Use of flexible intramedullary rods for fixation of femoral fractures in eight dogs.

High-density, polysulfone rods were used to repair 4 comminuted and 4 short-oblique, mid-diaphyseal femoral fractures in 8 dogs. Bony union was achieved in 2 dogs at 10 and 12 weeks after surgery. In one dog, the femoral fracture was healing when amputation of the limb became necessary because of sciatic nerve damage secondary to an ipsilateral pelvic fracture. In a fourth dog, fracture repair resulted in nonunion, despite normal clinical function at 18 months after surgery. In the remaining 4 dogs (50%), the rods failed at 3.5, 4, 6, and 22 weeks after surgery. These fractures were then stabilized by use of other methods. Although several factors may have contributed to failure of the rods, multiple autoclaving of the thermoplastic implants may have caused embrittlement and subsequent breakage.