The Sirveaux classification characterizes the severity of scapular notching after reverse total shoulder arthroplasty (rTSA). However, its reliability has not been validated. The goal of the current study was to determine the interobserver and intraobserver reliability of the Sirveaux classification. An online survey was sent to the American Shoulder and Elbow Surgeons (ASES), containing 10 radiographs showing a range of scapular notching. Members were asked to grade the degree of scapular notching with the Sirveaux classification system. Then ASES members from our institution regraded the images a second time after a minimum of 6 weeks. Fleiss' and Cohen kappa coefficients were calculated to determine the degree of interobserver and intraobserver reliability, respectively. A total of 50 ASES members graded the radiographs and 3 regraded images after more than 6 weeks. Fleiss' kappa coefficient was 0.2437, indicating fair interobserver agreement. Surgeons who perform more than 20 rTSA procedures per year (n=34) had a Fleiss' kappa of 0.2864. The mean Cohen kappa coefficient was 0.4763, indicating moderate intraobserver reliability. The Sirveaux classification system has fair interobserver and moderate intraobserver reliability. Surgeons should use additional means to describe the severity of notching, particularly when communicating with other physicians or publishing research. [ Orthopedics . 2022;45(4):239–243.]
