Use of transfixation pin casts to treat adult horses with comminuted phalangeal fractures: 20 cases (1993-2003)

OBJECTIVE: To determine the clinical applications, short and long-term survival, and complications of using transfixation pin casts for treatment of comminuted phalangeal fractures in adult horses. DESIGN: Retrospective case series. ANIMALS: 20 horses. PROCEDURES: Medical records were reviewed to obtain information regarding signalment, fracture location, treatment methods, complications, and short-term survival (discharge from hospital). Long-term follow-up information was obtained via contact with owners or trainers. RESULTS: 12 fractures were in a hind limb, and 8 were in a forelimb. Fourteen fractures occurred in a middle phalanx, and 6 occurred in a proximal phalanx. Eleven fractures were treated with internal fixation combined with transfixation pin casts, and 9 fractures were treated with transfixation pin casts alone. Transfixation pin casts were maintained for a mean of 52 days (median, 49 days; range, 1 to 131 days). Fourteen (70%) horses were discharged from the hospital, whereas 6 (30%) were euthanized during the treatment period. Reasons for euthanasia included secondary fracture of the third metacarpal or metatarsal bone, avascularity of the distal aspect of the limb associated with an open fracture, and displacement of the fracture after transfixation pin cast removal. A significantly greater number of horses was discharged from the hospital when the transfixation pin cast was maintained for > 40 days, compared with those in which the transfixation pin cast was maintained for < 40 days. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that horses should be maintained in a transfixation pin cast for a minimum of 40 days, as this was associated with an increase in short-term survival without an increased risk of catastrophic failure.