Effects of body position and clinical signs on L7-S1 intervertebral foraminal area and lumbosacral angle in dogs with lumbosacral disease as measured via computed tomography

Objective—To measure effects of dog position on L7-S1 intervertebral foraminal area and lumbosacral (LS) angle by means of computed tomography (CT) and determine whether changes in values between positions are associated with clinical signs in dogs with LS disease. Animals—86 dogs examined via a positional CT protocol that included flexion and extension scans of L7-S1. Procedures—Archived CT images and medical records were reviewed. Included dogs had good-quality flexion and extension CT scans of L7-S1 and no evidence of fractures, neoplasia, or previous LS surgery. One person who was unaware of CT findings recorded clinical status with regard to 3 signs of LS disease (right or left hind limb lameness and LS pain) at the time of CT evaluation. One person who was unaware of clinical findings measured L7-S1 foraminal areas and LS angles, with the aid of an image-analysis workstation and reformatted parasagittal planar CT images. Results—Intraobserver variation for measurements of L7-S1 foraminal area ranged...