When a joint is very badly damaged such that it becomes seriously unstable, one of our options is to take a mobile joint and turn it into one solid length of bone. It also becomes an option when patients experience such pain from the joint that we cannot control adequately.
Arthrodesis is the term given to this surgery to fuse the bones that make up a joint, so for example the picture on the right shows arthrodesis of the carpus joint. It will turn several individual bones into one solid length of bone. Whereas fixing a broken bone generally takes 6 to 8 weeks, it generally takes longer for this process to reach completion and it is not unusual for it to take up to 14 weeks for the bone to heal.
The cartilage is removed from the surfaces of all the individual bones and then they are secured in position with a metal plate. The gaps between the bones are filled in with bone taken from elsewhere on the body, or in some cases synthetic materials, or bone that has been donated.
Initially the structure is relatively weak because the metal plate or pins is doing all the work and taking all the stress and strain. A cast will be used, depending upon location, to support the area, and as healing progresses this will be halved and then replaced
Probably the commonest joints for this surgery are the hock and the carpus. It is also possible to complete this surgery on the elbow, shoulder and stifle, but none of these are done terribly often at all.
The x-ray on the left is Lis, is a working collie who damaged her hock when the leg was caught in a cattle grid. Whilst she will probably feel a twinge from this from time to time she certainly doesn't show it when speeding across the fields. The x-ray above on the left is the appearance when she initially damaged it.
Jack on the right is a retired greyhound and we assume that he damaged his hock whilst racing and the resulting discomfort was addressed by the surgery.
The section of bone that had broken and flipped up out of place is circled in red.
Despite being just a small section of bone , this seemed to cause quite a significant amount of discomfort.
We operated to use a pin and a wire to stabilise the joint.