder range of motion over and behind the head (combing hair, reaching to a high shelf), and thus post-operative expectations should be managed accordingly.