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

Abstract

Summary Background Pathology of the digital flexor tendon sheath is a significant cause of lameness in the horse. Imaging is important to identify lesions and inform on prognosis prior to tenoscopic surgery. Objectives To use a large population to evaluate 1) the sensitivity and specificity of digital flexor tendon sheath (DFTS) contrast radiographs in diagnosing manica flexoria (MF) tears, deep digital flexor tendon (DDFT) tears and constriction of the palmar/plantar annular ligament (PAL) using novel criteria; 2) predisposition to pathology in signalment and limb affected. Study design Multicentre retrospective cohort study. Methods The medical records of 206 horses with lameness localised to the DFTS, contrast radiographs and subsequent tenoscopic surgery were reviewed. Breed and limb predispositions were evaluated for pathology of the DDFT, MF and PAL constriction. Contrast radiographs of the DFTS were reviewed by four masked operators and for each pathology the sensitivity, specificity and interobserver variability were calculated. Results Contrast tenography was a sensitive test for MF tears (92% confidence interval [CI] 88.4–94.4%; specificity 56%, CI 51.1–61.1%) and specific for diagnosing DDFT tears (73%, CI 68.6–76.8%; sensitivity 54%, CI 47.8–60.2%) but had a lower sensitivity (71%, CI 65.1–75.9% ) and specificity (45%, CI 39.1–52.0%) for PAL constriction. It had good to substantial interobserver agreement for MF and DDFT tears (Krippendorff's alpha 0.68 and 0.46 respectively). Ponies (57%) and cobs (58%) were significantly more likely to be affected with MF tears (other breeds 20–39%, P = 0.003) and Thoroughbreds (50%), warmbloods (45%) and draught breeds (48%) were more likely to have DDFT tears (other breeds 22–34%, P = 0.01). MF tears and PAL constriction were overrepresented in the hindlimbs compared to DDFT tears in forelimbs. Main limitations No standardisation of contrast radiographs was possible. The subjectivity of diagnosis of PAL constriction may also have led to bias. Radiographs were read as JPEGS reducing ability to manipulate images. Conclusions Contrast radiography of the DFTS is accurate in the pre‐operative diagnosis of DFTS pathologies. Different pathologies are overrepresented in certain breeds and limbs.

Blinded Comparison of Palmaroproximal-palmarodistal-oblique and Dorsoproximal-palmarodistal Oblique Radiographic Projections With Contrast Medium in the Navicular Bursa in Dissected Horse Front Feet With Native Radiographs and Gross Pathology

“…There is only one study where the PaPr-PaDiO CE view is compared with gross pathology (Wuerfel and Hertsch 2005). The ability to show pathologic changes, especially tendon tears, with CE radiographs is known from the digital exor tendon sheath (Fiske-Jackson et al 2013; Kent et al 2020). To our knowledge, there is no study comparing DPr-PaDiO and PaPr-PaDiO CE with native radiographs and gross pathology.…”

Detection of lesions of the DDFT and the proximal Manica flexoria of the SDFT – Comparison of ultrasonographic and tenoscopic findings in equine aseptic tenosynovitis of the common digital flexor tendon sheath

“…palmare des Fesselgelenks (Denoix et al 1991). Am häufigsten treten Erkrankungen am lateralen Rand der TBS und an der MF auf (Wright und McMahon 1999, Smith und Wright 2010, Arensburg et al 2011, Fiske-Jackson et al 2013, wobei sie bei der MF vorwiegend (91 %) an der Hintergliedmaße zu finden sind (Smith und Wright 2010, Findley et al 2012, Fiske-Jackson et al 2013, Diekstall et al 2019, Kent et al 2019.…”

Deep Digital Flexor Tendon Injury at the Level of the Proximal Phalanx in Frontlimbs With Tendon Sheath Distension Characterized by Standing Low-Field Magnetic Resonance Imaging in Horses: 13 Cases (2015–2021)

“…The DFTS has historically been examined via tenoscopy, ultrasonography, and radiography including the use of negative and positive contrast ( 6 , 10 , 17 ). Ultrasonography has a sensitivity of 71% and specificity of 71% for detection of marginal tears of the DDFT ( 6 ).…”

“…Ultrasonography has a sensitivity of 71% and specificity of 71% for detection of marginal tears of the DDFT ( 6 ). Contrast (positive) radiography is reported to have specificity of 73% and sensitivity of 54% for diagnosing DDFT tears ( 17 ). Investigation of the tendon sheath using computed tomographic tenography has also been described ( 18 , 19 ).…”