Monday, July 12, 2010

Facet pain: Short falls of inteventional & non-interventional conservative management

How facet joint pain manifests?
Facet or zygapophysial joints are considered to be common sources of chronic spinal pain. In addition to causing localized spinal pain, facet joints may refer pain to adjacent structures. Cervical facet joint pain may radiate to the head, neck, and shoulders. Thoracic facets may produce paraspinous mid-back pain with neuralgic characteristics; and lumbar facet joints may refer pain to the back, buttocks, and proximal lower extremities.
Referred pain may assume a pseudoradicular pattern, making the underlying diagnosis difficult to confirm, without the use of diagnostic blocks.
Joint innervation:
Facet joints are well innervated by the medial branches of the dorsal rami. Neuroanatomic, neurophysiologic, and biomechanical studies have demonstrated free and encapsulated nerve endings in facet joints, as well as nerves containing substance P calcitonin gene-related peptide; facet joint capsules contain low-threshold mechanoreceptors, mechanically sensitive nociceptors and silent nociceptors ; and lumbar and cervical facet joint capsules can undergo high strains during spine loading.
Prevalence of facet pain in different areas of spine:
Consistent with criteria established by the International Association for the Study of Pain, facet joints may be a source of chronic pain in 15% to 45% of patients with chronic low back pain; 36% to 60% of the patients with chronic neck pain; and 34% to 48% of the patients with thoracic pain.

Difficulties associated with diagnosis & treatment of facet joint pain:

1. Clinically:
There is no definitive study to support that clinically facet joint pain can be diagnosed. Extension is the most incriminated movement to imply facet joint involvement. According to Van Eerd et al Clinically rotation and retroflexion (extension) are frequently painful or limited.
2. Investigations for facet joint are non-correlative: Direct correlation between degenerative changes observed with plain radiography, computerized tomography, and magnetic resonance imaging and pain has not been proven.
3. Short falls in non-interventional conservative approach: Conservative treatment options for cervical facet pain such as physiotherapy, manipulation, and mobilization, although supported by little evidence, are frequently applied before considering interventional treatments.
4. Short falls in interventional conservative approach: Facet joint pain may be managed by intraarticular injections, medial branch blocks, and neurolysis of medial branch nerves.

Evidence level:

a. Bogduk: A recent narrative review by Bogduk suggested that intraarticular facet joint injections were no better than placebo for chronic lumbar spine pain.
b. Slipman et al: Review of the evidence for the use of zygapophysial injections and radiofrequency denervation in the treatment of low back pain, found limited evidence for intraarticular injections in the lumbar spine and moderate evidence for radiofrequency neurotomy in the lumbar spine.
c. Boswell et al: Systematic review of therapeutic facet joint interventions for 3 regions of the spine, showed moderate evidence for lumbar intraarticular facet joint injections for short-term improvement, but only limited evidence for long-term improvement. The evidence was negative for cervical intraarticular facet joint injections. The evidence was moderate for cervical and lumbar medial branch blocks with local anesthetics and steroids. The evidence for pain relief with radiofrequency neurotomy of medial branch nerves was moderate to strong for cervical and lumbar regions.
d. European guidelines for the management of chronic nonspecific low back pain: (Analysis of data from January 1995 to November 2002) Concluded that intraarticular facet joint injections were ineffective in managing chronic low back pain. In this limited literature review, they showed no significant effectiveness of medial branch blocks.
The European guidelines concluded that there was conflicting evidence that radiofrequency denervation of the facet joints is more successful than placebo for eliciting short-term or long-term improvements in pain or functional disability in mechanical chronic low back pain. They also indicated that there was limited evidence that intraarticular denervation of the facet joints is more effective than extraarticular denervation.
e. Geurts et al: Concluded that there was moderate evidence that radiofrequency lumbar facet denervation was more effective for chronic low back pain than placebo, and there was only limited evidence for effectiveness of radiofrequency neurotomy for chronic cervical zygapophysial joint pain after flexion/extension injury.
f. Manchikanti et al: Evaluated medial branch neurotomy for the management of chronic spinal pain utilizing the Agency for Healthcare Research and Quality (AHRQ) criteria with inclusion of randomized and observational reports, and concluded that there was strong evidence for short-term relief and moderate evidence for longterm relief of facet joint pain.
g. Niemisto et al: in a systematic review of radiofrequency denervation for neck and back pain within the framework of Cochrane Collaboration Back Review Group, concluded that there was limited evidence that radiofrequency denervation had a positive short-term effect on chronic cervical zygapophysial joint pain, and a conflicting short-term effect on chronic low back pain.

References:
1. van Eerd M et al; Pain Pract. 2010 Mar;10(2):113-23. Cervical facet pain.
2. Boswell MV et al; Pain Physician 2007; 10:229-253


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