Influence of oblique proximal ulnar osteotomy on humeral intracondylar fissures in 35 spaniel breed dogs

Objective: To investigate the effects of oblique proximal ulnar osteotomy (PUO) on the healing of humeral intracondylar fissure (HIF) in spaniel breed dogs. Study Design: Clinical retrospective study. Sample Population: A total of 51 elbows from 35 spaniel dogs. Methods: An oblique PUO was performed in dogs diagnosed with HIF. The degree of healing of HIF was subjectively and objectively assessed on preoperative and long-term follow-up CT imaging. Objective assessment was performed by measuring the bone density in Hounsfield units (HU) of a rectangular region of interest (ROI) encompassing the entire hypoattenuated humeral fissure. Major and minor complications were recorded. Results: A total of 24 partial and 27 complete HIFs were diagnosed. The follow-up CT scan was performed at a median 18.5 months (range 10–49 months). Subjective assessment confirmed partial or complete healing of the HIF in 41 elbows (80.3%). Objective assessment confirmed a difference in mean HU of the HIF's ROI between preoperative (HU 640) and last follow-up CT images (HU 835) (p =.001). Young dogs (<14 months) had the highest increase in HU of the HIF's ROI. Major complications occurred in five dogs (6 limbs) of which four were related to the lack of healing of the fissure (7.8%). Conclusion: Oblique PUO resulted in partial or complete healing of HIF and pain resolution in the majority of dogs. Clinical Significance: This study introduces an innovative approach to achieve healing of the HIF in the dog, which may help reduce the high complication rate traditionally associated with the use of transcondylar screws.