Evaluation of navicular syndrome horses with magnetic resonance imaging to identify structures involved, prevalence and location of injury, and evaluation of a surgical approach for transection of the collateral sesamoidean ligament

The first goal of this study was to develop optimal, standardized magnetic resonance imaging protocols for the foot of the horse using a 1 Tesla magnet. The optimal magnetic resonance imaging evaluation was determined to contain proton density, T2-weighted, short tau inversion recovery, and gradient echo sequences in axial, sagittal, and coronal image planes. This enabled detailed examination of the front feet of horses with lameness localized to this area. The second goal of this study was to examine horses with recent and chronic onset of navicular syndrome to test the hypothesis that the pathologic changes found in the feet of these two groups of horses would be similar when evaluated with magnetic resonance imaging. These results provided evidence that the location, severity, and prevalence of structures affected is different in these two groups of horses and determinations could be made as to the likelihood of specific pathology based on the specific group the horse was in. The horses with chronic signs of navicular disease had an increased likelihood of having multiple structures affected within the foot and the overall prevalence of injury to each structure was increased. The third goal of this study was to determine if a surgical treatment involving desmotomy of the collateral sesamoidean ligament in normal horses could be a viable treatment option for use in horses with navicular syndrome that were clinically affected with pathologic change in this ligament. This surgical procedure did not cause long term lameness in normal horses and was determined to be a possible treatment option for horses clinically affected with pathologic change in the collateral sesamoidean ligament