The good news is that torn ligaments in the knee can be surgically repaired. The bad news is that sometimes these repairs fail. In the case of the anterior cruciate ligament (ACL) of the knee, a piece of tendon is usually taken from another part of the knee and grafted in place. If the graft doesn’t take, or if it gets torn, another operation is needed.
Many studies have shown that the ACL doesn’t heal well by itself. This is especially true when it has been completely ruptured in an accident or injury. There are many possible reasons for this poor healing response. The ACL doesn’t have a strong blood supply, and the cells that make up this ligament don’t have a good repair process.
But what happens when a tendon is grafted in place of the torn ligament, and then the tendon gets torn? Can it repair itself? One case report suggests this may be possible. A 19-year-old woman with a torn ACL from a soccer injury had a tendon graft repair. Four years after the repair, she injured her knee again while playing soccer.
After the second injury, doctors couldn’t find signs of an unstable knee. However, an MRI showed that the graft was ruptured. Surgery to repair the graft injury was planned but was delayed for seven weeks. When the doctor looked inside the joint during surgery, the graft had healed itself. The knee was stable, and the woman returned to sports after a brief rehab program.
This case is important because it points out that this kind of healing is possible. Finding out what conditions and factors support healing is the next step. Graft rupture with only a small amount of knee instability should be observed for a time before the next operation. Healing may take place without another surgery.