The reliability and reproducibility of the Hertel classification for comminuted proximal humeral fractures compared...

The Neer classification is the most commonly used fracture classification system for proximal humeral fractures. Inter- and intra-observer agreement is limited, especially for comminuted fractures. A possibly more straightforward and reliable classification system is the Hertel classification. The aim of this study was to compare the inter- and intra-observer variability of the Hertel with the Neer classification in comminuted proximal humeral fractures.

Four observers evaluated blinded radiographic images (X-rays, CT-scans, and CT-scans with 3D-reconstructions) of 60 patients. After at least two months classification was repeated.

Inter-observer agreement on plain X-rays was fair for both Hertel (κ = 0.39; 95% CI 0.23-0.62) and Neer (κ = 0.29; 0.09-0.42). Inter-observer agreement on CT-scans was substantial (κ = 0.63; 0.56-0.72) for Hertel and moderate for Neer (κ = 0.51; 0.29-0.68). Inter-observer agreement on 3D-reconstructions was moderate for both Hertel (κ = 0.60; 0.53-0.72) and Neer (κ = 0.51; 0.39-0.58). Intra-observer agreement on plain X-rays was fair for both Hertel (κ = 0.38; 0.27-0.59) and Neer (κ = 0.40; 0.15-0.52). Intra-observer agreement on CT-scans was moderate for both Hertel (κ = 0.50; 0.38-0.66) and Neer (κ = 0.42; 0.35-0.52). Intra-observer agreement on 3D-reconstructions was moderate for Hertel (κ = 0.55; 0.45-0.64) and substantial for Neer (κ = 0.63; 0.48-0.79).

The Hertel and Neer classifications showed a fair to substantial inter- and intra-observer agreement on the three diagnostic modalities used. Although inter-observer agreement was highest for Hertel classification on CT-scans, Neer classification had the highest intra-observer agreement on 3D-reconstructions. Data of this study do not confirm superiority of either classification system for the classification of comminuted proximal humeral fractures.