Comparison of pathological lesions in navicular bone (os sesamoideum distale) and analysis of remodelling capacity in warmblood and coldblood horses.

This study compares the pathological lesions on the navicular bone (a bone in the foot of a horse) between warmblood and coldblood horses, with an added focus on the ability of these bones to remodel or heal themselves. The study also aimed to align the findings from radiographic images with the actual anatomical state of the navicular bone. The results show differing patterns in the occurrence and characteristics of these lesions between warmblood and coldblood horses and across various age groups.

Research Participants and Procedure

• A total of 161 horses, 100 of which were warmbloods and 61 were coldblood horses, made up the sample for this research. The study involved a thorough examination of 280 navicular bones from these horses.
• The researchers specifically analyzed the flexor surface, distal border fragments, enthesophytes, and the process of obliteration of nutrient foramina in these bones.
• A part of the bones was also subjected to histology testing, a microscopic examination of the tissues.

Findings

• Coldblood horses displayed a higher tendency for obliteration of nutrient foramen, which are openings in the bone that allow blood vessels and nerves to pass through. The obliteration of these foramina can be seen as an increased instance of remodeling, which includes the closure of synovial invaginations and canaliculi within the navicular bone.
• Such obliteration leads to the disappearance of the synovial groove and prevents the entry of blood vessels into the distal border of the bone. There was also a higher occurrence of new bone formation at the distal border in coldblood horses.
• The development of enthesophytes (bony outgrowths at the area where tendons or ligaments insert into the bone) on both distal and proximal borders was influenced largely by the age of the horses, regardless of their type.
• Warmbloods, however, were found to have a higher incidence of lesions on the flexor surface, which could lead to deep erosions. These were evident even in very young horses as grooves crossing the sagittal ridge.
• The frequency and type of these lesions varied between warmblood and coldblood horses.

Significance

• This research contributes valuable insights to veterinary medicine, particularly in the area of equine foot pathology and radiology capabilities. Post-mortem analysis of navicular bones enabled more precise interpretations of radiographs, feeding into the ongoing development of diagnostic tools and treatment strategies.