The effects of tibial malrotation on the biomechanics of the tibiotalar joint.

The effects of tibial malrotation on the biomechanics of the tibiotalar joint were studied using a cadaveric model loaded in an Instron 8521 materials testing device and a TEKScan I-Scan thin-film resistive ink pressure measuring system. Testing of 23 legs was performed using rotational conditions of 10 and 20 degrees internal and external rotation as well as neutral rotation. All rotational conditions were found to decrease joint contact area. Peak pressures were significantly greater with 20 degrees internal rotation as well as 20 degrees external rotation. Total load across the joint was significantly lower for both 10 and 20 degrees of external rotation. In conclusion, rotational deformity across the tibiotalar joint results in significant alteration of overall joint biomechanics and should be minimized whenever possible.