HOW TO GET A LEG TO STAND ON

Dr Bill Bradley
Ku-Ring-Gai Veterinary Hospital
290 Bobbin Head Road
NORTH TURRAMURRA NSW 2074

first published in THE ABYSSINIAN, Journal of the Abyssinian Cat Club of Australasia Inc.,
July, 1999

Suki, the much loved Mangan Abyssinian, was presented to me with a non weight bearing lameness after an apparent fall at home. Despite the obvious lameness she was in good spirits (like all Abyssinians!). Clinical examination failed to demonstrate any other problems and a conscious radiograph showed an intertarsal instability of the right hind leg. The tarsal bones are the little bones between the tibia and the metatarsals. The top ones articulate with the tibia (to form the ankle joint) and the bottom ones articulate with the metatarsals (the long bones in your foot). In between they articulate with each other. These joints don’t actually move as they are firmly supported by ligaments.

After premedication, Suki was anaesthetized and stressed radiographs were taken. These accentuate the instability and allow us to work out which of these tiny little bones/joints have partially dislocated. In Suki’s case, she had luxated the central and the IV tarsal bones as well as the talus and central tarsal bones. She had done a good job on herself. If left untreated she would have marked problems walking on the leg and would have developed degenerative problems in these joints. After discussing Suki’s problems with the Mangans, we elected to operate.

The aim of the surgery was to arthrodese (fuse) the luxated joints to provide stability to the tarsal region but not to interfere with the function of the ankle joint. To do this we opened up the luxated joints and removed the articular cartilage. We then harvested a bone graft from Suki’s shoulder and packed it into the former joint spaces. The joints were then stabilised with a small pin, extending from the ankle down to the metatarsals, and a figure of eight tension wire. With this technique bone grows in the former joint spaces to fuse the joints. Post operative tension radiographs failed to demonstrate any instability. The surgery went well.

A dressing was applied to the leg and Suki was discharged from hospital the following day. As it was a sterile surgical procedure, no antibiotics were needed and the only problem we had was Suki deciding she didn’t agree that a dressing was necessary and tried to remove it. After counseling, Suki agreed with the wisdom of a dressing and was allowed to go home. She was redressed every 3 days until suture removal.

Approximately 8 weeks after the surgery a check radiograph showed that the joints had been successfully arthrodesed and the implanted metal was removed. A very slight deviation of the foot was noted but there was excellent weight bearing.

Amazingly, Suki still talks to me! While arthrodesis of intertarsal joints is a relatively straight forward procedure commonly used in dogs (I even did one on a kangaroo once), I have rarely performed it on cats. In Suki’s case it was well and truly indicated and worked well. As with all these surgeries, it is not just what we do but the care and commitment of the owners that help ensure the best outcome for the patient. In Suki’s case the Mangans more than provided that.