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

摘要

The aim of this study is 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 were 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 case 1-4 healed completely. However case 1 showed a slight cranial deviation of the segments in the fractured site. Case 2 and 3 had complications because of surgically treated fractures. Case 2 showed forelimb lateral rotation and non-union 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 was used to induce bone regeneration. However the treatment option was interrupted due to lack of response. The Ilizarov's fixator was maintained and the bone defect was treated using autogenous canecellous bone graft and biomaterials. Ulna filled out part of bone defects of the radius. It can be concluded that the Ilizarov's method may be used in the treatment of delayed union and non-union, but the circular external fixator is difficult to apply in small breed dogs..