Use of circular external fixator in the treatment of fracture complications of radius and ulna in small breed dogs

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">The aim of this study was to evaluate the Ilizarov’s method for treating complications of radius and ulna fractures in small breed dogs. A miniature Ilizarov‘s fixator constructed using aluminum rings and steel rods was used in three Miniature Poodles (cases 1, 2 and 3) and in one Pinscher (case 4). Because of previous treatment with splints, cases 1 and 4 showed delayed union of the mid-distal and distal aspect of the radius-ulna shaft, respectively. The frame was assembled using two proximal rings and one distal ring. Fractures in cases 1 and 4 healed completely. However, case 1 showed a slight cranial deviation of the segments in the fractured site. The other two cases (2 and 3) had complications because of surgically-treated fractures. Case 2 showed forelimb lateral rotation and nonunion of the distal aspect of the radial diaphysis associated with an intramedullary pin and two cerclage wires. The intramedullary pin and one of the cerclage wires were then 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. In case 3, bone reabsorption in diaphysis was observed 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 due to lack of response. The Ilizarov´s fixator was maintained and the bone defect was treated using autogenous cancellous bone graft and biomaterials. Ulna filled out part of bone defect of the radius. It was possible to conclude that the Ilizarov´s method may be used in the treatment of delayed union and nonunion, but the circular external fixator is difficult to apply in small breed dogs.