Cat's New Knee an Ortho-PET-ic Innovation

A photogenic 20-pound orange tabby was resting comfortably in an intensive care unit today following pioneering replacement of a cancer-weakened knee by veterinary surgeons at North Carolina State University whose work could advance the field of human prosthetics.

Veterinarians were monitoring the recuperation of Cyrano, a 10-year-old cat, "and if things continue to go well, he could go home in the next few days," said Tracey Peake, a university spokesperson. The School of Veterinary Medicine has been providing periodic updates on a blog.

Cyrano got a new lease on life thanks to top-tier veterinary care. He underwent life-saving chemotherapy and radiation for bone cancer at Colorado State University in 2010. However, while the thousands of dollars of treatments put Cyrano in remission, the combined ravages of his disease and treatment side effects left him with bone deterioration in his back leg and knee, causing pain and restricting his movements.

On Thursday, a 10-member surgical team led by Dr. Denis Marcellin-Little, an orthopedic surgeon at NCSU's College of Veterinary Medicine in Raleigh, N.C., spent hours giving Cyrano a customized implant designed and created during six months of collaborative work among U.S. and German veterinarians and engineers. They fashioned the implant, about the size of a tube of lip balm, from cobalt chromium and plastic.

Marcellin-Little has described the implant as being "as good as the implants used in human knee replacements."

The high-tech operation allowed Cyrano to escape amputation, the goal sought by his owner, Sandy Lerner, a founder of Cisco Systems, and owner of a farm in northern Virginia. Marcellin-Little and his fellow implant developers hope Cyrano's surgery will help make the procedure more available and affordable for other pets.

Cyrano isn't the first feline to get an artificial knee. That distinction belongs to a British cat named Missy, who suffered a crushed leg in 2009 when a car ran over her in West Sussex, England. Dr. Noel Fitzpatrick of Fitzpatrick Referrals in Surrey, outside London, best-known as the BBC's Bionic Vet, fitted her with a stainless steel joint cemented in place.

The NCSU implant developers said their work is more advanced because the materials they're using fuse with natural bone in a process known as osseointegration. Cyrano's implant comes from materials that more closely resemble partly porous natural bone, and was screwed in place about two inches above and two inches below the knee using techniques they've been refining since Marcellin-Little operated on a cat named George Bailey in 2005.

Marcellin and engineering professor Ola Harryson couldn't put a figure on the total cost of Cyrano's experimental surgery, because 14 people and several companies donated time and materials for the research. However, Lerner paid $20,000 of the total cost, Peake said.

The collaboration has implications for artificial limbs to help "people who have lost limbs to disease, accidents, or combat," said Dave Green, the top spokesman for NCSU's veterinary school.