Missy Is World’s First Cat to Have Artificial Knee Replacement

PeoplePets.com When Dr. Noel Fitzpatrick saw Missy, an 8-year-old tabby cat from West Sussex, England, she had been hidden in a bush for 48 hours after a speeding car hit her in the street last month. One hind leg was broken in eight places, and the other leg had a dislocated knee.

Louise Morris, Missy’s owner, heard her little cat, who was also cold and stressed, crying from a bush near the house and immediately took her to Dr. Fitzpatrick, the vet-owner of Fitzpatrick Referrals in Guilford, England, a practice specializing in bone and spinal diseases of cats and dogs.

"Missy was a much loved family cat and not ready to be put to sleep although both legs were hurt badly," Dr. Fitzpatrick tells PEOPLEPets.com from his home in England.

"She had nasty fractured bones in the arch of one foot and on the other leg, the knee was totally dislocated. Amputation was not an option since the other hind leg was broken in eight places. So I developed an artificial knee which had never before been done."

First, Dr. Fitzatrick fixed the broken leg by creating a collagen mesh from the bladder of a pig. Then the broken bones were placed in a mixture of pins called a SPIDER (Secured Pin Intramedullary Dorsal Epoxy Resin Frame).

"Basically, Missy's foot was set with pins that stuck out,” the vet explains. "The bones had to heal that way for three weeks."

From there, Fitzpatrick worked with several professionals on developing an artificial knee for Missy's other leg.

"We took a scan of her knee, measured all of her bones, put that information in a computer, then developed a knee out of metal. We worked like an architect would design a building."

The challenge was getting metal replacement small enough for little Missy, who the vet says is the "sweetest and most loving" cat imaginable. The replacement knee implant had to allow for her to crouch down and jump after it healed -- because this kitty loves to run and catch mice!

Fitzpatrick operated on Missy for 2 1/2 hours putting in a three-inch long implant made out of stainless steel. He attached it to the thigh and shin bones using cement.

"It took four weeks to heal and we are coming to the end of that time," Dr. Fitzpatrick says. "Missy is so happy because she can jump. But we still have her on a leash for another week or more just to be sure."

Needless to say, Missy’s owners are delighted with the results. "It is so heartwarming to see Missy cuddle in her mom's arms," says Dr. Fitzpatrick. "They absolutely love her."

Linda Marx