Morphometric analyses of the body and the branches of the normal third interosseous muscle (suspensory ligament) in Standardbreds

Abstract

SummaryThe third interosseous muscle (suspensory ligament, TIOM) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the body and the branches of right thoracic and pelvic limbs TIOM in sound horses to determine whether there are differences in CT, MT and AT between age, sex, limbs and levels. Right limbs from 11 sound horses were collected. Samples from 6 levels of the TIOM were embedded in paraffin or in Tissue-Tek ® . Most of the paraffin sections were shredded. Using the cryosection, some artefacts appeared.Cryoprotection was carried out, which produced the best results. Hematoxylin-phloxinesaffron and Hematoxylin-eosin gave a good contrast of colours between the tissues observed allowing the use of an image analysis programme to calculate percentage of each tissue within the TIOM. The percentage of MT and AT decreased significantly (P < 0.0001), whereas the percentage of CT increased significantly (P < 0.0001) with age and when descending from the proximal to the distal level of the TIOM. The percentage of MT was significantly higher (P < 0.0001) in females than males, while the percentage of CT was significantly higher (P < 0.0001) in males than females. The percentage of AT was significantly higher

Subclinical Ultrasonographic Abnormalities of the Suspensory Ligament Branches Are Common in Elite Showjumping Warmblood Horses

“…Grade 2 and 3 abnormalities were significantly more common in hindlimbs vs. forelimbs, which is not consistent with previously published data on frequency of clinical injury (5) where there was no significant difference shown between forelimbs and hindlimbs. Also, structural tissue type, quantity of collagen and muscle tissue is naturally symmetrical between thoracic and pelvic limbs (21). Similar studies published on subclinical ultrasonography for both Flat and National Hunt racehorses (7, 8) did not include ultrasonography of the hindlimbs, and as such, no data exists on subclinical abnormalities in forelimbs compared to hindlimbs.…”

The angle contrast ultrasound technique in the flexed limb improves assessment of proximal suspensory ligament injuries in the equine pelvic limb

“…; Shikh Alsook et al . ). These bundles divide the PSL into a major dorsal sagittal tendinous part and a peripheral tendinous part with medial, plantar and lateral parts ( Fig b ).…”

“…Distally, at the most proximal part of the body, the SL then becomes oval (Barone 1989). The PSL is mainly made of dense collagenous connective tissue (tendon) including 2 separate bundles made of fat, and containing striated muscles fibres, vessels and nerves (Denoix 2009;Schramme et al 2012;Shikh Alsook et al 2013). These bundles divide the PSL into a major dorsal sagittal tendinous part and a peripheral tendinous part with medial, plantar and lateral parts (Fig 3b).…”

Characterization of collagen fibrils after equine suspensory ligament injury: An ultrastructural and biochemical approach

“…The main role of the SL is to support the metacarpophalangeal joint and, together with the dorsal sesamoid ligaments, to protect it from hyperextension during the stance phase of the stride. Moreover, the SL limits palmar bending of the third metacarpal bone when compressive stresses act on the dorsal cortex of the bone (Gibson and Steel, 2002;Shikh Alsook et al, 2013).…”

“…The SL is a heterogeneous structure which consists of dense collagenous connective and adipose tissues surrounding muscle bundles (Shikh Alsook et al, 2013). It is known that the tensile mechanical properties of the connective tissue are determined primarily by the amount, type and arrangement of an abundant extracellular matrix component, collagen fibrils (Culav et al, 1999;Vesentini et al, 2013).…”