The Pauwels classification for intracapsular hip fractures: is it reliable?

The Pauwels classification for the femoral neck fracture is still broadly used in literature and clinical practise. However, this classification has never been tested for its reliability in terms of inter-observer agreement. We assessed whether or not it is reliable to use the Pauwels classification in pre-operative planning. Ten observers classified 100 intra-capsular femur fractures. The inter-observer agreement was calculated using the multi-rater Fleiss' kappa. The Pauwels classification showed an inter-observer agreement of κ0.31 (0.01). Classification of intra-capsular hip fractures according to the Pauwels classification using the Pauwels angle is unreliable and its use should be avoided.