A study of 118 cases of navicular disease: radiological features.

This study examines the radiological features of navicular disease in horses, using different radiographic projections to evaluate 118 cases. The researchers did not find a relationship between certain characteristics of the disease and the severity of lameness in affected limbs. However, other features such as defects in the flexor cortex and poor flexor corticomedullary demarcation did show a connection to the level of lameness, particularly in horses suffering from bilateral, asymmetrical lameness.

Methodology

• The researchers used several radiographic projections, namely dorsoproximal-palmarodistal oblique, lateromedial and palmaroproximal-palmarodistal oblique to examine horses exhibiting symptoms of navicular disease.
• The study focused on identifying and recording all the radiological features previously reported as significant changes in horses affected by this disease.
• Comparisons were made between symptoms in lame limbs vs. healthy ones in horses with unilateral lameness, as well as between more affected and less affected limbs in horses with bilateral but unequally distributed lameness.

Findings

• Although certain features of navicular bone issues were observed (such as distal border synovial invaginations, flattening or thinning of the flexor cortex), no clear relationship was found to separate these factors from the distribution or severity of lameness in the animals.
• Other issues, such as defects in the flexor cortex, medullary trabecular disruption and medullary sclerosis, appeared to be related to both the affected limb and the severity of lameness experienced by the horse.
• Proximal border enthesophytes and poor flexor corticomedullary demarcation were identified as characteristics potentially linked to the grade of lameness.
• In horses with both affected but unequally lame limbs, poor flexor corticomedullary demarcation and fragmentation of the distal border were observed to be related to the severity of lameness.
• The researchers were unable to perform a definitive analysis on certain characteristics such as peri-articular osteophytes and mineralisation of the flexor digitorum profundus due to their rarity in their sample size.