Q: When I was in my 20s, I tore up my anterior cruciate ligament pretty bad. After surgery, I ended up with a wide, wrinkly, ugly scar that measures eight inches long. I'm almost 40 now and I recently saw my son's friend's knee. He had an ACL repair last year. You wouldn't believe the two tiny, thin scars he ended up with. How are they doing this surgery now anyway?

A: Anterior cruciate ligament injuries can be repaired, but more often are reconstructed. In a repair procedure, the torn ligament is stitched back together and reattached inside the joint. Reconstruction involves removing the old, damaged ligament, harvesting some tendon tissue from someplace else, and using it to replace the ruptured ligament.

There are two common reconstructive procedures used today. In both, the surgeon removes a portion of the patient's own tendon tissue to use in replacing and rebuilding an ACL replacement. Donor tissue may come from the patellar tendon or from the hamstrings tendon. In the case of the patellar tendon graft, the donor tissue comes from the front of the knee where the quadriceps muscle inserts into the bone just under the kneecap at the tendon-bone interface (that's where the tendon inserts into the bone). For patients having a hamstring graft procedure, tendon tissue is taken from the hamstring muscle behind the thigh.

The surgery can be done arthroscopically as an arthroscopically-assisted minimally invasive procedure. That means the surgeon only needs a small incision to enter the joint. New surgical tools allow the surgeon to see inside the joint without making a large incision like you had. With less disruption of the tissue, wound healing is faster and cleaner. The result is the kind of scars you observed in your son's friend's knee.

But even with today's more modern techniques, there are some patients who end up with a less than cosmetically pleasing scar. Infection can delay healing and create more scar tissue than hoped for. And some people have the type of tissue that forms extra scar (fibrosis) creating a wider, thicker scar. Most, but not all, patients can expect the kind of result your young friend ended up with.

Reference:

David Jean Biau, MD, et al. Patellar Tendon Versus Hamstring Tendon Autografts for Reconstructing the Anterior Cruciate Ligament. In The American Journal of Sports Medicine. December 2009. Vol. 37. No. 12. Pp. 2470-2478.