Morphological studies in relation to the biomechanics of the thoracolumbar vertebral column and the pathogenesis of overriding or kissing spines in horses

107

Summary Reasons for performing study: Radiography and scintigraphy are used to aid diagnosis of the cause of back pain, but a large variation in appearance and radiopharmaceutical uptake in fully functioning horses make diagnosis difficult. Objectives: To describe the range of and compare scintigraphic and radiographic findings in the spinous processes of horses without clinical signs of back problems. Methods: Thirty‐three apparently normal riding horses underwent scintigraphic and radiographic examinations of the spinous processes in the thoracolumbar spine. Scintigraphic images were evaluated in a continuous blue, green and red colour scale, and the level of radiopharmaceutical uptake in the spinous processes from T10–L2 was graded into none, mild, moderate or severe increased radiopharmaceutical uptake. Structural changes along the borders of the spinous processes and the width of the interspinous spaces from T10–L2 were recorded. Results: Only 7 horses had no scintigraphic or radiographic findings. Nine horses had no increased radiopharmaceutical uptake, 17 had no sclerosis, 21 had no radiolucencies and 11 had normal spacing of the spinous processes (>4 mm wide). The majority of findings in 26 horses were located from T13–18 and were mild. Conclusions: The findings of a wide spectrum of scintigraphic and radiographic changes leads to the conclusion that changes within this range found in affected horses cannot be interpreted as clinically significant. Potential relevance: To determine whether scintigraphy and/or radiography can be used to separate horses with back pain from horses without clinical signs, the results from this study should be compared to the scintigraphic and radiographic findings in horses with clinical signs.

Section: Resultsmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Relationship between scintigraphic and radiographic evaluations of spinous processes in the thoracolumbar spine in riding horses without clinical signs of back problems

Erichsen

Eksell

Holm

et al. 2004

107

“…The most common site for impingement of the thoracic dorsal spinous processes is the saddle region (i.e. 12th to 17th thoracic vertebrae) and repeated overextension of the vertebrae is considered to be one factor in the development of impingement of the thoracic dorsal spinous processes. Athough some authors suggest that the rider's weight is the source for the over extension , impingement of the thoracic dorsal spinous processes has been identified in horses that had never been ridden .…”

Section: Discussionmentioning

confidence: 99%

“…12th to 17th thoracic vertebrae) and repeated overextension of the vertebrae is considered to be one factor in the development of impingement of the thoracic dorsal spinous processes. Athough some authors suggest that the rider's weight is the source for the over extension , impingement of the thoracic dorsal spinous processes has been identified in horses that had never been ridden . In the present study, intervertebral distances between the dorsal spinous processes in the saddle region were smaller than those in the cranial area, which could explain the more frequent changes identified in the saddle region.…”

Section: Discussionmentioning

confidence: 99%

Influence of head and neck position on radiographic measurement of intervertebral distances between thoracic dorsal spinous processes in clinically sound horses

Berner

Winter²,

Brehm

et al. 2012

SummaryReasons for performing study: Reductions in distances between dorsal spinous processes on radiographs are used as criteria for the diagnosis of impingement of the thoracic dorsal spinous processes in horses but are potentially altered by spine motion and different head and neck positions. Objectives: To determine the influence of head and neck positions on intervertebral distances between dorsal spinous processes on radiographs of thoracic spines of clinically sound horses. Methods: Lateral-lateral radiographs were obtained from 23 horses in 3 head and neck positions. The width of the thoracic dorsal spinous processes and intervertebral distances between adjacent thoracic dorsal spinous processes were measured at points perpendicular to a tangent between the dorsal spinous processes and the caudal extremity of the thoracic vertebrae. Results: A low head and neck position increased intervertebral distances between adjacent thoracic dorsal spinous processes from the 8th to 15th dorsal spinous processes whereas a high head and neck position had the opposite effect (P<0.05). Overall, intervertebral distances between adjacent thoracic dorsal spinous processes decreased from cranial to caudal in intermediate head and neck positions (P<0.01). The 12th thoracic dorsal spinous process was readily identifiable due to its significant difference to the narrower cranial and broader caudal dorsal spinous process (P<0.05). Conclusions:The head and neck position influences the distances between the dorsal spinous processes of the vertebrae of equine thoracic spine on radiography. Potential relevance: The measuring system reported here offers potential to improve and standardise radiographic evaluation of thoracic dorsal spinous processes.

Distances between thoracic spinous processes in Warmblood foals: A radiographic study

Sinding¹,

Berg²

2010

In this study none of the interspinous spaces were <4 mm and therefore none of the foals showed signs of impinged or overriding of dorsal spinous processes known as KSS based on the current definitions. Consequently, in this population, there did not appear to be a congenital narrowing of the interspinous space. However, long-term follow-up studies, including detailed information on imposed factors such as training, are needed in order to further elucidate a possible congenital component in the aetiology of KSS.