Jan 292007
Authors: Anica Wong

Oregon researcher Charles Roselli may be catching flack outing gay sheep, but Simon Turner is sure to garner praise for saving the wooly animals from cancer.

Turner, an orthopedic research veterinarian who works at the James L. Voss Veterinary Teaching Hospital is working along with orthopedic surgeon Dan Martin and James Johnston, an oncology surgeon, to construct a bone replacement device that could help people with bone cancer.

At the VTH, Turner, who is known as the “sheep doctor,” began his research for the prosthesis on sheep. Turner used sheep because they are easy to handle and are easily accessible. The animals are also old, retired breeding sheep that would have been killed because they had no further use.

“More important is that they have large bones to accommodate the size of the prosthesis that will be used in people,” Turner said of the sheep.

When someone has bone cancer and the infected part of the bone needs to be removed, there are three options. First, doctors can amputate the infected part as well as everything else below that point. Second, an allograft, or a piece of bone from someone else, can be put in to replace the infected part. Lastly, an artificial piece can be placed in the body, similar to an artificial knee or hip replacement.

These devices may loosen, causing pain and the possibility of more surgeries. All of these options come with downsides, and Turner wanted to find a new way to help those with bone cancer.

The prosthesis, called a distal femoral replacement, can replace segments of bone that must be taken out due to cancer. The device is spring loaded, which helps it to stretch in the case of a patient whose bones are still growing. During the trial period, the device was placed in the femur of the sheep and Turner found that the device encouraged bone growth. The device also stayed in place, which is often a downfall of an artificial piece placed in the body.

After two years of sheep research, the device was placed in a woman with a severe case of a bone cancer called distal femoral chodrosarcoma.

“This is a cancer that originates in bone but the cells that are multiplying and are ‘out of control’ are originating from cartilage cells,” Turner explained.

The surgery was a success and 14 years after the device was implanted there seems to be no problems.

Now the method is available to doctors through Biomet, a worldwide leader in producing and manufacturing devices for hip, knee and other joint replacements. In 2007 alone, the device has been used in 420 surgeries in the United States.

“Each year following the clearance, there has been an increase of 100 percent (in the device use),” said Joe Hammons, the manager of limb salvage reconstruction at Biomet.

“Now it is in a lot of people. We are starting to see the end result,” Turner said.

Turner said the research and manufacturing of the device was collaboration between three groups – veterinarians do the research, doctors use the device in humans and the industry produces the device.

“It is great that a few animals could benefit so many people,” Turner said. “It is very rewarding to see it making such a huge leap (from animals to people).”

Staff writer Anica Wong can be reached at news@collegian.com.

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