Lumbosacral Spine

• The minimum recommended projections of the lumbar spine are AP, lateral, oblique, and lateral L5/S1.
• The minimum recommended projections of the sacroiliac joint are AP axial and obliques.
• In the AP view, lordosis is preserved if the knees are extended.
• In the AP view, lordosis is eliminated if the knees are flexed.
• The interpedicular distances also represent the distance of the transverse diameter of the spinal cord.
• An increase in the interval between spinous processes may indicate a torn posterior ligament complex.
• Barge's angle is normally 53 plus or minus 4 degrees.
• Ferguson's angles is normally 41 plus or minus 2 degrees.
• A smaller Barge's angle and larger Ferguson's angle is associated with increased compressive forces.
• A larger Barge's angle and smaller Ferguson's angle is associated with increased axial forces.
• A posterior oblique view of the lumbar spine will always show the true and down side.
• An anterior oblique view of the lumbar spine will always show the false and upside.
• The IV foramina are best seen in the cervical spine in an oblique 45 degree view.
• The IV foramina are best seen in the thoracic and lumbar spine in a lateral view.
• The facet joints of the cervical spine are best seen on a lateral view.
• The facet joints of the thoracic spine are best seen on an oblique 70 degree view.
• The facet joints of the lumbar spine are best seen on an oblique 45 degree view.
• scotty dog

  A) transverse process

  B) pedicle

  C) pars

  D) inferior articular process

  E) lamina

  F) superior articular process

  
• Spondylolysis is a fracture of the pars due to extension. It is typically called a collar on the scottie dog.
• Spondylolisthesis is the forward displacement of a vertebrae.
• The spinous process sign of a fracture is a step-off above the level of the slip.
• The spinous process sign of a degenerative spondylolisthesis is a step off below the level of the slip.
• Grade one spondylolisthesis is 25% slippage.
• Grade two spondylolisthesis is 50% slippage.
• Grade three spondylolisthesis is 75% slippage.
• Grade four spondylolisthesis is 100% slippage.
• Sacroiliitis is inflammation of the SI joint.
• On a T2 MRI, the signal intensity of CSF is high.
• On a T2 MRI, the signal intensity of the IV disc is high.
• On a T1 MRI, the signal intensity of the IV disc is intermediate.
• Stenosis is defined as narrowing or constriction of the spinal canal secondary to adjacent soft tissue or bony enlargement.
• The radiologic characteristics of DDD of the lumbar spine are decreased disc space height, osteophytes at vertebral endplates, schmorl's nodes, and the vacuum phenomenon.
• The radiologic characteristics of DJD are decreased facet joint space, sclerosis, and osteophytosis at joint margins.
• The radiologic characteristic of spondylosis is osteophytes visible at vertebral joint margins.
• Spondylosis deformans are claw-like spurs cupping towards the IV discs. This must be present at more than one level for diagnosis.
• Diffuse idiopathic skeletal hyperostosis is a flowing ossification of at least four contiguous vertebrae. The disc height is preserved.
• Disc herniations are an extension of disc material beyond adjacent vertebral margins due to increased force leading to the degeneration of the annulus fibrosis.
• Anterior disc herniations are typically due to weakness in the attachment of the annulus to the vertebral rim via Sharpey's fibers.
• Anterior disc herniations may lead to spondylosis deformans.
• IV disc herniation is the result of the weakening of the vertebral endplate.