Hurley

Hurley, a 1 1/2-year-old German Shepard/Basenji mix, had a rough start in life. At just a week old, he and his littermates along with their mom were left at a shelter in New Mexico. The canine family was taken to a puppy rescue in Colorado where they were fostered until the pups were old enough for adoption. Julie Lutkus, looking to adopt, visited PetCo when PupSavers (now MuttSavers Rescue) was at the store for a puppy adoption event, saw Hurley and fell in puppy love. Hurley, smart and easy to train, quickly charmed his way into the Lutkus family’s hearts.

“He was just like most other puppies, growing fast and having fun. We would take him to the dog park to run and play, but when he was about 6 or 7 months old we noticed that sometimes he would just stop and hold up his left hind leg,” said Julie Lutkus. “I thought he might have stepped on something so would check his paw for any debris. But he still wouldn’t put his paw down. One time, I massaged his leg and felt his knee cap pop back into place. After that, we made an appointment to see our family veterinarian.”

Both human and dog knee caps, when functioning normally, work and move with the thigh bone musculature to aid in mobility, provide cover, and protect the front surface of the knee joint. In both humans and dogs, the knee cap (or patella) and its associated groove, can suffer from congenital deformities or blunt trauma that make it difficult for the knee to function properly and can cause the patella to slip out of place causing pain and hindering movement. Hurley has just such a set of knees on his hind legs, but was without a very good prognosis until an innovative patellar implant offered promise of less pain and more stable knees.

Model of patellar implant.

Patellar luxations are more common in small dogs, with surgery used to correct what is often a shallow groove. In larger dogs, like Hurley, bony abnormalities such as an abnormally curved femur may also play a role and corrective surgery is more challenging. His family veterinarian suggested the Lutkuses bring Hurley to Colorado State University and the Small Animal Orthopaedic team. At his initial visit X-rays were taken and showed problems with Hurley’s back legs, but his veterinary team at CSU decided wait until Hurley’s growth plates had fused before attempting corrective surgery on his left leg, the more severely afflicted of his hind legs.

“The original surgery in July was a tibial tuberosity advancement with deepening of the patellar groove to improve the alignment of Hurley’s leg,” said Dr. Felix Duerr, an Assistant Professor in the Department of Clinical Sciences and member of the Small Animal Orthopaedic Service team. “But later on it was found, due to the unusual malformation of his groove, the surgery normally used for patellar luxation was not effective. It soon became apparent that if Hurley were to have a good quality of life we would need a more comprehensive repair.”

Luxating patellas range in degree of symptoms, and are graded from I to IV. In Grade I, there may be no symptoms or only mild ones, such as intermittent limping in the rear leg. More severe cases, from grades II to IV can result in extreme lameness, with osteoarthritis eventually developing secondarily to the luxating patella. The surgery to correct a luxating patella often involves a deepening of the trochlear sulcus, the groove that the patella sits in, as well as a re-alignment of the attachment of the patella tendon on the tibia, and a tightening or releasing of the tissues on either side of the patella (depending on which side the patella is slipping).

Hurley's patellar implant.

Hurley’s case was even more challenging. Where doctors would normally deepen the groove to make the patella fit, Hurley didn’t have a ridge that would allow for that deepening to be able to hold the knee cap in place. Normal surgical options simply didn’t apply.

“His case was difficult to address with traditional therapies and we were out of options,” said Dr. Duerr. “Fortunately, I was aware of a new experimental implant that worked as an artificial groove – a patellar groove prosthesis that would basically be a partial knee replacement -- but this was a brand new procedure and the implant hadn’t been released yet.”

Dr. Duerr used his connections with KYON Veterinary Surgical Products in Zurich, Switzerland, to procure the implant, which the company graciously provided at half the cost. Hurley was a good candidate for the procedure because he didn’t really have any other treatment options. Hurley underwent his second surgery in December 2011 and the outcome so far, three months post-surgery, has been good.

“We followed Dr. Duerr’s instructions to the letter, even though it’s difficult to keep a big dog confined, and Hurley’s recovery, though long, went very smoothly,” said Julie Lutkus. “We also took him to rehab at CRCG (Canine and Conditioning Rehabilitation Group) in Broomfield and they were just phenomenal. In the middle of this, we moved from Colorado to Maine. We have had Hurley to a veterinary orthopaedic surgeon here who has reviewed his case, taken new X-rays, and coordinated with Dr. Duerr on Hurley’s continuing care.

“The great news is that Hurley is now acting just like a normal dog and is slowly building strength and learning to use his back legs again. He loves to run in the woods, go for walks at the YMCA, and I know he can’t wait to jump in the pond our property backs up to. Kudos to Dr. Duerr, Dr. Lane Hansen, and everyone at CSU. They gave Hurley a chance at life, and they couldn’t have been more wonderful.”

Eventually, Hurley may need to have surgery on his back right leg, but Lutkus just wants to let Hurley be a normal dog for a while. For Dr. Duerr, the success of Hurley’s patellar groove prosthesis surgery means he’ll be able to help a lot more dogs with luxating patellas that are not candidates for conventional procedures or surgery failed after these procedures.

“Now that we have seen success, we may offer this procedure more often,” said Dr. Duerr. “We definitely see patellar luxation cases where this novel procedure will help alleviate pain as well as potentially worse outcomes, particularly in those unique situations where we don’t have another option.”