Low agreement among 24 doctors using the Neer-classification; only moderate agreement on displacement, even between specialists

Twenty-four orthopaedic surgeons classified 42 pairs of radiographs according to the Neer system for proximal humeral fractures. Mean kappa value for interobserver agreement was 0.27 (95% CI 0.26-0.28) with no clinically significant difference between orthopaedic residents (n=9), fellows (n=6) and specialists (n=9). Mean kappa for agreement of displacement versus non-displacement was 0.41 (95% CI 0.39-0.43) overall, and 0.50 (95% CI 0.45-0.56) within the specialist group. The agreement found in our study is unsatisfactory from a clinical perspective.