Subchondral Bone Disease, Treatments, and Outcomes in Nonracing Horses

Introduction: Subchondral bone disease is frequently diagnosed on MRI, but no standardized treatment protocol exists. Our objectives were to review subchondral bone disease lesions and treatments in a population of horses referred for MRI and to assess outcomes (soundness and return to work).

Materials and Methods: MRI (1.5 T) reports from 2014 to 2023 and follow-up information from clients and referring veterinarians were reviewed. Lesions were categorized as either Grade 0 (margin irregularity), 1 (sclerosis/minimal bone loss), or 2 (bone loss/STIR hyperintensity). Treatments were grouped into rest/shoeing changes, conservative management more than rest/shoeing (e.g., injections), and surgical treatment. Data was analysed using chi-square analysis with significance at p ≤ 0.05.

Results: Eighty-seven subchondral bone lesions (67 limbs and 41 horses) were evaluated, with only the primary lame limb included for analysis. Follow-up was obtained in 36/41 cases, with 20 cases having bone lesions as the primary cause of lameness. No significant differences in outcomes were found between treatments (rest/shoeing changes 80% [4/5] sound and 100% [5/5] returned to work; conservative management 75% [6/8] sound and returned to work; surgical treatment 86% [6/7] sound and returned to work) or lesion grade. Compared with the number that returned to work (85%), horses were less likely (47%) to return at the same level or higher than they were performing pretreatment (p = 0.01).

Discussion/Conclusion: Treatment choice appeared to depend on the severity or type of lesion. Limitations include variation of lesion severity within grades. As long as some targeted treatment is provided for the diagnosed subchondral lesions, most horses appear to improve.

Acknowledgment

The study was funded through the University of Tennessee Center of Excellence Summer Veterinary Scholars Program.

Publication History

Article published online:
15 July 2025