Intracapsular neck of femur fractures secondary to civilian gunshot injuries: an inter- and intra-observer agreement study on classification and treatment using the AO/OTA classification

Numerous classification systems have been developed for neck of femur fractures, but none have been tested for reliability in gunshot injuries. Our primary objective was to assess the inter-observer and intra-observer reliability of the AO/OTA classification system when applied to intracapsular neck of femur fractures secondary to low-velocity civilian gunshots wounds (GSWs). Our secondary objective was to test the reliability of the AO/OTA classification system in guiding surgeon treatment choices for these fractures.

Eighteen reviewers (six orthopaedic traumatologists, six general orthopaedic surgeons and six junior orthopaedic fellows) were given a set of 25 plain radiographs and CT scans of femur neck fractures secondary to GSW. For each clinical case, all reviewers selected a classification as well as treatment option from a list of given options. Inter-observer reliability was measured at the initial classification. The exercise was repeated 10–12 weeks later by the same 18 reviewers to test intra-observer reliability.

The Fleiss kappa values indicate only slight agreement amongst raters, across all experience levels, for both injury classification and treatment. Intra-observer agreement was fair across all experience levels for both injury classification and treatment.

The AO/OTA classification showed only slight reliability in classification of gunshot fractures of the femur neck. With only fair reliability, it also failed to guide surgical treatment thus rendering its routine use in daily clinical practice of questionable value.