The radiographic frequency of impingement of the dorsal spinous processes at purchase examination and its clinical significance in 220 warmblood sporthorses

Abstract

Summary: A retrospective study of 220 horses was performed to investigate the association between the clinical signs and the radiological findings of impinging dorsal spinous processes (DSPs) in warmblood sporthorses. For this purpose radiographic records were assessed to identify all horses that had undergone radiographic examination of the back as part of a pre-purchase examination between January 2009 and December 2012. The dorsal spinous processes of 239 horses were assessed and each dorsal spinous process was individually graded (0 -3) using a modified 4-group grading system appropriate for routine grading of dorsal spinous processes as part of a pre-purchase examination. Fifty-five percent (n =121) had no radiological abnormalities of the DSPs (grade 0). However, 26,4 % had at least one DSP with grade 1 impingement, 11,8 % had at least one DSP with grade 2 and 6,8 % had at least one DSP with grade 3. Follow-up information was obtained by telephone responses from owners or trainers. The horses were assessed at a mean follow up time after pre-purchase examination of 25,19 ±12,52 months. Based on the clinical signs included in the questionnaire answers horses were divided into two groups; i) thoracolumbar back pain and ii) no thoracolumbar back pain. Only 11,5 % (N = 23) of the 220 horses had shown thoracolumbar back pain. There was no significant association between gender, age or discipline and clinical signs of thoracolumbar back pain. High maximum DSP grade is associated with an increased risk of clinical signs. The specificity of a grade 3 DSP on radiographic screening at pre purchase examinations is high, however the sensitivity is low. This suggests that there is a high risk of clinical signs in horses with grade 3 DSPs and no warranty can be offered for absence of clinical signs for grade 0,1,2.Keywords: back pain / horse / kissing spines / pre purchase / radiology Citation: de Graaf K., Enzerink E., van Oijen P., Smeenk A., Dik K. J. (2015) The radiographic frequency of impingement of the dorsal spinous processes at purchase examination and its clinical significance in 220 warmblood sporthorses. Pferdeheilkunde 31, 461-468

Inter‐ and intra‐observer agreement for grading radiographs of thoracolumbar spinous processes in healthy horses during a pre‐purchase examination

“…The current study is the first to describe inter‐ and intra‐observer agreement of different radiographic alterations found in equine thoracolumbar SP on PPE. Previously published scoring systems have not been validated and tested for reliability and these studies either graded their radiographic alterations by only one experienced observer or two observers in consensuses 4,14–19 …”

“…Grading systems that do not grade the SP separately but use a combined and generalized grading system for the thoracolumbar spine, as done in the previous grading systems, [14][15][16][17][18] were found to be of moderate to fair agreement in the current study for the most experienced observers. However, usage of multiple individual parameters per anatomical region of the SP also revealed some unreliable results.…”

“…Every single spinous process involved in the radiographic study in every horse was evaluated separately, with individual exceptions of those which were not included in the radiographic study and therefore not graded. A grading scale was designed involving structural changes leading to radiographic abnormalities described in previously used scoring systems 14–19 . For every single SP 16 different radiographic variables were graded, this involved ISW, modelling, radiolucencies and radiopacities along its margins and isolated opacities dorsal to the SP.…”

“…Previous used scoring systems all vary substantially and they have not fully described all possible radiographic abnormalities per SP. The results were generalized and rather focussed on the sum of all abnormalities in the thoracolumbar spine 14–18 . A limited amount of studies described a grading scale originating from a sum of grades per SP 4,19 .…”

A comment about the German Equine Radiology Guidelines

“…Auch die Formulierung "röntgenologisch keine Risikobefunde" sollte nicht verwendet werden. (Jeffcott et al 1979, 1980, Randelhoff 1997, Ranner 1997, Sager 1997, Erichsen et al 2004, Brunken et al 2005, Holmer 2005, Sinding et al 2010, de Graaf et al 2015.…”