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

Abstract

Pre-surgical investigation of digital flexor tendon sheath pathology remains challenging with current standard imaging techniques. The aim of this prospective, anatomical, pilot study was to describe the anatomy of the equine hind limb digital flexor tendon sheath using a combination of computed tomography (CT) and computed tomographic contrast tenography in clinically normal cadaver limbs. Ten pairs of hind limbs with no external abnormalities were examined from the level of the tarsometatarsal joint distally. Limbs initially underwent non-contrast CT examination using 120 kVp, 300 mAs, and 1.5 mm slice thickness. Sixty millilitres of ioversol iodinated contrast media and saline (final concentration 100 mg/ml) were injected using a basilar sesamoidean approach. The computed tomographic contrast tenography examination was then repeated, before dissection of the specimens to compare gross and imaging findings. The combined CT and computed tomographic contrast tenography examinations provided excellent anatomical detail of intra-thecal structures. The borders of the superficial and deep digital flexor tendons, and the manica flexoria were consistently identifiable in all limbs. Detailed anatomy including that of the mesotenons, two of which are previously undescribed, and the plantar annular ligament were also consistently identifiable. Dissection of all 10 pairs of limbs revealed there to be no pathology, in accordance with the imaging findings. In conclusion, the combination of CT and computed tomographic contrast tenography may be useful adjunctive diagnostic techniques to define digital flexor tendon sheath pathology prior to surgical exploration in horses.

Feasibility, indications, and radiographically confirmed diagnoses of standing extremity cone beam computed tomography in the horse

“…In the six diagnostic studies, three tendon border tears, three manica flexoria partial or complete tears, two tendon to sheath wall adhesions, two tendon surface erosions, one subcutaneous ganglion which communicated with the tendon sheath via a previously non diagnosed tract, and one intersesamoidean ligament erosion and perforation were diagnosed. The CT tendon sheath anatomy has been described 9,10 . One bilateral front limb CBCT venogram was performed for a clinical case of chronic laminitis.…”

Improved diagnostic criteria for digital flexor tendon sheath pathology using contrast tenography

“…Computed tomography (CT) and contrast CT of the DFTS have been described in cadaver limbs. This requires expensive equipment unavailable to some practitioners and usually requires general anaesthesia . In addition, the sensitivity and specificity of CT in diagnosing MF and DDFT tears have yet to be described.…”

Highlights of recent clinically relevant papers

“…The aim of this prospective, anatomical, pilot study by Rachel Agass and colleagues in the UK was to describe the anatomy of the equine hindlimb digital flexor tendon sheath using a combination of computed tomography (CT) and computed tomographic contrast tenography in clinically normal limbs .…”