Monday 22 February 2010

Reversing navicular bone damage

There is a common belief among horseowners and vets that once a horse has navicular bone damage, that damage is degenerative - it will get worse over time and cause the horse increasing lameness.

Perhaps this is partly due to the traditional view that navicular bony changes were the cause of the lameness; in fact we now know that they are a symptom, and usually only occur once the horse has been lame for a while, but you can still find lots of textbooks and websites which describe navicular as a degenerative bone condition.

Our own horse, Ghost, was diagnosed with navicular in 2000, on the basis of nerve-blocks and X-rays which showed mild bone damage. He has been sound and in work barefoot for many years now, and in 2007 we had him X-rayed again, only to find (as we expected) that his navicular bone no longer showed any evidence of damage.

If you think about it logically, you would expect that, as poor biomechanics can stress soft tissue and lead to inflammation and eventually bone damage, correct movement and loading will over time allow the bone to strengthen and remodel. Its a process which is well understood in human orthopaedic medicine, after all:

"in a deformed bone the internal structure was radically altered as a response to the static forces working on it. A normal bone will alter to meet a change in its function. If such change in mechanical environment is rectified, the bone will resume its former shape and structure."

JSR Golding

Its no coincidence that these types of horses show caudal hoof pain and are landing toe first - as well as the soft tissue damage which they will show on MRI, the reduced loading of the caudal hoof is bound to affect bone as well:

" when the loads are increased over normal levels, bone mass is increased, and when the loads are decreased, bone mass is lost"

MCH van der Meulen, P J Prendergast

This is a fascinating area, and I've got lots more about this tomorrow and Wednesday :-)

1 comment:

cptrayes said...

It bothers me why Vets can't get their heads around bone regeneration when human Doctors can!