Kinematics of healthy and meniscal repaired knees

Differences have been reported between in vitro and in vivo meniscal kinematics, and no clinical study to date has investigated the effect of meniscal repair on meniscal kinematics. Eleven subjects with healthy knees and eight subjects who had undergone meniscal repair for an isolated tear were scanned using magnetic resonance imaging. Sagittal plane scanning was performed at 0, 30, 60, 90, and 120 degrees of knee flexion. The mean composite lateral meniscus movements for the normal and meniscal-repaired subjects were 6.85 mm and 6.01 mm, respectively. The mean composite medial meniscus movement for the normal and meniscal repaired subjects were 8.22 mm and 5.91 mm, respectively. Anterior horn movements of the lateral and medial meniscus of normal subjects were 7.5 and 8.9 mm, respectively. The posterior horns of the lateral meniscus and medial meniscus displaced 6.2 mm and 7.6 mm, respectively. In comparing meniscal-repair subjects to the subjects with healthy knees, the lateral meniscus displaced approximately 6 mm for both groups. However, the medial meniscus moved 8.2 mm for the normal subjects and only 5.91 mm for the meniscal repair subjects. Posterior horn movement of the medial meniscus was determined to be reduced following meniscal repair.