Osseous spinal pathology and epaxial muscle ultrasonography in Thoroughbred racehorses

Abstract

SummaryReasons for performing study: The multifidus muscle plays a key role in spinal stabilisation. Multifidus atrophy ipsilateral to the side of osseous pathology has been demonstrated in man and pigs but has not been investigated in horses. Objectives: To measure cross-sectional area (CSA) left/ right symmetry of equine multifidus ultrasonographically and relate asymmetry of multifidus with osseous spinal pathology in Thoroughbred racehorses. We hypothesised that ipsilateral multifidus CSA would be reduced when osseous pathological changes are present leading to left/right asymmetry in CSA. Materials and methods: Twenty-two racehorses presented for euthanasia for primary reasons other than back pain were examined clinically. Ultrasonographic images on left/right sides were acquired at 5 thoracolumbosacral levels and CSA's of multifidus or sacrocaudalis dorsalis calculated. At necropsy, osseous pathological of the TL spine and pelvis were recorded by spinal level, anatomical site, and graded (0-3) according to severity. The mean typical measurement error in estimating multifidus/sacrocaudalis dorsalis CSA was used to determine the significance of left/right asymmetries. An association between multifidus CSA asymmetry and asymmetrical grading of pathological lesions was sought using Pearson's c 2 analysis. Results: All horses had significant left/right asymmetry of multifidus CSA at >2 spinal levels, most commonly at L5 with total of 74 sites affected (22 horses). Seventeen horses had severe (grade 3) pathology, 16 of these had ipsilateral atrophy of multifidus/sacrocaudalis dorsalis. There was a significant association between pathological grade and degree of multifidus asymmetry. Conclusions: Severe osseous pathological changes were common in this population of Thoroughbred racehorses and were associated with measurable left/right asymmetry in multifidus at or close to the level of pathology. Potential relevance: Ultrasonography of multifidus may be a useful clinical tool in diagnosis of back problems in horses.

Biometry by ultrasonography of the epaxial and pelvic musculature in equines trained with Pessoa's rein

“…O LD é o músculo epaxial mais superfi cial, sendo a atrofi a muito visível, enquanto que o GM, por ter também função postural, encontra-se em áreas mais profundas (DINGBOOM et al, 2002). Ainda, STUBBS et al (2010) relacionaram atrofi a destas musculaturas, com a ocorrência de cavalos com lombalgia. Contudo, na atual pesquisa, não foi observada atrofi a da musculatura epaxial (P>0,05), bem como não se verifi cou sensibilidade dolorosa à palpação da região, denotando que o treinamento imposto, com a rédea Pessoa, permitiu a manutenção do tônus muscular.…”

“…As imagens referentes ao Gluteus Medius (GM) foram obtidas na linha perpendicular (dorso-ventral) a terceira vértebra sacral (STUBBS et al, 2010); para o Biceps Femoris (BF), utilizouse da linha média entre a tuberosidade coxal e primeira vértebra coccígena (LINDNER et al, 2010), Semitendinosus (ST) foi mensurado a 20cm abaixo da linha tracejada, a partir da tuberosidade isquiática (LINDNER et al, 2010); e o Musculus Multifi dus (MM), na quinta vértebra lombar (L5) (STUBBS et al, 2011a).…”

“…As mensurações biométricas musculares auxiliam na avaliação funcional do músculo, por indicar sua característica como tamanho normal, atrofi ado ou hipertrofi ado, que são importantes, por exemplo, na verifi cação da efetividade de protocolo de treinamento (STUBBS et al, 2010). Estas medidas podem ser obtidas mediante uso de fi ta métrica (O'CONNOR et al, 2002), pela ultrassonografi a e por ressonância magnética (STUBBS et al, 2011b).…”

“…Em equinos, a ultrassonografi a tem sido usada com boa confi ança e repetibilidade na avaliação biométrica do Longíssimus Dorsi, Musculus Multifi dus, Gluteus Medius e Biceps Femoris (KERSTEN & EDINGER, 2004;STUBBS et al, 2010;LINDNER et al, 2010;STUBBS et al, 2011a). Nesse sentido, a utilização da rédea Pessoa em programas de treinamento, por modifi car a postura do cavalo em movimento e provocar alterações biomecânicas em comparação à locomoção sem a rédea, induziria a adaptações funcionais e modifi cações no tamanho de determinados músculos.…”

Muscular and neuromotor control and learning in the athletic horse

“…Neuromotor control in the lumbo-pelvic region during movement and the reactions in the system to pain and injury are important areas of research in the prevention and management of back and pelvic pain in humans and horses (Hodges et al, 2013;Stubbs et al, 2010). As mentioned above, an important muscle group for neuromotor control in the thoracolumbar region are the mm.…”