Deesha had a chronic lameness with her right hindleg. She would carry it or have a slight limp when walking.
On examining her leg, Mark found she had a dislocating kneecap (patella). Each time the leg bends, the patella normally slides up and down a nice smooth groove in the underlying bone.
In Deesha’s case, the groove had flattened (i.e. it was very shallow) and there was no ridge to stop her patella from sliding sideways to the inside of her leg. Each time her knee bent, the patella would slide sideways out of position. Over time, this has led to some arthritis.
The patella has a large group of muscles attached to the top of it, the quadriceps. The bottom part of the patella is joined to the bone below (the tibia) by the patella tendon (the one the doctors like to tap with their small hammer)
Because the patella had been pulling on the bone below from a different angle than normal, the attachment area (tibial crest) re-modelled itself and “moved” to the inside of the leg.
In other words, the whole quadriceps, patella, patella tendon and tibial crest were all out of alignment and had “moved” to the inside of the leg.
Fixing the problem meant 2 things:
- Deepen the groove the patella slides up and down in
- Moving the patella tendon and tibial crest back towards the midline
Deesha was placed on an IV drip and anesthetised with IV Alfaxan. She was then placed on Isoflurane gas and prepared for surgery.
Mark made an incision down the inside of her knee so he could see what the joint looked like. The groove was very flat and there was some arthritic bone build-up.
Using a bone saw and chisel, Mark removed a rectangular piece of the groove made up of shiny smooth cartilage on top and bone underneath. The underlying bone was deepened using a special bone rasp. The rectangular piece of bone and cartilage was then placed back into the deeper groove creating a nice ridge to stop the patella sliding sideways.
Mark closed the joint capsule and moved onto the second part of the surgery.
This involved moving the attachment of the patella tendon to the midline by sawing off the tibial crest and fixing it into a new central position using 2 small bone pins.
Mark closed the surgery site after it was flushed with sterile saline and Cephalexin antibiotic.
Deesha was given post op pain relief and Cephalexin antibiotic injections and kept on the IV drip overnight. The next day she was looking very bright and alert and she went home at lunchtime.
At day 4, the wound looked great with minimal bruising and swelling. Deesha was already placing some weight on the leg even though she was under strict confinement orders.
The stitches were removed at day 10 and a course of Cartophen injections started to improve healing.
Deesha is expected to make a great recovery as long as she take sit slow and steady over the next few months.