[Etiopathogenetic aspects of medial osteochondrosis dissecans tali]

In a cadaveric biostatic model the pressure distribution at the weightbearing ankle has been investigated under different joint positions and stages of artificial lateral ligament dissection mimicking a supination trauma. The location of the transduced contact area, the size of these areas and amount of pressure were evaluated after application of axial load. The results showed that the location, size of contact area and the maximum transduced pressure were depending on the joint position and stage of ligament dissection. Interestingly the peak pressure was located at the medial talar rim even without lateral ligament dissection. The transduced pressure areas were located at that locations were osteochondral lesions are mostly observed. In regard to these results the etiology and pathogenesis of osteochondritis dissecans tali is discussed. It is thought that supination traumas as well as other biomechanical factors such as overweight and lax ankle ligaments have an important influence on the development of osteochondritis dissecans at least at the medial rim of the talus.