Recently an international working group came together to compile recommendations to specific clinical questions regarding cervical facet joint procedures. The following is my summation (but don't rely on it - you should really read these yourself. But if it is TLDR...)
Original Article link:
TLDR version:
Q1: Can history and examination be used to help prognosticate Atlanto-axial and/or antlanto-occipital pain generators?
= Can be...
Q2: Can history and examination prognosticate a painful cervical facet joint?
= Not really.
Q3: Any correlation with radiological findings? Can we do SPECT/CT? Is MRI helpful? = = Not really.
Q4: Physical therapy compulsory before facet blocks?
= About 6 wks of therapy and >3mths of total pain is recommended beforehand
Q5: Do you need to use image guidance?
= Yes - Fluroscopy or US ideally (but can use CT but higher radiation).
Q6: Best techinque or AO/AA injection? Steroid or no steroid?
= ?? Nobody knows...
Q7: Best technique/approach for cervical MBB?
= No consensus. Maybe lateral approach.
Q8: Ideal volume for MBB injections?
= 0.3 mL or less (though up to 0.5 ml is likely ok)
Q9: To do intra-articular - or not to do intra-articular cervical facet injections..?
= Don't.
Q10: Bilateral cervical MBB or RFA in one visit? Limit amount of levels?
= MBB can do both. RFA Don't do bilateral. Generally max 2 levels of RFA in one setting.
Q11: Are facet injections (IA) Prognostic, diagnostic or both?
= Diagnostic Yes. Prognostic - probably not.
Q12: To use sedation or not for MBBs? More false positives?
= Best to do without if you could due to false positives.
Q13: What is the 'cut off' for a 'positive block'?
= >50% is positive
Q14: How many blocks before RFA?
= Single positive block is sufficient
Q15: Electrode positioning for RFA?
= Near parallel if possible
Q16: Sensory and/or motor testing before RFA?
= Motor yes for heat lesion. Sensory is less helpful.
Q17: Bigger (lesion) is better? How can you make lesions bigger?
= Larger lesions are more likely to pick up nerve and make pain relief last longer but with greater risk of collateral damage.
Q18: Complications of Cervical facet interventions?
= Rare severe complications. Common transient symptoms.
Q19: Should you repeat RFA? In who? And in what interval?
= Yes. No more than two times a year. In those that it worked the first time.
Q20: Different standards for RFA in clinical trials vs clinical practice?
= In summary - No.
Introduction demographics:
- Lifetime incidence of neck pain 37-48% (Europe)
- Most common cause of disability in North America between 25-64yo
- Increased age = increased neck pain
- Obesity is NOT directly related, but women > men.
- Cervical facets contribute to pain in 25-70% of patients with chronic neck pain and 50-60% following whiplash injury
- C2-3 and C5-6 joints are most commonly affected
Q1: Can history and examination be used to help prognosticate Atlanto-axial and/or antlanto-occipital pain generators? = Can be...
"Can be" seems to be the answer.
C0-C1 and C1-2 pain is less well studied than other areas and unclear
Signs of atlanto-axial disease include:
- Limited ROM with during rotation with flexion and extension, crepitus, prominent occipitocervical jnction, torticollis and kyphosis.
More commonly involved in rheumatoid arthritis
INTERESTING FACTOID! The trigeminocervical nucleus extends CAUDALLY from the brain down to the first 3-4 cervical spinal nerves. The trigeminal nerve comes from this area. Thus - this is thought to be where there is a cross over with oculofrontotemporal area pain.
The only way to be sure is local anaesthetic blockade
Q2: Can history and examination prognosticate a painful cervical facet joint? Not really.
- Thought to be a source of pain in 25-60% of patients with chronic neck pain
- Post-surgical necks the pain is often periarthrodesis levels
- Whiplash patients may have up to 71% involving facets
- Headache in whiplash implicates C2/3 facets
A prognostic criteria suggested is:
- Pain >4/10
- Radiating to the head, shoulder or upper arm
- >6 weeks in duration
- No neurological findings
It has been suggested that paraspinal tenderness may be more useful than facet loading in some studies.
C2/3 Facet
- Thought to be a source of cervicogenic headaches
- As innervation of C2/3 facets is from Third occipital nerve (TON), these were previously called third occipital headaches!
- Tenderness of C2/3 facet in one study suggested positive MBB with a sensitivity of 85%
Facet localising
FACTOID! Some mean doctor injected fluid into facet joints of patients to elicit pain and then to ask where that pain was referred to. And this is where we get the facet maps from!
C2-3 = Upper neck pain radiating to the ear, vertex, forehead or eye
C3-4 = Neck pain from suboccipital region into neck not involving shoulder
C4-5 = Lower neck pain, top of shoulder and lower part of neck
C5-6 = Lower neck, top of scapula, and shoulder (not distinguishable from C6-7)
How commonly was each facet involved (one study)?
C2/3 = 36%
C5/6 = 35%
C6/7 = 17%
C1/2, C3/4, and C4/5 were less than 5%
What about examination? = Not really. Helpfulish.
High sensitivity but low specificity is suggested (though controversial)
Proposed protocols for physical examination includes:
- Cervical spine ROM
- Extension-rotation testing (extend and rotate to end of motion. ?pain = positive)
- Manual spine examination (prone palpation of facets)
- Palpation of segmental tenderness (palpation of local muscles that have same innervation as facet joints)
Q3: Any correlation with radiological findings? Can we do SPECT/CT? Is MRI helpful? = No.
Unlike lumbar (where there is some evidence of correlation), small studies have suggested no clear correlation between pathology on CT/SPECT and positive MBBs.
MRI findings have not been conclusively useful to predict MBB positive outcomes
Q4: Physical therapy compulsory before facet blocks? = About 6 wks of therapy and >3mths of total pain is recommended
Most literature suggests most episodes of acute neck pain will improve by 6 weeks. Further benefit from this time plateaus. There is mixed evidence for physical therapies improving neck pain with likely benefit in short to medium term but long term benefit is lacking.
Therefore, the recommendations suggest 6 weeks of conservative therapy first before considering blocks and ideally >3 mths total of neck pain.
Q5: Do you need to use image guidance? = Yes - Fluroscopy or US ideally (but can use CT).
Suggestion that US could be used but studies are lacking and practitioners with enough skill are limited. CT could be used for RFA however as there is not significant benefit of CT over fluroscopy and fluroscopy has less radiation, fluroscopy is their main recommendation.
Q6: Best techinque or AO/AA injection? Steroid or no steroid? = ??
Do preprocedural imaging to confirm anatomy
Recommend posterior approach with IA spread and real time fluroscopy
Steroids may be beneficial but evidence unclear.
Q7: Best technique/approach for cervical MBB? = No consensus. Maybe lateral
Lateral approach for TON and C3 to C7 is best with posterior approach to C8 medial branch nerve is ideal.
Unclear if prone, lateral decubitus or supine is best
No studies compare lateral vs posterior approach for accuracy
They suggest lateral approaches for blocks - particularly with one needle approach - may be practical and less traumatic to perform
Safety is generally extremely good with all approaches and no difference between them
CT angiography suggests loop of vertebral artery may sit over TON block site in 5-8% of individuals!
Recommendation is to use 25G needles
Q8: Ideal volume for MBB injections? = 0.3 mL or less (though up to 0.5 ml is likely ok)
C5 MBB traverses the middle of the trapezoid whereas C3,4,6,7 are higher on the articular pillars
Q9: To do intra-articular - or not to do intra-articular...? = Don't.
Could do it in rare circumstances where RFA is contraindicated but otherwise benefits are minimal and RFA is superior
Avoid steroids routinely
Q10: Bilateral cervical MBB or RFA in one visit? Limit amount of levels? = MBB can do both. Don't do bilateral. Generally max >2 levels of RFA in one setting.
Too many risks of dropped head syndrome, prolonged dizziness (particularly with TON) and uncertainty about multiple levels in one sitting due to concern about affecting neck musculature.
Q11: Are facet injections (IA) Prognostic, diagnostic or both? = Diagnostic Yes. Prognostic - probably not.
Q12: To use sedation or not? More false positives? = Best to do without if you could.
Q13: What is the 'cut off' for a 'positive block'? = >50% is positive
Multiple trials between 30% and complete relief have been completed
Activity measures have also been looked at but there is no clear consensus.
Q14: How many blocks before RFA? = Single block
There is suggestion that multiple blocks may be more predictive but this is a small improvement for more cost and increased risk of false negative.
Q15: Electrode positioning? = Near parallel if possible
No evidence compairing electrode location or orientation.
Q16: Sensory and/or motor testing before RFA? = Motor yes for heat lesion. Sensory is less helpful.
Sensory is usually 50Hz with a threshold of <0.5 V. Patients are asked if they feel tingling in certain areas.
Motor stimulation is performed at 2Hz. Multifidus stimulation can reassure that position is appropriate
Q17: Bigger (lesion) is better? How can you make lesions bigger?
= Larger lesions are more likely to pick up nerve and make pain relief last longer but with greater risk of collateral damage.
Diameters of the nerves are <1mm and displaced from bone by 1-2 mm by areolar tissue
Nerves have variable courses (particularly C3, C6 and C7 - usually upper area of pillar)
Dorsal rami at C3, C4 and C6 medial branches often give off two medial branches
Lesions are made bigger by larger cannulas, longer duration of therapy, increased temperature.
Q18: Complications of Cervical facet interventions? = Rare severe complications. Several common side effects include: Bruising, light-headedness, flushing, sweating and nausea are common but transient. Sensorimotor weakness from local anaesthetic.
Haematoma formation (2%) local infection (3%) and temporary weakness/numbness (0.15%) can occur.
Severe complications include neurologic injury and/or death - usually from direct trauma to a nerve or vessel of the spinal cord causing infarction. Can also occur from particulate steroid into a feeder artery to the spinal cord or brain. Haematomas causing cord compression, dural puncture, or high/total spinal block are also possible. Most of these complications have been associated with epidural procedures.
Catastrophic blood vessel involvement is rare - and are more common with transforaminal epidural steroid injections. Particular steroids also add a significant risk.
Interestingly there is suggestion that continued use of anti platelet and anticoagulant medications in patients undergoing cervical facet procedures does not increase the risk of bleeding and haematoma. Actually stopping these may be associated with treater thromboembolic events (up to 0.2-0.4% for major thromboembolic events when anticoagulation is held). Heparin bridging did not make a statistically significant improvement.
A loop of the vertebral artery can be sitting over C2/3 joint line in up to 5.5% of patients. There is suggestion that the use of US may help mitigate this risk without a loss of efficacy of the overall procedure.
SIS recently found no cases of serious bleeding secondary to cervical facet procedures
MBB recommendations
Recommended aspirating and visualising spread of contrast with real-time fluoroscopy prior to performing MBB (Grade B recommendation).
Reviewing with MRI or CT scan of the cervical spine for vasculature around the pillars and/or a scout US before may further reduce risk (Grade C recommendation).
Positioining RF tip in the posterior two thirds of the C2/3 facet joint and avoiding the anterior part of the C2 facet pillar may avoid aberrant loops of vertebral artery (Grade C recommendation).
Risks are slightly higher with RFA however a systematic review of fluoroscopically-guided RFA of medial branches reported only minor and temporary adverse effects without serious complications.
Common side effects include: Post-procedural pain, cutaneous numbness, dysaesthesia, dizziness and ataxia lasting a few days to weeks. Pruritis, vasovagal syncope and transient neuritis occurs in less than 10% and is usually self-limiting.
TON RFA has a period of numbness in 70-90% of patients in the cutaneous distribution which then goes to dysaesthesia and pruritus and then to normal cutaneous sensation. Usually lasts only 1-3 weeks. Ataxia can also occur until patients adjust.
Antineuropathics and steroids have NOT been shown to significantly reduce post-procedural pain/symptoms.
Three days of diclofenac was suggested to reduce post procedure pain for up to 7 days after compared with placebo.
Neurologic injury has been reported but is exceedingly rare. The committee recommends using AP and lateral views always. Sensorimotor testing is likely beneficial also (Grade B)
Spinal muscles include the semispinalis cervicis and captious, multifidus, splenius crevices and wapitis, trapezius and levator scapulae are the major muscles of the neck. RFA of can affect musculature and in some rare circumstances lead to outcomes like dropped head syndrome.
The committee suggests only 2 joints maximum and no bilateral RFA should be performed in one sitting, There should be physical therapy between these also to allow for restoring of paraspinal muscles prior to and after RFA to improve outcomes (Grade C)
Implanted electrical devices vary in how significant bipolar or unipolar RFA may affect these devices. At a minimum neurostimulators should be programmed to an output of zero volts and turned off before a procedure. Pacemakers and defibrillators should be discussed with cardiologist.
Tissue burns are possible - but rare. Make sure grounding pad is appropriately placed to clean-shaven dry skin without tattoos or scars.
In patients with a fusion, many of these undergo RFA and outcomes are reportedly similar to those who have not had surgery. There have been no reported cases of burns, denervation of lateral branches, or coagulation of blood vessels with RFA procedures in patients with posterior spinal instrumentation. It is recommended that image-guidance helps assure that RF cannula is not in contact with pedicle screw to avoid thermal injury.
Q19: Should you repeat RFA? In who? And in what interval?
= Yes. No more than two times a year. In those that it worked the first time.
Relief often lasts between 6-14 months. RFA is commonly repeated when pain recurs. 85%-90% of patients having repeat RFA will have a successful second outcome.
Studies have followed patients who have had successful RFA 7 times with a duration of action lasting 11.5mths.
If it doesn't work the first time, the chance of success with a repeat is low (<30% at best)
Q20: Different standards for RFA in clinical trials vs clinical practice?
= In summary - No.
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