Abstract
Treatment recommendations differ for dogs with intervertebral disk extrusion vs. intervertebral disk protrusion. The aim of this retrospective, cross-sectional study was to determine whether clinical and magnetic resonance imaging (MRI) variables could be used to predict a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion in dogs. Dogs were included if they were large breed dogs, had an MRI study of the thoracolumbar or lumbar vertebral column, had undergone spinal surgery, and had the type of intervertebral disk herniation (intervertebral disk extrusion or protrusion) clearly stated in surgical reports. A veterinary neurologist unaware of surgical findings reviewed MRI studies and recorded number, location, degree of degeneration and morphology of intervertebral disks, presence of nuclear clefts, disk space narrowing, extent, localization and lateralization of herniated disk material, degree of spinal cord compression, intraparenchymal intensity changes, spondylosis deformans, spinal cord swelling, spinal cord atrophy, vertebral endplate changes, and presence of extradural hemorrhage. Ninety-five dogs were included in the sample. Multivariable statistical models indicated that longer duration of clinical signs (P = 0.01), midline instead of lateralized disk herniation (P = 0.007), and partial instead of complete disk degeneration (P = 0.01) were associated with a diagnosis of intervertebral disk protrusion. The presence of a single intervertebral herniation (P = 0.023) and dispersed intervertebral disk material not confined to the disk space (P = 0.06) made a diagnosis of intervertebral disk extrusion more likely. Findings from this study identified one clinical and four MRI variables that could potentially facilitate differentiating intervertebral disk extrusions from protrusions in dogs.
Highlights
Intervertebral disk herniation is a well-recognized and common spinal cord disorder in dogs.[1,2,3,4] Two types of degenerative intervertebral disk herniation have traditionally been recognized: intervertebral disk extrusion or Hansen Type-I, and intervertebral disk protrusion or Hansen Type-II disk herniation.[3]
Protrusionmorphology, partial disk degeneration, herniated disk material confined to the intervertebral disk space, ventral location of herniated disk material, spinal cord atrophy, lower compression ratio values, presence and type of intraparenchymal signal intensity changes, presence and type of endplate changes, presence of multiple intervertebral disk herniations, and presence of spondylosis deformans were significantly associated with a diagnosis of intervertebral disk protrusion
One clinical and four magnetic resonance imaging (MRI) variables were identified as independent predictors for the exact type of intervertebral disk herniation (Table 2)
Summary
Intervertebral disk herniation is a well-recognized and common spinal cord disorder in dogs.[1,2,3,4] Two types of degenerative intervertebral disk herniation have traditionally been recognized: intervertebral disk extrusion or Hansen Type-I, and intervertebral disk protrusion or Hansen Type-II disk herniation.[3]. 4,11 Apart from the above mentioned differences in pathophysiology and clinical presentation, intervertebral disk extrusions and protrusions are associated with different suggested treatment options 4,10,12-14, and possibly a different prognosis.[4] Intervertebral disk extrusions are typically treated by a hemilaminectomy.[5] Several studies have suggested this type of surgery would be inadequate for intervertebral disk protrusions and have suggested alternative surgical approaches, including additional vertebral stabilization[10] or a lateral corpectomy.[12,13] While a hemilaminectomy is considered a basic spinal surgical technique, a corpectomy should be considered more technically demanding
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
