The knee joint has many ligaments that contribute to the stability of the knee. The main ligaments are the cruciate ligaments (ACL and PCL) and the collateral ligaments (MCL and LCL). Collateral ligaments are important structures for the stability of the knee. These ligaments may be stretched or tethered and scarred in an arthritic knee as a result of worsening deformity such as knock-knee or bowed legs.
The Anterior Cruciate Ligament (ACL)
The Anterior Cruciate Ligament, or ACL, connects the femur to the tibia. The ACL is commonly injured in contact and non-contact type sports such as football and soccer. An injury will usually be associated with pain in the knee and swelling. Meniscus tears can commonly be found with ACL tears, but can also develop as a result of an ACL-deficient knee. Cartilage injuries will commonly occur at the time of the ACL injury and have been implicated in the development of post-traumatic arthritis in the knee. Many physicians will recommend surgically reconstructing the ACL in an active person that wants to decrease instability in the knee. A surgery may also decrease a person’s chance for developing further cartilage and meniscus damage as a result of persistent knee instability.
Cruciate ligament deficiency may cause one to feel their knee is not stable. It may buckle or give way and cause them to fall. This may be apparent when involved in sporting type activities such as jumping, pivoting or twisting. In severe cases, it may cause symptoms when performing activities of daily living such as walking or climbing stairs. Subsequent instability episodes in the ACL deficient knee have been implicated as risk factors for further cartilage and meniscus damage, which may further increase ones risk of post-traumatic arthritis. This may cause pain and mechanical symptoms such as clicking, catching or locking.