II. Epidemiology
- Ages affected
- Disc Herniation rarely occurs before age 20 years
- Age 20-30 years: Up to one third have at least one degenerative lumbar disc
- Most common ages 30 to 50 years
- Most common spinal levels affected (95% of lumbar disc)
- Olympic athletes (worldwide, multiple sports)
- L5-S1 disc displacement in 58%
- Ong (2003) Br J Sports Med 37(3): 263-6 [PubMed]
III. Mechanism
- Progressive degeneration of disc nucleus pulposus
- Results from normal aging or repetitive Trauma
- Protrusion of disc (most commonly posterior-lateral)
- Herniation affects spinal root one level below
- Other Changes: Spondylosis (Chronic disc deterioration)
- Spur Formation
- Disc space narrowing
- Facet joint degeneration
IV. Symptoms
- See Low Back Pain
- Always inquire about Low Back Pain Red Flags (e.g. Cauda Equina Syndrome symptoms, fever, IVDA, Cancer)
- Usually insidious onset
- Acute Trauma may have preceded symptoms
-
Low Back Pain (deep aching)
- Aggravated by activity, coughing, sneezing or Valsalva Maneuver
- Provoked by prolonged sitting and forward bending
- Relieved by rest
- Localized to affected disc
- Intense Radicular Pain
- See Sciatica
- Referred pain to iliac crest or buttock
- Radiation of pain down posterior thigh and calf
- Pain may radiate into foot
-
Paresthesias
- Numbness or tingling in distal extremity
V. Signs
- Restricted low back range of motion
- Pain exacerbated by bending to affected side
- Local tenderness and Muscle guarding
- Painful gait
- Posturing to avoid pressure on disc
- Bent away from affected side
- Hip and knee flexed on affected side
- Nerve Root Tension Tests
-
Neurologic Examination
- Deep Tendon Reflexes
- L4 Nerve Root (L3-4 disc): Patellar Reflex
- S1 Nerve Root (L5-S1 disc): Achilles Reflex
- Motor Exam
- Sensory Exam
- L4 Nerve Root (L3-4 disc): Medial malleolus
- L5 Nerve Root (L4-5 disc): Dorsal third metatarsophalangeal joint
- S1 Nerve Root (L5-S1 disc): Lateral heel
- Deep Tendon Reflexes
- Radicular patterns by disc Herniation type
- Central DIsk Herniation
- Nerve root affected is ABOVE the disc
- Example: Central L3 disc Herniation causes findings above the L2-3 Nerve root
- Paracentral disk Herniation
- Nerve root affected is AT the disc
- Example: Paracentral L3 disc Herniation causes findings at the L2-3 Nerve root
- Lateral disk Herniation
- Nerve root affected is BELOW the disc (foraminal effects)
- Example: Lateral L3 disc Herniation causes findings at the L3-4 Nerve root
- Central DIsk Herniation
VI. Diagnosis
- Findings with strongest Positive Predictive Value for Lumbar Disc Disease
- Symptoms: Sciatica pain associated with:
- Pain in leg worse than back
- Typical Dermatomal Distribution of pain
- Pain provoked by Valsalva Maneuver
- Exam findings
- Crossed Straight Leg Raise positive
- Weak ankle dorsiflexion
- Absent ankle reflex
- Calf Muscle wasting (late finding)
- Symptoms: Sciatica pain associated with:
- Findings with strongest Negative Predictive Value for Lumbar Disc Disease
- No Sciatica
- Negative Straight Leg Raise
VII. Differential diagnosis
- See Sciatica
- See Low Back Pain Red Flags
- See Musculoskeletal Low Back Pain
- Lumbar spine Degenerative Joint Disease
- Lumbar Radiculopathy due to spine degeneration (osteophytes or bone spurs) typically follows a fixed or progressive course
- Contrast with Lumbar Disc Herniation which tends to improve as the disc Herniation resorbs
- Spinal Cord Tumor
- Consider especially in age under 20 or over 60 years
- Relentless pain aggravated or not relieved with rest
VIII. Imaging
- See Low Back Imaging
-
Lumbar Spine MRI has a 50% False Positive Rate (asymptomatic findings)
- Correlate pain and symptoms with MRI findings
IX. Management: Rehabilitation
X. Course
- Mild cases frequently resolve within 1-2 weeks
- Spontaneous recovery is the rule (90% in 6 weeks)
- Other cases may persist with moderate pain for 6 months
- Long-term outcomes are not improved with surgery (outcomes the same at 2 years)