Biomechanical Analysis of Knee Cartilage Stress for Individuals With Anterior Cruciate Ligament Reconstruction

Every year, approximately 80,000 to 150,000 ACL tears occur.[1,2] Post-injury, ACL reconstruction (ACLR) is often recommended to restore functional stability and prevent long-term joint degradation. However, while surgical techniques have improved, individuals with ACLR have been shown to have a higher risk of developing osteoarthritis (OA) and a higher rate of re-injury.[3] The higher incidence and earlier onset of knee OA in individuals who have undergone ACLR may be a result of a post-injury movement strategy that utilizes a higher degree of muscle co-contraction of the hamstrings and the quadriceps muscles during landing to increase joint stability.[4] This increased co-contraction leads to a “stiff” landing pattern, decreases shock absorption, and increases the ground reaction forces. These changes in lower extremity biomechanics also may result in higher forces which likely place the knee cartilage under greater stress and higher risk of OA development and re-injury.