Knee medial compartment contact pressure increases with release of the type I anterior intermeniscal ligament.

Abstract

The anterior intermeniscal ligament of the knee is at risk during knee arthroscopy, anterior cruciate ligament reconstruction, and tibial nail insertion. Release of the anterior intermeniscal ligament, in knees with type I ligaments, will result in altered contact pressures in the medial compartment. Controlled laboratory study. Five fresh-frozen human cadaveric knees with intact type I anterior intermeniscal ligaments were chosen for testing in a modified MTS machine from 0 degrees to 60 degrees of flexion under 2 conditions: (1) intact and (2) after sharp sectioning of the anterior intermeniscal ligament. Measurements were made using inframeniscal contact pressure sensors covering the medial compartment. Poststudy analysis was done in 10 degrees increments between 0 degrees and 60 degrees of flexion, looking at peak contact pressure and the amount of contact area seeing pressure. Sectioning of the anterior intermeniscal ligament caused a statistically significant increase in the peak pressure at 20 degrees , 30 degrees , 40 degrees , and 50 degrees of knee flexion. The largest change occurred at 40 degrees of knee flexion, when the peak pressure increased by 27.5% (3.68 MPa to 4.69 MPa). Contact area decreased, although this difference was not statistically significant. Release of the anterior intermeniscal ligament results in increased peak contact pressures in the medial compartment of the knee. Care should be taken to avoid sacrifice of this ligament during surgery.