Combined physeal fractures of the distal radius and ulna: complications associated with K-wire fixation and long-term prognosis in six cats

Objective
To describe the complications and long-term outcome associated with K-wire fixation of combined distal radial and ulnar physeal fractures in six cats.

Methods
Medical records (2002-2014) of six referral institutions were searched for cats with combined distal radial and ulnar physeal fractures. Cases with complete clinical files, radiographs and surgical records were retrospectively reviewed. Long-term outcome was assessed via telephone interviews using an owner questionnaire.

Results
Complete files were available for six of nine identified cases (cases 1 to 6). All fractures were classified as Salter Harris type I or II. Five cases underwent open reduction and internal fixation via: cross-pinning of the distal radius and intramedullary pinning of the ulna (cases 1, 2, 3); fixation of the distal radial and ulnar physes with one K-wire each (case 4); K-wire fixation of the radial physis in combination with two trans-ulnoradial K-wires (case 5). One case underwent closed reduction and percutaneous cross-pinning of the distal radius under fluoroscopic guidance (case 6). The complications encountered were: reduced radiocarpal range of motion (ROM) (cases 1, 3, 4, 5); implant loosening/migration (cases 1, 2, 5) and radioulnar synostosis (case 4). None of the cats developed angular limb deformity. Long-term outcome (12 months to 7 years after surgery) was graded “excellent” by the owners in all cases.

Clinical significance
Prognosis is favourable for feline combined distal radial and ulnar physeal fractures following K-wire fixation. Implant removal after bony union is recommended to minimise reduction in ROM and to prevent implant loosening/migration.