Cervical Zygapophysial Joint Pain Research Articles

Cervical medial branch block progression to radiofrequency neurotomy: A retrospective clinical audit

BackgroundChronic axial neck pain (CANP) due to zygapophysial joint arthropathy is best diagnosed via cervical medial branch block (MBB). However, the paradigm by which MBB is used to select patients for cervical radiofrequency neurotomy (RFN) is contested. Dual diagnostic cervical MBB with a minimum of ≥80% pain relief to diagnose cervical zygapophysial joint pain has been accepted by some Medicare Local Coverage Determinations as the method for selecting patients for cervical RFN. There are some who would argue that the utility of the dual diagnostic MBB and the ≥80% pain relief cut off lacks utility in clinical practice. The suspicion being those who progress from MBB1 to MBB2 will then flow from MBB2 to RFN without fail. Does clinical practice using dual diagnostic MBBs and using an ≥80% pain relief cut off reduce patient eligibility for cervical RFN after both MBB1 and MBB2? MethodsA retrospective clinical audit was carried out at an academic institution spine center from January 1st to December 31st, 2019. Charts were selected based on Current Procedural Terminology codes for MBB, then included if the cervical medial branches were targeted. Charts were then reviewed for procedural progression. Results21/51 (24%, 95% Confidence Interval 12-35%) patients progressed from MBB1 to MBB2. Of those 21 patients, 13 patients progressed from MBB2 to RFN (62%, 95% CI 41-83%). In total, 13/51 (14%, 95% CI 14-37%) patients who were initially suspected to have CANP due to zygapophysial joint pain progressed to RFN. Both MBB1 and MBB2 hindered the progression of 30/51 patients (59%, 95% CI 45-72%) and 8/21 patients (38%, 95% CI 17-59%), respectively. ConclusionBoth MBB1 and MBB2 served to filter patients from progression to RFN using dual MBBs with an ≥80% pain relief cutoff.

Fear-Avoidance Beliefs in Chronic Cervical Zygapophyseal Joint Pain Relieve With Medial Branch Block

Background: Chronic posterior neck pain is common, affecting 50–75% of people for 1 year or longer. The zygapophyseal joint is reported to be one of most common causative factors. The fear-avoidance is a model that describes how individuals develop chronic pain as a result of avoidant behaviour based on fear. Previous studies shown that medial branch block (MBB) and radio frequency neurotomy were effective for intractable pain.Material And Method: Case 1, TMK, Male, 57 yo, left posterior neck pain, VAS neck 7-8, NDI 46 %, no radiating pain, no neurological deficit. FABQ-PA score showed high fear (60%). Physical examination provokes facet joint pain. Neuroimaging revealed facet degeneration on T1WI and T2WI MRI. Case 2, RDW, Male, 45 yo, left posterior neck pain, VAS neck 8-9, NDI 40 %, no radiating pain, no neurological deficit. FABQ-PA score showed high fear (63%). Physical examination provokes facet joint pain. Neuroimaging revealed facet degeneration on T1WI and T2WI MRI. Case 3, TAY, Female, 52 yo, bilateral posterior neck pain, VAS neck 8-9, NDI 52 %, no radiating pain, no neurological deficit. FABQ-PA score showed high fear (60%). Physical examination provokes facet joint pain. Neuroimaging revealed facet degeneration on T1WI and T2WI MRI.Results: Our study reveals that C-MBB might ensure pain relief and decrease analgesic need. Physical activity at 1-, 3- and 6-months post-CMBB intervention were 65%, 60% and 68% of patients, respectively, gained >50% pain relief.Conclusion: Therapeutic MBB may provide an option for chronic high fear-avoidance beliefs pain of zygapophyseal joint.

Improving Fluoroscopic Visualization for Lower Cervical Medial Branch Blocks with a Modified Swimmer’s View: A Technical Report

Neural blockade of the cervical medial branches is a validated procedure in the diagnosis and treatment of cervical zygapophyseal joint pain. Fluoroscopic visualization of the lower cervical medial branch target zones (CMBTZs) in lateral view is sometimes challenging or not possible due to the patient's shoulders obscuring the target. Large shoulders and short necks often exacerbate the problem. Clear visualization is critical to accuracy and safety. We aim to describe a method for optimal fluoroscopic visualization of the lower CMBTZs using a modified swimmer's view. A technical report. A private practice. Discussion with accompanying fluoroscopic images of the cervical spine, focusing on the lateral aspects of the lower cervical articular pillars in both the traditional lateral view and modified swimmer's view. Four authors served as volunteers for undergoing fluoroscopic x-rays in both views. Visualization of each lower CMBTZ was attempted and stored. The most caudal, clearly visualized levels were compared in both views for each participant. Visualization of the lower CMBTZs can be successfully obtained with the modified swimmer's view and in select patients is superior to a lateral view. A limitation to this study is the design as a technical report. A future prospective study is warranted. Modified swimmer's view can serve as a primary method of visualizing the lower CMBTZs or an alternate view when a lateral view is unable to clearly demonstrate target landmarks. This can improve the ease, accuracy, and safety of performing diagnostic cervical medial branch blocks (CMBBs). Swimmer's view, cervical medial branch block, facet joint, fluoroscopy.

Fear-Avoidance Beliefs in Chronic Cervical Zygapophyseal Joint Pain Relieve With Medial Branch Block

Fear-Avoidance Beliefs in Chronic Cervical Zygapophyseal Joint Pain Relieve With Medial Branch Block

Clinical Diagnostic Tests versus Medial Branch Blocks for Adults with Persisting Cervical Zygapophyseal Joint Pain: A Systematic Review and Meta-Analysis.

Purpose: A systematic review and meta-analysis were performed to identify clinical tests for diagnosing cervical zygapophyseal joint pain (CZP) and to determine their diagnostic accuracy. Method: A search strategy was carried out to find relevant evidence published in CINAHL, Embase, MEDLINE, and PEDro from 1980 to January 1, 2015, pertaining to the clinical diagnosis of CZP. Quality assessment was completed using the Quality Assessment of Diagnostic Accuracy Studies-2. Results were analyzed to pool sensitivity and specificity and clarify diagnostic value. Results: Seven articles (n=463) were included for data synthesis and review. Intersegmental mobility tests were found to have the highest diagnostic accuracy, with pooled sensitivity of 0.91 (95% CI: 0.85, 0.94) and specificity of 0.74 (95% CI: 0.65, 0.81). The pooled sensitivity for mechanical sensitivity (palpation) was 0.88 (95% CI: 0.78, 0.95), and specificity was 0.61 (95% CI: 0.50, 0.71). Conclusion: Limited studies are available that discuss the clinical diagnosis of CZP, and significant heterogeneity is present in the available data. In this review, intersegmental mobility tests were found to be the most accurate. Clustering of tests, agreement on a reference standard, and further exploration of CZP referral patterns are recommended.

Radiofrequency Denervation Improves Health-Related Quality of Life in Patients with Thoracic Zygapophyseal Joint Pain.

To describe a practical approach for the diagnosis and treatment of thoracic zygapophyseal joint pain and to present preliminary clinical data on the effects of this treatment approach on health-related quality of life. An observational study. Specialist outpatient pain clinic in northern Sweden. Patients with long-term thoracic pain. We describe a method of radiofrequency denervation of thoracic zygapophyseal joints. We compared health-related quality of life between patients who underwent radiofrequency denervation of thoracic zygapophyseal joints and patients who underwent radiofrequency denervation for lumbar and cervical zygapophyseal joint pain. Treatment according to the Spine Intervention Society Guidelines was performed on the lumbar region in 178 patients and in the cervical region in 55 patients. Another 82 patients were treated in the thoracic region with our proposed technique. A survival plot of improvements in health-related quality of life revealed that all three treatments were effective in 65% or more of patients. The improvement in health-related quality of life was maintained for 12 or more months after treatment in 47% to 51% of patients. Our results suggest that radiofrequency denervation of thoracic zygapophyseal joint pain is as effective as radiofrequency denervation, the standard treatment, for lumbar and cervical zygapophyseal joint pain. If these results can be confirmed by other centers, radiofrequency denervation is likely to become more widely available for the treatment of thoracic zygapophyseal joint pain.

A Shortened Radiofrequency Denervation Method for Cervical Zygapophysial Joint Pain Based on Ultrasound Localization of the Nerves

Radiofrequency neurotomy is a recognized treatment for cervical zygapophysial joint pain. In several studies, the method has provided complete pain relief in 60-70% of the patients for approximately 9 months. The validated technique has the disadvantage of procedural times of 2-4 hours because several lesions are performed to take into account the variable nerve course. We tested the hypothesis that ultrasound localization of the nerves would enable us to reduce the number of lesions performed, while reaching the benchmark of at least 80% pain relief in 80% of patients with a median duration of 35 weeks, as achieved by a previous investigation using the standard method. We prospectively studied 15 consecutive patients with diagnosed cervical zygapophysial joint pain. They were treated using a shortened radiofrequency procedure under fluoroscopic control, based on previous ultrasound localization of the joint supplying nerves, with only two thermal lesions performed per nerve. Successful treatment was defined as at least 80% pain relief in the visual analog scale as compared with pretreatment. Follow-up was performed until 12 months after treatment. Of the 15 patients, 14 were successfully treated (93%, 95% confidence interval [CI] 80-100%) with a median time of pain relief of 44 weeks. At 6 and 12 months, 13 (87%, 95% CI 70-100%) and 6 patients (40%, 95% CI 15-65%) reported successful treatment, respectively. The median duration of the procedure was 35 minutes. In patients with cervical zygapophysial joint pain, radiofrequency denervation according to a shortened protocol based on ultrasound localization of the nerves reached the benchmark of the standard technique.

On Cervical Zygapophysial Joint Pain After Whiplash

Narrative review. To summarize the evidence that implicates the cervical zygapophysial joints as the leading source of chronic neck pain after whiplash. Reputedly a patho-anatomic basis for neck pain after whiplash has been elusive. However, studies conducted in a variety of disparate disciplines indicate that this is not necessarily the case. Data were retrieved from studies that addressed the postmortem features and biomechanics of injury to the cervical zygapophysial joints, and from clinical studies of the diagnosis and treatment of zygapophysial joint pain, to illustrate convergent validity. Postmortem studies show that a spectrum of injuries can befall the zygapophysial joints in motor vehicle accidents. Biomechanics studies of normal volunteers and of cadavers reveal the mechanisms by which such injuries can be sustained. Studies in cadavers and in laboratory animals have produced these injuries.Clinical studies have shown that zygapophysial joint pain is very common among patients with chronic neck pain after whiplash, and that this pain can be successfully eliminated by radiofrequency neurotomy. The fact that multiple lines of evidence, using independent techniques, consistently implicate the cervical zygapophysial joints as a site of injury and source of pain, strongly implicates injury to these joints as a common basis for chronic neck pain after whiplash.

Ultrasound Anatomy of the Nerves Supplying the Cervical Zygapophyseal Joints

Nerve blocks and radiofrequency neurotomy of the nerves supplying the cervical zygapophyseal joints are validated tools for diagnosis and treatment of chronic neck pain, respectively. Unlike fluoroscopy, ultrasound may allow visualization of the target nerves, thereby potentially improving diagnostic accuracy and therapeutic efficacy of the procedures. The aims of this exploratory study were to determine the ultrasound visibility of the target nerves in chronic neck pain patients and to describe the variability of their course in relation to the fluoroscopically used bony landmarks. Fifty patients with chronic neck pain were studied. Sonographic visibility of the nerves and the bony target of fluoroscopically guided blocks were determined. The craniocaudal distance between the nerves and their corresponding fluoroscopic targets was measured. Successful visualization of the nerves varied from 96% for the third occipital nerve to 84% for the medial branch of C6. The great exception was the medial branch of C7, which was visualized in 32%. The bony targets could be identified in all patients, with exception of C7, which was identified in 92%. The craniocaudal distance of each nerve to the corresponding bony target varied, the upper limit of the range being 2.2 mm at C4, the lower limit 1.0 mm at C7. The medial branches and their relation to the fluoroscopically used bony targets were mostly visualized by ultrasound, with the exception of the medial branch of C7 and, to a lesser extent, the bony target of C7. The nerve location may be distant from the fluoroscope's target. These findings justify further studies to investigate the validity of ultrasound guided blocks for invasive diagnosis/treatment of cervical zygapophyseal joint pain.

Do Diagnostic Blocks Have Beneficial Effects on Pain Processing?

Diagnostic blocks of cervical zygapophysial joints have been used as part of the management strategy for patients with chronic neck pain. Little information is available regarding the sensory processing changes that occur after these common procedures. In a hypothesis-generating prospective study, the pressure-pain thresholds, electrical pain thresholds, and descending inhibitory modulation response using the conditioned pain modulation paradigm are described for 9 patients with cervical zygapophysial joint pain that underwent successful comparative diagnostic blocks. The study was designed as a prospective cross-sectional study in 9 patients with cervical zygapophysial joint pain with positive comparative diagnostic blocks using lidocaine and bupivacaine. Each patient underwent baseline Quantitative Sensory Testing (QST) measurement (QST 1) after inclusion. Subsequent QST measurements (QST 2 and 3) were performed only after comparative blocks proved positive and only after the neck pain returned after each diagnostic block. Despite the return of their neck pain after the local anesthetic agents wore off, the patients exhibited (1) less focal pressure hyperalgesia, (2) generalized electrical hypoalgesia, and (3) significantly reduced conditioned pain modulation responses. Our preliminary evidence suggests that the perturbations to the sensory processing system from effective diagnostic blocks affect the tonic inhibitory system in a positive manner. Conditioned pain modulation, however, needs to be interpreted in the context of altered pain thresholds, and future studies should aim to investigate the shift in the nociceptive balance between facilitatory and inhibitory control after therapeutic interventions.

Differences in sensory processing between chronic cervical zygapophysial joint pain patients with and without cervicogenic headache

It is not known why some patients with underlying chronic nociceptive sources in the neck develop cervicogenic headache (CEH) and why others do not. This quantitative sensory testing (QST) study systematically explores the differences in sensory pain processing in 17 CEH patients with underlying chronic cervical zygapophysial joint pain compared to 10 patients with chronic cervical zygapophysial joint pain but without CEH. The QST protocol comprises pressure pain threshold testing, thermal detection threshold testing, electrical pain threshold testing and measurement of descending inhibitory modulation using the conditioned pain modulation (CPM) paradigm. The main difference between patients with or without CEH was the lateralization of pressure hyperalgesia to the painful side of the head of CEH patients, accompanied by cold as well as warm relative hyperesthesia on the painful side of the head and neck. From this hypothesis-generating study, our results suggest that rostral neuraxial spread of central sensitization, probably to the trigeminal spinal nucleus, plays a major role in the development of CEH.

The effect of radiofrequency neurotomy of lower cervical medial branches on cervicogenic headache.

Cervicogenic headache (CGH) is known to be mainly related with upper cervical problems. In this study, the effect of radiofrequency neurotomy (RFN) for lower cervical (C4-7) medial branches on CGH was evaluated. Eleven patients with neck pain and headache, who were treated with lower cervical RFN due to supposed lower cervical zygapophysial joint pain without symptomatic intervertebral disc problem or stenosis, were enrolled in this study. CGH was diagnosed according to the diagnostic criteria of the cervicogenic headache international study group. Visual analogue scale (VAS) score and degree of VAS improvement (VASi) (%) were checked for evaluation of the effect of lower cervical RFN on CGH. The VAS score at 6 months after RFN was 2.7±1.3, which were significantly decreased comparing to the VAS score before RFN, 8.1±1.1 (p<0.001). The VASi at 6 months after RFN was 63.8±17.1%. There was no serious complication. Our data suggest that lower cervical disorders can play a role in the genesis of headache in addition to the upper cervical disorders or independently.

Nerve block—A reliable diagnostic tool?

Local anaesthetics have potent inhibitory effects on nerve transission in nociceptive nerve fibres, and are widely used to relieve cute pain. Sometimes, the pain relieving effect outlasts the duraion of the local anaesthetic blockade [1], and repeatednerve blocks ave been applied in an attempt to stop vicious cycles following hronic pain. Apart from that, reversible nerve blocks are mainly pplied as a diagnostic tool to localise peripheral pain generators. n this issue of Scandinavian Journal of Pain, Curatolo and Bogduk resent a highly relevant and learned review of diagnostic blocks 2]. Curatolo and Bogduk [2] differentiate between test blocks, diagostic andprognosticblocks: (1)A test blockdoesnotdistinguishone ource of pain from another; but serves to test if the blocked nerve s responsible formediating thepain related signals. (2) Adiagnostic lock is used to identify the anatomical structure that is suspected o be the source of pain. (3) A prognostic block testswhether a treatent will be successful or not. If the prognostic block is positive, a reatment of the primary lesion or a nerve ablation will most likely elieve the pain for a prolonged period. Peripheral nerve blocks vs neuraxial blocks and specific sympahetic blocks: Several peripheral nerves have been targeted such s the occipital, trigeminal, intercostal, ileoinguinal, genitofemoral, nd obturator nerves. These nerves are located superficially and re easy to access. Epidural and subarachnoidal injections of local naesthetics may have effects on both peripheral and central pain onditions, and they are not suitable for diagnosing more localised ain. Even peripheral nerve blocks may influence central pain conitions. Sympathetic inhibitors (guanethidine and phentolamine) nd local anaesthetics injected close to sympathetic ganglia have een used to test for sympathetically maintained pain. Chronic pain arising from spinal tissues and structures; importance f “comparative blocks”: Several spinal pain conditions are common nd often difficult to differentiate from each other. The clinical feaures overlap and the pain generatorsmay vary in the samepatient. mage guided block procedures, targeting the facet joints, or their erve supply, spinal nerves, and intervertebral discs have been escribed. To diagnose cervical zygapophysial joint pain compartive medial branch blocks are preferred [3]. The evidence level is igh (Evidence level I–II according to the modified U.S. Preventive

What Does Local Tenderness Say About the Origin of Pain? An Investigation of Cervical Zygapophysial Joint Pain

Mechanical pain sensitivity is assessed in every patient with pain, either by palpation or by quantitative pressure algometry. Despite widespread use, no studies have formally addressed the usefulness of this practice for the identification of the source of pain. We tested the hypothesis that assessing mechanical pain sensitivity distinguishes damaged from healthy cervical zygapophysial (facet) joints. Thirty-three patients with chronic unilateral neck pain were studied. Pressure pain thresholds (PPTs) were assessed bilaterally at all cervical zygapophysial joints. The diagnosis of zygapophysial joint pain was made by selective nerve blocks. Primary analysis was the comparison of the PPT between symptomatic and contralateral asymptomatic joints. The secondary end points were as follows: differences in PPT between affected and asymptomatic joints of the same side of patients with zygapophysial joint pain; differences in PPT at the painful side between patients with and without zygapophysial joint pain; and sensitivity and specificity of PPT for 2 different cutoffs (difference in PPT between affected and contralateral side by 1 and 30 kPa, meaning that the test was considered positive if the difference in PPT between painful and contralateral side was negative by at least 1 and 30 kPa, respectively). The PPT of patients was also compared with the PPT of 12 pain-free subjects. Zygapophysial joint pain was present in 14 patients. In these cases, the difference in mean PPT between affected and contralateral side (primary analysis) was -6.2 kPa (95% confidence interval: -19.5 to 7.2, P = 0.34). In addition, the secondary analyses yielded no statistically significant differences. For the cutoff of 1 kPa, sensitivity and specificity of PPT were 67% and 16%, respectively, resulting in a positive likelihood ratio of 0.79 and a diagnostic confidence of 38%. When the cutoff of 30 kPa was considered, the sensitivity decreased to only 13%, whereas the specificity increased to 95%, resulting in a positive likelihood ratio of 2.53 and a diagnostic confidence of 67%. The PPT was significantly lower in patients than in pain-free subjects (P < 0.001). Assessing mechanical pain sensitivity is not diagnostic for cervical zygapophysial joint pain. The finding should stimulate further research into a diagnostic tool that is widely used in the clinical examination of patients with pain.

Cervical Zygapophyseal Joint Pain Patterns

Cervical Zygapophyseal Joint Pain Patterns

Pulsed radiofrequency of cervical medial branches for treatment of whiplash-related cervical zygapophysial joint pain

Background The aim of this study is to assess the efficacy of pulsed RF lesioning of cervical medial branches in patients with whiplash-related chronic cervical zygapophysial joint pain in whom other conservative treatments failed. Methods Cervical zygapophysial joint pain was confirmed in 14 patients undergoing double diagnostic blocks. These patients underwent pulsed RF lesioning of the cervical medial branches. Pulsed RF procedures were performed in 2 cycles of 180 seconds after localization under fluoroscopy guide. Results Twelve (85.7%) patients had substantial pain relief at 1 month. Eleven (78.3%) patients still had more than 60% pain relief at 6 months. Only 5 (35.7%) patients recurred within 12 months. At 12-month follow-up, 9 (64.3%) patients had significant pain improvement. Medication requirements decreased in 13 (92.8%) patients at 1 month, 12 (85.7%) patients at 6 months, and 10 (71.4%) patients at 12 months. Conclusions Pulsed RF of cervical medial branches is a potential treatment for patients with chronic whiplash-related cervical zygapophysial joint pain that failed other conservative treatments. This treatment provides long-lasting pain relief and reduces pain medication requirements.

The Nature of Neck Pain in a Private Pain Clinic in the United States

To determine the prevalence of different causes of neck pain in a private practice clinic. A retrospective audit of records. A private spine pain clinic in the state of Washington, USA. All consecutive patients, seen between January 2003 and January 2005, in whom a diagnosis of neck pain was made. Interventions. The records of all patients were examined to determine the prevalence of various diagnostic entities determined by history, examination, and invasive test such as controlled diagnostic blocks and provocation discography. Using different denominators, the prevalence of various conditions was determined in all patients who presented with neck pain, in patients in whom investigations were undertaken, and in patients who completed investigations. A large proportion of patients (36%) did not pursue investigations, which diluted the crude prevalence of various conditions. A further 17% deferred completing investigations. Among the 46% of patients who completed investigations, the prevalence of zygapophysial joint pain was 55%, discogenic pain was 16%, and lateral atlanto-axial joint pain was 9%. A diagnosis remained elusive in only 32% of those patients who completed investigations. In a private practice setting, a patho-anatomic diagnosis for chronic neck pain can be established in over 80% of patients, provided that appropriate investigations are undertaken. The prevalence of cervical zygapophysial joint pain encountered in the present study corroborates the prevalence rates established in academic studies. Cervical discogenic pain does not appear to be common among patients with chronic neck pain.

Cervical Zygapophysial Joint Pain Maps

To determine the patterns of referred pain in patients with proven cervical zygapophysial joint pain. The pain drawings were analyzed of patients with neck pain or headache who underwent controlled, diagnostic blocks, to test whether a zygapophysial joint was the source of their pain. The distribution of pain reported by each patient who had a positive response to blocks at a particular segmental level was copied onto a grid map in order to construct a composite map of the pain patterns of that segment. Based on the prevalence of a particular joint being symptomatic and the frequency with which it referred pain to particular areas, maps were constructed to indicate the probability of a particular joint being the source of pain in a given area. As reported by patients, the location and distribution of pain from particular cervical zygapophysial joints varies considerably; more so than in studies of normal volunteers. Nevertheless, segmental patterns could be identified. Although the pain patterns of adjacent segments overlap, those of remote segments do not. Furthermore, certain guidelines could be derived by which practitioners might distinguish pain from adjacent segments. Pain maps based on areas in which patients are relieved of pain by controlled blocks provide a more representative guide to the recognition of the segmental origin of cervical zygapophysial joint pain than do maps derived from normal volunteers.

The validity of manual examination in assessing patients with neck pain

Background context Although manual therapists believe that they can diagnose symptomatic joints in the neck by manual examination, that conviction is based on only one study. That study claimed that manual examination of the neck had 100% sensitivity and 100% specificity for diagnosing painful zygapophyseal joints. However, the study indicated that its results should be reproduced before they could be generalized. Purpose The present study was undertaken to answer the call for replication studies. The objective was to determine the sensitivity, specificity, and likelihood ratio of manual examination for the diagnosis of cervical zygapophyseal joint pain. Study design The study was conducted in a private practice located in a rural town. The practice specialized in musculoskeletal pain problems. Patient sample The study sample was 173 patients with neck pain in whom cervical zygapophyseal joint pain was suspected on clinical examination, and who were willing to undergo controlled diagnostic blocks of the suspected joint or joints. Outcome measures The validity of manual diagnosis was determined by calculating its sensitivity, specificity, and positive likelihood ratio. Methods Patients who exhibited the putatively diagnostic physical signs of cervical zygapophyseal joint pain were referred to a radiologist who performed controlled, diagnostic blocks of the suspected joint, and other joints if indicated. The results of the blocks constituted the criterion standard, against which the clinical diagnosis was compared, by creating contingency tables. Results Manual examination had a high sensitivity for cervical zygapophyseal joint pain, at the segmental levels commonly symptomatic, but its specificity was poor. Likelihood ratios barely greater than 1.0 indicated that manual examination lacked validity. Although the results obtained were less favorable than those of the previous study, paradoxically they were statistically not different. Conclusions The present study found manual examination of the cervical spine to lack validity for the diagnosis of cervical zygapophyseal joint pain. It refutes the conclusion of the one previous study. The paradoxical lack of statistical difference between the two studies is accounted for by the small sample size of the previous study.

Poster 97: Cervical Zygapophyseal Joint Pain Maps

Objectives: (1) To determine the validity of previous pain maps for cervical zygapophyseal joint (Z-joint) pain, (2) to determine the prevalence of Z-joint pain in patients undergoing diagnostic blocks, (3) to determine the prevalence of Z-joint pain in particular segments, and (4) to construct new pain maps with greater validity. Design: Retrospective case series review. Setting: Academic spinal pain clinic. Participants: All patients seen between January 1999 and October 2003 who had completed an evaluation for neck pain. Intervention: Each patient completed investigations for cervical Z-joint pain, including completing a pain map of their pain, and undergoing double-blind, controlled diagnostic blocks at the segmental level(s) selected by the physician who performed the block(s). The areas of pain relieved or not by diagnostic blocks were copied onto a standardized grid. Frequencies of different pain patterns were recorded. Main Outcome Measure: Pain maps. Results: A total of 348 blocks were performed in 194 patients who met the inclusion criteria. 54% of the blocks were positive, and 69% of the patients had at least 1 symptomatic level. The most common symptomatic level was C2-3 (36%), followed by C5-6 (35%), and C6-7 (17%). When compared with previous pain maps, referred pain from C5-6 tended to stay along the posterolateral aspect of the shoulder and arm, while symptomatic C6-7 more often involved the medial scapula. Conclusions: (1) Our finding that 54% of all blocks were positive underscored that previous pain maps were able to accurately predict symptomatic Z-joints approximately half the time. (2) 69% of patients undergoing diagnostic blocks proved to have at least 1 symptomatic level. (3) Revised pain maps were created. Using the pretest probability maps created, a new algorithm for the use of diagnostic blocks can be followed.