Knee Medial Compartment Contact Pressure Increases with Release of the Type I Anterior Intermeniscal Ligament

Abstract

Background The anterior intermeniscal ligament of the knee is at risk during knee arthroscopy, anterior cruciate ligament reconstruction, and tibial nail insertion. Hypothesis Release of the anterior intermeniscal ligament, in knees with type I ligaments, will result in altered contact pressures in the medial compartment. Study Design Controlled laboratory study. Methods Five fresh-frozen human cadaveric knees with intact type I anterior intermeniscal ligaments were chosen for testing in a modified MTS machine from 0° to 60° 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° increments between 0° and 60° of flexion, looking at peak contact pressure and the amount of contact area seeing pressure. Results Sectioning of the anterior intermeniscal ligament caused a statistically significant increase in the peak pressure at 20°, 30°, 40°, and 50° of knee flexion. The largest change occurred at 40° 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. Conclusion Release of the anterior intermeniscal ligament results in increased peak contact pressures in the medial compartment of the knee. Clinical Relevance Care should be taken to avoid sacrifice of this ligament during surgery.