Cervical Myelopathy

Video

Western Health Orthopaedic Registrar presentation – Cervical Spondylosis, Radiculopathy & Myelopathy by Dr James Churchill

Definition

  • Spinal cord dysfunction
    • Demyelination of the lateral columns with degeneration of the anterior parts of the posterior columns
    • Destruction of the central grey matter

Epidemiology

  • Most common spinal cord dysfunction in patients > 55 years old

Aetiology

  • Extrinsic compression of cord (or its vascular supply or both) caused by degenerative disease of spine

Pathology

  • Maybe associated with congenital or developmental stenosis of the cervical canal
  • Disc degenerates
  • Secondary osteoarthritic changes occur in the facet & uncovertebral joints
  • Reduction of available space
  • Ligamentum Flavum invaginates into canal posteriorly
  • Disc & posterior vertebral body osteophytes encroach anteriorly – Pincher action

Differential Diagnosis

  • CVD
  • AV malformation
  • Demyelinating disease
  • Syringomyelia
  • Intracranial tumour
  • Hydrocephalus
  • Tabes dorsalis
  • Myopathy
  • Peripheral neuropathy
  • Metabolic or alcoholic encephalopathy

History

  • Neck pain
  • Difficulty walking
  • Unsteadiness on feet
  • Pain, numbness & weakness with clumbsiness of hands common
  • May also have radicular symptoms
  • Bladder dysfunction uncommonly occurs
  • co existent lumbar stenosis common

Examination

  • UMN in extremities below lesion & LMN signs at level of lesion
  • Can see UMN signs cephalad to lesion
  • Hoffman Reflex
    • Flexion of ipsilateral IPJ of index & thumb when long finger IPJ flicked & extension of neck ↑ sensitivity
  • Inverted Radial Reflex
    • Spontaneous flexion of digits when BR reflex elicited & indicates cord compression at C5 & C6 (commonest levels)
  • L’Hermitte sign
    • Flexion or extension of neck produces electric shock sensations in legs
  • Abnormal Plantar reflexes
    • Usually only abnormal when severe
  • Earliest sensory changes are dysdiadochokinesia & poor tandem gait
    • Vibration & Joint position sense affected early
    • Weakness & loss of proprioception leads to Wide Based Gait
    • Finger Escape Sign – deficient adduction or extension of ulnar digits of affected hand

Investigations

Cervical Myelopathy, sagittal mri of compressive cervical myelopathy at c6 to c7
Sagittal MRI of compressive cervical myelopathy at C6 to C7. Image by Jmarchn, Wikimedia Commons, CC BY-SA 3.0.

XRs

  • Narrowed joint space
  • C5/6 commonest level followed by C6/7
  • Osteophytic lipping with foraminal & uncovertebral osteophytes seen
  • Lateral may showListhesis
  • Lordosis
  • Kyphosis
  • Flexion / Extension views show instability
  • Pavlovs Ratio (A-P diameter of spinal canal divided by the A-P diameter of body at same level) indicator of developmental stenosis
  • Should be 1.0 & < 0.8 is narrowed & stenotic
  • diameter (A-P) reduced from normal (17mm) to relative (13mm) to absolute stenosis (10mm)
  • Remember that 70% of population have degenerative changes by 70 year

MRI

  • Evaluate soft tissues of the cord
  • High incidence or asymptomatic findings – 19% of asymptomatic patients have abnormality on MRI
  • Disc prolapse & cord oedema with signal change seen

CT – Myelography

  • Helps distinguish disc from osteophytes
  • Superior for cord compression due to subluxed body & ossification of the PLL
  • transverse diameter of cord at affected level on CT – Myelogram shown to be best prognostic indicator in spondylitic stenosis & ossification of PLL

Treatment

  • Natural history
    • suggests that > 50% of patients become worse if not treated
  • best spinal cord recovery seen in those treated with:
    • Decompression within 6 – 12 months
    • Early, mild myelopathic signs
    • Those whose transverse area of cord greater than 40 mm 2 postoperatively

Non-operative

  • Cervical collar
  • Nsaids
  • Physiotherapy with isometric strengthening
  • Ice, heat & massage
  • Follow up every 6-12 weeks initially followed by yearly if no progression
  • Traction & manipulation contraindicated

Operative

  • Absolute Indications
    • Progressive neurological deficit
    • Failure to improve with 6 /12 of non op treatment
    • Should try to operate prior to
      • Compression ratio < 0.4
      • Transverse spinal cord diam of < 40 mm2
      • Increased signal intensity of cord T2 MRI
    • patient with cervical & lumbar stenosis should have the cervical spine decompressed first because:
      • Risk of intubation damage to Cx spine reduced for lumbar surgery
      • Leg symptoms mat improve after the cervical decompression
  • Preoperative Considerations:
    • All NSAIDS ceased 2 weeks prior to surgery
    • Positioning should avoid hyperextension of cervical spine

Surgical Considerations

Positioning & Setup

  • Positioning for Anterior approach is
    • Supine with interscapular roll
    • Traction of 5 pounds
    • Head turned slightly to right for left sided approach to avoid rec laryngeal n
  • Positioning for the Posterior approach:
    • Prone
    • Mayfield head tongs in neutral
  • Should use the following ancillary devices:
    • Pneumatic compression stockings
    • IDC
    • Infiltration of skin with adrenaline solution

Bone Grafting Technique

  • Iliac crest autograft
    • preferred for the anterior interbody fusion rather than allograft
    • When > one segment fused then the failure of autograft was 17% cf 63% with allograft
    • iliac crest graft should be thick enough to provide at least 2mm more distraction than baseline disc height
    • Saw harvested tricortical grafts more strength than osteotome harvested

Soft Disc Herniation

  • Younger patients
  • Non op treatment often effective & indication for intervention include:
    • Failure of non op with >6 months of symptoms
    • Progressive myelopathy with correlative diagnostic studies
  • Important technical factors:
    • MRI reviewed carefully to exclude free disc lying behind the PLL
    • Should resect the disc until the longitudinal fibres of PLL seen & inspected carefully for defect
    • If no defect or MRI findings then should not routinely remove the PLL
  • Requirements for anterior approach include:
    • One, two or three level pathology
    • Pathology primarily at disc level
    • Anterior cord compression

Degenerative Disc Disease

  • Technical Factors:
    • Once disc removed the posterior body osteophytes removed
  • Disadvantages include
    • difficulty decompressing the nerve roots in foramen from front
    • difficult access to the posterior osteophytes
  • Cloward procedure allows better visualisation but risks include:
    • Fusion less stable
    • No distraction
    • Greater potential for collapse

One or Two Level Spondylosis with Developmental Narrowing of Canal

  • Pavlov ratio 0.8 to 1.0 Anterior approach favoured
  • if continued symptoms post-op & no ↑ in cord diameter then consider posterior laminectomy & fusion

Lesions of Two or More Levels

  • Preferred treatment is anterior vertebrectomy & strut grafting
    • this leads to better outcome of fusion over large number of motion segments
  • Can Never consider posterior decompression if the patient has kyphotic spine

Technical Factors

  • Lateral borders of body preserved
  • If > 7cm could consider vascularised fibula graft
  • Postop Halo immobilisation can minimise the risks of:
    • Graft dislodgement
    • Spinal malalignment
    • Pseudoarthrosis

Instability & Cervical Spondylitic Myelopathy

  • If severe instability with kyphosis then combined anterior & posterior procedures used
  • Anterior Decompression & Arthrodesis
    • Maintain physiological lordosis
  • Instrumentation can:
    • Maintain alignment
    • Improve graft stability
    • Eliminate need for halo in selected patients

The Use of Posterior Laminectomy over Anterior Considered in

  • Technical limitations of anterior approach
  • Prior anterior surgery
  • Lordotic cervical spine

Ossification of the PLL

  • Very common in asian population
  • 50% have associated DISH
  • Multiple levels usually involved with CT evidence best
  • Recommended procedure is posterior decompression
  • With the Anterior approach the dura may be absent or attached firmly to the dura & result in irreparable tears with CSF leaks
  • if Kyphosis present then should perform anterior decompression

Complications

Disease

  • Progressive loss of hand function and gait
  • Central cord syndrome after minor hyperextension injury

Surgery

  • C5 palsy after decompression in about 5%
  • Dural tear and CSF leak, more frequent with OPLL
  • Dysphagia and recurrent laryngeal nerve palsy after anterior surgery
  • Postlaminectomy kyphosis and axial neck pain without fusion
  • Pseudarthrosis and adjacent segment disease after fusion

Prognosis

  • Natural history is stepwise deterioration with plateau periods
  • 20% to 62% deteriorate without surgery over 3 to 6 years
  • Surgery halts progression and improves function in most patients
  • Poorer recovery with long symptom duration, older age and severe preoperative deficit
  • T1 hypointensity with T2 hyperintensity on MRI predicts poorer recovery
  • AO Spine guideline recommends surgery for moderate and severe myelopathy

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.