Congenital thoracic vertebral malformations in brachycephalic “screw-tailed” dog breeds: Validation of a human classification scheme and a method of Cobb angle measurement in the assessment of vertebral column deformity

摘要

Congenital vertebral malformations are common in brachycephalic “screw-tailed” dogudbreeds such as French bulldogs, English bulldogs, Boston terriers, and Pugs. Thoseudvertebral malformations disrupt the normal vertebral column anatomy and biomechanics,udpotentially leading to deformity of the vertebral column and subsequent neurologicaluddysfunction. The initial aim of this work was to study and determine whether theudcongenital vertebral malformations identified in those breeds could be translated in audradiographic classification scheme used in humans to give an improved classification, withudclear and well-defined terminology, with the expectation that this would facilitate futureudstudy and clinical management in the veterinary field. Therefore, two observers who wereudblinded to the neurologic status of the dogs classified each vertebral malformation basedudon the human classification scheme of McMaster and were able to translate themudsuccessfully into a new classification scheme for veterinary use.udThe following aim was to assess the nature and the impact of vertebral column deformityudengendered by those congenital vertebral malformations in the target breeds. As no goldudstandard exists in veterinary medicine for the calculation of the degree of deformity, it wasudelected to adapt the human equivalent, termed the Cobb angle, as a potential standardudreference tool for use in veterinary practice. For the validation of the Cobb angleudmeasurement method, a computerised semi-automatic technique was used and assessed byudmultiple independent observers. They observed not only that Kyphosis was the mostudcommon vertebral column deformity but also that patients with such deformity were foundudto be more likely to suffer from neurological deficits, more especially if their Cobb angleudwas above 35 degrees.