March 25, 1996
Media Contact: Sarah Goodwin at 404/727-5686, e-mail:

Azaleas are not all Emory orthopaedic surgeon Robert Frederick, M.D., will be planting this spring.

For qualified patients with damaged knee cartilage, he'll be planting within them healthy cartilage cells previously harvested from their own knee and "fertilized" in an enzyme soup.

The procedure is known as autologous chondrocyte transplantation, and Dr. Frederick is one of only a handful of Georgia surgeons - and among the first 100 in the nation to be trained in the technique.

Ideal candidates are between 15 and 50 years of age and have cartilage defects associated with the bottom surface of the thigh bone (femur), says Dr. Frederick, who is assistant professor of orthopaedic surgery at the Emory University 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 - either in isolation or in association with other meniscal or ligamentous injury.


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. Once the appropriate number is achieved, 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 (typically one of the femoral condyles at the base of the thigh bone). The injured area is trimmed to healthy tissue. A thin layer of living tissue (tibial periosteum) 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 transplanted area bathed in knee fluid rich in nutrients.

The patient's progress is checked every few weeks by clinical exam. Eventually the patient is returned to full activities as the cells "grow" and the damaged area "heals." The knee is frequently re-checked postoperatively via arthroscopy to evaluate the cells' progress.


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 in a series of 23 young, adult patients, who either had compromised cartilage in the part of the knee in contact with the thigh bone or knee cap (patella). Results in the femoral condylar transplant patients were impressive: "Two years after transplantation, 14 of the 16 patients had results that were graded either excellent (six patients) or good (in eight)," the authors reported. Results in the patellar transplant patients were less promising: three years after transplantation, two had excellent or good results, three had fair and two had poor outcomes.

"Initially, the transplant eliminated knee locking and reduced pain and swelling in all patients," the authors reported.

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 Chairman of Orthopaedics, Lamar Fleming, M.D., adds a note of caution, "This procedure is still experimental and final results of the technique -- though it looks good -- are not in."

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