The diagnostic value of facet joint injections

Pain Management in Neurosurgery: Back and Lower Extremity Pain, Trigeminal Neuralgia

Interventional anesthetic techniques are an integral component of a biopsychosocial approach and multidisciplinary treatment. Injection techniques are often used to diagnose disorders, decrease the need for surgery, or increase the time to surgery. The role of neural blockade techniques using local anesthetics and steroids in the assessment and treatment of pain continues to be refined. With the current opioid crisis and an aging population with increasing medical comorbidities, there is an emphasis on the use of nonopioid, nonsurgical, and multimodal therapies to treat chronic pain. This article reviews indications, goals, and methods of common injection techniques.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group

BACKGROUND

The past two decades have witnessed a surge in the use of lumbar facet blocks and radiofrequency ablation (RFA) to treat low back pain (LBP), yet nearly all aspects of the procedures remain controversial.

METHODS

After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, letters were sent to a dozen pain societies, as well as representatives from the US Departments of Veterans Affairs and Defense. A steering committee was convened to select preliminary questions, which were revised by the full committee. Questions were assigned to 4-5 person modules, who worked with the Subcommittee Lead and Committee Chair on preliminary versions, which were sent to the full committee. We used a modified Delphi method, whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chair, who incorporated the comments and sent out revised versions until consensus was reached.

RESULTS

17 questions were selected for guideline development, with 100% consensus achieved by committee members on all topics. All societies except for one approved every recommendation, with one society dissenting on two questions (number of blocks and cut-off for a positive block before RFA), but approving the document. Specific questions that were addressed included the value of history and physical examination in selecting patients for blocks, the value of imaging in patient selection, whether conservative treatment should be used before injections, whether imaging is necessary for block performance, the diagnostic and prognostic value of medial branch blocks (MBB) and intra-articular (IA) injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for a prognostic block, how many blocks should be performed before RFA, how electrodes should be oriented, the evidence for larger lesions, whether stimulation should be used before RFA, ways to mitigate complications, if different standards should be applied to clinical practice and clinical trials and the evidence for repeating RFA (see table 12 for summary).

CONCLUSIONS

Lumbar medial branch RFA may provide benefit to well-selected individuals, with MBB being more predictive than IA injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of more false-negatives. Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Incidence and pattern of epidural spread during lumbar facet joint injection: a prospective study

Background

In clinical practice, we have often observed contrast material spreading into the epidural space during lumbar facet joint injection. However, the exact incidence of epidural spread and contrast pattern have not been reported.

Purpose

To evaluate the incidence and pattern of epidural spread in lumbar facet joint injection.

Material and Methods

One hundred consecutive patients (38 men, 62 women; mean age 68 years; age range 20–88 years) who underwent lumbar facet joint injection at two sites between April 2014 and June 2014 were investigated in this prospective study. Initial oblique, final anteroposterior, and lateral fluoroscopic images were obtained and evaluated for the presence of epidural spread and its contrast pattern (based on direction and extent) with the consensus of three radiologists. The relationship between epidural spread and its potential predictors was analyzed using the chi-squared test, Fisher’s exact test, and the t-test.

Results

The incidence of epidural spread during lumbar facet joint injection was 64.6% (n=64) in 99 patients and 49.5% (n=95) in 192 procedures; ventral spread occurred in 29.2% and foraminal spread in 18.8%. When epidural spread occurred, the most commonly identified distributions were unilateral (73.7%), dorsal (92.6%), and cephalad (92.6%). Epidural spread increased significantly in the caudocephalic direction ( P < 0.0001), in men (relative risk [RR]=1.478), in the adjacency of posterior fusion level (RR=1.545), in patients with spondylolisthesis (RR=1.454), and when there was no other leakage (RR=0.334).

Conclusion

Epidural spread occurred at about half the number of lumbar facet joint injections and showed a contrast pattern similar to that seen with the interlaminar approach.

Characterization of degenerative human facet joints and facet joint capsular tissues

OBJECTIVE

Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue. These alterations in FJC tissues in pain stimulation were also assessed.

DESIGN

FJs were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no history of back pain. Histological analyses of the FJs were performed. Cytokine antibody array and quantitative real-time polymerase chain reaction (qPCR) were used to determine the production of inflammatory cytokines, and western blotting analyses (WB) were used to assay for cartilage-degrading enzymes and pain mediators. Ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues was also performed.

RESULTS

Increased neovascularization, inflammatory cell infiltration, and pain-related axonal-promoting factors were observed in degenerative FJCs surgically obtained from symptomatic subjects. Increased VEGF, (NGF/TrkA), and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs. Results from ex vivo co-culture of the DRG and FJC tissue demonstrated that degenerative FJCs increased the expression of inflammatory pain molecules in the sensory neurons.

CONCLUSION

Degenerative FJCs possess greatly increased inflammatory and angiogenic features, suggesting that these factors play an important role in the progression of FJD and serve as a link between joint degeneration and neurological stimulation of afferent pain fibers.

Acute Treatment of Facet Syndrome by CT-Guided Injection of Dexamethasone-21-Palmitate Alone and in Combination with Mepivacaine

OBJECTIVE

To compare the efficacy and tolerability of dexamethasone-21-palmitate and mepivacaine alone and in combination in the acute treatment of facet syndrome.

PATIENTS AND METHODS

A total of 157 patients requiring acute therapy for lumbar facet syndrome were treated with computed tomography (CT)-guided intra-articular infiltration of either an anti-inflammatory corticosteroid, a local anaesthetic or a combination of the two. Patients assigned to the first treatment group (n = 60) received the corticosteroid dexamethasone-21-palmitate (Lipotalon((R))); patients in the second group (n = 36) received the local anaesthetic mepivacaine (Meaverin((R))); patients in the third group (n = 61) received a combination of the two drugs. The study duration was from November 2002 until June 2003.

RESULTS

In all three groups, values for compression pain, stress pain and rest pain improved significantly from baseline within 1 hour of injection: in the dexamethasone monotherapy group there was a 13% reduction in compression pain, 20% reduction in stress, and 22% reduction in rest pain; in the groups that received mepivacaine only or a combination of the two drugs there was a 63% and 60%, respectively, reduction of compression pain, 81% and 83%, respectively, reduction of stress pain, and 84% and 77%, respectively, reduction of rest pain. After 72 hours, improvements in these variables were significantly greater in patients treated with dexamethasone-21-palmitate (either as monotherapy or in combination therapy) than in patients treated with mepivacaine alone. In both groups treated with dexamethasone palmitate there was a 57% and 64%, respectively, reduction of compression pain, 70% and 66%, respectively, reduction of stress pain, and 75% and 64%, respectively, reduction of rest pain. In the mepivacaine monotherapy group there was a 17% reduction in compression pain, 26% reduction in stress pain and 13% reduction in rest pain. Both physicians and patients also rated the dexamethasone-21-palmitate-containing regimens as more effective than mepivacaine alone at 72 hours. Over the entire observation period, combination therapy was, on average, superior to both monotherapy regimens. The proportion of patients using concomitant NSAID medication after 3 days was reduced by 50% in the mepivacaine group and by 76% and 100%, respectively, in the dexamethasone-21-palmitate and combination therapy groups. CT-guided infiltration treatment was well tolerated and was associated with virtually no side effects in this study.

CONCLUSION

CT-guided infiltration of dexamethasone palmitate, particularly in combination with mepivacaine, represents a safe and effective method for the acute therapy of lumbar facet syndrome. The combination is superior to the local anaesthetic alone with regard to pain reduction up to 3 days after injection.

Diagnostic value of lumbar facet joint injection: a prospective triple cross-over study

The diagnosis “lumbar facet syndrome” is common and often indicates severe lumbar spine surgery procedures. It is doubtful whether a painful facet joint (FJ) can be identified by a single FJ block. The aim of this study was to clarify the validity of a single and placebo controlled bilateral FJ blocks using local anesthetics. A prospective single blinded triple cross-over study was performed. 60 patients (31 f, 29 m, mean age 53.2 yrs (22–73)) with chronic low back pain (mean pain persistance 31 months, 6 months of conservative treatment without success) admitted to a local orthopaedic department for surgical or conservative therapy of chronic LBP, were included in the study. Effect on pain reduction (10 point rating scale) was measured. The 60 subjects were divided into six groups with three defined sequences of fluoroscopically guided bilateral monosegmental lumbar FJ test injections in “oblique needle” technique: verum-(local anaesthetic-), placebo-(sodium chloride-) and sham-injection. Carry-over and periodic effects were evaluated and a descriptive and statistical analysis regarding the effectiveness, difference and equality of the FJ injections and the different responses was performed. The results show a high rate of non-response, which documents the lack of reliable and valid predictors for a positive response towards FJ blocks. There was a high rate of placebo reactions noted, including subjects who previously or later reacted positively to verum injections. Equivalence was shown among verum vs. placebo and partly vs. sham also. With regard to test validity criteria, a single intraarticular FJ block with local anesthetics is not useful to detect the pain-responsible FJ and therefore is no valid and reliable diagostic tool to specify indication of lumbar spine surgery. Comparative FJ blocks with local anesthetics and placebo-controls have to be interpretated carefully also, because they solely give no proper diagnosis on FJ being main pain generator.

12. Pain originating from the lumbar facet joints

Although the existence of a "facet syndrome" had long been questioned, it is now generally accepted as a clinical entity. Depending on the diagnostic criteria, the zygapophysial joints account for between 5% and 15% of cases of chronic, axial low back pain. Most commonly, facetogenic pain is the result of repetitive stress and/or cumulative low-level trauma, leading to inflammation and stretching of the joint capsule. The most frequent complaint is axial low back pain with referred pain perceived in the flank, hip, and thigh. No physical examination findings are pathognomonic for diagnosis. The strongest indicator for lumbar facet pain is pain reduction after anesthetic blocks of the rami mediales (medial branches) of the rami dorsales that innervate the facet joints. Because false-positive and, possibly, false-negative results may occur, results must be interpreted carefully. In patients with injection-confirmed zygapophysial joint pain, procedural interventions can be undertaken in the context of a multidisciplinary, multimodal treatment regimen that includes pharmacotherapy, physical therapy and regular exercise, and, if indicated, psychotherapy. Currently, the "gold standard" for treating facetogenic pain is radiofrequency treatment (1 B+). The evidence supporting intra-articular corticosteroids is limited; hence, this should be reserved for those individuals who do not respond to radiofrequency treatment (2 B±).

Image-guided facet joint injection

Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable.

Psychopathology predicts the outcome of medial branch blocks with corticosteroid for chronic axial low back or cervical pain: a prospective cohort study

Background

Comorbid psychopathology is an important predictor of poor outcome for many types of treatments for back or neck pain. But it is unknown if this applies to the results of medial branch blocks (MBBs) for chronic low back or neck pain, which involves injecting the medial branch of the dorsal ramus nerves that innervate the facet joints. The objective of this study was to determine whether high levels of psychopathology are predictive of pain relief after MBB injections in the lumbar or cervical spine.

Methods

This was a prospective cohort study. Consecutive patients in a pain medicine practice undergoing MBBs of the lumbar or cervical facets with corticosteroids were recruited to participate. Subjects were selected for a MBB based on operationalized selection criteria and the procedure was performed in a standardized manner. Subjects completed the Brief Pain Inventory (BPI) and the Hospital Anxiety and Depression Scale (HADS) just prior to the procedure and at one-month follow up. Scores on the HADS classified the subjects into three groups based on psychiatric symptoms, which formed the primary predictor variable: Low, Moderate, or High levels of psychopathology. The primary outcome measure was the percent improvement in average daily pain rating one-month following an injection. Analysis of variance and chi-square were used to analyze the analgesia and functional rating differences between groups, and to perform a responder analysis.

Results

Eighty six (86) subjects completed the study. The Low psychopathology group (n = 37) reported a mean of 23% improvement in pain at one-month while the High psychopathology group (n = 29) reported a mean worsening of -5.8% in pain (p < .001). Forty five percent (45%) of the Low group had at least 30% improvement in pain versus 10% in the High group (p < .001). Using an analysis of covariance, no baseline demographic, social, or medical variables were significant predictors of pain improvement, nor did they mitigate the effect of psychopathology on the outcome.

Conclusion

Psychiatric comorbidity is associated with diminished pain relief after a MBB injection performed with steroid at one-month follow-up. These findings illustrate the importance of assessing comorbid psychopathology as part of a spine care evaluation.

Prevalence of lumbar facet arthrosis and its relationship to age, sex, and race: an anatomic study of cadaveric specimens

STUDY DESIGN

An anatomic, epidemiologic study of facet arthrosis in cadaveric lumbar spines.

OBJECTIVE

To define the prevalence of lumbar facet arthrosis in a large population sample and to examine its association with age, sex, and race.

SUMMARY OF BACKGROUND DATA

Arthrosis of lumbar facet joints is a common radiographic finding and has been linked to low back pain. However, no population studies have specifically defined the prevalence of facet arthrosis in the lumbar spine in relation to age, sex, and race.

METHODS

A total of 647 cadaveric lumbar spines were examined by a single examiner for evidence of lumbar facet arthrosis. Information on race, age, and sex were collected. Arthrosis at each facet was graded from 0 to 4 on a continuum from no arthritis to complete ankylosis.

RESULTS

Facet arthrosis was present in 53% (L1-L2), 66% (L2-L3), 72% (L3-L4), 79% (L4-L5), and 59% (L5-S1). By decade, facet arthrosis was present in 57% of 20- to 29-year-olds, 82% of 30- to 39-year-olds, 93% of 40- to 49-year-olds, 97% in 50- to 59-year-olds, and 100% in those >60 years old. Fisher exact test and t test demonstrated that men had a greater prevalence and degree of facet arthrosis than women at all lumbar levels (P < 0.001). The lumbar level with the highest prevalence and degree of arthrosis was the L4-L5 level, as compared with each of the other levels (P < 0.001). There was no difference in arthrosis between right versus left facet joints (P > 0.5).

CONCLUSION

Facet arthrosis is a universal finding in the human lumbar spine. Evidence of arthrosis begins early, with more than one half of adults younger than 30 years demonstrating arthritic changes in the facets. The most common arthritic level appears to be L4-L5. Men have a higher prevalence and degree of facet arthrosis than women.

Total dorsal ramus block for the treatment of chronic low back pain: a preliminary study

OBJECTIVE

To evaluate the use of total dorsal ramus block, which blocks all three major branches (medial, intermediate, and lateral branches) of lumbar dorsal ramus, for chronic low back pain.

METHODS

Spread of local anesthetics with radiocontrast dye (total volume of 5 ml per administration) after total dorsal ramus block to the L4-L5 level was evaluated using computed tomography (CT) in patients with chronic low back pain (n=14; mean age, 71 years). In another group of patients, the effects of the total dorsal ramus block (n=21; mean age, 71 years) were compared with those of trigger point injection (n=22; mean age 73 years).

RESULTS

In all cases, the CT findings after total dorsal ramus block revealed the injectant spread over medial, intermediate, and lateral branches of both L3 and L4, those innervate the L4-L5 facet joint and surrounding back muscles. Significant alleviation of rest and motion pains evaluated with visual analogue scale was observed after total dorsal ramus block compared to the trigger point injection up to 7 days after the treatment (p<0.01).

CONCLUSIONS

The results of this preliminary study show that the total dorsal ramus block procedure may sufficiently block all three branches of the lumbar dorsal ramus at the targeted level with significant pain reduction.

Injection therapy of lumbar facet syndrome: a prospective study

BACKGROUND

Chronic low back pain remains a major health problem. Facet joint injection therapy is an easy to perform therapeutic option. However, few prospective studies use a standardized protocol to investigate injection therapy. The aim of our study was to evaluate quantity and duration of clinical improvement after this protocol, and to identify the best time for additional repetitive injection therapy.

MATERIALS AND METHODS

Thirty-nine patients (21 men, 18 women; mean age 55.2 years [range, 29-87 years]) with lumbar facet syndrome were treated with injection using a standardized protocol (prednisolone acetate, lidocaine 1%, phenol 5%) under fluoroscopic control. Follow-up was based on a specially designed questionnaire. Analysis included MacNab criteria, visual analogue scale, and pain disability index.

RESULTS

Reduction of pain was found up to 6 months after treatment. The outcome was assessed excellent or good by 62% (24 patients) of the patients after 1 month, by 41% (16 patients) after 3 months, and by 36% (14 patients) after 6 months. There was no influence of age, body mass index, or previous lumbar spinal surgery on improvement after treatment. There were no severe side effects. Short-lasting self limiting mild side effects were found in 26% (increased back pain, numbness, heartburn, headache, allergy).

CONCLUSION

Facet joint injection therapy using a standardized protocol is safe, effective, and easy to perform. The clinical effect is limited, and we recommend repetitive injection according to this protocol after 3 months.

Imaging findings predicting the outcome of cervical facet joint blocks

To determine which cross-sectional imaging findings predict the short-term outcome of cervical facet joint blocks (FJB) and to evaluate the effect of combined intra-/periarticular versus periarticular injection on pain. Fifty facet joints in 37 patients were included in the study. Single, unilateral FJBs in 24 patients, and bilateral single level FJBs in 13 patients were performed, respectively. In all patients, pain relief was assessed using a visual analogue scale. All computed tomography (CT) examinations were blindly reviewed by two radiologists. Osteoarthritis was rated using the Kellgren classification. The presence of combined intra-/periarticular vs. sole periarticular injection of contrast was evaluated. Kellgren Grades 0 (n=23), 1 (n=5), 2 (n=3), 3 (n=9), and 4 (n=10) were found. Mean pain relief after injection was 35% (range: 0-100%). 40% of all injections were combined intra-/periarticular. There was neither a statistically significant difference between pain relief and combined intra-/periarticular versus sole periarticular injection (p=0.64) nor the grade of osteoarthritis (p=0.49). Pain relief after cervical FJBs does not correlate with morphologic alterations seen on CT. Periarticular FJBs are not less successful than combined intra-/periarticular FJBs.

Clinical predictors of screening lumbar zygapophyseal joint blocks: development of clinical prediction rules

BACKGROUND

Only controlled intra-articular zygapophyseal joint (ZJ) injections or medial branch blocks can diagnose ZJ-mediated low back pain. The low prevalence of ZJ pain implies that identification of clinical predictors of a positive response to a screening block is needed.

PURPOSE

To estimate the predictive power of clinical findings in relation to pain reduction after screening ZJ blocks.

STUDY DESIGN

As part of a wider prospective blinded study investigating diagnostic accuracy of clinical variables, a secondary analysis was carried out to seek evidence of variables potentially valuable as predictors of screening ZJ block outcomes.

PATIENT SAMPLE

Chronic low back pain patients received screening ZJ blocks (n=151) with 120 patients included in the analysis after exclusions.

OUTCOME MEASURES

Pain intensity was measured using a 100-mm visual analog scale, and responses were categorized according to 75% through 95% or more pain reduction in 5% increments.

METHODS

Patients completed pain drawings, questionnaires, and a clinical examination before screening lumbar ZJ blocks. History, demographic and clinical variables were evaluated in cross tabulation and regression analyses with diagnostic accuracy values calculated for variables and variable clusters in relation to different pain reduction standards.

RESULTS

At the 75% pain reduction standard, 24.5% responded to screening ZJ blocks and 10.8% responded at the 95% standard. The centralization phenomenon is not associated with pain reduction using any standard. No variables were useful predictors of post-ZJ block pain reduction of less than 90%. Seven clinical findings were associated with 95% pain reduction after blocks. Five useful clinical prediction rules (CPRs) were found for ruling out a 95% pain reduction (100% sensitivity), and one CPR had a likelihood ratio of 9.7, producing a fivefold improvement in posttest probability.

CONCLUSIONS

A negative extension rotation test, the centralization phenomenon, and four CPRs effectively rule out pain ablation after screening ZJ block. One CPR generates a fivefold improvement in posttest probability of a negative or positive response to ZJ block.

Therapeutic Efficacy of Facet Joint Blocks

OBJECTIVE

The objective of our study was to investigate outcome predictors of short- and medium-term therapeutic efficacy of facet joint blocks.

MATERIALS AND METHODS

Forty-two patients with chronic lower back pain who were undergoing facet joint blocks at one (n = 29) or two (n = 13) levels were analyzed. All patients underwent MRI or CT of the lumbar spine within 5 months before the facet joint blocks. The facet joint blocks were performed under fluoroscopic guidance. A small amount (< 0.3 mL) of iodinated contrast agent, 0.5 mL of local anesthetics and 0.5 mL of steroids, were injected. The initial pain response was prospectively assessed using a visual analogue scale. Additional data, including short-term effect (> 1 week) and medium-term effect (> 3 months), were collected by a structured telephone interview. CT and MRI were reviewed with regard to the extent of facet joint abnormalities. Multiple logistic regression analyses were conducted to identify outcome predictor for efficacy of facet joint blocks.

RESULTS

A positive immediate effect was seen in 31 patients (74%). A positive medium-term effect was found in 14 patients (33%). Pain alleviated by motion (p = 0.035) and the absence of joint-blocking sensation (p = 0.042) predicted pain relief. However, the extent of facet joint osteoarthritis on MRI and CT was not a significant predictor for outcome (p = 0.57-0.95).

CONCLUSION

Facet joint blocks appear to have a beneficial medium-term effect in one third of patients with chronic lower back pain and may therefore be a reasonable adjunct to nonoperative treatment. However, outcome appears to depend on clinical, not on morphologic, imaging findings.

Injection studies in spinal disorders

Spinal injections have an important role in many centers in the diagnostic assessment and treatment of patient with various spinal disorders. In the literature, many studies describe the application, techniques, and potential benefit of spinal infections. It is well accepted morphologic alterations and pain correlate weakly because many imaging findings in patients with spinal symptoms can be found in asymptomatic individuals. Accordingly, one rationale for spinal injections is to provoke or eliminate pain presumably caused by the target spinal structure; this ostensibly allows a physician to make a better assessment of whether a particular morphologic alteration does or does not cause symptoms. Another rationale is to use spinal injections to support conservative treatment in patients who have from nerve root compromise, spinal stenosis, or facet joint osteoarthritis. Despite the widespread use of these spinal injections, their application is based widely on anecdotal experience and evidence that is not evidence based. We highlight the need for prospective randomized trials on the clinical efficiency of spinal injections and stress the importance for future considerations of cost effectiveness to justify their further application.

LEVEL OF EVIDENCE

Level V (expert opinion). See the Guidelines for Authors for a complete description of the levels of evidence.

Spinal CT-guided interventional procedures for management of chronic back pain

PURPOSE

Image-guided interventional procedures have arisen as an alternative for management of back pain, with controversial indications and efficacy. This study describes the technique, clinical impact, and complications of computed tomography (CT)-guided infiltrations for the management of chronic back pain.

MATERIALS AND METHODS

One hundred eleven patients with chronic back pain treated with CT-guided infiltrations were studied prospectively. Procedures performed included nerve root, facet joint, epidural, and sacroiliac joint blocks. Pain intensity was evaluated with use of a visual analog scale.

RESULTS

Two hundred twenty-two infiltrations were performed in 111 consecutive patients. After 18 months of follow-up, pain improvement lasted for a mean duration of 9 months and the complication rate was less than 1%. Moderate to good pain response was seen in 95% of followed patients and 4% of patients required surgery.

CONCLUSION

Spinal CT-guided infiltration constitutes an effective therapy for chronic back pain. This series confirms a low complication rate, good response, and high therapeutic value.

Lumbar zygapophyseal joint injections in patients with chronic lower back pain

BACKGROUND

This study was designed to assess the diagnostic value and clinical benefits of lumbar zygapophyseal joint injections in patients with chronic lower back pain.

METHODS

Two hundred and seventy-seven patients (136 males and 141 females, aged 15-82 years) with chronic lower back pain were enrolled in the trial and met the following criteria: pain for more than 1 year; no root signs; and no history of back surgery. Under fluoroscope, a 0.8-1.5 mL mixture of lidocaine, betamethasone dipropionate and iopamidol (1:1:0.5) was injected into each joint after intra-articular localization of the needle tip was confirmed. A questionnaire with a pain scale was administered immediately or the day after injection, and then after 1, 3, 6 and 12 weeks. Partial arthrograms were reviewed by a radiologist.

RESULTS

Four hundred and forty-nine joint injections were performed in 277 patients (L3-4, n = 76; L4-5, n = 272; L5-S1, n = 101). Bilateral injections were performed in 117 patients (42.2%). The study group comprised 204 patients (73.6%) with an excellent or good response, whereas the control group comprised the remaining 73 patients (26.4%). The rates of good response in the study group were 72.1% (147/204) after 3 weeks, 40.7% (83/204) after 6 weeks, and 31.4% (64/204) after 12 weeks. Partial arthrograms revealed 25 patients (9.0%) with synovial cysts (L3-4, n = 3; L4-5, n = 14; L5-S1, n = 8); 23 of these patients (92.0%) had a good response to the injections. Five of the 6 patients with spondylolysis (83.3%), having abnormal communication between the injected and contiguous joint, had a good response to the injections. The abovementioned, abnormal partial-arthrogram findings correlated significantly with the rate of good response to the injections. Although 3 patients had contrast medium extravasated into the epidural space during injection, none of the 277 patients had deteriorating lower back pain after the injections.

CONCLUSION

Lumbar zygapophyseal joint injections, as a useful diagnostic tool for facet joint syndrome, could also have useful palliative effects in the management of chronic lower back pain.

Spinal injury considerations in the competitive diver: a case report and review of the literature

BACKGROUND CONTEXT

Despite significant literature associated with spinal injuries and recreational diving, few articles exist regarding competitive diving injuries, with no reports pertaining specifically to spinal injuries. As a result, a case report of a collegiate diver with C5-C6 ligamentous instability requiring operative stabilization is currently presented in addition to a review of the literature.

PURPOSE

Present a case report of cervical C5-C6 ligamentous instability in a collegiate diver.

STUDY DESIGN

Case report and literature review.

METHODS

Not applicable.

RESULTS

Not applicable.

CONCLUSIONS

Diving injuries pertaining to competitive diving do occur but to a lesser extent than would be expected given the large forces the spine experiences. Training, experience and appropriate technique greatly minimize potential spinal hazards. Persistent complaints of neck pain after a competitive diving injury mandate aggressive evaluation and further workup.

Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac provocation tests

Research suggests that clinical examination of the lumbar spine and pelvis is unable to predict the results of diagnostic injections used as reference standards. The purpose of this study was to assess the diagnostic accuracy of a clinical examination in identifying symptomatic and asymptomatic sacroiliac joints using double diagnostic injections as the reference standard. In a blinded concurrent criterion-related validity design study, 48 patients with chronic lumbopelvic pain referred for diagnostic spinal injection procedures were examined using a specific clinical examination and received diagnostic intraarticular sacroiliac joint injections. The centralisation and peripheralisation phenomena were used to identify possible discogenic pain and the results from provocation sacroiliac joint tests were used as part of the clinical reasoning process. Eleven patients had sacroiliac joint pain confirmed by double diagnostic injection. Ten of the 11 sacroiliac joint patients met clinical examination criteria for having sacroiliac joint pain. In the primary subset analysis of 34 patients, sensitivity, specificity and positive likelihood ratio (95% confidence intervals) of the clinical evaluation were 91% (62 to 98), 83% (68 to 96) and 6.97(2.70 to 20.27) respectively. The diagnostic accuracy of the clinical examination and clinical reasoning process was superior to the sacroiliac joint pain provocation tests alone. A specific clinical examination and reasoning process can differentiate between symptomatic and asymptomatic sacroiliac joints

General principles of diagnostic testing as related to painful lumbar spine disorders: a critical appraisal of current diagnostic techniques

STUDY DESIGN

The literature on diagnostic tests available to the spine clinician for the evaluation of chronic low back pain was reviewed.

OBJECTIVES

To review critically the available information and data on invasive diagnostic tests used for evaluation of chronic low back pain.

SUMMARY OF BACKGROUND INFORMATION

Numerous published studies have described the technique and clinical results of diagnostic blocks for chronic low back pain. There are various methodologies, but most lack of an adequate "gold standard" with which to compare the results of the diagnostic test.

METHODS

The available published studies of diagnostic tests commonly used in the evaluation of chronic low back pain were reviewed, with a focus on invasive techniques. The techniques were evaluated on the basis of the data available to support the conclusions that could be drawn for each of these techniques. The principles of diagnostic testing, including specificity and sensitivity, were reviewed and applied in the context of the data available for each of these invasive tests.

RESULTS

The essential features the clinician seeks in a diagnostic test are accuracy, safety, and reproducibility. It is essential to have a gold standard with which to compare the accuracy of a given diagnostic test. There is no completely reliable gold standard with which to compare a diagnostic test (or injection) when the absence of pain is the end point. The clinical setting in which the test is used directly affects the test results. The prevalence of the disease therefore affects the meaningfulness of the test results. Imaging studies have their greatest value in the exclusion of other conditions. These studies alone were not adequate for predicting the patients who would respond to controlled diagnostic blocks of the facet joint. Facet joint diagnostic blockade probably is most accurately performed by median nerve branch block. The greatest specificity for a positive response to a facet denervation procedure is achieved when the diagnosis is established via highly controlled anesthetic blocks. Over the past few decades, the sacroiliac joint has received varying degrees of interest as an important pain generator of low back pain. Despite testimonials to the contrary, no diagnostic physical examination has correlated with sufficient specificity to diagnose this condition reliably from a clinical standpoint. Lumbar discography has been one of the single most controversial subjects in the management of degenerative, painful lumbar spine conditions. The specificity and sensitivity are high for the diagnosis of disc degeneration. The question that revolves around discography concerns the accuracy of this test for the diagnosis of discogenic pain. An integral part of the problem is the lack of an adequate gold standard. In a comparison of nerve root blockade, sciatic nerve block, posterior ramus block, and subcutaneous injection in a cohort of patients with sciatica, the sensitivity of nerve root block was very high, with only a moderate level of specificity. In the case of diagnostic selective nerve blocks used for evaluation of complex or protean nerve compression, surgical confirmation and clinical results should be a reliable gold standard. Conflicting results have been presented depending on the target lesion and method of study.

CONCLUSIONS

There are inherent limitations in the accuracy of all diagnostic tests. The tests used to diagnose the source of a patient's chronic low back pain require accurate determination of the abolition or reproduction of the patient's painful symptoms.

Chronic low back pain and fusion: a comparison of three surgical techniques: a prospective multicenter randomized study from the Swedish lumbar spine study group

STUDY DESIGN

A multicenter randomized study with a 2-year follow-up period and an independent observer was conducted.

OBJECTIVE

To compare three commonly used surgical techniques to achieve lumbar fusion primarily in terms of their ability to reduce pain and decrease disability in patients with severe chronic low back pain.

SUMMARY OF BACKGROUND DATA

Lumbar fusion can be used to reduce pain and decrease disability in patients with chronic low back pain, and different surgical techniques are available. The reported results after fusion surgery vary considerably, but most studies are retrospective and/or performed on heterogeneous patient groups. Spine surgeons commonly use the techniques presented in this report. However, in the absence of randomized trials it is difficult to know whether any one of them is better than the others for these patients.

METHODS

From 1992 through 1998, 294 patients referred to 19 spinal centers were blindly randomized into four treatment groups: three surgical groups (n = 222) and one nonsurgical group (n = 72). The sociodemographic and clinical characteristics did not differ among the groups. Eligibility included patients 25 to 65 years of age with therapy-resistant chronic low back pain that had persisted for at least 2 years and radiologic evidence of disc degeneration (spondylosis) at L4-L5, L5-S1, or both. Only patients randomized to one of three surgical groups were analyzed in the current study: Group 1 (posterolateral fusion; n = 73), Group 2 (posterolateral fusion combined with variable screw placement, an internal fixation device; n = 74), and Group 3 (posterolateral fusion combined with variable screw placement and interbody fusion; n = 75). The "circumferential fusion" in Group 3 was performed either as an anterior lumbar interbody fusion (n = 56) or as a biomechanically similar posterior lumbar interbody fusion (n = 19). The groups were composed of 51%, 58%, and 40% men respectively, and the respective mean ages were 44, 43, and 42 years. The patients had experienced low back pain for at least 2 years (mean, approximately 8 years). They had been on sick leave for approximately 3 years. Pain was measured by a visual analog scale, and disability was assessed by the Oswestry Low Back Pain Questionnaire, the Million Visual Analogue Score, and the General Function Score. Depressive symptoms were measured by the Zung Depression Scale. The global overall rating of the result was assessed by the patient and an independent observer after 2 years. Hospitalization data including operation time, blood loss, blood transfusion, and days of hospitalization in connection with surgery were reported, along with complications and the fusion rate. Records from the Swedish Social Insurance Board providing information on sick leave and economic compensation for Swedish residents were used to evaluate the patients' work status.

RESULTS

An independent observer examined 201 (91%) of 222 patients after 2 years, after 18 "group changers" and 3 dropouts had been excluded from the analyses. All surgical techniques were found to reduce pain and decrease disability substantially, but no significant differences were found among the groups. In all three groups, the patients rated the overall outcome similarly, as did the independent observer. The more demanding techniques in Groups 2 and 3 consumed significantly more resources in terms of operation time, blood transfusions, and days in hospital after surgery. The early complication rate was 6% in Group 1, 16% in Group 2, and 31% in Group 3. The fusion rate, as evaluated by plain radiograph, was 72% in Group 1, 87% in Group 2, and 91% in Group 3.

CONCLUSIONS

All the fusion techniques used in the study could reduce pain and improve function in this selected group of patients with severe chronic low back pain. There was no obvious disadvantage in using the least demanding surgical technique of posterolateral fusion without internal fixation.

Imaging-guided injection techniques with fluoroscopy and CT for spinal pain management

Local spinal pain and radiculopathy are common conditions that debilitate millions of Americans annually. Most cases are successfully treated conservatively with rest or physical therapy. Chiropractic manipulation or, in some cases, surgery may also be performed. Percutaneous injection has been used for spinal pain management for many years, but many of these procedures have historically been performed without imaging guidance. Recently, however, newer minimally invasive, imaging-guided percutaneous techniques have been added to the list of available treatment options for spinal pain. Imaging-guided techniques with fluoroscopy or computed tomography increase the precision of these procedures and help confirm needle placement. Cervical, thoracic, lumbosacral, and sacroiliac pain can be evaluated and treated safely and effectively with injections of local anesthetics or long-acting steroids into facet joints, sacroiliac joints, selective nerve roots, spondylolytic areas, and the epidural space. Because imaging-guided techniques appear to provide better results and reduce complication rates, they are becoming more popular despite controversy regarding their effectiveness. Controversy will continue to surround these imaging-guided techniques until large, double-blinded studies become available. In the meantime, there is an increased demand for these procedures from referring physicians, and it is important to be able to safely perform them with a minimum of patient discomfort.

Facet Joint Pain and the Role of Neural Blockade in Its Management

Chronic spinal pain is a common medical problem with serious financial and social consequences. Among the various structures with potential for producing pain in the spine, facet joints as sources of chronic spinal pain have attracted considerable attention and controversy. Significant progress has been made in precision diagnosis of spinal pain with neural blockade, in the face of less than optimal diagnostic information offered by imaging and neurophysiologic studies. Research into the role of facet joints in spinal pain has shown that cervical facet joints are the cause of chronic neck pain in 54% to 60% of patients, whereas lumbar facet joints cause pain in 15% to 40% of patients with chronic low back pain. Local anesthetic blocks of medial branches have proven to be a reliable diagnostic test; they are target-specific when used appropriately with control blocks, either with two local anesthetics with different durations of action or with the addition of an inactive placebo injection. The literature is replete with reports on uncontrolled studies, case reports, and documentation from a few controlled studies, all of which offer supporting information on the rationale and effectiveness of facet blocks and neurotomy. Facet joint injections and medial branch blocks are considered to be of equal value. Lumbar intra-articular steroid injections have been proven effective to a certain extent, but evidence indicates that cervical intra-articular steroids are ineffective. The role of repeat medial branch blocks is not known. Radiofrequency neurotomy remains the only practical and validated treatment for cervical facet joint pain; however, its role in management of either lumbar or thoracic facet joint pain awaits validation.

Therapeutic infiltration of the facet joint in minor intervertebral disease

SUMMARY

A CT-guided infiltration technique of the facet joints was employed on a group of 20 patients suffering from sciatica without any signs ofmorphostructural alteration of the facet joints, secondary to Minor Intervertebral Disease (MID). The typical flouroscopically guided intra-articular facet arthrography has been substituted by a CT-guided technique that privileges therapy rather than diagnosis. The study involved 20 patients between 29 and 57 years of age (average 44.5), of both sexes (16 females and four males). The average time which elapsed from onset of symptomatology was 9.5 months. At seven days after the first treatment subjective results were considered excellent by 11 patients (55%), good by one (5%) and satisfactory by one (5%). Six out of20 patients (30%) failed to gain any relief of symptoms. Only one patient (5%) had a worsening of pain. Clinical evaluation by the physician at the same time showed a good result in 11 patients (55%), satisfactory in two (10%). In six patients (30%) the symptomatology was unchanged. At 4 months the subjective results were excellent in three (15%), good in six (30%) and satisfactory in two (10%) . Nine (45%) had no positive results. The clinical examination was excellent in tWo (10%), good in seven (35%), satisfactory in two (10%) and without any relief of symptomatology in nine (45%). These results encourage the use of CT-guided infiltration that, together with the small amount of contrast medium injected into the joint space, make it a safe technique for patients, avoiding or reducing complications.

Specificity of diagnostic nerve blocks: a prospective, randomized study of sciatica due to lumbosacral spine disease

Temporary nerve blocks using local anesthetic are employed extensively in the evaluation of pain problems, particularly lumbosacral spine disease. Their specificity and sensitivity in localizing anatomic sources of pain have never been studied formally, however, and so their diagnostic and prognostic value is questionable. There have been anecdotal reports of relief of pain by temporary blocks directed to areas of pain referral, as opposed to areas of documented underlying pathology; but there has been no study to define the frequency or magnitude of this effect. We have examined the specificity and sensitivity of a battery of local anesthetic blocks in a series of 33 patients with a chief complaint of sciatica, attributable in all cases to spinal disease (radiculopathy, with some clinical features of arthropathy). As determined by blinded patient analog ratings in randomized sequence, three different nerve blocks were significantly more effective than control lumbar subcutaneous injection of an identical volume of 3 ml of 0.5% bupivacaine (P < 0.05). Not only paraspinal lumbosacral root blocks and medial branch posterior primary ramus blocks (at or proximal to the pathology), but also sciatic nerve blocks (distal or collateral to the pathology) produced temporary relief in a majority of patients. This confirmed the study hypothesis that false positive results are common, and specificity is low. For sciatic nerve blocks, specificity was between 24% and 36%. Patterns of responses specific to the established diagnosis of radiculopathy (i.e., root block most effective) had sensitivities between 9% and 42%. Statistical analysis of clinical and technical prognostic factors revealed that the only association with pain relief by any block were the effects of other blocks. The strongest association was between relief by sciatic nerve block and relief by medial branch posterior primary ramus (facet) block (P = 0.001, odds ratio 16.0). There were no associations between the results of blocks and clinical findings (history, physical examination, diagnostic imaging) in these patients, chosen for their homogeneous clinical presentation and absence of functional signs. Our findings indicate a limited role for uncontrolled local anesthetic blocks in the diagnostic evaluation of sciatica and referred pain syndromes in general. Negative blocks or a pattern of responses may have some predictive value, but isolated, positive blocks are non-specific. This lack of specificity may, however, be advantageous in therapeutic applications.

Prevalence and clinical features of lumbar zygapophysial joint pain: a study in an Australian population with chronic low back pain

OBJECTIVES

To determine the prevalence of pain arising from the zygapophysial joint in patients with chronic low back pain and to determine whether any clinical features could distinguish patients with and without such pain.

METHODS

Sixty three patients with chronic low back pain were studied prospectively. All patients underwent a detailed history and physical examination as well as a series of intra-articular zygapophysial joint injections of 0.5% bupivacaine starting at the symptomatic level to a maximum of three levels or until the pain was abolished. They also received injections of normal saline into paraspinal muscles to act as controls.

RESULTS

All patients proceeded with the injections. Twenty (32%; 95% confidence interval (CI) 20 to 44%) obtained greater than 50% relief of their pain following the administration of saline. Fifty seven patients completed the study; 23 of them (40%; 95% CI 27 to 53%) failed to obtain relief following the injection of saline but obtained relief following one or more intra-articular injections of local anaesthetic. None of the historical features or clinical tests could discriminate those patients with and those without zygapophysial joint pain.

CONCLUSION

Pain originating from the zygapophysial joint is not uncommon, but this study failed to find any clinical predictors in patients with such pain.

The false-positive rate of uncontrolled diagnostic blocks of the lumbar zygapophysial joints

One hundred and seventy-six consecutive patients with chronic low back pain and no history of previous lumbar surgery were studied to determine the false-positive rate of single diagnostic blocks of the lumbar zygapophysial joints. All patients underwent diagnostic blocks using lignocaine. Those patients who obtained definite or complete relief from these blocks subsequently underwent confirmatory blocks using bupivacaine. Eighty-three patients (47%) had a definite or greater response to the initial, lignocaine injection at one or more levels but only 26 (15%) had a 50% or greater response to a confirmatory injection of 0.5% bupivacaine. Using the response to confirmatory blocks as the criterion standard, the false-positive rate of uncontrolled diagnostic blocks was 38% and the positive predictive value of these blocks was only 31%. Because the positive predictive value of a test is lower when the pre-test probability (prevalence) is low, and because the prevalence of lumbar zygapophysial joint pain is likely to be less than 50%, uncontrolled diagnostic blocks will always be associated with an unacceptably low positive predictive value. These features render uncontrolled diagnostic blocks unreliable for the diagnosis of lumbar zygapophysial joint pain not only in epidemiologic studies but also in any given patient.

The management of chronic spinal pain by blockades: a review

This review of the use of blockades in the diagnosis and symptomatic treatment of spinal pain syndromes is based on increasing knowledge of the innervation of the spine as their rationale. Several clinical syndromes related to the spine are considered. Problems in making a correct diagnosis are discussed. Because of the relative aspecificity of signs and symptoms in spinal pain, a substantial part of the diagnosis may rely on test blockades. The place of test and therapeutic blocks is determined as far as possible. Problems of a pain classification system are discussed. Benefit for the patient depends on the following conditions being achieved: correct diagnosis, careful patient selection, the availability of technical equipment (e.g., fluoroscopy), and a well-designed and well-performed technique in experienced hands.

Radiofrequency lumbar facet denervation: analysis of prognostic factors

Percutaneous radiofrequency lumbar facet denervation has been in use as a treatment for intractable, mechanical low back pain for over 2 decades. A number of case series have been reported with high rates of success in selected patients; however, there has been limited objective outcome assessment, long-term follow-up, and analysis of prognostic factors. We have reviewed our experience with diagnostic lumbar facet blocks and percutaneous radiofrequency denervation at a mean follow-up interval of 3.2 years. Long-term outcome has been assessed by disinterested third party interview. Of 82 patients selected for these procedures, 56 had undergone prior low back surgery. Following diagnostic medial branch posterior primary ramus blocks, 42 reported at least 50% relief of pain and proceeded to radiofrequency denervation. Forty-five percent of patients undergoing denervation reported at least 50% relief of pain at long-term follow-up. Among the 40 patients who only underwent temporary blocks, 13% reported relief (i.e., spontaneous improvement or placebo effect) by at least 50% at long-term follow-up). By multivariate statistical analysis, patients undergoing bilateral blocks for bilateral or axial symptoms were significantly more likely to achieve temporary relief, and to proceed to permanent denervation. There was no difference, however, between the long-term results of bilateral denervation for bilateral or axial pain and those of unilateral denervation for unilateral pain. There was no significant difference in the rate of response between the 56 patients who had undergone prior lumbosacral spine surgery and the 26 who had not. There were no complications from the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous facet denervation in chronic thoracic spinal pain

In 40 patients with chronic thoracic spinal pain of more than 12 months duration which failed to respond to conservative treatment and with a previous evaluation by specialists, mainly neurologists and orthopaedic surgeons, the diagnosis of facet syndrome was made. This diagnosis was based on clinical criteria and a transient positive response to a prognostic blockade of the medial branch of the dorsal ramus of the thoracic spinal nerve. They were selected to undergo percutaneous radiofrequency denervation of the facet joints. The short and long-term results of 51 percutaneous thoracic facet denervations in 40 patients are described. After 2 months, 19 patients (47.5%) were pain-free, 14 patients (35%) had more than 50% pain-relief, and 7 patients (17.5%) had no relief. After a follow-up of 18-54 (average 31) months in 36 cases (3 patients had died because of malignancy, and 1 had undergone a spinal fusion), 16 patients (44%) were pain-free, 14 patients (39%) had more than 50% pain-relief and in 6 cases (17%) the result was poor. Adverse effects consisted of postoperative pain in 5 patients (12.5%). When conservative treatment fails, percutaneous thoracic facet denervation can be a safe and beneficial therapy in chronic thoracic spinal pain originating from the facet joints.

Lumbosacral spine imaging: physioanatomic method

Noninvasive evaluation of low back and leg pain has progressed rapidly over the past decade. The development of computed tomography, single-photon emission-computed tomographic bone scan, and magnetic resonance imaging has markedly increased diagnostic accuracy in detecting pathologic conditions. With this increased accuracy has come recognition of a 50% prevalence of underlying abnormalities in patients between 20 and 60 years old who have no symptoms. When such patients have a back injury, subsequent imaging will show in half of the population studied abnormalities that are not related to an acute injury. Degeneration of the spine progresses in all patients throughout their lifetime, and nearly all of the population will have back discomfort at some time. Political- and judicial-based compensation for back injuries related to accidents and on-the-job injuries provides an incentive for patients not to improve on therapy and to exaggerate symptoms, further complicating the clinical evaluation of their condition. The goal of physioanatomic noninvasive and invasive imaging evaluation presented in the following chapters is to increase specificity by differentiating pain generators from asymptomatic underlying pathologic conditions. When used with intensive conservative management and psychologic testing, this physioanatomic approach has resulted in much better treatment outcomes in our experience. The physioanatomic approach is quite simple, consisting of rigorous correlation of pathologic changes demonstrated by noninvasive imaging modalities (computed tomography, single-photon emission-computed tomographic bone scan, and magnetic resonance), or invasive modalities (diskography-enhanced computed tomography, nerve root block and facet block) with the patient's symptoms to evaluate whether the symptoms and the pathologic lesion are concordant or discordant. Patient symptoms and history are evaluated by use of a pain drawing and information sheet. The patient's pain pattern is categorized into a nonspecific pattern or into one of four recognizable pathway patterns (radicular, dorsal ramus, polyneuropathy, and sympathetic). Because each spinal lesion is typically manifested primarily via one of the four symptom pathways, the distribution of expected symptoms from each pathologic feature can be compared with the patient's pain drawing, and an assessment of the significance of imaged lesions can be made. The patient's presenting symptoms are also used to determine the most cost-effective and efficacious use of initial diagnostic imaging evaluation. In a minority of patients the findings on noninvasive imaging either will not correlate with the patient's symptoms or will demonstrate multiple abnormalities that could account for the patient's symptoms. In these patients, invasive techniques are extremely helpful in defining a pain generator or pain generators.(ABSTRACT TRUNCATED AT 400 WORDS)