Characteristics of anterior tibial translation with active and isokinetic knee extension exercise before and after ACL reconstruction

Abstract

The aim of this study was to investigate the biomechanical characteristics of anterior tibial translation (ATT) in anterior cruciate ligament (ACL)-deficient or -reconstructed knees with active and isokinetic knee extension exercise. Forty-nine patients with unilateral isolated ACL-deficient knees were enrolled. Follow-up examinations were carried out at a mean of 24 months postoperatively. An electrogoniometer system was applied to compare the amount of ATT in ACL-deficient and -reconstructed knees. For both active and isokinetic knee extension, the mean ATT of ACLdeficient knees was considerably greater than that for the normal side, within a range of flexion 0°–70° and 0°–60°, respectively. In contrast, no mean ATT differences were seen during both active and isokinetic exercise from 90° to 0° at follow-up. Within a range of flexion between 50° and 70°, the side-to-side difference in ATT with active knee extension was significantly greater than that with isokinetic extension in ACL-reconstructed knees. These results suggest that the amount of ATT is significantly improved with both active and isokinetic exercise, postoperatively. However, postoperative ATT with isokinetic extension is smaller than that with active knee extension from 50° to 70°.