Monday, March 29, 2010


Bone Grafts for Fracture Repair

Posted: 29 Mar 2010 02:25 PM PDT

Miles-Dr.Larry-chatting-it-up As I well know, sometimes broken bones don't heal properly. I spent most of 2008 dealing with a broken wrist from my mountain biking habit. After and unsuccessful cast I had surgery where a plate was applied to the fracture. Along with the plate I had what is called a bone allograft. That means that I had bone supplied by a tissue bank from some other human donor. This bone was packed into the fracture site along with the plate to help bridge the gap created by the non union.

Using bone from a tissue bank is common practice in human orthopedic surgery. The other option is to harvest bone from the surgical patient at the same time you are doing the fracture repair. Called an autograft as opposed to an allograft, bone is usually taken from the patient's hip for use at the fracture site. 
This was the golden standard for years but it does have drawbacks. For one thing you have to take the time to do the harvest procedure in addition to any repair work, so the patient is under the knife and under anesthesia longer with the associated risks. For another, human patients report significant pain at the harvest sight up to two years post surgery. There are other problems, too. Sometimes it's not possible to get enough material from the donor site to do the repair job.
With allografts all that hassle and extra surgical risk goes away.Twiggy-broken-leg-in-dogpark
Well, now we have the advantages of allografts in veterinary medicine too. Thanks to a company called Veterinary Transplant Services (VTS) any Veterinarian can order banked bone tissue for fracture repairs on dogs, cats and horses. That's pretty cool.
VTS offers a number of products. One is called Osteoallograft Orthomix and is described as a natural, real bone allograft made especially for Veterinary Medicine. The cool thing about Orthomix is that it provides both osteoconductive and osteoinductive properties.
That means that it not only contains the osteoconductive bone chips that provide a scaffold for new bone, it also contains osteoinductive demineralized bone. This demineralized bone contains growth factors including bone morphogenic proteins (BMP's) that stimulate the bone forming cells to produce new bone. The result is faster healing time. In fact the use of this material is as good as the old method without the trauma of harvest.
VTS also provides pieces of bone in various shapes to aid in serious fracture repair. A comminuted fracture is one where the bone is broken into several smaller pieces. Dogs that get hit by cars often have comminuted fractures. Sometimes the fracture site is a mess of broken bone pieces and there is nothing big enough or stable enough to hold pins, screws or plates. In these cases it's helpful to have a chunk of bone graft to put the pieces back together.
It's a good thing to have allograft options for dogs and cats. They have the same surgical risks and pain perceptions as people. If Miles ever had a bad fracture I'd want only the best for him. 


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