Effects of osteochondral fragmentation and intra-articular triamcinolone acetonide treatment on subchondral bone in the equine carpus.

This study analyzes how osteochondral fragmentation and an intra-articular corticosteroid treatment impact bone remodelling and fragility in horses. The researchers found that the corticosteroid treatment did not significantly change bone remodelling or fragility, but the fragmentation did have a significant impact.

Experiment Design

• The study involved 12 horses, in each of them, a unilateral, 8 mm osteochondral fragment was created in the distal aspect of one radiocarpal bone.
• Half of the horses were treated in the fragmented joint, and the other half were treated in the nonfragmented joint with 12 mg of triamcinolone acetonide (TA), a corticosteroid. The treatment was administered 14 and 28 days after surgery.
• All horses were exercised on a high-speed treadmill starting 15 days and ending 72 days after surgery.

Finding 1: Lameness Reduction after TA Treatment

• Horses that underwent the TA treatment on the joints with fragments showed significantly less lameness compared to those treated in the nonfragmented joints, suggesting a potential pain-relieving effect of TA on injured joints.

Finding 2: Increased Vascularity and Remodelling in Fragmented Joints

• Significantly higher vascularity, single labelled surface, total labelled surface, and mineralising surface were observed in the subchondral and subjacent trabecular bone of joints with fragments.
• There also appeared to be a trend towards higher vascular canal volume and osteochondral junction remodelling sites in the bones from fragmented joints.

Finding 3: No Significant Impact of TA on Bone Remodelling

• No significant variations were found in microdamage density or size, between fragmented and nonfragmented joints.
• Most importantly, the TA treatment did not have a significant impact on bone remodelling or fragility, suggesting that the corticosteroid, while helpful in reducing lameness, does not significantly influence these parameters.

Implication of the Findings

• The results indicate that while osteochondral fragmentation significantly alters bone remodelling, the administration of TA into joints with fragments does not significantly alter this remodelling process or the fragility of the bone.
• The findings could have clinical significance for understanding how to manage joint injury and osteoarthritis in horses, and potentially in other animals or humans as well.