ANTEROLATERAL LIGAMENT COULD IMPACT FUTURE ACL TREATMENTS

Recently, two Belgian orthopedic surgeons, Dr. Steven Claes and Dr. Johan Bellemans, published a paper describing the location and function of a previously unknown body part: the anterolateral ligament (ALL). The structure is located on the outside of the knee, and attaches the femur (thighbone) to the tibia (shinbone). Though other doctors have seen the structure during surgery and dissections dating back to the late nineteenth century in Paris, most scientists and doctors thought the ALL was a continuation of the iliotibial band, not its own unique structure. It was not until Bellemans and Claes that doctors have been able to isolate this ligament and study its role in providing stability to the knee.

The discovery could impact orthopedic surgeons all over the world in regards to treating ACL reconstructions. Like most surgeries, ACL reconstruction is not 100% successful. About 85-90% of patients get back to doing all desired activities and are happy with their knee. However, the other 10-15% of people experience continued instability and weakness. Dr. Claes and Dr. Bellemans were perplexed about why this percentage of patients has continued instability despite a mechanically successful ACL reconstruction. They hypothesized that there must be another structure at work that provides additional stability to the knee. Using 41 donated cadaver knees, the surgeons used delicate dissection techniques and identified the suspected structure which they called the anterolateral ligament due to is location on the outside, front part of the knee. Claes and Bellemans have hypothesized that since this ligament provides the same stability as the ACL—preventing the knee from twisting too much—it could tear simultaneously with the ACL. Thus, when the ACL is fixed some patients still experience lingering instability because this additional stabilizing ligament is ruptured.Many more studies will be needed before doctors can answer treatment questions related to a torn ALL. Not enough is known yet about the ligament’s ability to heal, or how it should be reconstructed for stability. It is the hope that future studies will be able to help the 10-15% of ACL reconstruction patients who suffer from knee problems after surgery.

Many more studies will be needed before doctors can answer treatment questions related to a torn ALL. Not enough is known yet about the ligament’s ability to heal, or how it should be reconstructed for stability. It is the hope that future studies will be able to help the 10-15% of ACL reconstruction patients who suffer from knee problems after surgery.