Cervical Spine Disorders

Cervical Anatomy & Biomechanics - Neck's Atlas & Axis

• Atypical Vertebrae:
  • C1 (Atlas): No body/spinous process. Ring-like. 📌 Atlas: No body, holds head.
  • C2 (Axis): Dens for rotation.
  • C7 (Vertebra Prominens): Long, non-bifid spinous process.
• Typical Vertebrae (C3-C6): Small body, bifid spinous process, transverse foramina (vertebral artery).
• Key Ligaments:
  • Transverse Lig.: C1-C2 stability (holds dens).
  • ALL/PLL: Limit extension/flexion.
  • Ligamentum Flavum: Elastic, connects laminae.
• Joints & Artery Path:
  • Uncovertebral (Luschka): C3-C7, guide motion.
  • Vertebral Artery: Enters C6 transverse foramen, ascends C1-C6.

  ⭐ The vertebral artery typically enters the transverse foramen at C6 and passes through C1-C6, but NOT C7.

• Nerve Root Exit:
  • C1-C7: Above corresponding vertebra.
  • C8: Below C7 (between C7-T1).
• Normal ROM (approx.): Flexion 45-50°; Extension 50-60°; Lat. Flexion 45°; Rotation 80° (C1-C2 ~50%).

Cervical Spondylosis & PIVD - Aging Neck Pains

Degenerative cascade: disc desiccation, osteophytes, facet arthropathy, ligamentum flavum hypertrophy. Common at C5-C6, C6-C7.

• Features: Axial neck pain, stiffness. Radiculopathy (Spurling's +ve; arm pain, weakness, paresthesia). Myelopathy (gait issues, UMN signs, bowel/bladder changes).
• Imaging:
  • X-ray: Osteophytes, ↓ disc height, foraminal stenosis.
  • MRI: Gold standard. Disc herniation (protrusion, extrusion, sequestration), cord compression/signal changes.
• Management:
  • Conservative: Rest, NSAIDs, physiotherapy, collar.
  • Surgical: Progressive neuro deficit, myelopathy, intractable pain after 6-12 wks conservative trial.

⭐ C5-C6 is the most common level affected by cervical spondylosis and disc herniation.

Cervical Myelopathy & Radiculopathy - Pinched Nerves & Cord

• Definitions: Myelopathy (spinal cord compression); Radiculopathy (nerve root compression).
• Causes: Spondylosis, PIVD, trauma, tumor.

• Myelopathy Severity Scales: Nurick grade, mJOA score.
• 📌 Mnemonic (Cervical Roots): "C5 keeps deltoids alive, C6 for biceps/wrist extension fix, C7 triceps/wrist flexion heaven, C8 finger flexion great, T1 intrinsics state."

⭐ Cervical myelopathy often presents with a combination of UMN signs below the level of compression and LMN signs at the specific level(s) of compression.

Cervical Spine Trauma - Fractures & Fixes

• Mechanisms: Flexion, Extension, Axial Load, Rotation.
• Stability: Denis 3-column (adapted): ≥2 columns → Unstable. White & Panjabi: >3.5mm displacement, >11° angulation.
• Clearance: NEXUS (No midline Tenderness, Intoxication, altered Alertness, Neuro deficit, Distracting injury). Canadian C-Spine Rule.

• Fractures:
  • Jefferson (C1 burst): Axial load.
  • Hangman's (C2): Hyperextension; C2 pars fracture.
  • Odontoid (Dens) Fx:
    • Type I: Tip (Stable).
    • Type II: Base (Unstable). 📌 "Type II is Unstable & Nasty"
    • Type III: Into C2 body (Stable).
  • Teardrop Fx: Flexion (unstable) or Extension.
  • Clay-shoveler's Fx: C7 spinous process; stable.
• SCIWORA: Spinal Cord Injury Without Radiographic Abnormality (children).
• Management: ATLS, immobilization.

⭐ Type II Odontoid fractures are most common and have highest non-union risk due to precarious blood supply.

High‑Yield Points - ⚡ Biggest Takeaways

• Jefferson fracture: C1 burst due to axial load; highly unstable.
• Hangman's fracture: Traumatic spondylolisthesis of C2 over C3 (bilateral C2 pars fractures); unstable.
• Odontoid fractures: Type II is most common, most unstable, often needing surgery.
• Cervical spondylosis: Degenerative; osteophytes cause radiculopathy or myelopathy.
• Klippel-Feil syndrome: Congenital fusion; triad: short neck, low hairline, limited neck motion.
• Positive Spurling's test indicates radiculopathy; Hoffman's sign suggests myelopathy_