Hung LW, Wu S, Lee A, et al. - Researchers conducted the study for analyzing the effect of preoperative muscle quality and postoperative implant positioning on patient-reported outcomes following reverse total shoulder arthroplasty (rTSA). They assessed 88 rTSA-treated shoulders that had an available preoperative MRI. Preoperative muscle quality was assessed, including fatty infiltration, rotator cuff muscle volume and total tear size. Univariate analysis revealed that American Shoulder and Elbow Surgeons (ASES) score was significantly lower in patients with teres minor muscle hypertrophy compared with those with normal muscle. The independent negative predictor of patient-reported outcomes after rTSA is teres minor muscle hypertrophy.