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Computed Tomographic Tenography of the Equine Carpal Flexor Tendon Sheath.

Abstract: Exploratory tenoscopy is considered the gold standard technique to identify intrathecal pathology of the equine carpal flexor tendon sheath (CFTS). Preoperative diagnosis allows for more precise prognostication and surgical planning, potentially associated with improved surgical outcomes. This prospective, descriptive, anatomical study aimed to describe the anatomy of the equine CFTS using noncontrast and contrast CT in clinically normal cadaver limbs. Ten pairs of equine forelimbs free of gross external abnormalities were examined from mid-antebrachium to distal metacarpus. Specimens initially underwent noncontrast CT examination using 135 kVp, dynamic mAs, and 1 mm slice thickness. Contrast media (iohexol) diluted in saline (total 60 mL, final concentration 75 mg/mL) was injected into the CFTS from a lateral approach before the CT examination was repeated. Tenoscopy was then performed using the conventional lateral approach. Dissection was used to compare the gross, tenoscopic, and imaging findings. The combined noncontrast CT and contrast CT examinations provided excellent anatomical detail of intrathecal and extrathecal structures. Detailed anatomy of the previously undescribed proximal mesotenon and manica of the common mesotenon were also identified. The distal termination of the CFTS was beyond the mid-metacarpus in most specimens, which is significantly more distal than previously reported. This is an important consideration when administering local anesthesia in orthopedic examinations to prevent potential iatrogenic CFTS penetration, which may induce sepsis if the aseptic technique is not followed. Noncontrast and contrast CT can be used to accurately identify CFTS anatomy. Documentation of new intrathecal structures provides a greater understanding of CFTS anatomy.
Publication Date: 2025-03-10 PubMed ID: 40059445DOI: 10.1111/vru.70019Google Scholar: Lookup
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  • Journal Article

Summary

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The study focuses on using computed tomographic tenography, a non-invasive imaging technique, to explore and detail the anatomy of the equine carpal flexor tendon sheath (CFTS) in horse limbs. This technique provided new insights into the CFTS, including the identification of new anatomical structures and a more precise idea of the flexor tendon sheath’s extent being more distal than previously noted.

Objective of the Study

  • The main objective of this anatomical study was to explore and describe the anatomy of the CFTS in horse limbs using non-contrast and contrast-enhanced CT (Computed Tomography).
  • Such a detailed description of the CFTS is expected to aid in preoperative diagnosis, resulting in improved surgery planning and prediction of the prognosis.

Methodology

  • The research team examined ten pairs of normal horse forelimbs, extending from the mid-antebrachium to the distal metacarpus.
  • Initial examination on the limbs was carried out using a non-contrast CT. Post this, contrast media (Iohexol) diluted in saline, totaling 60 ml and with a concentration of 75 mg/ml was injected into the CFTS from a side angle, and the CT examination was done once more.
  • To compare and validate the findings from the imaging, dissections followed by tenoscopy were conducted.

Key Findings

  • It was noted that both non-contrast and contrast-enhanced CT scans provided excellent details of the intrathecal (within the sheath) and extrathecal (outside the sheath) structures.
  • The anatomy of previously unreported structures like the proximal mesotenon and manica of the common mesotenon was identified.
  • The study found that the termination of the CFTS extended beyond the mid-metacarpus in most specimens, which is a more distal positioning than what past studies have reported.

Implications

  • This finding has substantial implications for administering anesthesia during orthopedic examinations. Noting the distal end of the CFTS helps prevent unwanted penetration into the CFTS, which could lead to an induced infection should proper aseptic techniques not be followed.
  • Also, the new intrathecal structures that have been documented provide a deeper insight into CFTS anatomy and help understand the functioning and potential pathologies better.

Cite This Article

APA
Woods TDC, Dixon J, Fraser BSL, Melvaine C. (2025). Computed Tomographic Tenography of the Equine Carpal Flexor Tendon Sheath. Vet Radiol Ultrasound, 66(2), e70019. https://doi.org/10.1111/vru.70019

Publication

ISSN: 1740-8261
NlmUniqueID: 9209635
Country: England
Language: English
Volume: 66
Issue: 2
Pages: e70019

Researcher Affiliations

Woods, Thomas David Chisholm
  • School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia.
Dixon, Jonathon
  • Rainbow Equine Hospital, Rainbow Farm, Old Malton, Yorkshire, UK.
Fraser, Barny Simon Lovat
  • School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia.
Melvaine, Chris
  • School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia.

MeSH Terms

  • Animals
  • Horses / anatomy & histology
  • Tomography, X-Ray Computed / veterinary
  • Cadaver
  • Tendons / diagnostic imaging
  • Tendons / anatomy & histology
  • Prospective Studies
  • Forelimb / diagnostic imaging
  • Forelimb / anatomy & histology
  • Contrast Media
  • Carpus, Animal / diagnostic imaging
  • Carpus, Animal / anatomy & histology

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Citations

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