The cross‐sectional areas of normal equine digital flexor tendons determined ultrasonographically

Abstract

Summary Fifty‐two animals, comprising 22 Irish Draught crosses (Group A), 15 Thoroughbreds (Group B) and 15 ponies (Group C) were examined ultrasonographically using a 7.5 mHz linear array probe and stand‐off pad. All animals were free of tendon disease as determined from clinical and ultrasonographical examination. The superficial (SDFT) and deep (DDFT) digital flexor tendons were scanned at 7 transverse (axial) levels between the carpus and metacarpophalangeal joint. Each transverse image was digitised using a commercially available frame grabber and the cross‐sectional areas of each tendon at each level measured using a dedicated software application. Excellent accuracy (averaging less than 5%) was demonstrated between the ultrasound generated areas and those measured from the tendons post mortem in 12 limbs. The mean, s.d. and tolerance intervals of both SDFT and DDFT cross‐sectional areas at each level were determined for each group of horses. There was no statistically significant difference between Groups A and B and these 2 groups were, therefore, combined for further analysis. The cross‐sectional areas of both tendons were statistically smaller for Group C when compared to Groups A and B. The ratio of SDFT to DDFT cross‐sectional areas was calculated for each level and this demonstrated less variation between groups. The difference in measurements between limbs of the same horse was analysed. The mean differences for all groups were 9.13 mm2 for the SDFT and 11.64 mm2 for the DDFT. Upper limits (95% of the population) were 22.67 mm2 (SDFT) and 29.22 mm2 (DDFT). Weight (Groups A and C), height and mid‐metacarpal circumference (all groups) were measured and these physical parameters related to the tendon size at each level for Groups A and B combined and Group C. Tolerance limits and normograms were calculated. No significant regression was found for the horse group over the range of physical parameters measured while regression was shown for the ponies. The cross‐sectional areas measured in this study may be useful for determining increased tendon size in cases of bilateral tendonitis or where there is minimal disruption to the internal ultrasonographic architecture of the tendon.

Caracterização ultrassonográfica das estruturas flexoras musculotendíneas e ligamentares da porção distal dos membros de novilhas cruzadas

“…Convém ressaltar que, em equinos, aumentos de áreas transversais da estrutura tendínea da ordem de 20% já indicam a ocorrência de lesão (Smith et al, 1994;Wrigley, 2006).…”

The cross-sectional area of the superficial digital flexor tendon of trained and untrained Thoroughbred racehorses

“…The CSA of the SDFT tendon has been determined in vivo in several studies (SMITH et al, 1994;GILLIS et al, 1995;GENOVESE et al, 1996;REEF, 1998;AGUT et al, 2009); nevertheless, the relation between normal values of the CSA of the right and left forelimbs SDFT for Thoroughbreds racehorses that had been in continuous race training and Thoroughbreds racehorses that had not been in athletic training has not yet been performed.…”

Ultrasonographic evaluation of cross-sectional area of tarsal ligaments in Standardbred Trotter Horses

“…Ultrasonographic evaluation of the CSA measurements in forelimb tendinous structures (i.e. superficial and deep digital flexor tendons) have proven to be an useful method for non-invasive tendon assessment (Smith et al 1994;Gillis et al 1995a;Pickersgill et al 2001;Perkins et al 2004;Agut et al 2009;Raes et al 2010;Korosue et al 2015). Quantitative ultrasound parameters had increased their application in equine clinical practice, and CSA analysis has become an useful technique for non-invasive assessments of tendons and ligaments, even if inter-breed variations have been proven Gillis et al 1995b;Agut et al 2009;Vilar et al 2011;Korosue et al 2015;Spinella et al 2015Spinella et al , 2016.…”

“…Echogenic evaluations of equine tendon and ligament texture and size have been described in order to recognize disorders in both adult horses and foals, particularly within the palmar metacarpal regions (Biller and Myer 1989;Chhem et al 1994;Smith et al 1994;Gillis et al 1997;Reef et al 2004;Agut et al 2009;Korosue et al 2015;Spinella et al 2015;El-Shafaey et al 2016;Spinella et al 2016). Likewise, ultrasound investigations of tendon and ligament aspects within the tarsal region have been previously reported (Ruohoniemi 1993;Santschi et al 1993;Tomlison et al 2000;Reef et al 2004;Raes et al 2010;Vilar et al 2011).…”