Emory orthopaedic surgeon Robert Frederick is one of only a handful of Georgia surgeons--and among the first 100 in the nation--to be trained in autologous chondrocyte transplantation, a new treatment for patients with damaged knee cartilage. Developed by a Swedish medical team, the treatment has the potential for postponing or eliminating the need for total joint replacement.
Ideal candidates are between 15 and 50 years of age and have cartilage defects associated with the bottom surface of the thigh bone (femur), according to Frederick, assistant professor of orthopaedic surgery at the School of Medicine and a sports medicine specialist at the Emory Sports Medicine Center. The cartilage surface is typically damaged from trauma to the knee.
The series of procedures begins with the removal, via arthroscopic surgery, of a small amount of healthy cartilage tissue from the involved knee. The cells are then sent to a Genzyme Corp. laboratory in Cambridge, Mass. They are grown in a sterile culture medium for two to three weeks, so the cells can multiply into the millions. The cells are collected in a syringe and returned to the surgeon for transplantation. At the time of transplantation, the knee is opened to provide access to the area of damaged cartilage, and the injured area is trimmed to healthy tissue. A thin layer of living tissue is sewn over the defect, and a water-tight seal is achieved with fibrin glue. The new cells are injected underneath.
The patient is kept from bearing weight on the extremity, and a continuous passive motion machine is used to keep the area bathed in knee fluid rich in nutrients. Eventually the patient is returned to full activities as the damaged area heals.
The technique was first described by a Swedish medical team in the Oct. 6, 1994, issue of the New England Journal of Medicine. The group performed the procedure on 23 young adult patients who had compromised cartilage either in the part of the knee in contact with the thigh bone or knee cap. Results in the femoral condylar (thigh bone) transplant patients were impressive: "Two years after transplantation, 14 of the 16 patients had results that were graded either excellent or good," the authors reported. Results in the patellar (knee cap) transplant patients were less promising: three years after transplantation, two had excellent or good results, three had fair and two had poor outcomes.
According to the authors, about 95,000 total knee replacements and some 41,000 other knee surgeries are performed each year in the United States. "If the treatment of cartilage injuries of the knee at an early stage could prevent the development of osteochondritis (a form of arthritis), the need for a total joint replacement might be postponed or eliminated," the authors said.
Emory's Chair of Orthopaedics, Lamar Fleming, added a note of caution: "This procedure is still experimental and final results of the technique -- though it looks good -- are not in."
-- Lorri Preston