Anterior horn lateral meniscus tear, repair, and meniscectomy.

The purpose of this study was to describe the effect of anterior horn of the lateral meniscus (AHLM) tears on tibiofemoral contact pressures and the ability to restore normal parameters with repair. Eight fresh-frozen cadaveric knees were used. The specimens were subjected to a load of 1,000 N at 0 and 30 degrees of flexion and peak pressure, force and contact area were recorded. The test was repeated for four different instances. Peak force in the lateral compartment was significantly increased at 0 degrees of knee flexion from 37 N intact to 47 N after the tear and 56 N postmeniscectomy. At 0 degrees of knee flexion, the peak pressure of the lateral meniscus was significantly increased from 1.1 MPa in the intact state to 1.9 MPa after meniscectomy. The peak pressure in the nontraumatized medial compartment was significantly increased after partial lateral meniscectomy (p < 0.05). This cadaveric study demonstrated a significant increase in tibiofemoral peak forces in both the medial and lateral compartments with a tear of the AHLM. It also showed an increase in peak contact pressure after meniscectomy. With repair, the preinjury condition peak forces were restored to normal, suggesting the importance of repairing tears of the AHLM.