Deformities, gonarthrosis and function after distal femoral fractures.

Sixty-two patients treated for distal femoral fractures from 1969-1976 were re-examined, after a mean follow-up period of 5 years, to study deformities, gonarthrosis and function. These fractures occur mainly in elderly persons with bone fragility due to age and disease. The deformities were analysed from precisely defined radiographic projections. An anatomical classification into supracondylar, unicondylar and bicondylar fractures, with subdivisions for undisplaced and displaced fractures was used. A special group for transcondylar fractures was included. Displaced bicondylar fractures mostly healed with varus and anterior angulation, medial unicondylar fractures with varus and lateral unicondylar fractures with valgus angulation. Most of the healed supracondylar fractures showed varus angulation. Three patients developed arthrosis in both the femoro-tibial and patellar compartments, and eleven only in the patellar area. Intercondylar or transcondylar diastasis, or difference of level in the joint surface exceeding 3 mm, caused a significant degree of gonarthrosis. Function was assessed using the Knee Disability Sheet prepared at the Hospital for Special Surgery. The necessity of radiographic examination of the patellar joint in the axial projection on admission is stressed. Accurate reduction and adequate stabilization of intra-articular fractures seem to be important for reducing the risk of gonarthrosis and later impairment of function.