Defining the "mediolateral widening of tibial plateau" as a guide for reduction in tibial plateau fractures: An Indian perspective.

Purpose: The primary aim in fixation of the tibial plateau fractures is the restoration of normal anatomy. Evaluation of the widening of the tibial plateau, which has been linked with adverse long term outcomes, still needs precise markers for quantification. The purpose of this study is to analyze the normal limits of tibial plateau widening in the Indian population in relation to the distal femur in a standardized manner to provide important radiological parameters for the same.

Methods: We retrospectively analyzed electronically archived true AP radiographs of uninjured normal knee joints during one year between 2018 and 2019. We measured the mediolateral width of the articular surface and extraarticular extent of the tibial plateau and compared them with the distal femoral articular and extra-articular extents. The measurements were compared between the male and female groups.

Results: Tibial plateau articular width was found to be 4% wider in relation to the distal femoral articular surface. The medial articular rim of distal femur matches closely to the medial articular rim of the tibial plateau. The lateral articular rim of distal femur lies medial to the lateral articular rim of tibial plateau with a mean distance of 3.49 mm.

Conclusions: Owing to individual variations in bony extents around the knee, the differential extent of tibial plateau relative to distal femur would be a more reliable parameter than absolute measurements. Medially the articular extent of distal femur matches closely with the articular extent of tibial plateau while the lateral extra-articular extent of distal femur matches closely with the lateral tibial articular extent. Gender-based differences do not significantly affect these two parameters.