The cruciate ligaments are the important central 'stays' of the knee joint, contributing significantly to knee stability. Page updated June 2024 by Dr Sheila Strover (Clinical Editor)
The knee joint from the front. The word 'cruciate' means 'crossed', referring to the fact that the two cruciate ligaments cross over one another in the centre of the joint in the area called the 'notch'.
In this illustration, just to help you understand, the bones are distracted and you are looking from the side so that you can see the attachments of both anterior and posterior cruciate ligament.
The posterior cruciate ligament (PCL) attaches to the tibia at the back of the knee and the anterior cruciate ligament (ACL) attaches to the tibia at the front of the knee.
Note in the sketch on the left the dynamic arrangement of the fibres of the ACL when the knee is bent and straightened. This is one of the reasons why ligament replacements do not do as good a job as the original ligament as this cannot be mimicked by the replacement.
Injury to the ACL may occur while cutting and running to that side during a fast non-contact activity like football, or from landing from a twisting jump on that leg while the body still has momentum and continues to twist. Almost invariably, the person is unable to continue with the activity.
In several...."studies, the injury rate in female athletes has ranged from two to six times the rate in male athletes..."
"Injuries to the anterior cruciate ligament (ACL) of the knee are immediately disabling, take a significant amount of time to rehabilitate, are often associated with other[/no-lexiocn] concomitant articular injuries, and result in an increased risk of early onset posttraumatic osteoarthritis..."
Rarely an ACL tear will heal on its own, if the knee is braced and activities limited. Usually, however, patients will elect for reconstructive surgery - or repair surgery in the case of children.
Reconstruction utilises tendon material for replacing the torn ligament, while repair is usually a matter of pulling an avulsed ligament back into contact with its bone attachment and holding it there until healing takes place.
"....Patients with an ACL tear should be advised that surgical repair is not the only option for continuing sporting activities; a conservative approach consisting of a strict and vigorous rehabilitation plan can suffice.....The principal purpose of surgery is to enhance knee stability...."
"....Whatever therapy they choose....the risk of future knee lesions and osteoarthritis remains substantial, especially if they return to high-risk pivoting activities...."