Q: I had a procedure called a mosaicplasty to plug a hole in my knee cartilage. I'm not sure it really worked. It's been six months and I still have pain and swelling in that knee -- enough to interfere with my ability to walk, run, and hike. The surgeon who did the procedure has suggested an arthroscopic exam for what she calls a second look. I'm undecided -- is there really any value in this?

A: Mosaicplasty is a procedure that involves harvesting plugs of cartilage and bone from one part of the knee joint and transferring it to another. The donor plugs are used to fill in holes and defects that go all the way down to the bone.

The donor tissue is taken from an area that has relatively little weight-bearing and moved to the defect (usually the defect is in a weight-bearing zone). Sometimes only one donor graft is needed but some patients need more than that for larger defects.

Mosaicplasty can help save the joint and protect it from further wear and tear around the defect site. But biomechanics of joint movement that are off or uneven in any way (and not repaired before mosaicplasty) can contribute to uneven forces or load on the joint. Joint degeneration is the result of overuse and uneven weight bearing.

Symptoms of continued pain and swelling may be an indication that the knee alignment is still not balanced. On the other hand, even in high-demand athletes, problems that occur (e.g., pain with weight-bearing) are temporary and seem to go away within the first six weeks up to one year.

You may be someone who will see gradual improvement over time. But a second look through an arthroscopic exam might reveal something that needs attention now before the problem contributes to further degeneration of the joint.

There could be a new injury that wasn't present at the time of the first surgery. Bleeding into the joint, infection, or stiffness of the healing tissue are other potential reasons for ongoing symptoms. If these have not gone away as expected, then it might be time to take a second look in order to formulate the best plan of care for you.

Reference: László Hangody, MD, PhD, et al. Clinical Experiences with Autologous Osteochondral Mosaicplasty in an Athletic Population. In The American Journal of Sports Medicine. June 2010. Vol. 38. No. 6. Pp. 1125-1133.