Tibiofemoral Contact Mechanics with Horizontal CleavageTears and Resection of the Lateral Meniscus in the Human Knee

OBJECTIVES: Knee menisci are known to increase contact area, reduce contact pressure and absorb shocks. Meniscectomy is considered likely to lead to arthritic changes to the knee. The effects of a horizontal cleavage meniscus tear, repair and meniscectomy are still not clear for the lateral meniscus. The purpose of this study was to explore the impact of these conditions on tibiofemoral contact mechanics. METHODS: Eleven fresh frozen human cadaveric knees were used in this study. Testing conditions included the intact meniscus, horizontal cleavage tear, inferior leaf resection and resection of both inferior and superior leaves of the lateral meniscus. The test was performed at 0° and 60° of knee flexion under 800 N axial loading force. Tekscan(®) pressure sensors were used to measure the tibiofemoral contact area and pressure. RESULTS: Horizontal cleavage tears and subsequent repair of the lateral meniscus resulted in no significant changes in contact area and peak contact pressure compared to the intact condition. Resection of the inferior leaf resulted in a significant drop in contact area (34.6 ± 14.1% at 0° and 23.9%[Office1] ±14.8% at 60° knee flexion; p < 0.05). Peak contact pressure after resection of the inferior leaf significantly increased by 27.0 ± 22.1%at 0° and 37.9 ±33.6% at 60° knee flexion (p<0.05). Additional resection of the superior leaf resulted in a further decrease in contact area (49.5 ±7.2% at 0° and 47.9± 16.7% at 60° knee flexion compared to the intact condition; p < 0.05). Peak contact pressure increased correspondingly (by 38.6% ± 24.3 at 0° and 55.5 ±34.7%at 60° knee flexion compared to intact; p < 0.05). CONCLUSION: Resection of the inferior leaf or resection of both leaves of the lateral meniscus after horizontal cleavage tear resulted in decreased contact area and increased peak contact pressure at both knee flexion and extension.