Overview of Cervical Disc Herniation.pptx

Cervical disc herniation and management

1. Cervical Disc Herniation Department of Neurosurgery Dr RE Anto 31/10/2023

2. Applied Anatomy of Cervical Spine Primary function: Mobility Support Protection of spinal cord and nerve roots

3. Consists of 7 vertebral bodies From the base of the skull to thoracic spine Atypical: C1 + C2 + C7 Typical: C3 – 6

4. Intervertebral disc Cartilaginous structure: Inner nucleus pulposus Outer annulus fibrosis Lamellae Endplates that anchor the discs

5. Ligaments Anterior longitudinal ligament Posterior longitudinal ligament Ligamentum nuchae Supraspinous ligament Interspinous/Intertransverse ligaments Ligamentum flavum

6. Vasculature

7. Spinal canal dimension Normal cervical spinal canal diameter from C3-C7 is 17 – 18mm in normal adults But < 15 mm in most cases of myelopathy Cervical cord: roughly 10mm in diameter

8. Etiology Process of disc herniation: Acute: more likely from trauma Chronic: disc becomes degenerated or desiccated as part of an aging or osteodegenerative process

9. Epidemiology Increases with age for both women and men Most common: Third to Fifth decade of life Slight predominance in females (60%)

10. Pathophysiology Static mechanical cord compression Dynamic mechanical cord compression Impaired circulation within the cord

11. Encroaching upon the spinal canal space resulting in stenosis Osteophytes Spinal ligaments Disc material Can occur simultaneously Static Mechanical compression

12. Dynamic Mechanical Cord Compression Flexion of the neck – compression against osteophytic bars Extension – buckling of ligamentum flavum and compression MICROTRAUMA

13. Impaired circulation within the cord Anterior spinal artery can be compressed Critical medullary feeders Impaired venous drainage NEURO-ISCHEMIC MYELOPATHY

14. Inflammation Nerve irritation from herniated disc: Inflammatory cytokines IL-1, IL-6, substance P, bradykinin, TNF-a and prostaglandins Trajectory of nerve root As it exits neural foramen Close to associated pedicle More susceptible

15. Clinical evaluation Neck pain Myelopathy Radiculopathy Marginal symptoms

16. Physical evaluation - Myelopathy Upper motor neuron findings: Usually in lower extremity Weakness with no atrophy or fasciculations Spasticity: scissoring of legs Sensation: any loss below the level of involvement Complete loss Brown-Sequard (ipsilateral vibratory and position sense loss and contralateral loss of pinprick) Central cord sx (suspended sensory loss in UL) Reflexes: Hoffmans reflex, Babinksi sign, Ankle clonus

17. Physical evaluation - Radiculopathy Lower motor signs Weakness usually in one myotome on one side Atrophy + fasciculations may be present Sensation: Dermatomal pattern Same as myotomal weakness Reproduction of radicular symptoms with axial loading of the head

18. Provocative tests – Cervical Root Compression SPURLING TEST LHERMITTE SIGN

19. Nerve Root Compression Syndromes

20. Imaging Xray Look at the vertebral bodies Quality of bone Intervertebral disc space Osteophytes Calcified PLL Dynamic views for subluxation

21. CT and CT Myelogram When more in-depth bony assessment is required Any associated fractures Ossified PLL Levels: C5-6 (good) C6-7 (artefact from shoulders) C7-T1 (poor) CT Myelogram: Not commonly used Invasive

22. MRI Gold Standard Evaluate discs T1 + T2 sagittal T2 GRE sequence Dark material next to disc space is bone Disc is higher signal CSF is high signal

23. Miyazaki M, Hong SW, Yoon SH, Morishita Y, Wang JC. Reliability of a magnetic resonance imaging-based Grading System For Cervical Intervertebral Disk degeneration. J Spinal Disord Tech 2008;21(4):288–292 Thompson disc degeneration staging.

24. Electrodiagnostic (EMG + NCS) EMG: Can be normal in sensory only radiculopathy Challenging due to many muscles having shared innervation Biceps + Deltoid + Brachioradialis + Infraspinatis + Supraspinatus (C5-6) NCS: Can be helpful in differentiating a peripheral neuropathy from proximal radiculopathy Good physical exam should be the base E.g C6 neuropathy from carpal tunnel sx

25. Treatment Modalities Non-operative (Conservative) 70 – 80 % will improve Physical therapy Interventional pain management Anti-inflammatory + step wise analgesics Facet blocks Trigger point injections Epidural steroid injection

26. Operative - Indications Continuing or worsening symptoms consistent with nerve root or cord injury Failure of conservative Rx (3 – 4 months) Surgery typically avoided for isolated axial neck pain

27. Operative Options Anterior cervical discectomy: Without fusion (rarely used) Combined with interbody fusion With or without anterior cervical plating Artificial disc (cervical disc arthroplasty) Posterior approaches: Cervical laminectomy Without fusion With lateral mass fusion Keyhole laminotomy

28. Anterior Cervical Discectomy + Fusion Indications Positioning Supine Neck slightly extended (carefully – might need fiber-optic intubation by anesthetic team to avoid over-hyperextension) Shoulders retracted downwards ( esp to visualize with fluoroscopy) Roll between scapula

29. Approach – Superficial Dissection Incise the fascial sheath over the platysma Split the platysma longitudinally Anterior border of the SCM and retract laterally Retract the tracheoesophageal structures medially Horizontal incision along Langers lines

30. Deep dissection The carotid sheath is now exposed Develop a plane between the carotid sheath and midline structures. Retract the carotid sheath and SCM laterally. Deep to the pre-tracheal fascia, the cervical vertebrae should be visible. Split the longus colli muscles longitudinally RLN is at risk during this approach; protect it with placement of retractors under the medial edge

31. Discectomy Performed with curette and pituitary ronguers Caspar pins to aid exposure Any osteophytes can be removed PLL is opened with blunt dissection (nerve hook) Microscope can be used

32. Implants/Hardware Bone grafts – auto or allograft PEEK ( polyetheretherketone ) Carbon fibre Anterior cervical plates + screws

33. Complications Horner’s Syndrome Usually cervical retractors above longus colli Hoarseness RLN injury/irritation Dysphagia Pressure or retraction on esophagus Prevent by intermittent relaxation of retractors Partially deflating ETT cuff when retractors in Retropharyngeal haematoma Resp distress and tense neck mass Prevent with portovac drain Treatment – emergency decompression

34. Complications Vertebral artery injury CSF leak Failure of fusion (pseudoarthrosis) Graft extrusion/migration Infection Complex Regional Pain Syndrome Pneumothorax (C7-T1)

35. Cervical Disc Arthroplasty Alternative to fusion Artificial disc to preserve motion Surgical pointers: Wax decorticated bone ends to prevent fusion Height should be snug (not too big or else wont be able to flex or extend neck) NSAIDS for 2 weeks post-op (inhibit bone growth) No cervical collar (preserve motion)

36. Posterior approaches Cervical laminectomy Multiple levels Posterior compression (ligamentum flavum and spinal stenosis) Risk of RLN significant Keyhole laminoforaminotomy Monoradiculopathy with posterolateral soft disc sequestration Lower C7, C8 or T1 or Upper C3, C4 cervical nerve root compression in a patient with short thick neck Anterior approach might be difficult

37. References Tew JM, Mayfield FH. Complications of Surgery of the Anterior Cervical Spine. Clin Neurosurg . 1976;23:424–434 Gore DR, Sepic SB. Anterior Cervical Fusion for Degenerated or Protruded Discs. A Review of One Hundred and Fifty-Six Patients. Spine. 1984; 9:667– 671 Collias JC, Roberts MP, Schmidek HH, et al. Posterior Surgical Approaches for Cervical Disc Herniation and Spondylotic Myelopathy. In: Operative Neurosurgical Techniques. 3rd ed. Philadelphia: W.B.Saunders ; 1995:1805–1816 Greenberg, Handbook of Neurosurgery, 10 th edition Spine’s Essential Handbook, 2 nd edition