To our knowledge, no independent analysis of the inter-rater agreement of the widely used Walch classification for osteoarthritic glenoid morphology has been performed. The computed tomography scans of 24 shoulders with primary osteoarthritis were used by 4 experienced shoulder surgeons to classify the glenoids independently according to Walch et al. The weighted k statistic was calculated to determine the inter-rater and intrarater agreement among observers. The overall inter-rater agreement for the Walch classification was fair (k = 0.37) when classified into the 5 types (A1, A2, B1, B2, and C). Agreement for the various subclassifications was as follows: A1, k = 0.22; A2, k = 0.33; B1, k = 0.17; B2, k = 0.32; and C, k = 0.86. When the classification system was simplified to just the 3 major types (A, B, and C), overall agreement was moderate (k = 0.44). Agreement for each type was moderate for A (k = 0.59) and B (k = 0.59) and almost perfect for C (k = 0.89). Overall intrarater agreement was fair (k = 0.37). We conclude that only fair agreement was found among experienced shoulder surgeons when classifying arthritic shoulders using the classification system of Walch et al. A glenoid classification scheme that relies more upon glenoid morphology and less upon humeral head position may demonstrate greater observer agreement and, therefore, may offer greater value.
Copyright remains with the authors and publisher.
To our knowledge, no independent analysis of the inter-rater agreement of the widely used Walch classification for osteoarthritic glenoid morphology has been performed. The computed tomography scans of 24 shoulders with primary osteoarthritis were used by 4 experienced shoulder surgeons to classify the glenoids independently according to Walch et al. The weighted k statistic was calculated to determine the inter-rater and intrarater agreement among observers. The overall inter-rater agreement for the Walch classification was fair (k = 0.37) when classified into the 5 types (A1, A2, B1, B2, and C). Agreement for the various subclassifications was as follows: A1, k = 0.22; A2, k = 0.33; B1, k = 0.17; B2, k = 0.32; and C, k = 0.86. When the classification system was simplified to just the 3 major types (A, B, and C), overall agreement was moderate (k = 0.44). Agreement for each type was moderate for A (k = 0.59) and B (k = 0.59) and almost perfect for C (k = 0.89). Overall intrarater agreement was fair (k = 0.37). We conclude that only fair agreement was found among experienced shoulder surgeons when classifying arthritic shoulders using the classification system of Walch et al. A glenoid classification scheme that relies more upon glenoid morphology and less upon humeral head position may demonstrate greater observer agreement and, therefore, may offer greater value.
Copyright remains with the authors and publisher.