A proposed classification of supracondylar femur fractures above total knee arthroplasties.

A new classification system is proposed for supracondylar femur fractures above total knee arthroplasties based on fracture location relative to the femoral component. Radiographs of 28 cases were evaluated and classified according to the proposed system by 12 physicians: 3 trauma specialists, 3 adult reconstruction specialists, 3 musculoskeletal radiologists, and 3 orthopaedic residents. The same 12 physicians reevaluated the same 28 cases 3 months later. The mean reliability coefficient for all observers was 0.74 (substantial agreement). The coefficient for reproducibility after 3 months was 0.85 (almost perfect). The power of the study was 80%. The proposed classification system is easy to use and has good interobserver reliability among orthopaedic residents, orthopaedic attendings--trauma and reconstruction--and radiologists. Intraobserver reliability was also excellent at 3 months.