Subchondral bone density changes of the talus in dogs with tarsocrural osteochondrosis

Osteochondritis dissecans (OCD) and osteochondrosis (OC) are multifactorial developmental joint diseases that can occur in various anatomical locations, including the tarsus of immature, rapidly growing large breed dogs. The pathogenesis of canine OCD and OC involves a disruption in endochondral ossification, resulting in a failure of matrix calcification and vascular invasion. This study aimed to investigate the subchondral bone density changes in Labrador Retrievers with tarsocrural OCD/ OC.

A total of 8 dogs with unilateral tarsocrural OCD/ OC were included in the study and density was evaluated with Computed Tomography osteoabsorptiometry (CTOAM ). The findings revealed a significant decrease in subchondral bone density at the location of the OCD/ OC lesion, particularly at the medial trochlear ridge. This area of low density was surrounded by a higher density rim. Furthermore, the contralateral joint showed a significantly higher overall mineral density.

These results highlight the significant changes in bone mineral density associated with tarsocrural OCD/ OC. The lower density in the affected joint suggests pathological alterations in the subchondral bone, which may impact the bone turnover and contribute to the development of secondary osteoarthrosis, subsequently. The higher density observed in the contralateral joint emphasizes the role of altered joint loading and adaptation in the subchondral bone.