Personalize knee implant offers relief for arthritis

April 26, 2010 3:14:30 PM PDT
It's a problem that plagues more than 21 million Americans: Osteoarthritis causes cartilage in the joints to break down. When it hits the knees, walking - even standing - is painful. For the majority of patients, knee replacements are the best option, but the implants are one size fits all. A new personalized approach is helping one grandmother keep up with her busy life.

A year ago, keeping up with her grandson would have been impossible for Irma Minott.

"I could not stand more than four hours on my leg, and it was very painful," Minott said.

Osteoarthritis in her knee made it difficult to keep up.

"Most of the time, I had to sit down, take care of him while I'm sitting down," Minott said.

"Once you start to get a knee that's bowlegged or knock-kneed, then the pressures become abnormally high on one side of the joint or the other, and the cartilage wears out," said Dr. John L. Stanton, an orthopedic surgeon at The Bone and Joint Group in Clarksville, Tenn.

When injections and surgery didn't help, Dr. Stanton recommended a new personalized knee replacement.

"So the implant is not just close to fitting or gender specific, but it is patient specific," Dr. Stanton said.

A CT scan of Minott's knee was used to create a 3-D computer model. Then the doctor made plastic implants identical to her knee. Even the surgical instruments were tailored to fit her body.

"These implants really cover the bone nicely and distribute the weight, as well, so you have good coverage of the bone, and this again should give a long-lasting result," Dr. Stanton said.

For Minott, the knee replacement was a success. Two days after surgery, she was back walking. Seven months later?

"I could even run right behind him, which to me was amazing because I couldn't do that," Minott said.

A woman who doesn't take one moment -- or movement -- for granted.

The new implant is used only for partial knee replacements. Dr. Stanton says since the procedure requires very little bone to be removed and leaves ligaments intact, it makes it much easier to perform a total knee replacement down the road.