What vertebral pathologies are common causes of radiculopathy?

Vertebral Pathologies Causing Radiculopathy

The most common vertebral pathologies causing radiculopathy are cervical disc herniation and cervical spondylosis (degenerative changes), followed by foraminal stenosis from facet or uncovertebral joint hypertrophy, with lumbar disc herniation at L4-L5 and L5-S1 being the predominant cause in the lumbar spine. 1, 2

Primary Compressive Causes

Disc-Related Pathology

• Disc herniation: The most frequent cause, typically occurring posterior-laterally and compressing nerve roots at the neural foramen 1, 2

  • Cervical: Most common in patients >30 years of age
  • Lumbar: Highest risk in ages 20-39 years, particularly at L4-L5 and L5-S1 levels 3
  • 57% of patients with low back pain and 65% with radiculopathy demonstrate disc herniation on imaging 3

• Degenerative disc disease: Progressive disc degeneration with associated osteophyte formation, typically beginning in the 20-29 age range with osteophytes developing from the fifth decade onward 4

Bony Pathology

• Cervical spondylosis: Degenerative changes causing neural foraminal narrowing through:

  • Facet joint hypertrophy
  • Uncovertebral joint hypertrophy
  • Associated disc bulging 1

• Spinal stenosis: Narrowing of the spinal canal causing bony constriction of nerve roots 3, 5

  • Central stenosis compressing the cauda equina
  • Lateral recess stenosis
  • Foraminal stenosis 6

• Spondylolisthesis: Vertebral slippage predisposing to nerve root compression, particularly in the lumbar spine 3

• Osteoarthrosis of apophyseal joints: Age-related degenerative changes, strongly associated with mechanical stress from heavy occupations 4

Less Common Vertebral Causes

Fracture-Related

• Osteoporotic vertebral fractures (OVFs): Can cause radiculopathy through:
  • Lumbar canal stenosis (most common presentation)
  • Lumbar foraminal stenosis (high frequency following OVF)
  • Combined stenosis patterns 6

Vascular Anomalies

• Vertebral artery loop formation (VALF): Rare but significant cause where an ectatic or anomalous vertebral artery compresses nerve roots within the foramen, particularly at C4-5 and C5-6 levels 7, 8
  • Critical to identify preoperatively to prevent iatrogenic injury during surgery
  • Requires specialized imaging (MR/CT angiography) for diagnosis

Infectious/Inflammatory

• Vertebral osteomyelitis: Constitutes 1-5% of all osteomyelitis cases

  • Cervical spine involvement in 3-6% of vertebral osteomyelitis cases
  • Risk factors: diabetes, immunosuppression, IV drug use, prior spinal instrumentation 9

• Discitis: Infection of the disc space with potential nerve root involvement

Neoplastic

• Primary tumors: Schwannomas, neurofibromas (benign), malignant peripheral nerve sheath tumors (rare) 10
• Metastatic disease: Secondary involvement of vertebral bodies with nerve root compression 3

Age-Related Patterns

Critical distinction: The pathology varies significantly by age:

• Ages 20-39: Disc herniation predominates
• Ages 40-60: Mixed disc herniation and spondylotic changes
• Ages >60: Spondylosis, spinal stenosis, and osteoarthrosis become primary causes 4

Important Clinical Caveats

High false-positive rate on imaging: Degenerative changes are commonly identified in asymptomatic individuals >30 years of age and correlate poorly with symptoms 1. Disc abnormalities appear in 20-28% of asymptomatic patients, increasing to 57-65% in symptomatic patients 3.

Lateral disc herniations: May be missed on standard lumbar spine MRI but detected on lumbosacral plexus MRI, as they compress the distal nerve root lateral to the neural foramen 10.

Multiple level involvement: Multilevel radiculopathy can occur simultaneously, and cervical myelopathy may coexist with radiculopathy 11, 12.