FRACTURE TREATMENT IN THE HORSE
Plate luting strength

This photo shows in vitro (outside the body) single cycle to failure of two equine MC3s (cannon bones) plated with plate luting (top) and non-luting (bottom). The specimens show significant differences--although both specimens broke at the end of the plate, the non-luted specimen opened its osteotomy site (the plated gap) and bent the screws that can be seen sticking out of the plate. This movement occurred at the first cycle, and further movement following cycling will cause failure of the implants. The luted specimen had no such movement and therefore will cycle longer (go more steps) before failure.

Images courtesy David M. Nunamaker, VMD, Dipl. ACVS

Pool recovery

A pool raft recovery following fracture treatment shows the horse being removed from the raft on its way to the recovery stall. This recovery system has proven to be quite valuable for preventing injury immediately following fracture repair.

Model III External Fixator

The Model III external fixator developed by Nunamaker's team uses two 7.94-mm pins inserted horizontally through the cannon bone and anchored within tapered metal sleeves to welded vertical supports on either side of the fractured leg for weight bearing. The vertical supports terminate in a walking plate at the ground, which allows the horse to move around by loading his weight onto the pin/fixator combination rather than the fractured area of the limb.

Palmar view of fracture

This comminuted P2 fracture (fracture of the second phalanx, or short pastern bone, where it is broken into several pieces) in an adult Thoroughbred mare was treated in an external fixator (see below).

Lateral view of fracture Lateral view of the above injury.
Mare in fixator Mare wearing the external fixator.
Fracture after 6 months The mare went on to a fusion of the joint as shown by this radiograph taken six months after the operation, when she had full use of the limb.