EFFECT OF TIBIAL ROTATION INHIBITION ON ACL INJURY AT DIFFERENT FLEXION ANGLES

This study investigates the damages to the knee joint due to impact load and inhibition of tibia rotation. A rig was manufactured to test fifteen fresh porcine knee specimens replicating single leg landing. Three knee flexion angles (22.5o, 37.5o and 52.5o) were tested. For each angle, 5 specimens were fixed and consecutive displacement control loads with increments of 0.5 mm were applied to tibia until catastrophic failure happened. Anterior cruciate ligament avulsions were found in greater flexion angles but not at low flexion angles. No significant difference was observed in the following parameters in different knee flexion angles; peak compressive force, internal tibia torque, and posterior femoral displacement. Our results also suggest that an optimum tibia rotation may be needed to avoid ACL injury while its inhibition could lead to intrachondral fracture