Facet Mediated Pain

Author(s): Patricia W. Nance, MD and Elise M Adcock, MD

Originally published:11/11/2011

Last updated:03/24/2017

A. Disease/Disorder:

Definition

Facet joint pain (facet syndrome) refers to pain arising from the vertebral facets (zygapophyseal, z-joints) in the neck, mid or low back.

Etiology

Facet pain results from abnormal loading and excessive biomechanical stress secondary to poor posture, disrupted anatomy, debility, trauma (eg, whiplash), fracture, inflammation, degenerative disc changes, degenerative facet arthropathy and/or spondylolisthesis.

Epidemiology including risk factors and primary prevention

As the most common cause of disability in adults over 45 years old, 70-80% of adults experience an episode of low back pain at least once during their lifetime.1 The prevalence of facet joint pain in the cervical spine ranges from 36% to 55%. In the lumbar spine it is 15% to 40%. In whiplash disorders, the overall prevalence is 60% for C2-3 or below. Predisposition to injury includes physical, socioeconomic, general medical health, psychological and occupational environmental factors. Primary prevention will require early identification, reduction or modification of risk factors.

Patho-anatomy/physiology

Spinal diarthrodial joints are formed by the articulation of the superior articular process of one vertebra and the inferior articular process of the vertebra above. The medial branch of the dorsal ramus innervates the corresponding facet joint and one level below. The joint contains a fibrous capsule, synovial membrane, articular cartilage and menisci.

Together with the intervertebral disc, the joint functions as a motion restricting unit. Z-joints oriented in the sagittal plane resist shearing forces (backward and forward sliding); whereas, joints oriented in a coronal plane resist axial rotation.2 Several studies have shown a positive correlation between degenerative spondylolisthesis and a sagittal orientation of the lower lumbar facet joints.3 With age, the joints transition from a primarily coronal orientation to sagittal positioning.4

The z-joint and capsule are replete with nociceptors sensitive to capsular stretching or compression.5 Pain can arise from the joint or by impingement on local nerves by an adjacent space occupying structure such as a synovial cyst.

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

New onset / acute– Facet arthropathy is usually the result of years of accumulated repetitive strain and minor trauma. In response to repetitive strain or an acute tearing of the joint capsule or stretching it beyond its limits, the synovial joints fill with fluid and distend, resulting in pain associated with this capsular stretch.6 Clinical features include local pain and limited range of motion.

Subacute– Without the removal of the pathogenic stimulus, ongoing degeneration proceeds. Inflammatory changes including vasodilation, venous congestion, and the invasion of neutrophils with inflammatory cytokines develop.6 Joint hypertrophy and distention of the synovial capsule can produce laxity of the z-joint capsule as well as impinge the exiting nerve root in the spinal canal or neuroforamin causing concomitant radiating lower limb symptoms or radiculopathy.

Chronic / stable– Chronic inflammation causes central sensitization of both nociceptive and proprioceptive cells, characterized by decreased pain stimuli thresholds and an increased firing rate.7 Chronically, neuroplasticity develops. In the terminal phase, fibrosis of the facet joint capsule with bridging osteophyte formation severely restricts segmental motion.

Specific secondary or associated conditions and complications

Facet joint dysfunction is present commonly in patients with discogenic pain and/or sacroiliac joint pain. Recurrent rotational stresses causing degeneration of the facet joints can induce and accelerate degeneration of the intervertebral disks. Capsular irritation can also result in reflex spasm of the paraspinal muscles.6

Additional complications that can arise from facet arthropathy include headaches (particularly with C1-2 and C2-3 joints), degenerative spondylolisthesis, facet joint cyst and neuroforaminal stenosis, which can result in cervical or lumbar radiculopathy. Inflammatory autoimmune arthritis, infection or local inflammation, like synovitis or pseudogout, can also affect the facet joints.2

B. Essentials of Assessment

History

The primary pain patterns involve the neck, shoulders, low back, sacroiliac (SI) joints and lateral hip with referred pain to the cervical/upper limb region, lumbar region, gluteal region, trochanteric, lateral thigh, posterior thigh and groin. The pain is typically described as a nearly constant dull ache with episodic stabbing pain. It tends to be associated with morning stiffness, worsened by spinal extension. Pain from the lower lumbar facet joints present with referred pain to the groin; whereas, pain from the upper facet joints usually refer to the flank, hip, or lateral thigh.2

Physical examination

Inspection of posture is essential because increased or decreased lordosis, muscle atrophy, postural asymmetry or alignment are diagnostic elements. Palpation of tender points along paravertebral regions and transverse processes as well as any pain referral patterns from trigger points adds to the formulation of a focused treatment plan. Perform range-of-motion evaluation to include limits and pain evoked with flexion, extension, rotation, lateral flexion. In the cervical spine include protrusion and retraction of the scapula. Neurologic examination is recommended, to assess the possible presence of radiculopathy due to nerve root compression.

Although multiple studies have failed to statistically demonstrate consistent clinical features that are indicative of lumbar facet joint pain, there are some studies that report common findings. The physical exam is important to rule out other possible etiologies of low back pain. Salient characteristics of facet pain include pain on extension, either with or without  combined rotation movements. Facet mediated pain does not usually radiate below the knee. 8 Pain from the facet joints can be referred as above noted, accompanied by hamstring tightness. Hamstring tightness may limit lower limb mobility and yield a false positive straight leg raise maneuver.

Functional assessment

Note dynamic posture during functional movement, such as during transfers and lifting  light objects, particularly as it applies to proper body mechanics. Look for inconsistencies and signs of symptom amplification, as well as signs of depression or anxiety.

Laboratory studies

Laboratory studies are sometimes indicated to rule out rheumatologic conditions, inflammatory disease or infection.

Imaging

Plain radiographs are a good screen to detect instability (include flexion/ extension views) and fractures. Osteoarthritis can be assessed using an oblique view to show the spaces of these joints. Single-photon emission computed tomography (SPECT) images and, less optimally, bone scan are useful for detection of bone remodeling as in spondylolysis, metastasis, infection or occult fracture. SPECT radionuclide scanning has been a reliable objective technique to identify facet syndrome. 10

Computed tomography (CT) can be used to evaluate facet arthropathy, fractures or progression of fusion. Magnetic resonance imaging (MRI) is useful to further evaluate facet arthropathy, effusions and especially synovitis using axial fat-suppressed images.9 MRI is a more commonly ordered test and, recently, studies have shown that structural findings onT2 weighted MRI images correlated with SPECT activity. MRI evidence of facet articular cartilage discontinuity was a sensitive (0.79) indicator of a symptomatic facet joint, while  lateral tears of the synovial capsule was highly specific (0.95) for a positive SPECT test.10

MRI is indicated to image disc herniation or z-joint cyst causing nerve root entrapment.

Surprisingly, degenerative findings on facet joints on radiographic studies are not shown to correlate with z-joint mediated pain.2

Supplemental assessment tools

A pain diagram should be compared to the established z-joint referral diagrams (Fig 1).

Unfortunately, the failure of multiple studies to identify any clinical features that are indicative of lumbar facet joint pain leaves diagnostic blocks as the only means of diagnosing facet pain syndrome. 2 Fluoroscopically guided medial branch blocks or intra-articular, arthrographically confirmed anesthetic injections are considered the “gold standard” for diagnosis, with at least 50% and preferably 75% to 90% reduction of pain. To minimize the false positive response (38%) that occurs with one injection, guidelines recommend two separate blocks using different duration anesthetics.. The evidence for accuracy of diagnostic facet joint nerve blocks is level 1 or 2 in the diagnosis of lumbar and cervical facet joint pain.11

Early predictions of outcomes

Psychiatric comorbidity is associated with diminished pain relief after medial branch nerve blocks in the cervical and lumbar spine. Strong evidence supports the use of antidepressants for chronic LBP and muscle relaxants in acute back pain.12 Bone scintigraphy with SPECT can help identify patients who would benefit from facet joint injections.13 It is likely that T2 weighted MRI would provide similar information.

Environmental

Low socioeconomic status and lower level of education are associated with disability retirement from back pain. Poor ergonomic positioning, worker dissatisfaction, monotonous tasks, obesity, tobacco use and perceived poor general health are factors that make a patient vulnerable to low back pain disability. 1

Social role and social support system

Psychosocial variables and cognitive factors such as attitude, passive copying and fear-avoidance beliefs have more impact than biomedical factors on back pain disability and with transition from acute to chronic pain disability.12 Patients adopt a “sick role” in which interaction with their environment, social obligations and normal responsibilities become more difficult.

Professional Issues

Facet pain is commonly present in motor vehicle and work accidents with questions on causal relationship, maximal medical improvement and impairment ratings. Unethical treatment can be present at times; for example, in the case of providers performing blocks or radiofrequency ablation without following established guidelines.

C. Rehabilitation Management and Treatments

Available or current treatment guidelines

No form of conservative treatment, drugs, physical therapy, or manual therapy has ever been tested for efficacy for proven lumbar z-joint pain. In the cervical spine, evidence of therapeutic efficacy is limited for intraarticular interventions, moderate for facet joint nerve blocks and strong for radiofrequency (RF) therapy. In the lumbar spine, the evidence is moderate for all three interventions, however no significant difference has been detected for pain relief and functional improvement between intra-articular steroid infiltration or RF denervation.10

At different disease stages

New onset / acute Initial treatment emphasizes education, local pain control with nonsteroidal anti-inflammatory drugs (NSAIDs), topical cream, some modalities and physical therapy that includes instructions on therapeutic proper posture and spine mechanics, activity modification, exercises avoiding direction of pain and spinal mobilization or manipulation. On occasion, an intraarticular steroid injection of the painful facet joint may be indicated to facilitate participation in physical therapy. Strong evidence supports the use muscle relaxants in acute back pain. 12

Sub-acute– (Recovery phase). The main focus of this phase is to increase stability, core strength and to restore motion. Rehabilitation exercises are done primarily with the spine in a neutral or in a flexion biased posture to reduce stress on facet joints. The focus of physical therapy is spine stabilization, core stabilization, posture correction and a strengthening program followed by restoring functional movements. If medial branch nerve blocks are indicated for residual pain and if the patient responds positively to diagnostic and confirmatory blocks, then RF ablation is indicated.

Chronic /Stable– This is the maintenance phase in which  strengthening exercises using eccentric muscle contraction are done, followed by functional exercises (standing in multiple planes) with transition to a home program. If pain persists during this phase and the patient has a positive response to diagnostic and confirmatory medial branch nerve blocks, then radiofrequency ablation is indicated. 2 Judicious use of medications such as NSAIDs, or narcotics (short term) for selected patients, can be necessary to maintain function and quality of life. For psychiatric comorbidities, evidence supports the use of antidepressants for chronic LBP. 12

Patient & family educatio

Coping mechanisms, home exercise program and family teaching is an essential part of the rehabilitation program.

Emerging/unique Interventions

Impairment-based measurements

In the 6th edition of the AMA Guides to the Evaluation of Permanent Impairment, an individual with facet joint dysfunction who is at the point of maximal medical improvement will be classified as Class 0 or Class 1 depending on symptoms, physical exam, nonorganic findings, and Pain Disability Questionnaire. This classification results in a whole-person impairment of 0% for Class 0 or 1% to 3% for class 1, depending on net adjustment equation results.14

Measurement of Patient Outcomes

The Oswestry Low Back Pain Questionnaire, Neck Disability Index, Pain Disability Questionnaire, Roland- Morris Disability Questionnaire, the visual analog scale, numeric pain rating, SF 12 or 36, and McGill Pain Questionnaire facilitate evaluation of treatment effectiveness, functional improvement and quality of life.

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

Standard of care remains education, activity modification, physical therapy and medications. Diagnostic and therapeutic use of facet joint nerve blocks and radiofrequency ablation are treatment options. It is important to follow available established guidelines to minimize false positive results and unnecessary treatments.

D. Cutting edge/emerging and unique concepts and practice

Cutting edge concepts and practice

RF ablation to denervate the facets is performed with either conventional continuous RF current (standard of care) or pulsed RF current. In conventional continuous RF therapy, probe tip temperatures reach more than 60 degrees C and are intended to produce long-term pain relief through a more uniform and larger lesion. Pulsed radiofrequency, which consists of short bursts of current, is suggested as a possibly safer alternative to thermal radiofrequency. However, temperatures for pulsed radiofrequency do not exceed 42 degrees C and therefore produced primarily temporary neural blockade. If the therapy proves beneficial, the pain relief attained by pulsed RF ablation will be of shorter duration than that provided by conventional RF therapy.10

Ultrasound-guided cryoablation is becoming more popular for the use of neuropathic pain management, including lumbar facet blocks. Two hypothermic freezing cycles to temperatures of -50 degrees C cause temporary neuroablation without the complications of neuralgia or neuroma formation. With cryoablation, the endoneurium is not disrupted, allowing for normal regeneration of the nerve. The procedure can be repeated after axonal regeneration occurs, usually within 3-6 months, some analgesic effects lasting up to 2 years.15,16

A novel treatment featuring interpositional facet arthroplasty (IFA) is being tested in cadaveric spines as a long-term treatment option for facetogenic pain.17 Laser facet joint denervation and Nu-fix fusion stabilization of facet joints require further research studies to look at biomechanical results and specific sub-groups that might benefit from these procedures.

E. Gaps in the evidence-based knowledge

Gaps in the evidence-based knowledge

Chiropractic or osteopathic manipulation, back braces, traction, acupuncture, and facet interventions (injections, ablation procedures, surgical interventions) are treatments that can be of help for facet joint pain with more evidence of short- and long-term benefits for radiofrequency ablation. Further research is necessary to further establish the short-term and long-term benefits of these long used modalities.

References

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  3. Grober LJ, Robertson PA, Novotny JE, Pope MH: Etiology of spondylolisthesis: Assessment of the role played by lumbar facet joint morphology. Spine 1993; 18:80-91.
  4. Bogduk N. Chapters 3, 10, 13, 15. In: Clinical Anatomy of the Lumbar Spine and Sacrum. 3rd ed. Edinburgh, UK: Churchill Livingstone; 1997:33-42,133-135,174-175,200-202.
  5. Cavanaugh JM, Ozaktay AC, Yamashita HT, King AI: Lumbar facet pain: Biomechanics, neuroanatomy and neurophysiology. J Biomechanics 1996, 29:1117-29.
  6. Dory MA: Arthrography of the lumbar facet joints. Radiology 1981; 140:23-7.
  7. Cavanaugh JM, Ozaktay AC, Yamashita HT, Aramov A, Getchell TV, King AI: Mechanisms of low back pain: A neurophysiologic and neuroanatomic study. Clin Orthop Relat Res 1997; 335:166-80.
  8. Helbig T, Lee CK: The lumbar facet syndrome. Spine 1988; 13:61-4.
  9. Czervionke LF, Fenton DS. Fat-saturated MR imaging in the detection of imflammatory facet arthropathy (facet synovitis) in the lumbar spine. Pain Med 2008; 9:40-6.
  10. Lakemeier S, Line M, Schultz W, Fuchs-Winklemass S, Timmesfeld N, Foelsch C, Peterlein CD. A comparison of Intraarticular Lumbar Facet Joint Steriod Injections and Lumbar Facet Joint Radiofrequency Denervation in the Treatment of Low Back Pain: A Randomized, Controlled, Double Blind Trial. Anesth Analg. 2013 Jul;117(1):228-35.
  11. Manchikanti L, et al. Comprehensive evidence based guidelines for interventional techniques in the management of chronic spinal pain. Pain Physician. July 2009;12:699-802.
  12. Polatin PB, Kinney RK, Gatchel RJ, Lillo E, Mayer TG: Psychiatric illness and chronic low back pain: The mind and the spine—which goes first? Spine 1993; 18:66-71.
  13. Pneumaticos SG, Chatziioannou SN, Hipp JA, Moore WH, Esses SI. Low back pain: prediction of short-term outcome of facet joint injection with bone scintigraphy. Radiology. 2006; 238:693-698.
  14. Rondinelli R, Genovese E, Brigham C, eds. American Medical Association.Guides to the Evaluation of Permanent Impairment. 6th ed. Chicago, IL: AMA. 2008 (updated 2009).
  15. Connelly NR, Malik A, Madabushi L, Gibson C. Use of ultrasound-guided cryotherapy for the management of chronic pain states. J of Clinical Anesthesia (2013) 25, 634-636.
  16. Bellini M, Barbieri M. Percutaneous cryoanalesia in pain management: a case series. Anesthesiology Intensive Therapy 2015, vol. 47, no 4, 333-335
  17. Dahl MC, Freeman AL. Kinematic and fatigue biomechanics of an interpositional facet arthroplasty device. The Spine Journal 16 (2016) 531-539.

Other Resources

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Original Version of the Topic

Ricardo Nieves, MD. Facet Mediated Pain. 05/19/2013

Author Disclosure

Patricia W. Nance, MD
Nothing to Disclose

Elise M Adcock, MD
Nothing to Disclose

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