Surgery

In December of 2005, I saw a second orthopedic surgeon, an expert in cartilage repair. He went over my history and the report of my original arthroscopy. He did some xrays which showed a mild degree of malalignment in my left knee, which he felt was the reason for the excess wear on the articular cartilage.

There are two commonly done techniques for repairing articular cartilage defects. One is OATS - osteochondral autologous transfer surgery. In this technique, a plug of bone with overlying cartilage is taken from a healthy, non-weight bearing part of the knee & implanted in the damaged area. Kind of like a patching a bare spot on the lawn. The second technique is ACI - autologous chondrocyte implantation. In this 2 stage process, a small biopsy of health cartilage is taken from the knee arthroscopically. New cells are then grown in the lab (by Genzyme). This takes several weeks. The surgeon then opens the knee up and debrides away the damaged carilage. The then covers the hole with a patch (made from shin periosteum in my case - the fibous tissue that covers bones), and then injects the cartilage cells under the patch. Then - hopefully - the cells settle in and form healthy new cartilage, a process that takes 12 to 18 months.

The doctor told me I wasn't a good candidate for OATS because I had too large an area of damage, and he was concerned the patella might also need work, and OATS isn't done on the patella. He also told me I would need a concurrent TTO - tibial tubercle osteotomy. This is a procedure where the attachement point of the patellar tendon below the knee is moved to improve alignment of the patella into the trochlear groove. He told me he thought it was about 85% likely that I would be better after surgery, 10% I would not really be different, and 5% I would be worse. He told me to give this some thought & let him know what I decided.