The purpose is to determine how reliably degenerative changes in the facet joints (FJs) and intervertebral discs (IvDs) can be assessed on computed tomography (CT) scans.
At least six raters, including neurosurgeons and CT specialists, will independently evaluate anonymized CT scans covering the T9-L3 levels. The study will assess reproducibility of the Pathria grading scale for FJ degeneration and of quantitative measurements such as FJ space width and FJ angulation.
availability of CT scans covering the T9-L3 vertebrae;
absence of imaging artifacts at the level of interest.
bone mineral density of the vertebrae of <100 HU;
systemic diseases of bone or joints associated with changes in the FJs and IvDs (including diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, rheumatoid arthritis, etc.);
previous spinal surgery, including procedures performed without instrumentation;
spinal fractures involving injury to the posterior structures;