Vertebral column Flashcards
Changes in aging IV disks
- Nuclei P dehydrate
- Elastin & proteoglycan down, collagen up
- IV disk: turgor lost, stiffer, NP dry & stiff, NP merge with annulus fibrosis
- AF greater vertical load
- Vertebral bodies = increasingly concave
- IV disks = increasingly convex
- AP diameter increase 10%F & 2%M
Herniation of nucleus pulposi
- Cause lower back, limb pain
- Posterior portion of AP thinnest
- Herniations generally extend posterolaterally (here AF is relative thin & no support from post/ant ligaments
- Most common in Lumbar and Lumbosacral regions
- 95% of lumbar disk protrusions occur at L4-L5 or L5-S1
- Diagnosis of acute herniation in old suspicious, more likely increased ossification compressing nerves
Cause of localized back pain following NP herniation
- Usually acute pain
- Pressure on longitudinal ligaments & periphery of AF
- Local inflammation from chemical irritation (irritants form NP contents)
Non-local back pain following NP herniation
- Usually referred pain
- Perceived as coming from dermatome of compressed nerve
- Chronic pain
Lumbago
- Acute mid/lower back pain
- Due to mild posterolateral protrusion of lumbar IV L5-S1
- Affects pain receptors on post longitudinal ligament
Sciatica
- Pain in low back & hip, radiates down back of thigh/leg
- Caused by herniated lumbar disk compressing L5 or S1 component of sciatic nerve
- IV formamin in lumbar region small, nerves larger
- Flexing thigh w/ knee extended (Kerning maneuver) worsens (most of the time)
- HERNIATION COMPRESSES NERVE EXITING 1 BELOW HERNIATED DISK
Injury and disease of zygapophysial joints
- Injury/osteoarthritis = pain in dermatomes, spasm of myotomes
- Denervation is treatment
- Posterior rami of nerve root at affected foramina + 1 above sectioned or destroyed w/ radiofrequency percutaneous rhizolysis
- Articular branch of post rami at level + 1 level above ablated
Fracture of dens
- Transverse ligament is stronger than dens
- Fractures = unstable > transverse ligament becomes interposed > den has no blood supply
- Dens has no blood supply > avascular necrosis
- If fracture is below dens on body of axis, blood supply maintained > heals
Rupture of transverse ligament of atlas
- Results in atlantoaxial subluxation
- Softening of transfers ligament and adjacent ligaments > subluxation
- Spinal cord may become entrapped between posterior arch and dense > quadriplegia or death
- Steele rule of thirds: 1/3 fluid & CT, 1/3 Spinal cord, 1/3 dens
Rupture of alar ligament
- Alar = weaker than transverse ligament
- Combined flexion and rotation can tear (FR-ALAR)
- 30% increase in range of movement to the contralateral side
Compression of the C2 spinal ganglion
- Atlantoaxial rotation may compress C2 SN
- Hyperextention + head turned > compression of C2 SN > headache and cervio-occipital pain
Fractures and dislocations vertebrae
- Sudden forceful flexion > crush/compression fracture
- Anterior movement of vert + compression > anterior displacement > displaces + fractures articular facets & ruptures interspinous ligaments
Spondylolysis
- Break at pars interarticularis
- Indicated by broken neck of “scotty dog”
Spondylolisthesis
- Dislocation b/t adjacent vertebrae
- Common at L5-S1 due to angle of joint
Structures that receive innervation from back and can be a source of pain
- Fibroskeletal (periosteum, ligaments, AF of IV discs): recurrent meningeal
- Meninges:recurrent meningeal
- Synovial: post rami articular branch
- Muscle: post rami muscular branch
- Nervous tissue
(FMSMN)
Most common sources of localized lower back pain (LBP)
Muscular, joint, fibroskeletal
Source of fracture pain
Periosteum
Source of dislocation pain
ligaments
Kyphosis
- Erosion of anterior part of vertebrae > abnormal increase in thoracic curvature
- Dowager’s hump
Lordosis
- Anterior rotation of pelvis > Increase in lumbar curvature
- Cause weakened trunk muscles
- Obesity and pregnancy can also cause
Scoliosis
- Abnormal curvature and rotation of vertebrae
- Weakened trunk, especially anterolateral abdominal muscles
- Myopathic scoliosis: caused by asymmetrical weakness of intrinsic back muscles
- 80% of all structural scoliosis is idiopathic
Hemivertebra
- Failure of 1/2 a vertebra to form
- Cause of structural scoliosis
Kyphoscoliosis
- Scoliosis + kyphosis
- Abnormal AP diamater > restriction of thorax and lung expansion
