There are many factors to consider as to why lower back pain exists. The lumbar facets are the joints in the back of the vertebra that are paired and hook the rear of the top vertebra to the back of the vertebra below. With movement, they are important in guiding the spine to track properly and create normal spinal alignment. The disk in front absorbs shock and dampens motion but it is the facets in back that are important to guide the motion of the vertebra like railroad tracks guide a train (read more Introduction to the Function of the Lumbar Spine).
When it comes to bearing weight, the disc in front carries almost 80% of the weight and the facets only 20%. This weight bearing distribution changes with forward and backward bending. Bending forward causes the disc to bear almost all the load and bending backwards causes the facets to bear almost 70% of the weight of the upper body.
The facets are real joints similar to a hip or knee joint. A joint is essentially a movable surface located where two bones join together. In this type of joint, called a diarthrodial joint, both joining bones have smooth caps of cartilage that covers the surfaces. These facet joints are held together with a strong flat sheet of collagen called a capsule that surrounds the joints. Lining this capsule is the synovium, a thin sheet of specialized cells that make the lubricant- synovial fluid- similar to WD 40 oil.
The joint surfaces are so perfectly matched and smooth that with the synovial fluid, there is a vacuum that holds the joints together. Breaking this vacuum causes a popping sound similar to removing a wet glass from a smooth counter. There is no danger in breaking this vacuum and it can feel quite good, as when a Chiropractor manipulates the spine.
Abnormal movement of the facets, as commonly seen with an associated degenerative disc can cause uneven wear of the cartilage and even cause some of the joint surface to sheer off. The smooth lining of these facets (the cartilage) has a very poor blood supply and cannot heal if injured. “Degenerative facet arthritis” or lumbar “degenerative facet disease” is the term used for the wearing down of the cartilage surfaces in the spine.
The facets mechanically are “door stops”. Looking carefully at a side view of a normal lumbar x-ray, the vertebra all line up perfectly. With lumbar degenerative facet disease, changes of the disc and the height of the disc is lost. The vertebra involved will slide backwards on the one below (called a retrolysthesis) because they are shaped like a ramp facing backwards. However, in spite of a degenerative disc being present, if the facets have worn out and eroded down, the vertebra will slide forward. This condition is called a degenerative spondylolysthesis. If the facets break off, the condition is called isthmic spondylolysthesis. Please see the separate section on this condition elsewhere in this web site. There is also a very informative video about degenerative spondylolysthesis (a common cause of lower back pain).
The facets, when they become degenerative, develop bone spurs. If the bone spurs push medially (inside the spinal canal), then lateral recess stenosis of the spine occurs (crowding of the traversing nerve root). If the spurs form in front, foraminal stenosis results (crowding of the exiting nerve root). If the facet spurs tear the capsule, a ganglion cyst can form which can cause stenosis in either location. Please see these topics covered elsewhere in this web site.
Interesting enough, most of the time, lumbar degenerative facet disease is painless and does not cause chronic lower back pain. Many individuals have no significant pain receptors in the facets and it does not register in their brain that their facets have arthritis of the spine. Pain can be generated by nerve compression in the spine and that manifests as buttocks and leg pain. Lateral recess stenosis, lumbar foraminal stenosis, ganglion cysts in the spine, degenerative spondylolysthesis, central stenosis of the spine, and isthmic spondylolysthesis are the typical conditions that occur associated with degenerative facet disease. Instability of the lumbar spine can also occur with lumbar degenerative facet disease.
Treatment for lumbar degenerative facet disease is based upon the specific facet disease condition that is present (see above). In most cases, if there are no symptoms, there is no need for treatment. If the patient has actual facet pain from arthritis of the spine, physical therapy, chiropractic, medications, activity avoidance and facet injections can be helpful. If facet injections help but last only temporarily, dorsal facet rhizotomies can be effective.
A rhizotomy is an outpatient procedure that attempts to desensitize the facet by burning the small sensory nerves that supply the facet. Its effectiveness in the right setting is about 70% but may have to be repeated in one year as the sensory nerves attempt to grow back.
Surgical treatment depends upon the cause of pain. If there is nerve compression and no significant instability, a simple decompression can be helpful. If instability is present, a fusion would be required.
Nat Rev Rheumatol. 2013 Feb;9(2):101-16. doi: 10.1038/nrrheum.2012.198. Epub 2012 Nov 20.
Facetogenic pain, also known as zygapophysial joint pain, is a frequent cause of mechanical spine pain. Diagnostic blocks (for example, medial branch blocks [MBBs]) are the only reliable approach to identify facetjoints as the source of neck or back pain. In the absence of a reference standard, MBBs actually serve more of a prognostic than diagnostic role, enabling the selection of patients who might respond to radiofrequencydenervation treatment–the standard treatment for facet joint pain. Using double blocks reduces the false-positive rate of MBBs, but will invariably reduce the overall treatment success rate. No studies have evaluated non-interventional treatments for confirmed facetogenic pain, but data from studies in non-specific back pain suggest a modest, short-term beneficial effect for pharmacotherapy and some non-traditional treatments. Trials of intra-articular steroid injections for lumbar and cervical facet joint pain have yielded disappointing results, but evidence suggests that a subpopulation of patients with acute inflammation derive intermediate-term benefit from this therapy. Radiofrequency denervation provides some benefit for up to a year in approximately 60% of individuals. Increasing this success rate might involve enhancing diagnostic specificity and phenotyping, as well as techniques that increase the likelihood of successful nerve ablation, such as maximizing lesion size.
Acta Neurochir (Wien). 2011 Apr;153(4):763-71. doi: 10.1007/s00701-010-0881-5. Epub 2010 Nov 30.
The objective of this review is to evaluate the efficacy of Pulsed Radiofrequency (PRF) treatment in chronic pain management in randomized clinical trials (RCTs) and well-designed observational studies. The physics, mechanisms of action, and biological effects are discussed to provide the scientific basis for this promising modality.
We systematically searched for clinical studies on PRF. We searched the MEDLINE (PubMed) and EMBASE database, using the free text terms: pulsed radiofrequency, radio frequency, radiation, isothermal radiofrequency, and combination of these. We classified the information in two tables, one focusing only on RCTs, and another, containing prospective studies. Date of last electronic search was 30 May 2010. The methodological quality of the presented reports was scored using the original criteria proposed by Jadad et al.
We found six RCTs that evaluated the efficacy of PRF, one against corticosteroid injection, one against sham intervention, and the rest against conventional RF thermocoagulation. Two trials were conducted in patients with lower back pain due to lumbar zygapophyseal joint pain, one in cervical radicular pain, one in lumbosacral radicular pain, one in trigeminal neuralgia, and another in chronic shoulder pain.
From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regards to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the methodological quality of the included study. PRF application to the supracapular nerve was found to be as efficacious as intra-articular corticosteroid in patients with chronic shoulder pain. The use of PRF in lumbar facet arthropathy and trigeminal neuralgia was found to be less effective than conventional RF thermocoagulation techniques.
Describe the clinical presentation, diagnostic evaluation, and successful treatment of a case of symptomatic unilateral lumbosacral junction pseudarticulation using a novel radiofrequency nerve ablationtechnique.
A 56-year-old female patient who had suffered with low back and right upper buttock pain for 16 years experienced incomplete relief with L4/5 facet joint radiofrequency ablation. She was found to have an elongated right L5 transverse process that articulated with the sacral ala (Bertolotti’s syndrome). Fluoroscopically guided local anesthetic/corticosteroid injection into the pseudarthrosis eliminated her residual right buttock pain for the duration of the local anesthetic only. Complete pain relief was achieved by injecting local anesthetic circumferentially around the posterior pseudarthrosis articular margin. Accordingly, bipolarradiofrequency strip thermal lesions were created at the same locations. Complete pain relief and full restoration of function was achieved for 16 months postprocedure.
This case report describes a novel radiofrequency technique for treating symptomaticlumbosacral junction pseudarticulation that warrants further evaluation.
Int J Med Sci. 2010 May 25;7(3):120-3.
Retrospective, observational, open label.
We investigated the efficacy of facet debridement for the treatment of facet joint pain.
SUMMARY OF BACKGROUND DATA:
Facet joint disease, often due to degenerative arthritis, is common cause of chronic back pain. In patients that don’t respond to conservative measures, nerve ablation may provide significant improvement. Due to the ability of peripheral nerves to regenerate, ablative techniques of the dorsal nerve roots often provide only temporary relief. In theory, ablation of the nerve end plates in thefacet joint capsule should prevent reinnervation.
All patients treated with endoscopic facet debridement at our clinic from 2003-2007 with at least 3 years follow-up were included in the analysis. Primary outcome measure was percent change in facet-related pain as measured by Visual Analog Scale (VAS) score at final follow-up visit.
A total of 174 people (77 women, 97 men; mean age 64, range 22-89) were included. Location offacet pain was cervical in 45, thoracic in 15, and lumbar in 114 patients. At final follow-up, 77%, 73%, and 68% of patients with cervical, thoracic, or lumbar disease, respectively, showed at least 50% improvement in pain. Mean operating time per joint was 17 minutes (range, 10-42). Mean blood loss was 40 ml (range, 10-100). Complications included suture failure in two patients, requiring reclosure of the incision. No infection or nerve damage beyond what was intended occurred.
Our results demonstrate a comparable efficacy of endoscopic facet debridement compared to radiofrequency ablation of the dorsal nerve branch, with durable results. Large scale, randomized trials are warranted to further evaluate the relative efficacy of this surgical treatment in patients with facet joint disease.
back pain; facet syndrome; minimally invasive; nerve ablation; vertebral arthritis
Arch Orthop Trauma Surg. 2010 Sep;130(9):1103-10. doi: 10.1007/s00402-009-0983-9. Epub 2009 Oct 24.
BACKGROUND AND AIMS:
Facet joint denervation is a frequently performed technique to treat facet jointsyndrome. Most often this technique is used under fluoroscopic guidance implicating high radiation doses for both patients and surgeons. This prospective study was performed to evaluate the effectiveness in reducing radiation dose during radiofrequency ablation therapy of the lumbar facet joints and to evaluate the feasibility and possibilities of the new real time image guidance system SabreSource.
MATERIALS AND METHODS:
As much as 20 consecutive patients with radiofrequency ablation therapy of the facet joints L4 to S1 were included. Ten patients were treated by fluoroscopic control alone; the following 10 patients were treated with the SabreSource image guidance system. A total of 40 thermal ablations to thefacet joints were performed. Each patient was given one thermal ablation on both sides of the vertebral segment, either to the facet joints of L4-L5 or of L5-S1. Pain, according to the visual analogue scale (VAS), was documented before and 6 h after the intervention. Radiation dose, time of radiation and the number of shots needed to place the radiofrequency cannula were recorded.
No complications occurred. Before therapy, the mean VAS in all patients was 7.6 (range 6-10). After therapy the mean VAS in all patients was 3.4 (range 0-5). Compared to the fluoroscopy-guided thermalablation therapy the SabreSource system significantly reduced the number of fluoroscopy exposures (reduction 23.53%, p = 0.02), the time of radiation exposure (reduction 21.2%, p = 0.03) and the mean entrance surface dose (reduction 30.46%, p = 0.01).
The SabreSource System reduces radiation exposure and radiation dose in theradiofrequency denervation therapy of the lumbar facet joints and can be applied for other minimally invasive techniques.
Eur Spine J. 2009 Jun;18 Suppl 1:49-51. doi: 10.1007/s00586-009-0987-8. Epub 2009 May 9.
Approximately 80% of the adult population suffers from chronic lumbar pain with episodes of acute back pain. The aetiology of this disorder can be very extensive: degenerative scoliosis, spondiloarthritis, disc hernia, spondylolysis, spondylolisthesis and, in the most serious cases, neoplastic or infectious diseases. For several years, the attention of surgeons was focused on the articular facets syndrome (Lilius et al. in J Bone Joint Surg (Br) 71-B:681-684, 1998), characterised clinically by back pain and selective pressure soreness at the level of the facets involved. The instrumental framework highlights widespread zigoapophysary arthritis and hypertrophy/degeneration of articular facets due to a functional overload. This retrospective study analyses the patients who arrived at our observation and were treated with a neuroablation using a pulsed radiofrequencyprocedure, after a CT-guided infiltration test with anaesthetic and cortisone. From the data collected, it would seem that this procedure allows a satisfactory remission of the clinical symptoms, leaving the patient free from pain; furthermore, this method can be repeated in time.
J Clin Anesth. 2008 Nov;20(7):534-7. doi: 10.1016/j.jclinane.2008.05.021.
To compare the efficacy of continuous radiofrequency (CRF) thermocoagulation with pulsed radiofrequency (PRF) in the treatment of lumbar facet syndrome.
Prospective, randomized, double-blinded study.
Ambulatory pain clinic at a level-I trauma center and teaching institution.
50 ASA physical status I, II, and III patients, at least 18 years of age, scheduled to undergo CRF or PRF for lumbar back pain.
Target facet joints were identified with oblique radiographic views. Continuousradiofrequency thermocoagulation was delivered at 80 degrees C for 75 seconds, while PRF was delivered at 42 degrees C with a pulse duration of 20 ms and pulse rate of two Hz for 120 seconds.
Visual analog scale (VAS) pain assessment and Oswestry Low Back Pain and Disability Questionnaire (OSW) were administered at baseline and then at three months. Comparisons between groups and within groups were made of the relative percentage improvement in VAS and OSW scores.
No significant differences in the relative percentage improvement were noted between groups in either VAS (P = 0.46) or OSW scores (P = 0.35). Within the PRF group, comparisons of the relative change over time for both VAS (P = 0.21) and OSW scores (P = 0.61) were not significant. However, within the CRF group, VAS (P = 0.02) and OSW scores (P = 0.03) showed significant improvement.
Although there was no significant difference between CRF and PRF therapy in long-term outcome in the treatment of lumbar facet syndrome, there was a greater improvement over time noted within the CRF group.
Pain Pract. 2008 Sep-Oct;8(5):385-93. doi: 10.1111/j.1533-2500.2008.00227.x. Epub 2008 Aug 19.
There are currently 6 reviews on (pulsed) radiofrequency (RF) for the management of spinal pain. Two reviews on interventional pain management techniques in general also discuss RF. The outcomes of those reviews depend on the type of studies included and the opinion of the reviewers, which may result in different evidence levels. Radiofrequency denervation at the cervical and lumbar level has produced the most solid evidence. The differences in treatment outcome registered in the 5 randomized controlled trials (RCTs) regarding lumbarfacet denervation can be attributed to differences in patient selection and/or inappropriate technique. There is not sufficient evidence supporting the use of RF facet denervation for the management of cervicogenic headache. The studies examining the management of cervical radicular pain suggest a comparable efficacy for RF and pulsed RF (PRF). The PRF treatment is supposed to be safer and therefore should be preferred. The superiority of RF treatment adjacent to the lumbar dorsal root ganglion for the management of lumbarradicular pain has not been demonstrated in an RCT. Information regarding RF treatment of sacroiliac jointpain is accumulating. No randomized sham-controlled trials on the value of RF treatment of the Gasserian ganglion for the management of idiopathic trigeminal neuralgia have been published. One RCT indicates superiority of RF over PRF for the management of idiopathic trigeminal neuralgia. Future research to confirm or deny the efficacy of (P)RF should be conducted in carefully selected patient populations. The tests used for patient inclusion in such a trial could potentially help the clinician in selecting patients for this type of treatment. The value of PRF treatment of the peripheral nerves also needs to be confirmed in well-designed trials.
Spine (Phila Pa 1976). 2008 May 20;33(12):1291-7; discussion 1298. doi: 10.1097/BRS.0b013e31817329f0.
A randomized controlled study of percutaneous radiofrequency neurotomy was conducted in 40 patients with chronic low back pain (20 active and 20 controls).
The aim of the study was to evaluate the possible beneficial effect of percutaneousradiofrequency zygapophysial joint neurotomy in reducing pain and physical impairment in patients with pain from the lumbar zygapophysial joints, selected after repeated diagnostic blocks.
SUMMARY OF BACKGROUND DATA:
Facet or zygapophysial joint pain may be one of the causes of chronic low back pain and may be treated by a percutaneous radiofrequency denervation. Patients may possibly be identified by a positive diagnostic block. These blocks need to be repeated as false positive responses to single blocks occur.In all previous studies patients treated with radiofrequency denervation have been selected after single diagnostic blocks resulting in a varying degree of relief.
All patients were examined by an orthopedic surgeon before and 6 months after the treatment (sham or active). Inclusion criteria were 3 separate positive facet blocks. Denervation was achieved by multiple lesions at each level in an effort to provide effective denervation.
The active treatment group showed statistically significant improvement not only in back and leg pain but also back and hip movement as well as the sacro-iliac joint test. Pre operative sensory deficit and weak or absent ankle reflex normalized (P < 0.01) and (P < 0.05), respectively. There was significant improvement in quality of life variables, global perception of improvement, and generalized pain.The improvement seen in the active group was significantly greater then that seen in the placebo group with regard to all the above-mentioned variables. None of our patients had any complication other than transient postoperative pain that was easily managed.
Our study indicates that radiofrequency facet denervation is not a placebo and could be used in the treatment of carefully selected patients with chronic low back pain.
Pain Med. 2006 Sep-Oct;7(5):435-9.
The use of pulsed radiofrequency (PRF) for treatment of the medial branch is controversial.
A retrospective study of the results of PRF treatment of the medial branch in 48 patients with chronic low back pain was carried out. Patients who did not respond were offered treatment with conventionalradiofrequency heat lesions.
Patients were included who had low back pain and >50% pain relief following a diagnostic medial branch block. The mean age was 53.1 +/- 13.5 years, the mean duration of pain was 11.4 +/- 10.9 years (range 2-50). Nineteen patients had undergone surgery.
Pain scores on a numeric rating scale of 1-10 were noted before and after the diagnostic nerve block, before the procedure, and at 1-month and 4-month follow-up. PRF was applied for 2 minutes at a setting of 2 x 20 ms/s and 45 V at a minimum of two levels using a 22G electrode with a 5 mm active tip. Heat lesions were made at 80 degrees C for 1 minute. OUTCOME DEFINITION: A successful outcome was defined as a >60% improvement on the numeric rating scale at 4-month follow-up.
In 21/29 nonoperated patients and 5/19 operated patients, the outcome was successful. In the unsuccessful patients who were subsequently treated with heat lesions, the success rate was 1/6.
The setup of our study does not permit a comparison with the results of continuousradiofrequency (CRF) for the same procedure, other than the detection of an obvious trend. When comparing our results with various studies on CRF of the medial branch such a trend could not be found. Based on these retrospective data, prospective and randomized trials, for example, radiofrequency vs PRF are justified.
Spine J. 2003 Sep-Oct;3(5):360-2.
Chronic zygapophyseal joint arthropathy is a cause of back and neck pain. One proposed method of treating facet joint pathology is ablation of medial branches and dorsal rami with pulsedradiofrequency (RF) waves.
Assessment of efficacy of pulsed RF application for treatment of chronic zygapophyseal joint pain.
Retrospective study of 114 patients at a pain management clinic.
A total of 114 patients with clinical signs of facet joint involvement and a favorable response to a diagnostic medial branch block using local anesthetic, including 82 females and 32 males with a mean age of 52.8+/-12.6 years. Mean duration of pain was 7.52+/-5.26 years. Twenty-seven had previous back surgery, 83 patients had low back pain and 31 had cervical pain. Pain was on the left side in 47 patients, on the right side in 45 patients, bilateral in 22.
Result was regarded as successful if pain reduction was more than 50% on visual analog scale and the duration of effect was more than 1.5 months.
After obtaining positive stimulation, pulsed RF was applied to medial branches of dorsal rami for 120 seconds with temperature at the tip of the electrode 42 C.
Of 114 patients, who had positive response to diagnostic block, 46 patients did not respond favorably to pulsed RF application (pain reduction less than 50%). In 68 patients, the procedure was successful and lasted on average 3.93+/-1.86 months. Eighteen patients had the procedure repeated with the same duration of pain relief that was achieved initially. Previous surgery, duration of pain, sex, levels (cervical vs. lumbar) and stimulation levels did not influence outcomes.
The results of our study showed that the application of pulsed RF to medial branches of the dorsal rami in patients with chronic facet joint arthropathy provided temporary pain relief in 68 of 118 patients.