Case report: broken femur head in a young rabbit
Can amputation be avoided ?
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Neil was a rescue from the University of Victoria campus in Victoria, BC, Canada, where close to 1000 rabbits were about to be ‘exterminated’. (All have now made it out safely).
He was found living in a thicket by the side of a road, just eight weeks old or so with a left rear leg that stuck out perpendicular to his body. A visiting veterinarian had spotted the little guy and mentioned it looked like a crush injury. Neil was taken to a vet in Vancouver who recommended immediate amputation. I hesitated, the rabbit was malnourished and loaded with worms (roundworms and hookworms). I opted to get him in better shape before risking the surgery. While fostering and medicating him at home, I observed no discomfort with the limb, and continued to delay the surgery.
He was transferred to another foster home and my decision was questioned by my fellow rescuers. Opinions differed whether it was a genetically splayed leg or an injury and what the best course of treatment would be, although most, if not all, suggested amputation.
Two months after the rescue, a rescuer thought he was acting a bit lethargic and took him into another vet.
Note: X-rays were taken by different veterinary technicians that were just giving us the free x-rays on their own time (with permission of course) and we gave those pictures to the vets.
New X-rays were taken which were passed around to the vets and vet techs in the clinic. One said the bone was compromised, another said the femur is being eaten and it looked like cancer or infection, another also mentioned osteomyelitis.
They all advised immediate amputation.
How to proceed with such different opinions ?
At this point, I sent the x-rays to MediRabbit. The rabbit could not be seen physically, but it was suggested that the problem appears likely to be the result of a crush or a traumatic injury with detachment of the femur head and displacement of the femur head, accompanied by bone regrowth/malunion.
Neil rabbit would need:
1. A proper physical examination;
2. X-rays taken while rotating and pulling the affected hind limb, on a fully anesthetized rabbit;
3. Blood test (CBC) to rule out the presence of an active infection, e.g., osteomyelitis;
4. Bone biopsy, to help determine the nature of the mass, if head of the femur or tumor.
If the mass turns out to be the head of femur + bone regrowth/malunion, it must be checked if there is pain, if movement is disturbed. If not, the rabbit can continue this way. If it disturbs movement and/or causes pain, an orthopedic surgeon should be consulted to discuss different options such as removing the femoral head, but keeping the femur.
Amputation is really a major surgery, this appeared to be an old injury and this bunny's leg really didn't seem to be bothering him. I decided to wait. Several people questioned this decision and I was pretty much accused of being neglectful, and that the x-rays were showing infection or even cancer, and that the leg needed to be amputated.
I was always reluctant when it came to broken bones in rabbits, I've seen a lot of operations using pins and rods go wrong (I've seen just as many neglected breaks heal on their own), so amputation has been considered the lesser of the evils. Although I'll still agree that three-legged rabbits get along just fine and that amputation surgery isn't a huge risk, I agree that we're also a little too quick to go that route.
Is amputation the most likely ‘for sure’ for Neil rabbit ?
After sending the x-rays to MediRabbit for consultation, the answer was that limb amputations were done too frequently, without considering possible long term side-effects of bearing weight and/or wrong positioning on the other hind limb in aging amputated rabbits. If there is no infection, no mass, when the limb with the broken/malunion/nonunion bone has remained functional and when the rabbit has adapted and is ambulating well, without pain, why sacrifice this limb ?
Risks when leaving the malunion bone heal ?
On the long term, pododermatitis, lameness, degenerative joint disease or arthritis, or ankylosis of a joint due to slow destruction of cartilage and/or bone, may eventually occur at some time.
I asked my own vet, who had initially recommended amputation, and he agreed the bones were knitting, but none-the-less again recommended amputation. The rabbit was reluctantly taken in for the surgery. He was on the table ready to get the anesthetic when my vet did another examination and found absolutely no pain responses in the leg. He decided not to operate.
It is two or three months later and the rabbit is a happy, healthy and active little guy. His leg sticks out to the side and he'll occasionally bang it on something, but it doesn't bother him.
A very heartfelt thanks to MediRabbit (Switzerland) and to Dr Amir Maurer (Companion and Exotic Animal Veterinary Center, Holon, Israel), who took upon their time to look at the X-rays. Their precious advice helped avoid the amputation surgery on this rabbit.