Cervical and Lumbar Spondylosis: A Comprehensive Review

DEFINITION

• Bradley and Daroff's Neurology in Clinical Practice
• Firestein & Kelley's Textbook of Rheumatology

AETIOLOGY & RISK FACTORS

Common to Both Cervical and Lumbar Spondylosis

Cervical-Specific Risk Factors

• Frequent lifting and carrying heavy loads
• History of excessive driving (sustained vibration)
• Dystonia and cervical movement disorders - predispose to premature degeneration
• Most commonly affects C5-C6, followed by C6-C7

Lumbar-Specific Risk Factors

• Heavy physical labour and prolonged sitting
• Most commonly affects L4-L5 ("the backache disc"), followed by L5-S1
• Major cause of morbidity with significant financial impact
• Miller's Review of Orthopaedics, 9th Edition
• Bradley and Daroff's Neurology in Clinical Practice

PATHOLOGY

The Degenerative Spinal Cascade (Kirkaldy-Willis, 1970s)

• In youth: nucleus pulposus is gelatinous; annulus fibrosus is firm and collagenous
• By age 40: dehydration and shrinkage of the nucleus pulposus begins
• Necrosis and fibrosis of the annulus fibrosus
• Sclerosis and microfractures at the subchondral vertebral endplate

• Loss of disc height leads to loss of normal spinal curvature (lordosis)
• Increased loading on facet joints and (in the cervical spine) uncovertebral joints (joints of Luschka)
• Facet joint capsules contain sensory receptors contributing to pain and proprioceptive abnormalities

• Osteophyte formation (spondylotic bars/hard disc)
• Ligamentum flavum hypertrophy
• Facet joint arthrosis with medial encroachment
• Spinal canal stenosis - neural compression from combination of:
  • Disc herniation (soft disc)
  • Disc-osteophyte complex (hard disc)
  • Ligament hypertrophy
  • Facet joint enlargement
  • Congenital narrow canal

• Neck extension: cord compressed between spondylotic bar anteriorly and hypertrophic facets + infolded ligamentum flavum posteriorly
• Neck flexion: slight increase in canal diameter, temporary relief
• Miller's Review of Orthopaedics, 9th Edition
• Adams and Victor's Principles of Neurology, 12th Edition

CLASSIFICATION

Cervical Spondylosis - Four Clinical Entities

1. Discogenic neck pain (axial pain) - disc degeneration without neural compression
2. Cervical radiculopathy - nerve root compromise
3. Cervical myelopathy - spinal cord compression
4. Cervical myeloradiculopathy - combined cord and root compromise

• Normal: 1.0
• Abnormal (risk factor for neurological involvement): <0.8

Lumbar Spondylosis - Four Clinical Entities

1. Discogenic back pain - isolated disc degeneration without instability or neural compression
2. Lumbar disc herniation - with or without sciatica/radiculopathy
3. Spondylolisthesis - segmental instability from disc collapse and facet incompetence
4. Lumbar spinal stenosis - neurogenic claudication:
   • Central stenosis - thecal sac compression (absolute stenosis: cross-sectional area <100 mm² or AP diameter <10 mm)
   • Lateral recess / subarticular stenosis
   • Foraminal stenosis

• Miller's Review of Orthopaedics, 9th Edition

CLINICAL FEATURES

CERVICAL SPONDYLOSIS

1. Discogenic Neck Pain

• Insidious onset of neck pain, exacerbated by motion
• Occipital headache common
• Normal neurological examination (normal motor, sensory, reflexes)
• No radiculopathy or myelopathy

2. Cervical Radiculopathy

• Pain originates from the neck, radiates down the arm
• Subscapular/interscapular pain common (especially C7)
• Dysesthesias, paresthesias, numbness
• Increased by coughing, Valsalva, or the Spurling maneuver (neck extension + rotation toward the painful side + axial compression)
• Shoulder abduction sign (relief of arm pain when hand placed on head) suggests cervical origin

3. Cervical Myelopathy (Spondylotic Myelopathy)

• The most frequently observed myelopathy in general practice (Adams and Victor's)
• Characteristic triad:
  1. Painful stiff neck, brachialgia (neck, shoulder, upper arm pain - aching or radicular)
  2. Numbness and paresthesias of the hands - "wearing gloves," "coated with glue"; involves distal limbs especially hands
  3. Spastic leg weakness - Babinski signs, wide-based gait, Romberg sign, tabetic unsteadiness
• Lhermitte's sign - neck flexion produces lightning-like electric sensations down the spine
• Finger clumsiness, deterioration of handwriting, difficulty with fine motor tasks
• Myelopathy hand - difficulty with rapid hand movements
• Finger escape sign - small finger spontaneously abducts (weak intrinsics)
• Inverted radial reflex - finger flexion occurs when brachioradialis reflex elicited
• Hyperreflexia, Hoffmann sign, clonus, Babinski sign
• Urinary retention, urgency, or frequency in advanced cases
• Rarely: Brown-Séquard syndrome pattern

• Stepwise deterioration followed by stability: 65-80% (most common)
• Slowly progressive decline: 20-25%
• Rapidly progressive decline: 3-5%

In ~40% of patients >50 years: cervical crepitus, pain, or restriction of lateral flexion/rotation

LUMBAR SPONDYLOSIS

1. Discogenic Back Pain

• Back pain greater than leg pain
• No radiculopathy, no tension signs
• Paucity of physical findings
• Exacerbated by motion

2. Lumbar Radiculopathy / Disc Herniation

• Most herniations are posterolateral (posterior longitudinal ligament weakest laterally)
• L4-L5 herniation affects the L5 root; L5-S1 herniation affects the S1 root
• Sciatica: pain radiating down the leg in a dermatomal distribution

• Straight leg raise (SLR) / Lasègue sign - reproduction of radicular leg pain with hip flexion and knee extension (sensitive for L4/L5/S1 root irritation)
• Contralateral SLR - raising the asymptomatic leg produces pain in the symptomatic leg; more specific for axillary disc herniation
• Femoral tension sign - prone patient, passive knee flexion with hip extended; reproduces anterior thigh symptoms (L2, L3, L4 root irritation)

3. Lumbar Spinal Stenosis / Neurogenic Claudication

• Neurogenic claudication: bilateral leg pain, numbness, weakness with walking/standing
• Relieved by sitting, forward flexion (shopping cart sign), or lying down
• Distinguished from vascular claudication by relief with lumbar flexion (not just rest)
• More common in men; affects older population

INVESTIGATIONS

Imaging Approach

Plain Radiographs (X-Ray)

• First-line imaging in most cases
• Shows: disk-space narrowing, osteophytes, vertebral endplate sclerosis, loss of lordosis, foraminal narrowing
• Lateral cervical film: measure AP canal diameter between posterior vertebral body (line 3) and spinolaminar line (line 4)
• Flexion-extension views: assess segmental instability (especially pre-operatively)
• Important limitation: radiographic findings correlate poorly with symptoms; they are present in >90% of people >60 years without symptoms

• Major trauma (MVA, fall from height)
• Minor trauma in older/osteoporotic patients
• Prolonged corticosteroid use
• Age >70 years
• History of cancer
• Constitutional symptoms (fever, weight loss)
• Risk factors for spinal infection
• Pain worse supine or severe at night

MRI (Magnetic Resonance Imaging) - Gold Standard for Neural Compression

• T2-weighted: shows disc degeneration (dark disc = decreased signal = dehydrated nucleus), cord compression, cord signal change (myelomalacia = high T2 signal within cord = ischaemia), annular tear, high-intensity zone (HIZ)
• T1-weighted: bony anatomy, disc herniation contour
• Gadolinium enhancement: best for recurrent disc herniations (differentiates scar from recurrent disc)
• False-positive MRI is very common - clinical correlation is essential
• Cord signal change on MRI correlates with worse prognosis in myelopathy

CT / CT Myelography

• CT myelogram: if MRI contraindicated; superior for defining bony anatomy; useful after previous surgery
• CT: measures canal cross-sectional area (absolute lumbar stenosis: <100 mm²)

Electrodiagnostic Studies (EMG / Nerve Conduction Studies)

• Identifies the level and severity of radiculopathy
• Distinguishes radiculopathy from peripheral neuropathy or plexopathy
• Especially useful when imaging findings are multiple and clinical localisation is uncertain

Discography

• Controversial preoperative study
• Needle injected into disc under fluoroscopy; concordant pain reproduction is a positive result
• Falling out of favour - evidence suggests it may accelerate symptomatic disc degeneration

DIAGNOSIS

Cervical Spondylosis

1. History: age, onset, character of neck/arm/hand symptoms, gait disturbance
2. Examination: neurological localisation (root vs cord vs both), special tests (Spurling, shoulder abduction sign, Hoffmann, Lhermitte)
3. Imaging: MRI is modality of choice - confirms level and severity of compression and presence of cord signal change

• Tumour (primary or metastatic)
• Multiple sclerosis
• Motor neuron disease (ALS)
• Syringomyelia
• Subacute combined degeneration (B12 deficiency) - symmetric sensory symptoms identical to spondylotic myelopathy
• Peripheral neuropathy

Lumbar Spondylosis

1. History: character of back vs leg pain, posture-dependence, walking distance before symptoms (claudication)
2. Examination: SLR, neurological level, tension signs
3. Imaging: MRI lumbar spine - must correlate with clinical findings (false positives are common)

MANAGEMENT

Conservative (Non-operative) Treatment - First Line for Most

Surgical Management

• Progressive motor weakness
• Persistent disabling pain despite adequate conservative therapy (typically ≥6-12 weeks)
• Cervical myelopathy (natural history is typically progressive - surgery frequently indicated)
• Bladder/bowel dysfunction

CERVICAL SURGERY

• ACDF (Anterior Cervical Discectomy and Fusion) - removal of herniated disc + osteophytes + interbody fusion with or without plating; single or multilevel
• ACCF (Anterior Cervical Corpectomy and Fusion) - for pathology behind the vertebral body; corpectomy + strut graft fusion
• Anterior procedures can be used for both kyphotic and lordotic sagittal alignment

• Posterior keyhole laminoforaminotomy - for radiculopathy secondary to posterior compression (facet hypertrophy) or lateral soft disc herniations; contraindicated for central herniations
• Laminectomy + fusion or Laminoplasty - for multilevel myelopathy; contraindicated in fixed cervical kyphosis (cannot indirectly decompress cord in this position)

• Cervical total disc replacement (arthroplasty) - for single- or (FDA-approved) two-level spondylosis causing radiculopathy/myelopathy; maintains kinematics; equivalent outcomes to ACDF at 7-10 year follow-up; contraindicated with deformity, instability, or facet arthropathy
• Complication: heterotopic ossification (7-69%)

LUMBAR SURGERY

• Hemilaminotomy and discectomy - most common procedure
• Open, limited open, microscope-assisted, and endoscopic approaches are equally effective
• Total laminectomy for large central herniations
• Fusion is not typically required unless there is pre-existing instability at the herniation level

• Laminectomy (decompression) - mainstay
• Fusion added if instability or spondylolisthesis present

• Conservative treatment almost always preferred
• Surgery controversial; interbody fusion or disc arthroplasty are options after failed conservative therapy
• Total disc arthroplasty (L4-L5 or L5-S1): equivalent to fusion at 2-year follow-up but concerns about long-term results

SUMMARY TABLE

• Bradley and Daroff's Neurology in Clinical Practice - Ch. 104 (Spinal Osteoarthritis and Spondylosis)
• Adams and Victor's Principles of Neurology, 12th Edition - Ch. 15 (Cervical Spondylosis with Myelopathy)
• Miller's Review of Orthopaedics, 9th Edition - Ch. 8 (Cervical and Lumbar Degenerative Disc Disease)
• Firestein & Kelley's Textbook of Rheumatology - Ch. 47 (Lumbar Spondylosis)