What causes ACL tears? What are the symptoms?
One of the most common knee injuries is an anterior cruciate ligament (ACL) tear. Athletes who participate in sports like soccer, football and basketball are most at risk for tearing his or her ACL.
The ACL runs diagonally in the middle of the knee, providing rotational stability to the knee and prevents the tibia or shinbone from sliding out in front of the femur or thighbone.
ACL tears are most commonly caused by a rapid change in direction. For example, when an athlete stops suddenly, lands awkwardly from a jump or slows down while running. These injuries most commonly do not involve direct contact; however, can be caused by a direct blow.
There are a few symptoms associated with an ACL tear. “At the time of injury, an athlete may feel and hear a ‘pop’ in the knee,” said Dr. Corey Kendall, a sports medicine surgeon at OrthoIndy West. “The injured player is generally unable to complete the game. Frequently, there is significant swelling and stiffness after the injury and usually a feeling of instability.”
If an ACL injury is suspected, the individual should consult with an orthopaedic surgeon immediately. “If an ACL tear is suspected, a careful history of the injury will be taken along with a physical exam,” said Dr. Kendall. “The orthopaedic surgeon will conduct a few tests to determine the stability of the ACL and X-ray’s will usually be obtained to ensure there is no fracture. An MRI is also typically sought in order to conﬁrm the diagnosis, as well as to evaluate for other ligament injuries or meniscal tears.”
After the individual has been diagnosed with an ACL tear, the ﬁrst decision to be made is whether or not to “ﬁx” or reconstruct the ACL. The ACL, unfortunately, will not heal itself. Less active, typically older patients may be able to modify their activity so that their knee functions adequately. Athletes and active patients will generally require surgery.
“The procedure itself involves replacing the torn ligament with a tissue graft. This graft can be obtained from the patient or a cadaver (allograft). Grafts can be harvested from the patellar tendon, hamstrings or quad tendons. Each approach has individual advantages and disadvantages. The surgeon will choose the approach based on the patient, their activity level and their expectations for returning to their sport.”
After surgery, the length of recovery depends on the type of graft used, response of the patient to therapy and the speciﬁc sport. This typically takes at least five to six months. Generally, athletes do not feel “back to normal” athletically for up to a year.