Comparison of two grafting methods in 4.0-mm drill defects in the third metacarpal bone of horses.

This study aimed to compare the effectiveness of two bone grafting methods – cancellous bone cylinders and cancellous bone slurry – in treating 4.0-mm drill defects in the third metacarpal bone of horses.

Methodology

• Researchers conducted the study using 6 horses. In each horse, three 4.0-mm unicortical drill holes were made bilaterally in the metacarpal.
• In a randomized fashion, they filled one series of holes with a sternal 4.0-mm cancellous bone cylinder, the second series with a slurry of cancellous bone, and left the third series unfilled as a control group.
• They then performed postoperative lateral metacarpal xeroradiographs at monthly intervals in all horses, allowing them to monitor the holes’ density over time.
• Half the horses were examined after 4 months, and the remaining half after 6 months.

Results

• The xeroradiographs up to 4 months post-operation showed increased density in the holes filled with cancellous cylinders. However, there was no observable difference between the slurry-treated holes and the untreated control group.
• After 5 months, the radiographs indicated no difference between the three treatment categories: cancellous bone cylinders, cancellous bone slurry, and control.
• They also found no consistent histological differences between all the treatment groups.

Conclusion

• The study concluded that there is no clear benefit to grafting 4.0-mm unicortical dorsal metacarpal drill holes in horses using either cancellous bone cylinders or cancellous bone slurry. The results showed no difference in bone healing between the two grafting methods and the control group.
• This research suggests that the body’s natural bone healing mechanisms may be sufficient to fill such drill holes without requiring additional grafting techniques.