How is an osteochondral allograft (OCA) transplant performed?
Osteochondral allograft transplant is a relatively simple procedure that is done on an outpatient basis. Light sedation and regional anesthesia is used for this surgery. Because Dr. Williams is replacing large areas of cartilage, osteochondral allograft transplantation requires the use of a small incision just adjacent to the patella tendon. Most implanted allografts are cylindrical and are called dowel grafts; the top of the graft is cartilage and the bottom in bone. After Dr. Williams makes the incision, he measures the defect. He prepares the damaged cartilage area in preparation for allograft implantation. The sterile allograft is sized to fit perfectly over the damaged section that was prepared. Most graft are placed as a “press fit”; screws or pins are not typically needed to stabilize these grafts. Graft stability is ensured by bony ingrowth into the base of the implanted graft. Long term graft survival is maintained by the live cells that reside within the cartilage of the donated graft.
Patients use crutches for one week, and then are allowed to full-weight bear. A small brace is used early during the rehabilitation process; bracing discontinued after approximately 3 weeks. Physical therapy starts one week after surgery and continues for about 3 months following the procedure.