Respect the bones (Day -293)

Vet School Bones and Skeletons

Unfortunately today started badly with a me walking into a resus this morning, sadly the prognosis once an animals heart stops is very very poor. Even when we are able to get an animal back after their heart stops it is a low chance that the animal will leave the hospital alive.

However today is not about that – today is about something a lot more amazing. The bones of the body are probably one of the least understood yet most important parts of nature. There is a lot that can go wrong with bones and a lot of causes of diseases related to the bones.

Whilst there is well established procedures and techniques for dealing with things like fractures, and now even joint replacement. There is little to understanding the way bones grow.

We’ve got a new European Diplomat in Equine Surgery on staff at the vet school and today he gave a lecture looking at skeletal diseases in foals. Now when you consider that horses often have to grow to support 500kg of weight you realise just how important the skeleton is. However when growing, and in fact even during development within the womb bones develop sometimes in ways that will not be compatible with carrying that weight.

I know some of the equine surgical procedures, however I was amazed to learn that if done in the right place at the right time you can simply change the way a bone grows simply by sticking a needle into it. Whilst this is a crazy idea, it gets worse in that no one actually understands why it happens that way. Why does a needle stimulate bone to grow faster?

This is actually therapy used in foals when the leg is not straight to correct the angle the leg grows at because one side of the bone is growing faster than the other. And you would be right in thinking if we can speed up the growth on one side to fix the problem = what about slowing it down on the other side?

So to understand this you need to know that growing bones have two separate parts at every joint. There is the shaft of the bone which is the long bit, and at each end of this there is a separate part called the growth plate. Now the bone grows longer by growth between the shaft and the growth plate until the animal is mature and then these parts fuse together to form the normal end of the bone seen in adults.

Originally it was actually all about slowing down the growth on the side that grew too fast. Initially this was by using screws and wire to compress the growth plate. This worked however was not great to have things sticking out the side of the bone, so now is done using a single screw placed between the shaft of the bone and the growth plate.

Now doing this will slow down the speed of growth on that side of the bone – downside is that you need a second surgery to remove the screw. This is why it’s better to speed up growth of the other side.

This single lecture left me with so many questions… What else can we use to affect bone growth? Will laser affect it? Why does it speed up growth with needles? How do we know when this happens? Can this be used in animals other than horses?