A couple of weeks ago I was interviewed by a reporter about pet owner administered first aid for dogs and cats when an injury may have resulted in a fractured bone. The article has good information for pet owners to read now in preparation for a potential emergency in the future. This blog post will pick up where that article left off and explain the fracture repair techniques used by veterinary surgeons the Animal Medical Center (AMC).
For the veterinarian, the critical piece of successful fracture management is to immobilize the fracture. This can be accomplished using one of several different methods. For some fractures, more than one method might be appropriate and for others there may be only one solution to fix the broken bone. All x-rays were taken by the AMC’s Diagnostic Imaging Department.
For centuries, fractures have been treated by immobilization using casts or splints. These days the old style plaster of Paris cast has been replaced in human medicine by plastic or fiberglass. In animals we tend to use splints of fiberglass or plastic for repair of simple fractures where the bones do not need realignment. The arrows in the photo to the right point to two toe fractures in a young dog which healed when the paw was placed in a splint.
Optimal healing of a fracture requires the joints above and below the fracture be immobilized. When the fracture occurs in a location where these joints cannot be adequately immobilized by an external bandage or cast, the fracture must be repaired internally via a surgical procedure. The x-ray to the left shows the use of two small pins in the front of the hind leg bone known as the tibia.
If a bone is fractured in multiple places or spirals along the length of a bone, a simple pin will not provide enough support to immobilize the fracture and allow healing. Shown below are before and after x-rays of a fractured arm (radius and ulna) in a dog. Notice the splint on the before films. The AMC’s emergency service placed the splint to immobilize the fracture until surgery could be performed. The AMC surgeons chose to repair the leg with a plate and screws since both bones of the leg were broken.
As research discovers more about fracture healing, methods of repair are changing. When possible, minimally invasive procedures are chosen as large invasive surgeries disturb the covering of the bone (periosteum), the blood clot at the fracture site and the muscles which provide the blood supply to the fracture. The AMC surgeons are using a new technique called MIPO (minimally invasive plate osteosynthesis) or percutaneous plating. This method of fracture stabilization, involves application of a bone plate through small skin incisions on either end of the fracture site. The fracture is aligned and the plate and screws are placed using guidance from a special intraoperative x-ray machine. Not all fractures are amenable to MIPO.