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Back to CIM Cases
SpineSpine/Rheumatology

Rheumatoid Arthritis - Cervical Spine

Spine
Intermediate
6 min
High Yield
rheumatoid arthritisatlantoaxial instabilitybasilar invaginationsubaxial subluxationADIPADIcervical myelopathyoccipitocervical fusionC1-C2 fusionRanawat classification
6:00
Start the timer to simulate exam conditions

CIM Case: Rheumatoid Arthritis - Cervical Spine

Clinical Scenario

Patient: 58-year-old female Presentation: 20-year history of seropositive rheumatoid arthritis, 6 months of progressive unsteadiness, occasional suboccipital headaches worse with neck movement, episodes of dizziness, one fainting spell Relevant history: On methotrexate and prednisolone, multiple joint replacements (bilateral THR, right TKR), poorly controlled inflammation recently (elevated CRP) Examination findings:

  • Obvious RA deformities - MCP subluxation, swan neck deformities, ulnar drift bilateral hands
  • Bilateral foot deformities (hallux valgus, claw toes)
  • Wide-based gait
  • Romberg positive
  • Upper limbs: Generalised weakness (4/5), difficult to assess due to joint disease
  • Lower limbs: Hyperreflexia bilateral (3+)
  • Hoffman's sign positive bilateral
  • Ankle clonus (3 beats bilateral)
  • Babinski upgoing bilateral
  • Sensation: Reduced proprioception lower limbs
  • Bladder: No incontinence, no urgency

Investigations Provided

Laboratory Results

TestResultNormal RangeInterpretation
Haemoglobin108 g/L120-160Anaemia of chronic disease
WCC7.2 × 10⁹/L4-11Normal
Platelets385 × 10⁹/L150-400Normal
ESR65 mm/hr0-20Elevated - active RA
CRP42 mg/L<5Elevated - active inflammation
Rheumatoid factorPositive (256 IU/mL)<14Seropositive RA
Anti-CCPPositive (>300 U/mL)<20High titre - erosive disease
Creatinine85 μmol/L60-110Normal (important for methotrexate)
ALT35 U/L<40Normal (methotrexate monitoring)

Imaging

Image 1: Cervical Spine Radiographs - AP, Lateral, Flexion-Extension

Radiological features:

  • Neutral lateral:
    • Atlantodental interval (ADI) = 6mm (normal <3mm)
    • Posterior atlantodental interval (PADI) = 12mm (concerning <14mm)
    • No obvious basilar invagination on lateral
  • Flexion view:
    • ADI increases to 10mm
    • Significant C1-C2 instability demonstrated
  • Extension view:
    • ADI reduces to 4mm
    • Dynamic instability confirmed
  • Subaxial spine:
    • C3-4 and C4-5 subluxation ("stepladder" appearance)
    • Disc space narrowing C4-5, C5-6
    • No obvious basilar invagination

Image 2: MRI Cervical Spine with Brainstem

MRI findings:

  • Pannus formation around odontoid (soft tissue mass posterior to dens)
  • Moderate cord compression at C1-C2 level from pannus
  • Cord signal change (T2 hyperintensity) at C1-C2 level - myelomalacia
  • Subaxial stenosis C4-5 with mild cord compression
  • No cord signal change at subaxial level
  • Odontoid intact, no erosion through tip

Image 3: CT Cervical Spine

CT findings:

  • Erosion of odontoid peg laterally
  • C1-C2 facet erosions
  • No fracture
  • Lateral mass anatomy preserved (important for fixation planning)

Questions & Model Answers

Q1

What are the three patterns of cervical spine involvement in rheumatoid arthritis and how do they present?

Q2

What are the clinical features of cervical myelopathy in RA, and how do you grade severity?

Q3

What imaging would you order and what measurements are critical?

Q4

What are the indications for surgery in RA cervical spine? What procedure would you recommend for this patient?

Q5

What are the specific perioperative considerations in RA patients undergoing cervical spine surgery?

Q6

What are the expected outcomes and complications of surgery? How do you follow up these patients?


Key Teaching Points

Pattern Recognition

This pattern suggests RA Cervical Spine Involvement:

  • Longstanding seropositive RA with peripheral joint destruction
  • Suboccipital headache and neck pain
  • Myelopathic features (UMN signs) out of proportion to peripheral disease
  • Unsteadiness, gait abnormality
  • Vertebrobasilar symptoms (dizziness, fainting)

Three Patterns of Involvement:

PatternFrequencyKey MeasurementSurgical Concern
Atlantoaxial instability65%ADI, PADIC1-C2 fusion
Basilar invagination20-25%Ranawat, McRaeOccipitocervical fusion
Subaxial subluxation20-25%>3.5mm translationExtended fusion

Critical Management Points

  1. PADI <14mm = surgery indicated - even if asymptomatic
  2. Flexion-extension views essential - demonstrate dynamic instability
  3. MRI shows pannus and cord - T2 signal change is poor prognostic sign
  4. Awake fibreoptic intubation - safest for AAI
  5. Continue methotrexate, stop biologics - medication management
  6. Ranawat IIIA is optimal timing - don't wait until non-ambulatory

Common Examiner Follow-ups

Q: "What is pannus and why is it important?"

AspectDescription
DefinitionInflammatory synovial tissue proliferation
LocationForms behind the dens, around the odontoid
EffectCompresses cord, erodes bone, causes instability
Treatment responseMay reduce with DMARDs/biologics
Surgical relevanceMay need to excise if causing compression even after fusion

Pannus can persist even after successful fusion and may need anterior resection if compression continues.


Q: "Why is pre-operative assessment important before other joint surgery in RA patients?"

ConcernAction
AAI may be asymptomaticCervical X-rays before any GA
Intubation riskAvoid neck manipulation
Positioning riskLateral for hip surgery stresses neck
RecommendationFlexion-extension views pre-op if longstanding RA

Patients with ADI >5mm or PADI <14mm need awake fibreoptic intubation and may need cervical stabilisation before elective surgery.


Q: "What is the difference between Harms-Goel and Magerl techniques?"

AspectHarms-GoelMagerl
ScrewsSeparate C1 lateral mass + C2 pedicleTransarticular C1-C2
TrajectoryC2 → C1 (two screws per side)C2 → C1 single screw per side
ReducibilityCan reduce then fixMust reduce before placing
VA riskLowerHigher (screw crosses VA territory)
Current preferenceMost commonLess used now

Harms-Goel is preferred because it allows reduction after screw placement and has lower VA injury risk.


Related Topics

  • Rheumatoid Arthritis - General
  • Atlantoaxial Instability
  • Cervical Myelopathy
  • Occipitocervical Fusion
  • Basilar Invagination
  • Upper Cervical Spine Trauma
Quick Stats
Category
Spine
DifficultyIntermediate
Time Allowed6 min
Reading Time46 min
Investigation Types
imaging
Exam Tips

Read the clinical scenario carefully

Structure your answers systematically

Consider differential diagnoses

Justify your investigation choices

Think about management priorities