Anterior cruciate ligament reconstruction does not fully restore normal 3D knee kinematics at 12 months during walking and walk-pivoting: A longitudinal gait analysis study

The purpose of the current study was to longitudinally evaluate how preoperative knee kinematics change after ACL reconstruction. Three-dimensional gait analysis using the point cluster method was undertaken on the same subjects preoperatively and at 3, 6, and 12 months after ACL reconstructive surgery. Thirteen subjects (7 males, 6 females) were examined while performing 2 different activities at self-selected speeds: walking and walk-pivoting (walking, pivoting toward the landed limb side and walking away). The contralateral knees of subjects at 12 months postoperatively were selected as control knees. Flexion range in the stance phase increased with time after surgery, but remained lower than in the contralateral knee, even at 12 months postoperatively (P < .05) during walking and walk-pivoting. The rotation pattern during walking and walk-pivoting showed an offset toward external rotation by 6 months postoperatively compared with control knees, while at 12 months postoperatively the offset had nearly disappeared and the movement pattern resembled that in control knees. These findings suggest that a return to sport participation by 6 months after ACL reconstruction requires careful consideration. Depending on the type of sport, activity restriction even after 12 months may need to be considered to allow complete kinematic restoration.