Charlie had his right knee surgically repaired yesterday. He had a grade four medial luxating patella.
A dog’s patella, also known as his kneecap, normally rides in the trochlear groove at the bottom of the femur. The femoropatellar (above) and patellar (below) ligaments hold the patella in the trochlear groove. It’s usually a congenital problem (though it can also arise from blunt force trauma injuries) and is most common in small and toy dogs.
There are four diagnostic grades of patellar luxation, each more severe than the previous:
- In a grade I luxation the patella can be manually pushed out of place but it returns to the normal position when released;
- The patella can also spontaneously luxate in a grade II injury and the patella remains luxated until it is either manually reduced (put back into place) or popped back into place by the animal.
- In grade III luxations the patella stays luxated most of the time. It can only be put back into place when the knee is extended.
- Grade IV luxations like Charlie’s are the most severe. The patella is permanently out of place and can’t be manually repositioned. The trochlear groove is shallow or absent, and there is the quadriceps muscles are displaced in the direction of luxation.
Patellar luxations are typically caused by congenital abnormalities of the femur that result in abnormal forces on the kneecap that cause it to ride outside the groove. The groove may be to shallow to hold the patella and the ligaments may be positioned incorrectly on the tibia. It they’re not repaired, patellar luxations in young animals can cause the tibia and femur bones to become twisted.
When the trochlear groove is shallow, it is surgically deepened to create a deeper groove for the patella to ride in. If the tibial crest where the patellar ligament connects to the tibia is in the wrong position, it is surgically repositioned. The bony crest is cut away and then reattached in a position so that the patella can ride in the trochlear groove. Pins fasten the bone in place.
One of Charlie’s many nick-names is Chuckie Ray. Even though he’s turning into a sweet, snuggly puppy, the name fits him pretty well this week. His skinny, shaved, betadiene-stained leg earned him another charming moniker: Chucky Chicken Leg.
The clinic let me take Charlie home late the afternoon of this surgery. They typically keep dogs overnight after this surgery, but he was stressed by the clinic environment and they knew I’d keep a close eye on him. I *heart* that clinic.
He’s been very good – so far. I’m sure that post-surgical pain and the after effects of the anesthesia have a lot to do with this and I expect him to turn into a major pain in the ass in the next week or so.
Charlie and I will have to endure eight weeks of restricted activity. He’s on strict crate / leash rest and I’ve got a physical therapy regimen to follow with him. He’s a very bright, athletic, driven little dog and I’ll have to be creative to keep his mind busy while his body heals. Once he starts to feel better I plan to teach him some stationary tricks and maybe work on teaching him the names of some of his body parts using Kayce Cover’s methods.