Treatment of antebrachial deformities secondary to premature closure of the distal radial physis using circular external skeletal fixation and distraction osteogenesis in skeletally immature dogs.

Abstract

OBJECTIVE: To report clinical outcomes of skeletally immature dogs with antebrachial deformities secondary to premature closure of the distal radial physis (PCDRP) treated with angular corrections and distraction osteogenesis using circular external skeletal fixation (CESF). STUDY DESIGN: Retrospective multi-institutional case series. ANIMALS: A total of 12 client-owned dogs with premature distal radial physeal closure. METHODS: Medical records from four hospitals between 2009 and 2022 were reviewed. Preoperative and final radiographic measurements of limb alignment and osteoarthritis were compared. Long-term outcomes were obtained using an owner questionnaire. RESULTS: Mean ± SD age and bodyweight were 7.5 ± 1.7 months and 12.8 ± 11.1 kg. Distal radial corrective osteotomies and distraction osteogenesis were performed in all dogs. Mean ± SD time between surgery and fixator removal was 78 ± 20 days. Uncomplicated osseous union was documented in 9/12 dogs. Final mean affected limb anatomic lateral distal radial angle (aLDRA) of 85.6° was higher than preoperative values 71.6° and within reported normal ranges. A total of 10 of 12 dogs had mild non-progressive elbow osteoarthritis at final follow up, including two dogs with mild residual elbow incongruity. Major complications occurred in two dogs and included permanent carpal flexor contracture and radial fracture through a pin tract. Minor complications including persistent loss of carpal extension, radioulnar synostosis, and pin tract drainage occurred in 10/12 dogs. Owner questionnaires were obtained from 8/12 dogs and all reported good to excellent function. CONCLUSION: Angular correction and lengthening using CESF can achieve target alignment and improved clinical function with moderate complications in growing dogs with PCDRP. CLINICAL SIGNIFICANCE: Distraction osteogenesis and angular corrections can be considered as a treatment option for PCDRP in skeletally immature dogs.