Abstract

The purpose of this study was to advance prior techniques and studies regarding the effects of fibular and talar displacement of contact areas of the tibio-talar joint. Type IV supination external rotation injuries were experimentally created on five fresh cadaveric specimens. Tibio-talar contact and peak pressures were measured using Fuji pressure-sensitive film with the talus in a neutral position and then displaced 1, 3, 4, 5, and 8 mm laterally as well as a repeat measurement following reduction and plate fixation. Results demonstrated a 50% reduction in contact area with only 1 mm of talar displacement along with a linear increase in average peak pressures. Reapproximation of the fibular osteotomy with a plate and rereduction of the talus allowed for return to normal pretesting contact areas. This study confirms prior studies demonstrating the significance of 1 mm of talar displacement in regards to marked reduction in contact area of the tibio-talar joints. In addition, restoration of the normal anatomy and fixation of the osteotomy allows for return of normal contact areas.