L-Spine

Lumbar Disc Herniation

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Lumbar Disc Herniation, Lumbar Disc Disease, Lumbar Disk Herniation, Lumbar Disk Disease

  • Epidemiology
  1. Ages affected
    1. Most common ages 30 to 50 years
    2. Rarely occurs before age 20 years
  2. Most common spinal levels affected (95% of lumbar disc)
    1. Vertebral level L4-5
    2. Vertebral level L5-S1
  • Mechanism
  1. Progressive degeneration of disc nucleus pulposus
    1. Results from normal aging or repetitive Trauma
  2. Protrusion of disc (most commonly posterior-lateral)
    1. Herniation affects spinal root one level below
  3. Other Changes: Spondylosis (Chronic disc deterioration)
    1. Spur Formation
    2. Disc space narrowing
    3. Facet joint degeneration
  • Complications
  • Symptoms
  1. Usually insidious onset
    1. Acute Trauma may have preceded symptoms
  2. Low Back Pain (deep aching)
    1. Aggravated by activity, coughing, and sneezing
    2. Relieved by rest
    3. Localized to affected disc
  3. Intense Radicular Pain
    1. See Sciatica
    2. Referred pain to iliac crest or buttock
    3. Radiation of pain down posterior thigh and calf
    4. Pain may radiate into foot
  4. Paresthesias
    1. Numbness or tingling in distal extremity
  • Signs
  1. Restricted low back range of motion
  2. Pain exacerbated by bending to affected side
  3. Local tenderness and muscle guarding
  4. Posturing to avoid pressure on disc
    1. Bent away from affected side
    2. Hip and knee flexed on affected side
  5. Nerve Root Tension Tests
    1. Straight Leg Raise
  6. Neurologic Examination
    1. Deep Tendon Reflexes
      1. L4 Nerve Root (L3-4 disc): Patellar Reflex
      2. S1 Nerve Root (L5-S1 disc): Achilles Reflex
    2. Motor Exam
      1. L4 Nerve Root (L3-4 disc): Ankle dorsiflexion
      2. L5 Nerve Root (L4-5 disc): Great toe dorsiflexion (extensor hallucis longus)
      3. S1 Nerve Root (L5-S1 disc): Ankle plantar flexion (gastrocnemius-soleus complex)
    3. Sensory Exam
      1. L4 Nerve Root (L3-4 disc): Medial malleolus
      2. L5 Nerve Root (L4-5 disc): Dorsal third metatarsophalangeal joint
      3. S1 Nerve Root (L5-S1 disc): Lateral heel
  7. Radicular patterns by disc Herniation type
    1. Central DIsk Herniation
      1. Nerve root affected is ABOVE the disc
      2. Example: Central L3 disc Herniation causes findings above the L2-3 Nerve root
    2. Paracentral disk Herniation
      1. Nerve root affected is AT the disc
      2. Example: Paracentral L3 disc Herniation causes findings at the L2-3 Nerve root
    3. Lateral disk Herniation
      1. Nerve root affected is BELOW the disc (foraminal effects)
      2. Example: Lateral L3 disc Herniation causes findings at the L3-4 Nerve root
  • Diagnosis
  1. Findings with strongest Positive Predictive Value for Lumbar Disc Disease
    1. Symptoms: Sciatica pain associated with:
      1. Pain in leg worse than back
      2. Typical dermatomal distribution of pain
      3. Pain provoked by Valsalva Maneuver
    2. Exam findings
      1. Crossed Straight Leg Raise positive
      2. Weak ankle dorsiflexion
      3. Absent ankle reflex
      4. Calf muscle wasting (late finding)
  2. Findings with strongest Negative Predictive Value for Lumbar Disc Disease
    1. No Sciatica
    2. Negative Straight Leg Raise
  • Differential diagnosis
  1. See Sciatica
  2. See Low Back Pain Red Flags
  3. See Musculoskeletal Low Back Pain
  4. Lumbar spine Degenerative Joint Disease
    1. Lumbar Radiculopathy due to spine degeneration (osteophytes or bone spurs) typically follows a fixed or progressive course
    2. Contrast with Lumbar Disc Herniation which tends to improve as the disc Herniation resorbs
  5. Spinal Cord Tumor
    1. Consider especially in age under 20 or over 60 years
    2. Relentless pain aggravated or not relieved with rest
  • Imaging
  • Course
  1. Mild cases frequently resolve within 1-2 weeks
  2. Spontaneous recovery is the rule (90% in 6 weeks)
  3. Other cases may persist with moderate pain for 6 months
  4. Long-term outcomes are not improved with surgery (outcomes the same at 2 years)