Use of Circular External Fixator in the Treatment of Fracture Complications of Radius and Ulna In Small Breed Dogs
Management of fracture-related complications is a complex issue and several surgical procedures may be necessary to achieve complete resolution. The Ilizarov's method has been successfully used for treating conditions such as bone loss, nonunion, malunion and osteomyelitis1,2, specially in human medicine. The aim of this study was to evaluate the Ilizarov's method for treating some types of fracture-related complications (nonunion or segmental bone defect of the radius and ulna) in small breed dogs. A miniature Ilizarov`s fixator composed by aluminum rings and steel rods was used in three Miniature Poodles (cases 1, 2 and 3) and one Pinscher (case 4). Because of previous treatment with splints, cases 1 and 4 were presented with nonunion of the distal and mid-distal aspect of the radius-ulna shaft, respectively. The frame was assembled with two proximal rings and one distal ring. Fractures in cases 1 and 4 healed completely. However, case 1 presented a slight craniocaudal deviation of the segments in the fractured site. The other two cases (2 and 3) had complications because of surgically-treated fractures. Case 2 was presented with lateral rotation of the forelimb and nonunion of the distal aspect of the radial diaphysis with presence of an intramedullary pin and two cerclage wires. The intramedullary pin and one of the cerclage wires were removed and fracture-derotation was done. The frame was assembled as in cases 1 and 4. Fracture healing was achieved with moderate caudal deviation of the bone shaft. Case 3 had bone reabsorption in diaphysis due to inadequate use of pin-resin external fixator. Bone transport with the Ilizarov´s fixator was used to induce bone regeneration. However, this treatment option was interrupted because of the lack of response. The Ilizarov´s fixator was maintained and the bone defect was treated using autogenous cancellous bone graft and biomaterials. Radialization of the ulna was observed in the bone defect. It was possible to conclude that the Ilzarov´s method may be used in the treatment of nonunion, but the circular external fixator is difficult to apply in small breed dogs.
1. Gugenheim JJJr. The Ilizarov method. Orthopedics and soft tissue applications. Clin Plast Surg 1998; 25:567-578.
2. Rahal et al. Large segmental radius and ulna defect treated by bone transportation with the Ilizarov technique. Aust Vet J 2003; 11:15-18.