Spinal procedures

Types of Spine Procedures

A. Epidural steroid injections

• Places a corticosteroid and an anesthetic into the epidural space by either an interlaminar, transforaminal, or caudal approach.
• Addresses radicular pain secondary to intervertebral disc herniation or spondylotic central, lateral recess, or foraminal stenosis.
• Believed to reduce pain by interrupting the inflammatory cascade, blocking C-fiber transmission, increasing microcirculation around ischemic areas, and modulating pain transmission in the dorsal horn.^1,2

B. Zygapophyseal (facet) joint injections/medial branch blocks and sacroiliac joint injections

• Intra-articular placement of corticosteroid and an anesthetic into the facet joints or use of local anesthetic to block the nerves providing nociceptive output from the facet joints.
• Intra-articular placement of corticosteroid into the sacroiliac joint
• These procedures are utilized for diagnostic value, particularly medial branch blocks while intra-articular injection provide both diagnostic and potentially therapeutic value.

C. Radiofrequency Ablation (RFA)

• RFA uses the application of radiofrequency current to create heat to lesion the afferent nerve supply of the facet and sacroiliac joints.⁴
• Performed subsequent to diagnostic medial branch blocks or intra-articular joint injection.
• Performed to provide pain relief by denervation these joints for an extended period of time.
• Nerve regeneration is expected to occur over 9 to 12 months.

D. Discography

• Placement of contrast dye within the intervertebral disc under fluoroscopy followed by computed tomography (CT) imaging of the spine.
• To identify the disc as the source of a patient’s axial pain.
• Validity of discography remains controversial.
• There is concern that discography may cause accelerated disc degeneration.⁵
• Infrequently utilized in contemporary practice, however is useful for research purposes.

E. Thermal annuloplasty

1. Application of heat along the annulus to denervate the annulus and/or reconfigure the collagen structure of the disc.⁶
2. Heat-based procedures include the following:
   1. Biacuplasty involves the utilization of bipolar and monopolar RFA electrodes to create lesions in the posterior and posterolateral annulus.
   2. Coblation nucleoplasty involves use of a bipolar radiofrequency current to decrease the volume of the disc tissue.
   3. Intradiscal electrothermal therapy.
      1. Involves the placement of an electrode or catheter into the annulus of the disc to apply electrothermal energy to denervate the annulus.
      2. Has received noncoverage status from the Center for Medicare and Medicaid Services because of the lack of supporting evidence.⁷
   4. Effectiveness of these interventions has not been established with randomized trials.

F. Percutaneous disc decompression

1. Aims to remove a portion of the disc material in order to reduce intradiscal pressure to decompress the involved nerve.⁸
2. To address radicular pain secondary to intervertebral disc herniation.
3. Vertebroplasty and kyphoplasty

G. Vertebroplasty consists of injecting a polymethyl methacrylate (PMMA) cement into the vertebral body.

1. Kyphoplasty inflates a balloon within the vertebral body prior to the application of PMMA.
2. Mechanism of action is a combination of thermal necrosis and chemotoxicity of the intraosseous pain receptors.⁹
3. In 2 large randomized trials, vertebroplasty did not show benefit over sham or placebo interventions.⁷

H. Spinal cord stimulation of the dorsal columns

1. Theorized to block transmission of pain by way of Melzack and Wall’s gait control theory.¹⁰ However, exact mechanism of action has not been established.
2. Conventional paresthesia based systems are utilized to address radicular pain symptoms
3. Newer systems utilize high frequency, non-paresthesia based treatment which have been shown to effectively address back and leg pain symptoms.¹⁷

I. Intrathecal drug delivery system:

1. Delivers opioid medication intrathecally to maximize its effectiveness.
2. This reduces systemic side effects and eliminates the risk of opioid abuse and diversion.

J. Minimally invasive lumbar decompression (MILD ®):

1. A treatment option for patients with lumbar spinal stenois with neurogenic claudication and verified ligamentum flavum hypertrophy.
2. A percutaneous intervention of debulking hypertrophied ligamentum flavum after failure of more conservative treatment methods.

Risks Associated With Invasive Procedures

A. Medication related complications

1. Local anesthetic medications
   • Anesthetic allergic reactions are rare, but can occur either because of the anesthetic or its preservative, methylparaben.
   • Central nervous system toxicity can occur because of excessive anesthetic use.
     • Signs of toxicity include the following: disorientation, light-headedness, nystagmus, tinnitus, and muscle twitching in the face or extremities.¹¹
     • Cardiovascular effects may include chest pain , shortness of breath, palpitations and hypotension
2. Corticosteroid preparation related side effects
   • Intrathecal injection can cause arachnoiditis, attributed to polyethylene glycol, a preservative in methylprednisolone.
   • Epidural administration can cause fluid retention, steroid-induced myopathy, irregular menses, epidural lipomatosis with prolonged use, digestive irritation, and elevations in serum glucose.
   • Less common side effects include the following: elevated temperature, euphoria, depression, mood lability, local fat atrophy, skin pigmentation changes, and pain flare.
   • Rare complications include the following: weight gain, deep vein thrombosis, hypertension, and Cushing syndrome.¹¹

B. Fluoroscopic guidance related issues

1. Contrast media related effects
   • Spine procedures are typically performed under fluoroscopy to confirm proper needle positioning.
   • Injection of contrast under real-time fluoroscopy or with digital subtraction angiography can assess for vascular injection.¹
   • Anaphylactic reactions to contrast have been reported at 0.04%.¹¹
   • Patients with contrast sensitivity should be premedicated with the following:
     • Histamine H1 blocker (ranitidine)
     • Histamine H2 blocker (diphenhydramine)
     • Corticosteroid (prednisone)
2. Radiation exposure can be minimized by considering the following:
   • Proximity to radiation source
   • Duration of exposure
   • Radiation shielding

C. Infection related risks

1. Epidural abscesses have been reported in the cervical, thoracic, and lumbar spine.¹¹
   • Most common bacteria identified was Staphylococcus aureus.
   • Typical presentation includes the following: fever, spinal pain, radicular pain, and/or progression of neurologic deficits.
   • Symptoms occur from 3 days to 3 weeks following the injection.
2. Meningitis can occur when the dura is punctured during epidural procedures.^11,12
   • Types of meningitis reported include bacterial, fungal, and aseptic.
   • Patients have presented with headache, fever, nausea, leg pain, and convulsions.
3. Osteomyelitis and discitis have been reported in cervical, thoracic, and lumbar discography.¹¹
   • Typical signs include the following: fever, malaise, lethargy, pain, and neurologic changes.
   • These can present 1 to 4 weeks after the injection.
4. Infectious risks are minimized by use of strict sterile technique.
5. Early detection is necessary to minimize morbidity and mortality.¹¹

D. Bleeding related complications

1. Increased risk in patients with the following:
   • Hemophilia
   • von Willebrand disease
   • Thrombocytopenia
   • Idiopathic thrombocytopenic purpura
2. Baseline complete blood count prior to spinal injections can identify the presence of thrombocytopenia.
3. Epidural hematomas following lumbar epidural puncture have been reported because of altered coagulation in liver and renal disease.
4. The following anticoagulant medications should be held for procedures:
   • Warfarin must be stopped for 5 days and an international normalized ratio of 1.3 or less.
   • Aspirin 325mg must be stopped for 7 days. Aspirin 81 mg may be discontinued for intermediate risk procedures if patient is taking for primary prophylaxis, but may be continued for secondary prophylaxis.  Aspirin may be continued for low risk procedures.
   • Nonsteroidal anti-inflammatory medications must be stopped for 5 days; only for high risk procedures such as SCS placement.
   • Ticlopidine must be stopped for 14 days.
   • Clopidogrel must be stopped for 7 days .
   • Glycoprotein IIb/IIIa receptor antagonists must be stopped for:
   • abciximab: 2-5 days
   • – eptifibatideand tirofiban: 8-24 hrs.¹¹
5. Epidural hematomas
   • Typically, a result of impaired coagulation.
   • Must be identified and treated early to minimize morbidity; this is a medical emergency
   • Symptoms include the following:
     • Unexpected duration or spread of sensory or motor deficits
     • Unexplained severe spinal or radicular pain
     • Bowel or bladder dysfunction

E. Neurologic complications of epidural injections

1. Possible nerve root and spinal cord injury
2. In transforaminal epidural steroid injection (ESI)
   • Rare catastrophic complications in the cervical spine
     • Caused by embolic events because of inadvertent intra-arterial injection; greater association with particulate steroids than non-particulate steroids. This remains a contraversial topic.
     • Complications include the following: brain infarction (cervical procedure), spinal cord infarction, cortical blindness, high spinal anesthesia, and seizures.^1,11
3. Interlaminar ESI
   • Dural puncture with cord trauma
   • Postdural puncture headache(PDPH)
     • Incidence is reduced by using a smaller gauge needle.
     • Symptoms include the following: nausea, vomiting, hearing loss, tinnitus, vertigo dizziness, paresthesia’s of the scalp, and limb pain.
     • The incidence of PDPH is higher in older population (>51 yo) compared to younger population (<50 yo)¹⁸
     • Spontaneous recovery is typical within 6 weeks for most patients.
     • Application of a blood patch is the most definitive treatment for spinal headaches.¹¹

F. Respiratory risks and complications

1. Rare and can be seen from excessive sedation.
2. Seen in needle trauma to the spinal cord or lung (pneumothorax) in cervical and thoracic procedures.
3. With greater than 25% lung collapse, chest tube placement is warranted.
4. In cervical injections, injury of the recurrent laryngeal nerve can lead to transient reduced airway protection and voice hoarseness.¹¹

G. Urologic risks and complications

1. Rare and the most common is urinary retention.
2. Urinary retention is seen with injection of spinal local anesthetic.
3. Urologic compromise can be seen with an epidural abscess or hematoma, leading to cauda equina and/or cord compresion.¹¹

Given the potential risks, care must be taken to identify appropriate candidates. Clinical evaluation includes the following:

A. Comprehensive history

1. Necessary in order to evaluate patients for the treatment of spine pain.
2. Should include pain onset, location, character, intensity, duration, and associated symptoms.
3. History of a directional bias can help further identify the probable pain generators.
   • Pain on flexion can suggest discogenic or vertebral body pain as a pain source.
   • Pain on extension suggests facet joint involvement or central, lateral recess, or foraminal nerve impingement.
4. Attention must be paid to red flags that can signal the presence of serious systemic disease.¹³
5. Care should be taken to identify medications which could impact safety of the procedure such as anti-platelet/anticoagulant medication and to obtain necessary preprocedural clearance to discontinue these medications as indicated.
6. Thorough review of allergies
7. Thorough review of imaging studies and to obtain necessary studies to optimize treatment safety and efficacy.

B. Physical examination of the spine

1. Includes inspection of posture and alignment, palpation for concordant pain provocation, range of motion, and provocative maneuvers/special tests.
2. Joints in close proximity to the spine must be evaluated, because their pain can mimic spine pain.
3. Neurologic exam to assess for upper and lower motor neuron dysfunction:
   • Manual muscle strength testing
   • Sensory examination
   • Deep tendon reflexes
   • Gait

C. Laboratory tests

1. Performed to exclude the presence of an occult malignancy, indolent infection, or an inflammatory disease.
2. The following laboratory tests are commonly performed¹⁴:
   • Complete blood cell count
   • Basic metabolic panel
   • International normalized ratio (INR)

D. Imaging of the spine¹⁵

1. Plain radiographs
   • Often used as the first-line imaging study in spinal pain.
   • Limited value because of the inability to see soft tissue structures, such as spinal discs, nerves, muscles, and ligaments. May be useful to assess for segmental stability, degenerative changes and surgical hardware failure.
2. Magnetic resonance imaging (MRI)
   • Most commonly utilized modality for the investigation of spinal radiculopathy.
   • High sensitivity and low specificity.
   • Lacks the radiation exposure of CT and bone scintigraphy.
3. CT
   • Gives superior visualization of cortical bone when compared with MRI.
   • Of value when MRI is contraindicated in the presence of
     • Pacemakers
     • Spinal cord stimulators
     • Metallic artifacts
4. Bone scintigraphy (single-photon emission computed tomography and triple-phase bone scan)
   • Bone scintigraphy can identify areas of altered metabolic activity.
   • Can identify areas of increased osteoblastic activity and blood flow.
   • Most useful to identify stress fractures, joint inflammation, and metastatic disease.

Formal procedure guidelines have been published by the International Spine Intervention Society and the American Society of Interventional Pain Physicians.19

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2. Stout A. Epidural steroid injections for low back pain. Phys Med Rehabil Clin N Am. 2010;21:825-834.
3. Kennedy D, Shokat M, Visco C. Sacroiliac joint and lumbar zygapophysial joint corticosteroid injections. Phys Med Rehabil Clin N Am. 2010;21:835-842.
4. Mazin D, Sullivan J. Lumbar and sacral radiofrequency neurotomy. Phys Med Rehabil Clin N Am. 2010;21:843-850.
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6. Helm S, Deer T, Manchikanti L, et al. Effectiveness of thermal annular procedures in treating discogenic low back pain. Pain Physician. 2012;15:E279-E304.
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9. Lavelle W, Carl A, Lavelle E, et al. Vertebroplasty and kyphoplasty. Anesthesiology Clin. 2007;25:913-928.
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11. Botwin K, Brown L, Sakalkale D, et al. Side effects and complications of injection procedures: anticipation and management. In: Slipman C, Derby R, Simeone F, et al, eds. Interventional Spine an Algorithmic Approach. 1st ed. Philadelphia, PA: Saunders Elsevier; 2008:213-227.
12. Kainer M, Reagan D, Nguyen D, et al. Fungal infections associated with contaminated methylprednisolone in Tennessee. N Engl J Med. 2012;367:2194-2203.
13. Alexander E. History, physical examination, and differential diagnosis of neck pain. Phys Med Rehabil Clin N Am. 2011;22:383-393.
14. Dreyer S, Boden S. Laboratory evaluation in neck pain. Phys Med Rehabil Clin N Am. 2003;14:589-604.
15. Mena J, Sherman A. Imaging in radiculopathy. Phys Med Rehabil Clin N Am. 2011;22:41-57.
16. Jee H, Lee JH, Kim J, et al. Ultrasound-guided selective nerve root block versus fluoroscopy-guided transforaminal block for the treatment of radicular pain in the lower cervical spine: a randomized, blinded, controlled study. Skeletal Radiol. 2013;42:69-78.
17. Kapural L., et al. Novel 10-kHz High-frequency Therapy (HF10 Therapy) Is Superior to Traditional Low-frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain. Anesthesiology, 123(4)
18. Wadud, Roheena & Laiq, Nasreen & Akhtar Qureshi, Fayyaz & Said Jan, Akbar. (2006). The frequency of postdural puncture headache in different age groups. Journal of the College of Physicians and Surgeons–Pakistan : JCPSP. 16. 389-92.
19. Bogduk N (ed). Practice Guidelines for Spinal Diagnostic and Treatment Procedures, 2nd edition. International Spine Intervention Society, San Francisco, 2013.