Comparison of tenoscopic and ultrasonographic methods of examination of the digital flexor tendon sheath in horses

 

 Buy Article Permissions and Reprints

Summary

The purpose of this study was to compare sonographic and tenoscopic findings with the purpose of establishing the accuracy and limitations of ultrasonography as a non-invasive diagnostic modality in evaluating the DFTS and its enclosed tendons. The medical records from 22 horses which underwent tenoscopic desmotomy of the palmar/plantar annular ligament were evaluated in a retrospective study. The qualitative assessment of sonographic and tenoscopic findings were documented for the digital flexor tendon sheath (DFTS), the palmar/plantar annular ligament (PAL), the superficial digital flexor tendon (SDFT) and the deep digital flexor tendon (DDFT). The abnormalities diagnosed sonographically within the DFTS were verifiable tenoscopically with a sensitivity of 90.9% and a specificity of 53.8%. The positive predictive value of sonographic examination at the DFTS was 62.5%. The sensitivity of the sonographic examination at the PAL was 68.8%, the specificity was 50% and the positive predictive value 73.3%. Sonographic examination of the SDF tendons revealed abnormal findings in 12 tendons. The tenoscopic examination confirmed these findings on six tendons when they had a pronounced fibrillated or rough tendon surface or tear on the border. Six superficial flexor tendons and seven deep digital flexor tendons had abnormalities seen tenoscopically which were not visible on sonographic examination. Sonographic examination located lesions of the DDFT in four limbs. On tenoscopic examination the lesions could be detected in seven other DDF tendons, including signs of inflammation at the tendon surface that were not seen ultrasonographically (sensitivity 36.4%). Recognition of the limitations of sonographic results should be kept in mind so as not to misinterpret findings, especially if echogenic materials are observed.

• References

• 1 Van den Berg MJ, Rijkenhuizen ABM, Nemeth F. et al. The fetlock tunnel syndrome: A macroscopic and microscopic study. Vet Q 1995; 17: 138-42.
  CrossrefPubMedGoogle Scholar
• 2 Dik KJ, Dyson SJ, Vail TB. Aseptic tenosynovitis of the digital flexor tendon sheath, fetlock and pastern annular ligament constriction. Vet Clin N Am Equine Pract 1995; 11: 151-62.
  CrossrefPubMedGoogle Scholar
• 3 Dik KJ, Van den Belt AJM, Keg PR. Ultrasonographic evaluation of fetlock annular ligament constriction in the horse. Equine VetJ 1991; 23: 285-8.
  PubMedGoogle Scholar
• 4 Smith RKW, Marr C, Whitton RC. Practical diagnostic imaging. In: Manual of equine practice. Rose RJ, Hodgson DR. (eds) London: WB Saunders; 2000: 51-93.
  Google Scholar
• 5 Nixon AJ, Sams AE, Ducharme NG. Endoscopically assisted annular ligament release in horses. J Vet Surg 1993; 22: 501-7.
  PubMedGoogle Scholar
• 6 Fortier LA, Nixon AJ, Ducharme NG. et al. Tenoscopic examination and proximal annular ligament desmotomy for treatment of equine “complex” digital sheath tenosynovitis. J Vet Surg 1999; 28: 429-35.
  PubMedGoogle Scholar
• 7 Nixon AJ. Endoscopy of the digital flexor tendon sheath inhorses. JVet Surg 1990; 19: 266-271.
  PubMedGoogle Scholar
• 8 Reef VB. Artifacts. In: Equine diagnostic ultrasound. Reef VB. (ed) Philadelphia: Saunders; 1998: 24-38.
  Google Scholar
• 9 Nixon AJ. Annular ligament constriction. In: Current Practice of Equine Surgery. White NA, Moore JN. (eds) Philadelphia: Lippincott; 1990: 435-41.
  Google Scholar
• 10 Wilderjans H, Boussauw B, Madder K. et al. Tenosynovitis of the digital flexor tendon sheath and annular ligament constriction syndrome caused by longitudinal tears in the deep digital flexor tendon: a clinical and surgical report of 17 cases in warmblood horses. Equine Vet J 2003; 35: 270-5.
  CrossrefPubMedGoogle Scholar
• 11 Röthlisberger U, Kaegi B, Geyer H. et al. Das Fesseltunnelsyndrom beim Pferd: Literaturübersicht und retrospektive Untersuchung. Schweiz Arch Tierheilk 2001; 143: 285-93.
  PubMedGoogle Scholar
• 12 Stashak TS, Vail TB, Park RB. et al. Fetlock annular ligament syndrome: results of desmotomy and factors that affect outcome in 49 horses. Proc ECVS Ann Meeting. 1996 5. 72.
  PubMedGoogle Scholar
• 13 Genovese RL, Rantanen NW, Simpson B. The use of ultrasonography in the diagnosis and management of injuries in the equine limb. Comp Cont Educ Pract Vet 1987; 9: 945-55.
  PubMedGoogle Scholar
• 14 Neummeier W, Waibl H, Meyer W. Topographie und Struktur des Vinculum tendinis in der Fesselbeugesehnenscheide des Pferdes. Pferdeheilkunde 2004; 20: 37-41.
  PubMedGoogle Scholar
• 15 Barr AR, Dyson SJ, Barr FJ. et al. Tendonitis of the deep digital flexor tendon in the distal metacarpal/ metatarsal region associated with tenosynovitis of the digital sheath in the horse. Equine Vet J 1995; 27: 348-55.
  CrossrefPubMedGoogle Scholar
• 16 Wright IM, McMahon PJ. Tenosynovitis associated with longitudinal tears of the digital flexor tendons in horses: Areportof 20cases. Equine Vet J 1999; 31: 12-8.
  CrossrefPubMedGoogle Scholar
• 17 Nickel R, Seiferle E, Frewein J. Aktiver Bewegungsapparat, Muskelsystem, Myologia; Eigenmuskulatur der Schultergliedmaße des Pferdes. In: Lehrbuch der Anatomie der Haustiere Band 1. Nickel R, Schummer A, Seiferle E. (eds) Stuttgart: Parey; 2001: 479-92.
  Google Scholar