ABSTRACT
Objective To identify the differences of three-dimensional knee kinematics of unilateral anterior cruciate ligament (ACL) deficient patients with and without the meniscus injury.Methods A total of 39 subjects including unilateral isolate ACL-deficient patients (ACL group,n=13),ACL deficient patients combined with meniscus tear (ACL+M group,n=13) and healthy controls (C group,n=13) participated in this study.In the gait analysis,three-dimensional knee kinematic and kinetic parameters were collected synchronously and compared.Results The peak knee flexion angles were greater in the ACL+M group and C group compared with the ACL group (P=0.001,P=0.001),with no significant differences between the former two groups (P=0.847).Lower first peak vertical ground reaction force,peak posterior ground reaction force,sagittal plane knee excursions and peak knee extension moment were found in ACL-injured side compared with the contralateral side (P=0.001,P＜0.001,P=0.006,P=0.001).Greater peak knee abduction moment was found in group ACL+M compared with both the ACL and C groups (P=0.045,P=0.014).However,no significant difference was observed between the ACL group and C group in peak knee abduction moment (P=0.616).Conclusions The altered loading in unilateral ACL deficient patients can lead to lower ground reaction force in injured knee and greater ground reaction force in the contralateral side,which may increase the risk of developing knee osteoarthritis.The greater internal knee abduction moment in ACL deficient patients combined with meniscus injury may be a risking factor for the knee osteoarthritis.