In Vivo Kinematic Analysis of Lateral Meniscal Allograft Transplantation With Soft Tissue Fixation

Background: Lateral meniscal deficiency increases the pivot shift in the knee, and although meniscal allograft transplantation (MAT) is a well-established procedure with satisfactory clinical results, biomechanical studies have failed to show whether this procedure is able to restore knee kinematics. Purpose: To assess, in vivo, the kinematic effect of lateral MAT in anterior cruciate ligament–intact knees, with a particular focus on the pivot-shift maneuver. Study Design: Controlled laboratory study. Methods: Enrolled in this study were 10 consecutive patients undergoing lateral MAT. A surgical navigation system was used to acquire and quantify the following variables: anterior-posterior displacement at 30° of flexion (AP30) and 90° of flexion (AP90), varus-valgus rotation at 0° of flexion (VV0) and 30° of flexion, and dynamic laxity on the pivot-shift test, which was determined through anterior displacement of the lateral tibial compartment (APlat) and posterior acceleration of the lateral tibial compartment during tibial reduction (ACC). Data from before and after MAT were compared. Results: From pre- to postoperatively, there was a significant decrease in tibial translation of 2.8 mm (43%; P =.005) for AP30 and 1.9 mm (38%; P =.018) for AP90 as well as a significant difference of 3.6° (64%; P =.001) for VV0. There was also a significant pre- to postoperative reduction in the pivot shift of 7.4 mm (39%; P =.021) for APlat and 302.9 mm/s2 (75%; P =.005) for ACC. Conclusion: Lateral MAT improved knee kinematic parameters at time zero after surgery; the biomechanical effect of MAT was particularly evident during the pivot-shift maneuver.