Effects of tibial malalignment on the knee and ankle.

It is widely believed that excessive angulation of the tibia may predispose the ankle and knee to osteoarthritic degeneration. There is no general agreement, however, regarding the acceptable limits of angulation. The authors used cadaver models to measure the contact areas for the cartilage in the ankle, as well as the contact areas and pressures for the cartilage in the knee, as a function of the level and magnitude of simulated angular deformities of the tibia. The quantitative relationships between fracture angulation and joint contract conditions developed in these experiments may help in the formation of more specific guidelines for the treatment of tibial fractures.