How Three Methods for Fixing a Medial Meniscal Autograft Affect Tibial Contact Mechanics

Abstract

We evaluated three methods for fixing a medial meniscal autograft to determine which method restored tibial contact mechanics closest to normal. The contact mechanics (maximum pressure, mean pressure, contact area, and location of the center of maximum pressure) of the medial tibial articular surface were determined using pressure-sensitive film while knee specimens were loaded in compression to 1000 N at 0°, 15°, 30°, and 45° of flexion. Pressure was measured for the intact knee, the knee after meniscectomy, and the knee with the original meniscus removed and reimplanted as an autograft using three different fixation methods. The contact mechanics of the autograft reinserted with bone plug fixation were closest to normal; however, the maximum pressure was significantly greater than in the intact knee. Adding peripheral sutures neither improved nor worsened the contact mechanics. Fixation with sutures only did not restore normal contact mechanics. We concluded that medial meniscal transplantation requires anatomic fixation of bone plugs attached to the anterior and posterior horns to restore contact mechanics closest to normal. Fixation of the meniscal horns with sutures alone cannot be recommended.