ABSTRACT
Anterior cruciate ligament (ACL) deficiency is a common clinical injury that seriously affects the function of the knee. Although ACL reconstruction (ACLR) can rebuild the structure of the ACL, it does not restore the normal kinematics and dynamics of the knee. In recent years, motion analysis has been widely applied in sports science and rehabilitation. In clinics, motion analysis is mainly applied to the evaluation of clinical outcomes of the ACLR knee. It is also a scientific objective tool to assess the potential risk factors of secondary injury and early onset of osteoarthritis after ACLR. In-depth understanding of the knee functional kinematics and kinetics after ACLR will significantly improve the efficacy of current ACL deficiency treatment and rehabilitation regime. This paper reviewed studies of the knee joint motion analysis after ACLR in the past decade. The current knowledge of the ACLR knee motion from studies using optical motion capture and biplanar fluoroscopic imaging system based tracking technique was synthesized. Clinical studies have reported that regardless of the type of graft and surgical technique of the ACLR, the postoperative knee still exhibits abnormal kinematics in functional tasks, but the relationship between early-onset OA and the biomechanical changes in the ACLR knee remains unknown. Restoring the rotational stability of the knee is still one of the biggest challenges in clinical ACLR surgery. Future studies should explore the impact of ACLR on the biomechanical mechanisms of the knee joint through an appropriate research design and long-term follow-up, and help clinicians and physiotherapists to develop more effective interventions.