Computed tomographic evaluation of Finnhorse cadaver forefeet with radiographically problematic findings on the flexor aspect of the navicular bone.

This study uses computed tomography (CT scans) to examine forefeet of deceased Finnhorses with known radiographic changes to the navicular bone. The goal was to confirm the original radiographic findings and to investigate if CT scans could provide further information on the flexor aspect of the bone.

Research Methodology

• The study worked with 12 Finnhorse cadaver forefeet, all of which had known radiographic changes in the navicular bone.
• The abnormalities in the navicular bone ranged from poorly defined corticomedullary junctions and irregular appearances of the flexor central eminence, to inconsistencies in the thickness of the flexor cortex, and irregular outlines of the proximal or distal flexor margin.
• The researchers utilized computed tomography to not only confirm the radiographic findings but also possibly get further information about the flexor aspect of the bone.

Findings Discovered with CT Scans

• The CT scans showed significant variations in the midsagittal outline and the internal structure of the bones. Various combinations of trabecular and compact bone were found within the flexor central eminence.
• The scans often revealed lucencies (areas of increased radiolucency indicating possible bone loss) within the compact bone, primarily in the proximal half of the eminence.
• However, in a few cases, lucencies were also identified in the distal half of the eminence. Radiographic evaluation of the shape and internal structure of the flexor central eminence was often found to be challenging due to the partial overlapping of the bone and the varying composition of the eminence.
• Interestingly, the flexor cortex typically appeared thinner in CT scans than in traditional radiographs.

Radiographic Overinterpretations

• Medullary sclerosis (hardening of the bone marrow) and poor flexor corticomedullary junction were commonly over-interpreted in radiographs.
• New bone formation on the proximal flexor margin of the navicular bone was generally visible in radiographs, but CT scans also allowed for the analysis of the internal structure of the bone.
• In one case, a fragment on the distal flexor margin was visible in CT images but not in radiographs.

Conclusions Drawn

The researchers concluded that the evaluation of the flexor aspect of the navicular bone could be difficult to accurately conduct with conventional radiography. This suggests that computed tomography may offer a more reliable method for assessing these bone structures, particularly in the presence of complex bone morphologies or conditions.