Clinical trial extended for S.T.A.R. ankle replacement

Friday, March 28, 2003

JACKSONVILLE, Fla. — The Food and Drug Administration (FDA) has extended clinical trials of the Scandinavian Total Ankle Replacement (STAR) device. A total of 150 more patients may be enrolled at nine U.S. centers including Mayo Clinic in Jacksonville. Dr. James DeOrio, an orthopedic surgeon at Mayo Clinic, has performed 70 total ankle replacements with the STAR device since the clinical trial began in 2000. He can perform 30 more under the FDA trial. STAR is approved in Europe and has been used there for more than 10 years.

The STAR design uses a unique three-piece system. One piece of metal fits into the tibia, the thicker of the two bones in the lower leg. Another metal piece fits into the talus bone of the ankle. A piece of polyethylene plastic floats between the two metal pieces. "Because of its non-constrained design, there's little if any friction, which means less probability of the polyethylene liner wearing out," DeOrio says. "In the European studies there was no deterioration of the results after seven and eight years. Patients who did well, continued to do well," he says.

Ankle replacement surgery has been performed as an alternative to ankle fusion for about 30 years. Early results were disappointing, but durability of the replacement joint has greatly improved with newer implant designs.

Injury and arthritis can destroy the cartilage that cushions the bones that make up the ankle joint. When the resulting pain can no longer be managed with conservative measures such as medication or braces, patients turn to surgery. "You really only have two choices once you say, 'I've got to get something done,'" says DeOrio. "That's fusion or replacement." Ankle replacements leave the patient with a degree of up and down motion in their ankle and a more normal gait, things sacrificed with an ankle fusion.

Donald Nichols played sports all his life. The 75-year-old pastor first injured his right ankle playing basketball in high school. He played competitive softball until he was 58 when overuse injuries and arthritis started taking a toll. Nagging pain sidelined Nichols altogether in his early 70s. "My doctor told me that within three years I wouldn't be able to play golf and said in three years I wouldn't be able to drive," Nichols says.

He heard about ankle replacement and came to Mayo Clinic to see if it was an option for him. "Dr. DeOrio spoke to me and said you can leave it the way it is, have it fused or have the STAR. I said, 'If the STAR doesn't work, can we still do fusion?' And he said yes. So I said, 'Well, let's go with STAR.'" That was two years ago. Nichols says three months after his surgery he was playing a few holes of golf and dancing at his daughter's wedding. Today he works out and plays golf twice a week. "It gave me new life," he says. "It really has. I feel very, very blessed."

DeOrio says those who benefit the most from replacement over fusion have an opposite bad ankle or arthritis in any other portion of their foot or knee. This is because a more normal gait reduces the stress on adjacent and opposing joints. "Patients who have had previous fusions below the ankle are especially good candidates," he says, "because if they've already had everything fused below the ankle, and then have the ankle fused, they're really left with a peg leg. So retaining that motion becomes especially important for patients who've had other injuries, arthritis or fusions in the areas below the ankle."

Patients with bone infections, dead bone or severe malalignment of the ankle joint are not candidates for STAR.

The surgical procedure takes about an hour and a half and can be done under general or spinal anesthesia. Recovery time generally takes between two and three months and includes crutches and immobilization of the ankle.

Medicare and some insurance companies cover the procedure. Those interested may call (904) 953-2075 for more information about the STAR trial.

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