An in vitro study of the Müller anterolateral femorotibial ligament tenodesis in the anterior cruciate ligament deficient knee

Abstract

The biomechanical effectiveness of the Müller antero lateral femorotibial ligament (ALFTL) iliotibial band ten odesis on anterior stability and internal rotational sta bility of the ACL deficient knee was investigated in six cadaver knees. Anterior drawer and internal rotation of the tibia were measured at 15° increments from 0° to 90° in response to 50 N of anteriorly applied tibial force and 3 Nm of internally applied internal torque, respec tively, in the intact knee, the ACL excised knee, and following the ALFTL reconstruction. A strain gage was used to measure the resting graft tension and to meas ure strain in the graft during the load-displacement tests. The Müller ALFTL tenodesis failed to return normal anterior stability to the ACL deficient knee (P < 0.05). The tenodesis did, however, reduce the anterior laxity of the ACL deficient knee from 30° to 90° of knee flexion (P < 0.05). The tenodesis overconstrained inter nal tibial rotation of the ACL excised knee from 30° to 90° (P < 0.05). Measurements of strain in the tenodesis supported the load-displacement findings that the ten odesis was most effective in constraining anterior drawer and internal tibial rotation from 30° to 90° of knee flexion.