The distal femur is a reliable guide for tibial plateau fracture reduction: A study of measurements on 3D CT scans in 84 healthy knees

Background: Limited data have been published regarding the typical coronal dimensions of the femur and tibia and how they relate to each other. This can be used to aid in judging optimal operative reduction of tibial plateau fractures. The purpose of the present study was to quantify the width of tibial plateau in relation to the distal femur. Methods: We reviewed 3D computed tomography (CT) scans taken between 2013 and 2016 of 42 patients (84 knees). We measured positions of the lateral tibial condyle with respect to the lateral femoral condyle (dLC) and the medial tibial condyle with respect to the medial femoral condyle (dMC) in the coronal plane. Positions of the articular edges of the lateral and medial tibia were also measured with respect to the femur (dLA and dMA). Results: The mean (± standard deviation) measurements were as follows: dLC, - 0.1 ± 1.9 mm; dMC, - 4.7 ± 4.1 mm; dLA, 0.9 ± 1.0 mm; and dMA, 0.1 ± 1.5 mm. The mean (± standard deviation) ratio of tibial to femoral condylar width was 0.91 ± 0.03, and the ratio of tibial to femoral articular width was 1.01 ± 0.04. Conclusions: The articular width of the tibia laterally and medially was slightly wider than the femoral articular width. These small differences and deviations indicate that the femur might be used as a reference to judge tibial plateau width reduction.