Bone marrow lesions of the distal condyles of the third metacarpal bone are common and not always related to lameness in sports and pleasure horses.

This study explores the prevalence and significance of bone marrow lesions in the distal condyles of the third metacarpal bone in sports and pleasure horses. It found that such lesions were common and not always associated with lameness or the type and level of activity in horses, indicating the complexity of interpreting these findings.

Objectives and Methodology

• The research was aimed at understanding the prevalence and anatomic distribution of bone marrow lesions in the distal condyles of the third metacarpal bone, and to analyze any correlation between the presence of such lesions, lameness, and the type and level of activity in sports and pleasure horses.
• This prospective, retrospective, observational study included all sports and pleasure horses that underwent standing low-field MRI of the front fetlock region between 2009 and 2016.
• Horses were divided into three lameness groups based on diagnostic analgesia results. Bone marrow lesions were analyzed and graded with comparison between anatomical locations and lameness groups.

Study Findings

• A total of 166 horses were surveyed for the study, of which 76.5% (127/166) showed bone marrow lesions.
• The dorsal aspects of the medial condyle (31%, 39/127) and the sagittal ridge (28%, 36/127) were the most frequently affected locations.
• The study did not find a significant difference in the observation of lesions between the lame and non-lame limbs within the same horse.
• The severity of lesions was not associated significantly with the lameness group nor with the type or level of activity of the horses.

Conclusion

• The research points towards a high prevalence of bone marrow lesions in the distal condyles of the third metacarpal bone in the studied horse population.
• The clinical significance of these lesions remains unclear, as they were not always associated with lameness or the level and type of a horse’s activity.
• The results indicate the need for further studies to better understand the clinical implications of bone marrow lesions in sports and pleasure horses.