I have a torn ACL and a small piece of joint cartilage that has come loose but is not detached. The surgeon thinks the cartilage will heal on its own. I keep thinking I should have surgery to repair both problems at the same time. What's the thinking on this kind of knee problem?

Damage to the articular cartilage is fairly common with ACL tears. This is especially true in young, active athletes. Most of the lesions occur on the femoral condyle (bottom knob of the femur or thigh bone). Cartilage doesn't have a very good blood supply so it doesn't heal well. And we don't have very good treatments yet to encourage proper healing.

There are probably more unanswered questions about cartilage injuries than answered questions. The size of the defect doesn't seem to make a difference. According to some studies, the long-term effects are the same in patients with mild versus severe injuries.

The location within the joint articular cartilage doesn't seem to matter either. But even when the lesions occurred on other locations than the femoral condyle, the final results after weren't any different than for patients with femoral lesions.

Differences in knee function as measured by the International Knee Documentation Committee (IKDC) test didn't show up based on location of the chondral lesions. X-rays didn't really show any signs of knee joint degeneration but this may be because of the young age of the patients and the fact that signs of joint degeneration don't appear until there is quite a bit of damage.

The jury is still out on whether or not to routinely repair chondral (cartilage) defects when doing a reconstruction surgery on the anterior cruciate ligament (ACL). There is plenty of evidence to support your surgeon's recommendation. Each patient must be considered individually. A decision is made based on patient age, activity level, and type of injuries. The surgeon can review any pros and cons for your particular case.