Sometimes surgery to reconstruct the anterior cruciate ligament (ACL) fails. Another surgery, called revision knee surgery, may be needed. Because this is rare, doctors haven’t decided the best way to approach a second or third surgery to repair the ACL.
Two orthopedic doctors kept track of failed ACL repairs, which numbered 11 out of 2,264 cases. The 11 patients with failed surgeries had each had at least two ACL repairs. Each repair was done using a piece of tendon at the knee called the patellar tendon. This piece of tissue was taken from the patient’s own knee and used in place of the torn ACL.
When operating for the third time, the doctors faced a difficult decision. Could they take more tissue from the patellar tendon? They had already taken tendon and a small piece of bone from both knees. Would the “recycled” tissue hold up? Could patients afford to lose more patellar tendon tissue? Would the injured knee be restored to its full strength and stability? What about the muscle that attaches to the patellar tendon (the quadriceps)? Would the quadriceps on the donor leg regain its normal strength?
The doctors rolled up their sleeves and got to work. They collected information over a 10-year period. They read every report that came out on this subject and compared results. They put together two separate rehabilitation programs: one for patients who had grafts retaken (reharvested) from the ACL-injured knee, and one for patients with grafts taken from the uninjured knee.
As part of the testing before surgery, MRI (magnetic resonance imaging) was used to look at the donor tissue. Each patellar tendon was examined carefully. This made it possible to use the healthiest part of the patellar tendon.
The results of this study showed that reharvesting donor tissue from the injured knee is not as good as taking normal tissue from the uninjured knee. There were more complications and less use of the knee joint with reharvested tissue from the injured knee.
Sometimes surgery is needed to revise a previous ACL surgery. When this occurs, an MRI scan of the opposite knee can be used to find healthy donor tissue. Doctors can take a portion of the patellar tendon from the uninjured knee and use it in place of the torn ACL. This results in a strong and stable knee with normal muscle strength in both legs.