Factors Associated With Poor Outcomes For Female Patients Undergoing Total Shoulder Arthroplasty.

Abstract

Numerous studies have demonstrated gender disparities in outcomes following total shoulder arthroplasty (TSA), with female patients typically having inferior outcomes^{12, 13, 35}. 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 (rTSA) total shoulder arthroplasty between March 1, 2016 and January 1, 2022 with a two-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 PASS for the SANE score (75%) at two years postoperatively, and compared based on demographic factors, surgical indication, preoperative range of motion, and postoperative outcome scores (Visual analog scale (VAS) pain, American shoulder and elbow surgeons (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, 264 patients (64.5%) achieved PASS (SANE>75) and 145 patient (35.4%) did not achieve PASS. The patients that achieved PASS had significantly superior outcome scores compared to those that 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<0.001). Reverse TSA (OR: 0.38, 95% CI [0.23-0.65]; p<0.001) and prior ipsilateral shoulder surgery (OR:0.53, 95% CI [0.32-0.87]; p=0.013) were negatively associated with achieving PASS in female patients at 2 years postoperatively. Conversely, never smoking (OR:1.8, 95% CI [1.12-2.91], relative to current smoker; p=0.016) was positively associated with achieving PASS. The ability to perform the tasks of combing hair (gamma=0.808, p<0.001), reach up to a high shelf (gamma=0.737, p<0.001), and perform usual work (gamma=0.715, p<0.001) postoperatively were most predictive of PASS achievement at 2-years postoperatively. Smoking, previous shoulder surgery, and rTSA were found to independently associate with inferior outcomes in female patients following shoulder arthroplasty, 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 postoperative expectations should be managed accordingly.