Interobserver Reliability and Intraobserver Reproducibility in Suprascapular Notch Typing

The size and shape of the suprascapular notch may be a factor in suprascapular nerve entrapment. The suprascapular notches of 623 scapulae were digitally photographed and used to determine notch type and area. Three researchers used to different classification systems for suprascapular notch typing. These systems were compared for interobserver reliability and intraobserver reproducibility using the kappa test. The mean kappa value for the classification used by Rengachary and colleagues was 0.468 and for the classification used by Ticker and associates was 0.531 for the inferior border of the notch and 0.736 for the superior border of the notch. The classification system used by Ticker and associates was more reliable and reproducible and produced both a superior and an inferior classification, making it possibly more clinically relevant than the classification system used by Rengachary and colleagues.