Since my last post was about my convocation, I figured this next one should be about my first non-elective surgery. It was an orthopaedic surgery, and I performed it just before heading back to Guelph for convocation. For those of you keeping track, that would be just one month after I started working as a vet. Taking it on may have gotten me a nick name at work that went something like “Dr. Big Balls”.
What was it? A Femoral Head Osteotomy, FHO for short.
Say what? Basically you chop off the head of the femur.
Still confused? Okay, I’ll try to break it down for ya. . . *ahem*
The hip joint is a ball and cup joint. The pelvis has a nice hollow cup in it on either side, and there’s a knob on the top of the femur that just sits in there, creating a joint. There’s a joint capsule around this, holding in lubricating joint juices. There are a lot of muscles connected to the pelvis bone and the femur, that move that leg around, tra la la. Now, turns out, if you walk on four legs, you can get by pretty spectacularly without this joint. Especially if you’re a little dog or a cat. Seriously. Remove the ball, and the muscles compensate, a fibrous joint is formed, and bob’s your uncle you’re walking.
Why would I do this? Why would I go and break a perfectly functional bone? Well, if you’ve been paying attention, I’m sure you know I’m probably breaking bones with good reason. . .
Most FHOs are done for trauma related reasons. If the hip has been dislocated – the head of the femur has been knocked out of its cup – and you can’t reduce it (put it back where it belongs), an FHO is a dandy salvage procedure. Otherwise, the animal will walk gimpy because the head of the femur is rubbing up on the pelvis where it does not belong, and be in chronic pain.
Another traumatic reason for going in and removing the femur head? If it’s already broken at the neck. Then you just have to go in and remove the head and smooth out the edges of the bone left behind.
There can also be genetic reasons to modify the hip joint. Legg–Calvé–Perthes disease can affect dogs, and in many cases an FHO is an effective cure if conservative management wasn’t successful. This is where dogs are better than people… far as I can tell, FHO is not so much an option for people. Probably something to do with walking upright. Silly people.
The procedure itself is not quite as simple as a full on limb amputation. . . First off you have to get down to the joint, without causing too much muscle trauma as you want to leave all that muscle behind. Sometimes the joint capsule is already torn open, and that makes things easier because things are loosey goosey. When the joint capsule is intact, you know you’ve achieved your goal when joint juices gush out at you. Fun! Then you clean up the neck of the femur, and literally take a hammer and chisel to that sucker. Tappity tap tap, pop goes the weasel! There’s a knack to it, have to position things right, so that you don’t break off to much femur. Once the head is out, you take a bone rasp to the left behind bit and make the edges smooth and comfortable. Then once you’ve got things tidy and sewed back up, take some post-op rads to make sure there’s no bone bits or pointy bits you missed that might cause discomfort later. Bit o’ pain management and physiotherapy, and the patient is usually barely limping within days of the operation (depending a bit on how long standing the injury was and how much muscle atrophy or shortening happened..)
My first FHO was a little dog who had been missing for a week and came home with a dislocated hip. My boss and I both tried with all our might to reduce it to no avail, so the surgery had to happen. That lil’ puppers did very well after surgery, and I have the head of his femur in a pill vial on my book shelf. Gives me a bit of confidence if some bad cases start getting me down. I have since become the go to assistant for FHOs when other vets in the practice have them. . . ‘cause I loves breaking bones!