KEY FACTS Imaging Location Discs and synovial joints of spine Joints of axial skeleton, less commonly peripheral joints Tendon and ligament attachments (entheses) Sacroiliac joints (SIJs): Bilaterally symmetric erosive arthropathy → fusion Facet, uncovertebral joints: Erosions → fusion Squaring of…
KEY FACTS Terminology Metabolic arthropathy Crowned dens syndrome: Pain due to calcium pyrophosphate dihydrate deposition around dens Imaging Soft tissue calcifications Usually linear, occasionally globular Seen in ligaments, discs, facet joint capsules, hyaline cartilage Horseshoe-shaped calcification around dens Erosions of…
KEY FACTS Imaging Erosions of dens, uncovertebral joints, facet joints Atlantoaxial instability in 20-86% patients with RA Atlantoaxial subluxation in 5% of cervical RA Cranial settling occurs in 5-8% of RA patients Lower cervical spine: Facet and uncovertebral joint erosions,…
KEY FACTS Terminology Defects in pars interarticularis (PI) thought to result from repetitive stress injury Pars is junction of pedicle, lamina, and facet Imaging Most common at L5: 80-90% Discontinuity in neck of “Scotty dog” on oblique plain films Elongation…
KEY FACTS Terminology Anterolisthesis: Anterior displacement of vertebral body relative to 1 below Retrolisthesis: Posterior displacement of vertebral body relative to 1 below Imaging Lateral flexion and extension to evaluate for instability Napoleon's-hat sign on AP plain film Instability uncommon…
KEY FACTS Terminology Ossification of posterior longitudinal ligament (OPLL) Imaging Flowing multilevel ossification posterior to vertebral bodies Relatively minimal degenerative disc disease, absent facet ankylosis Midcervical (C3-C5) > midthoracic (T4-T7) PLL ossification narrows AP spinal canal dimension → spinal stenosis,…
KEY FACTS Terminology Diffuse idiopathic skeletal hyperostosis (DISH) Forestier disease, senile ankylosing hyperostosis, asymmetrical skeletal hyperostosis Imaging Flowing anterior vertebral ossification with minimal degenerative disc disease, facet arthropathy, absent facet ankylosis Thoracic spine (100%) > cervical (65-80%), lumbar spine (68-90%);…
KEY FACTS Terminology Spinal canal and neural foraminal narrowing in cervical spine secondary to multifactorial degenerative changes Imaging Completely effaced cerebral spinal fluid in cervical spine at disc levels Cervical spine, ventral epidural, centered at disc levels Sagittal diameter of…
KEY FACTS Terminology Reduced AP canal diameter secondary to short, squat pedicles and laterally directed laminae Imaging Central canal diameter is smaller than normal Cervical spine: Absolute AP diameter < 14 mm Spinal stenosis present if AP canal diameter at…
KEY FACTS Terminology Spinal canal narrowing in lumbar spine Secondary to multifactorial degenerative changes, being progressive and dynamic process Imaging Trefoil appearance of lumbar spinal canal on axial imaging Sagittal diameter of bony lumbar canal < 10 mm Top Differential…