Last year, I sprained my ankle but that wasn’t the worst of it. Evidently, the injury was enough to damage the joint surface of the talus bone. Now I have a hole (the orthopedic surgeon calls it a “defect”) that needs filling. Is this like having a filling put in a tooth? How does it work?

When a joint is injured as a result of a joint sprain or fracture, there can be damage done to the layer of cartilage just above the joint surface. These are called osteochondral or chondral lesions and they occur in up to half of all ankle injuries. Surgical transplantation techniques to fill in the defect (hole or lesion) and repair/restore the cartilage have been developed and improved over the last 10 years.

There are several different way to do this — a few may seem like filling a tooth. For example, autologous osteochondral transplantation is a filling of the defect with a tubular unit of donor hyaline cartilage and bone. Autologus means the plug of donor tissue is taken from the patient (usually the knee). Osteochondral allograft transplantation is another method for filling large defects but uses tissue harvested from a separate donor rather than from the patient (that’s what allograft means).

There is a more complex, two-stage autologous chondrocyte implantation technique available. It involves removing good, healthy chondrocytes (cartilage cells), taking them to the lab and making more chondrocytes, and then reimplanting the cells into the lesion (defect or hole in the cartilage). Again, this is somewhat like filling a hole in a tooth.

Each method of repair has its own advantages and disadvantages. The operative treatment for this problem is carefully selected for each patient in order to provide the best possible results. The surgeon who is treating you will explain which approach is recommended for you and why. You can certainly ask this question at your next appointment to better understand the treatment planned for you.