Tubby tabby gets revolutionary new knee joint

RALEIGH, N.C. -- Because Cyrano weighs more than 20 pounds, amputating his cancer-weakened leg was out of the question. So the tubby tabby's owners turned to doctors and engineers at North Carolina State University to get him back into mice-catching trim.

On Jan. 26, the 10-year-old cat from Upperville, Va., received what doctors believe is the first feline total knee replacement in the U.S.

Dr. Denis Marcellin-Little shows off an artificial cat knee joint Jan. 25 during a news conference at North Carolina State University. He was part of a team performing what he believes is the first feline total-knee replacement.

"This is the most complex implant that NC State has made and really, in all honesty, that anyone has built for any situation that I know of," said surgeon Denis Marcellin-Little, a French-born veterinarian.

Cyrano -- his full name is Mr. Cyrano L. Catte II -- underwent treatment last year at Colorado State University for cancer in his left hind leg. The disease is in remission, but the treatment left the leg nearly useless and extremely painful.

Marcellin-Little and NCSU engineer Ola Harrysson are pioneers in osseointegration, a process that fuses a prosthetic limb with living bone. In 2005, Marcellin-Little performed the world's first surgery to fuse leg implants with a cat's bone tissue, so Cyrano's owners turned to him for help.

Britain's Dr. Noel Fitzpatrick was credited with the world's first total knee replacement in 2009 on a cat named Missy, whose leg was crushed by a car. But Marcellin-Little said Cyrano's plastic and cobalt chromium alloy implant is more like those used in humans.

"It has a form of articulation that is unique -- that allows the implant to bend and rotate," he said, demonstrating with a model during a news conference the day before the surgery. "The devil is in the details."

Such implants have become commonplace in dogs. But a cat's smaller anatomy has proved more difficult to work with, and Cyrano's damaged bones posed an additional challenge, Marcellin-Little said.

Unlike other joints, which are machined, Cyrano's knee -- in cats, it's actually called a "stifle" -- was fabricated using a laser process that hardens metal powder to exactly replicate his bones. More than a dozen people worked on developing and testing the implant, each half of which is about 2 inches long.

Marcellin-Little practiced the procedure four times on plastic models before the Jan. 26 surgery.

Technicians X-ray Cyrano's knee following surgery Jan. 26 at North Carolina State University in Raleigh, N.C.

Dr. Denis Marcellin-Little operates on a cat named Cyrano at North Carolina State University in Raleigh, N.C., on Thursday, Jan. 26, 2012. The 10-year-old tabby is believed to be the nation's first recipient of a feline total-knee replacement. (AP Photo/Allen Breed)

The operation began around 10:30 a.m. Attendants did not wheel Cyrano to the intensive care unit until almost 5 p.m.

Marcellin-Little said the tabby's girth and big bones were a plus. He said Cyrano should be up and around in about a week, though he won't be climbing trees for a while yet.

"We would like him to take it easy for about three months after surgery," the doctor said. "And then we will let him be himself."

Because so much of the time and material were donated, university representatives could not give a total cost estimate.

"Part of this is a pure research project, in a way," said Harrysson, an NCSU professor of industrial and systems engineering.

The bill to owners Sandra Lerner and Len Bosack will be around $20,000. Sitting in a waiting room after the surgery, a visibly exhausted Lerner -- who helped found electronics giant Cisco Systems -- said "Rat Boy" is worth every penny.

"He's my child. And if it were your child, would you begrudge the money?" she said.

"I have a personal philosophy that people are, at best, equal with the other inhabitants of the planet. And I'm very, very grateful that I have the money and [am] able to do it."