Collagen organization in the crural interosseous membrane and its relationship to fibular osteotomy.

The organization of collagen fibres in the crural interosseous membrane was measured using X-ray diffraction. The fibres were found to be highly aligned and steeply angled in a distal direction from tibia to fibula with a mean angle of 13 degrees. This organization will lead to a very stiff, ligament-like structure which will transmit forces to the tibia generated by the muscles attached to the fibula. It also suggests an optimum site for a fibular osteotomy about 4 cm distal to the tibial fracture site.