University Of Florida Orthopaedic Surgeons Test First Implant For Certain Knee Injuries

GAINESVILLE, Fla.---It's summer, and snow skiing is the furthest thing from most Floridians' minds. But Eric Bath can't stop thinking about his last dizzying run down a Colorado mountain.

On his final day of vacation several months ago, Bath, of Gainesville, was racing to the bottom when he wiped out, injuring his right knee.

"I went flying," he said. "Once I stopped rolling, I definitely knew I had popped something. I managed to get back to Gainesville, but by the time I got home, I was in a lot of pain and limping severely."

Tests revealed he had a tear in the meniscus, a crescent-shaped shock absorber that prevents the ends of the bones forming the knee joint from rubbing directly against each other.

Conventional arthroscopic surgery to remove the damaged portion would have spelled the end of his daily two-mile jogs and could have put him at risk for severe arthritis. Instead, Bath, 44, opted for an experimental procedure offered by University of Florida orthopaedic surgeons, who replaced the injured section with the first artificial mensicus replacement, made of cow collagen.

"The collagen is organized to recreate the framework of a normal human meniscus," said Peter Indelicato, an orthopaedic surgeon at UF's College of Medicine and the study's principal investigator. "We're studying whether the patient's own tissue will eventually grow and replace the bovine collagen and whether it will function normally at the end of that transformation process."

Researchers are seeking approximately 200 patients at 12 medical centers nationwide, including the Cleveland Clinic, the Hospital for Special Surgery in New York, the University of Washington in Seattle and the Stedman Hawkins Clinic in Vail, Colo., where the research originated. The study is sponsored by ReGen Biologics Inc., of Redwood City, Calif.

Study participants, ages 18 to 60, fall into two categories: those who have undergone partial removal of the meniscus but now complain of pain or discomfort in their knee, and those who have a torn meniscus and are facing surgery to remove it. They are randomly assigned to either receive the investigational implant or undergo traditional surgery to remove the meniscus.

Following surgery, patients remain on crutches for six weeks and must undergo physical therapy. They will be tracked for at least two years. At the end of the first year, surgeons will perform arthroscopic surgery to view the implant and take tissue samples to assess whether the procedure has been effective.

The meniscus is easily damaged with twisting or squatting, Indelicato said. Many times, a portion has to be removed in order to prevent further damage to the knee joint. As people age, the meniscus becomes more brittle, losing its elasticity.

"At the age of 40 or 50, getting out of the car or squatting down to tie your shoe could be all that's necessary to tear the structure," said Indelicato, also team physician for the Florida Gators and former team physician for the Miami Dolphins.

"After part of the meniscus has been removed, the knee becomes vulnerable to developing some arthritic changes," he added. "Anything that would increase the loading of the knee, such as a patient being overweight or the pounding of an intense jogging program, would accelerate this wearing out or arthritic process in the knee joint."

Bath said if the implant doesn't work it will be removed.

"I'm very physically active," he said. "That's why I wanted to go through this. I'm hoping the long-term benefits will outweigh any short-term inconvenience."

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