Standing repair of long frontal plane fractures of the proximal phalanx in UK Thoroughbred racehorses: A retrospective analysis of 13 fractures.

Background: Sagittal plane fractures of the proximal phalanx (P1) are commonly observed in the UK Thoroughbred racehorse, with the technique and outcome following standing lag screw fixation widely reported. Long frontal plane P1 fractures propagating from the central third of the proximal articular surface occur less frequently, with information concerning repair methods and outcomes currently lacking.

Objective: To describe a surgical technique for standing lag screw fixation of long frontal P1 fractures and report on post-operative performance in a UK Thoroughbred population.

Study design: Single centre retrospective case series.

Methods: Horses with long frontal plane P1 fractures propagating from the central third of the proximal articular surface were identified within Donnington Grove Equine Hospital records. Patient history, fracture location, preoperative diagnostics, surgical rubrics, and follow-up examinations were documented. Pre- and post-operative performance data were collected using an online database. Descriptive data were generated including median and range and percentage success.

Results: Eleven horses fulfilled inclusion criteria. Two horses sustained frontal fractures of 2 separate limbs on different occasions for a total aggregate of 13 fractures. All fractures occurred in hindlimbs and were biarticular in two cases, uniarticular and complete in three cases, and incomplete in eight cases. Repair was performed with a median of four screws (range 2-5) and median surgical time was 30 min (18-104 min). Seventy-three per cent (8/11) of horses returned to racing at a median of 356 days (178-728 days); 2 horses had <6 months follow-up. A post-operative complication necessitating removal of the screws at 257 days occurred in one case.

Main limitations: Small number of patients fulfilling inclusion criteria.

Conclusion: Select long frontal fractures of P1 can be successfully repaired in the standing horse. The post-operative performance data are comparable to that of sagittal P1 fractures, with a good outcome for return to racing. This study provides data on a previously under-reported condition.