Osteoclastic resorption of equine cranial and postcranial bone in vitro.

The researchers conducted a study on horse bones to evaluate the differences between the degradation (or resorption) rates of skull and leg bones. They found that despite skull bone being perceived as more resilient in grafting processes, it can be resorbed just as readily as leg bone.

Research Methodology

• The team performed experiments on slices of horse skull (frontal) and leg bones (specifically, first phalanx or third metacarpus).
• They introduced embryonic chick bone cells to these bone slices and let them grow for 20-24 hours.
• Post this, they dried the specimens after removing the cells.
• Using a video-rate reflection confocal microscope system, they measured the areas and volumes of over 800 resorption pits (areas where the bone had been degraded) for each set.

Comparing Mineralization Density and Resorption Pits

• The comparative measurement was done using quantitative electron backscattering analysis to determine the relative mineralization densities.
• Leg bones had a greater mean mineralization density than skull bones.
• However, the researchers found that even though the skull bones had larger areas of resorption pits, their mean depths were smaller than in the leg bones.
• In both experiments, the volume/area ratios of resorption pits were smaller in the skull bones compared to the leg bones (1.98 micrometers frontal vs 3.79 micrometers leg in the first experiment, and 2.70 micrometers vs 4.20 micrometers in the second).
• Skull bones had larger areas in terms of medians (286 micrometers and 324 micrometers) compared to leg bones (242 micrometers and 201 micrometers).

Conclusion

• The study noticed a clear difference in the shape and size of resorption pits formed in skull and leg bones of horses in laboratory conditions.
• Contrary to the common clinical belief that skull bone is more robust – hence, used as grafting material – it may be resorbed as quickly as postcranial (behind the skull) bone.

This study opens a new perspective in the field of bone grafting, suggesting further research to support its findings.