Circular external fixator used to heal broken foot bones in three dogs

Abstract

CASE HISTORY: Three dogs that presented with multiple metacarpal or metatarsal fractures, between January 2004 and November 2008. CLINICAL FINDINGS: Case 1 had sustained closed fractures of metacarpal bones II-V, resulting in a valgus angulation of the manus. Case 2 had 2-week-old open, infected, comminuted diaphyseal fractures of metatarsal bones II-IV. Case 3 had sustained open fractures of metacarpal bones II-V, that were initially stabilised with intramedullary Kirschner wires, but had gone to non-union 5 months after the initial surgery. TREATMENT: Circular external skeletal fixation was used in each of the three dogs. In Case 1, the fixator was used to perform a closed reduction, to align the overridden, angulated fractured metacarpus, by distracting the frame. In Case 2, the fixator was applied after a limited open reduction, and was used to provide stable fixation of the comminuted infected fractures while facilitating open wound management. In Case 3, the fixator was applied in buttress fashion, following open debridement and placement of an autogenous cancellous bone graft at the non-union fracture sites. CLINICAL OUTCOME: All three dogs developed drainage tracts from the fixator wire. There was minimal associated lameness or pain in two of the dogs, but Case 3 developed a transient lameness ascribed to infection associated with the wire tracts, which resolved following administration of antibiotics. Inflammation of wire tracts resulted in the fixator being removed prior to radiological evidence of union of all fractures in each dog, and the mean time from surgery to removal of the frame was 12 (range 7-24) weeks. None of the dogs had residual lameness or discomfort associated with the fractures at the time of long-term evaluation, which ranged from 10-45 months following surgery. CLINICAL RELEVANCE: These three cases illustrate the utility of circular external skeletal fixation for the stabilisation of complicated fractures of the metacarpus and metatarsus. The fixators were applied without inducing substantial iatrogenic trauma, and the small-diameter fixation wires provided effective stability of the short metacarpal and metatarsal fracture segments, allowing the fractures to heal. Although complications associated with wire tracts should be anticipated, circular external skeletal fixation should be considered as a viable method for managing complex fractures of the metacarpus and metacarpus in dogs.