Computed tomographic contrast tenography of the digital flexor tendon sheath of the equine hindlimb.

This paper presents a pilot feasibility study that investigates the use of computed tomography (CT) and computed tomographic contrast tenography to evaluate equine digital flexor tendon sheath anatomy in hind limbs of clinically normal horses. The application of this approach may enhance diagnostic procedures for identifying digital flexor tendon sheath pathology before conducting surgical interventions.

Introduction

• This study emerged from the need for better pre-surgical diagnostic techniques for assessing digital flexor tendon sheath pathology in the hindlimbs of horses.
• Current standard imaging techniques have proven challenging in accurately identifying these pathologies.
• Computed Tomography (CT) and Computed Tomographic Contrast Tenography offer potential alternatives for clearer visualization of the digital flexor tendon sheath.

Methodology

• The study made use of ten pairs of equine hindlimbs, all of which showed no external abnormalities.
• The limbs initially underwent a non-contrast CT scan, using parameters of 120 kVp, 300 mAs, and 1.5 mm slice thickness.
• Following this, sixty millilitres of an iodinated contrast media (ioversol) and saline solution were injected using a basilar sesamoidean approach. This allowed for a contrast tenography examination to be conducted.
• The limbs were then dissected to allow for comparison between the actual anatomical structure and the imaging findings.

Results

• The combined CT and computed tomographic contrast tenography provided excellent anatomical detail, allowing for a clear identification of intra-thecal structures within the limbs.
• The borders of the superficial and deep digital flexor tendons, as well as the manica flexoria, were consistently identifiable in all limbs.
• Previously undescribed mesotenon anatomical structures and the plantar annular ligament were also consistently identifiable.
• The dissection of all the limbs revealed no pathology, consistent with the imaging findings.

Conclusion

• The combination of CT and computed tomographic contrast tenography is viable for use as a diagnostic tool for determining digital flexor tendon sheath pathology in horses prior to surgical exploration.
• This finding, once confirmed by further research, could potentially improve the outcomes of surgical interventions by ensuring that they are only carried out when absolutely necessary and with a clear understanding of the pathology at hand.