***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Chronic pain in the cervical zygapophyseal joints is a common problem after a whiplash injury . Treatment with intraarticular injections of corticosteroid preparations has been advocated , but the value of this approach has not been established . We compared the efficacy of a depot injection of a corticosteroid preparation with the efficacy of an injection of a local anesthetic agent in patients with painful cervical zygapophyseal joints . METHODS Sixteen men and 25 women with pain in one or more cervical zygapophyseal joints after automobile accidents ( mean age , 43 years ; median duration of pain , 39 months ) were r and omly assigned to receive an intraarticular injection of either bupivacaine ( 0.5 percent ) or betamethasone ( 5.7 mg ) under double-blind conditions . The patients were followed by means of regular telephone contact and clinic visits until they reported a return to a level of pain equivalent to 50 percent of the preinjection level . The time from treatment to a 50 percent return of pain was compared in the two groups with the use of a survival analysis . RESULTS Less than half the patients reported relief of pain for more than one week , and less than one in five patients reported relief for more than one month , irrespective of the treatment received . The median time to a return of 50 percent of the preinjection level of pain was 3 days in the 21 patients in the corticosteroid group and 3.5 days in the 20 patients in the local-anesthetic group ( P = 0.42 ) . CONCLUSIONS Intraarticular injection of betamethasone is not effective therapy for pain in the cervical zygapophyseal joints after a whiplash injury BACKGROUND Chronic pain in the cervical zygapohyseal joints is a common problem after whiplash injury , but treatment is difficult . Percutaneous radiofrequency neurotomy can relieve the pain by denaturing the nerves innervating the painful joint , but the efficacy of this treatment has not been established . METHODS In a r and omized , double-blind trial , we compared percutaneous radio-frequency neurotomy in which multiple lesions were made and the temperature of the electrode making the lesions was raised to 80 degrees C with a control treatment using an identical procedure except that the radio-frequency current was not turned on . We studied 24 patients ( 9 men and 15 women ; mean age , 43 years ) who had pain in one or more cervical zygapophyseal joints after an automobile accident ( median duration of pain , 34 months ) . The source of their pain had been identified with the use of double-blind , placebo-controlled local anesthesia . Twelve patients received each treatment . The patients were followed by telephone interviews and clinic visits until they reported that their pain had returned to 50 percent of the preoperative level . RESULTS The median time that elapsed before the pain returned to at least 50 percent of the preoperative level was 263 days in the active-treatment group and 8 days in the control group ( P=0.04 ) . At 27 weeks , seven patients in the active-treatment group and one patient in the control group were free of pain . Five patients in the active-treatment group had numbness in the territory of the treated nerves , but none considered it troubling . CONCLUSIONS In patients with chronic cervical zygapophyseal-joint pain confirmed with double-blind , placebo-controlled local anesthesia , percutaneous radio-frequency neurotomy with multiple lesions of target nerves can provide lasting relief STUDY DESIGN A prospect i ve double-blind r and omized trial in 31 patients . OBJECTIVES To assess the clinical efficacy of percutaneous radiofrequency denervation of the lumbar zygapophysial joints in reducing pain , functional disability , and physical impairment in patients with back pain originating from the lumbar zygapophysial joints . SUMMARY OF BACKGROUND DATA Chronic low back pain is a major health problem in the industrialized world . A treatment option is percutaneous radiofrequency denervation of the lumbar zygapophysial joints . Its clinical efficacy has never been formally tested in a controlled trial . METHODS Thirty-one patients with a history of at least 1 year of chronic low back pain were selected on the basis of a positive response to a diagnostic nerve blockade and subsequently r and omly assigned to one of two treatment groups . Each patient in the radiofrequency treatment group ( 15 patients ) received an 80 C radiofrequency lesion of the dorsal ramus of the segmental nerve roots L3 , L4 , and L5 . Patients in the  control group ( n = 16 ) underwent an the same procedure but without use of a radiofrequency current . Both the treating physician and the patients were blinded to the group assignment . Before treatment , physical impairment , rating of pain , the degree of disability , and quality of life were assessed by a blinded investigator . RESULTS Eight weeks after treatment , there were 10 success patients in the radiofrequency group ( n = 15 ) and 6 in the sham group ( n = 16 ) . The unadjusted odds ratio was 3.3 ( P = 0.05 , not significant ) , and the adjusted odds ratio was 4.8 ( P < 0.05 , significant ) . The differences in effect on the visual analog scale scores , global perceived effect , and the Oswestry disability scale were statistically significant . Three , 6 , and 12 months after treatment , there were significantly more success patients in the radiofrequency group compared with the sham group . CONCLUSIONS Radiofrequency lumbar zygapophysial joint denervation results in a significant alleviation of pain and functional disability in a select group of patients with chronic low back pain , both on a short-term and a long-term basis Radiofrequency neurolysis of lumbar medial branch is currently the only proven way to treat patients with chronic lumbar zygapophysial joint pain , however , in some patients it can cause transient postoperative pain due to an inflammation caused by trauma of the electrode insertion and the thermal lesion around the target nerves . The aim of this study was to assess the effectiveness of intraoperative injection of methylprednisolone or pentoxifylline in comparison with placebo ( saline ) to prevent this process . 45 consecutive patients seen by one physician at one pain management clinic were included . Patients were r and omly assigned to 3 groups of 15 patients treated with radiofrequency neurotomy procedure with an addition of methylprednisolone , pentoxifylline or saline , respectively , and were observed for 6 months . Pain intensity , summed pain intensity difference , minimum 50 % reduction of pain intensity , Patients Satisfaction Score , and local tenderness were determined . The 50 % reduction of pain intensity was achieved in 80 % of patients one week after the procedure , and at 6 months such results were reported by 60 % of patients . There was a significant reduction of pain intensity in all three groups at all time points compared to baseline , however , there were no differences between the three groups . There was a significant difference in local tenderness as a measure of postoperative pain indicating effectiveness of both , methylprednisolone and pentoxifylline . No other complications were noted in any of the patients . Radiofrequency neurotomy is a safe and effective method to treat patients with zygapophysial joint pain . An addition of pentoxifylline and methylprednisolone can reduce postoperative pain commonly appearing within a short time after the procedure , however , neither pentoxifylline nor methylprednisolone influences long-term follow-up results & NA ; 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 st and ard , 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 Cervicogenic headache is still a controversial disease entity , and good and reliable treatment is lacking . In the present r and omized , sham-controlled , patient- and evaluator-blinded study , 12 patients with a disabling , long-st and ing and treatment-resistant strictly unilateral cervicogenic headache were included . The diagnosis was based on purely clinical criteria . Six were r and omized to receive radiofrequency neurotomy of facet joints C2-C6 ipsilateral to the pain , and six were r and omized to sham treatment . Patients were followed for 2 years with diary registration of pain for 14-days periods after 1 , 3 , 6 , 12 , 18 and 24 months , and also followed with algometry and neck mobility measurements at 3 , 12 and 24 months . Side-effects were minor and short-lasting , and those patients who were treated with neurotomy were somewhat improved at 3 months , but later there were no marked differences between the groups . In conclusion , the procedure is probably not beneficial in cervicogenic headache Background and Objectives The use of radiofrequency ( RF ) procedures in the peripheral nervous system to treat  chronic spinal pain  has been the subject of controversy . Publications concerned only uncontrolled studies , and irreversible nervous tissue damage was believed to be responsible for the effect , if any . In recent years , r and omized , controlled studies have appeared , which have attested to an increasing use of these techniques . This is a systematic review of r and omized controlled trials on RF procedures for spinal pain . Methods We performed a st and ardized literature search for r and omized , controlled trials . Three adjudicators independently registered trial methodology and outcome using vali date d and subject-related instruments . Interadjudicator disagreement was resolved by discussion . It was found necessary to devise additional parameters of study assessment . Results Six trials met the inclusion criteria . This small number , along with clinical and technical heterogeneity precluded statistical analysis . All studies , whether high or low quality , reported positive outcomes . Conclusions We conclude that there is moderate evidence that RF lumbar facet denervation is more effective for chronic low back pain  than placebo . Limited evidence exists for efficacy of RF neurotomy in chronic cervical zygapophyseal joint pain after flexion-extension injury . There is limited evidence that RF heating of the dorsal root ganglion is more effective than placebo in chronic cervicobrachialgia .  We recommend the systematic application of our additional parameter assessment s for future evaluations of RF studies . These additional parameters should also be used in the preparation of future trial protocol s of RF procedures for the treatment of chronic pain Study Design . A prospect i ve double-blind r and omized controlled trial was performed . Objective . To assess the efficacy of percutaneous radiofrequency articular facet denervation for  low back pain .  Summary of Background Data . Uncontrolled observational studies in patients with low back pain have reported some benefits from the use of facet joint radiofrequency denervation . Because the efficacy of percutaneous radiofrequency had not been clearly shown in previous studies , a r and omized controlled trial was conducted to assess the efficacy of the technique for improving functional disabilities and reduce pain . Methods . For this study , 70 patients with low back pain lasting of more than 3 months duration and a good response after intraarticular facet injections under fluoroscopy were assigned r and omly to receive percutaneous radiofrequency articular facet denervation under fluoroscopic guidance or the same procedure without effective denervation ( sham therapy ) . The primary outcomes were functional disabilities , as assessed by the Oswestry and Rol and -Morris scales , and pain indicated on a visual analog scale . Secondary outcomes included spinal mobility and strength . Results . At 4 weeks , the Rol and -Morris score had improved by a mean of 8.4 % in the neurotomy group and 2.2 % in the placebo group , showing a treatment effect of 6.2 % ( P = 0.05 ) . At 4 weeks , no significant treatment effect was reflected in the Oswestry score ( 0.6 % change ) or the visual analog pain score ( 4.2 % change ) . At 12 weeks , neither functional disability , as assessed by the Rol and -Morris scale ( 2.6 % change ) and Oswestry scale ( 1.9 % change ) , nor the pain level , as assessed by the visual analog scale ( −7.6 % change ) , showed any treatment effect . Conclusions . Although radiofrequency facet joint denervation may provide some short-term improvement in functional disability among patients with chronic low back pain , the efficacy of this treatment has not been established Facet joints have been described as an important source of low back pain . The value of medial branch blocks in the diagnosis of facet joint mediated pain is considered important . However , the therapeutic value of medial branch blocks has not been determined . This study was design ed to evaluate the duration of relief obtained and therapeutic value following controlled medial branch blocks with or without adjuvant agents Sarapin ( High Chemical Company , Levittown , PA ) and Depo-medrol ( Pharm 
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With regard to pharmacotherapy , most , but not all , systematic review s have found tricyclic antidepressants to be beneficial , although the effect size is small , and the studies are limited to short-term follow-up .
The authors found that the pre-RF injection of any type of fluid significantly increased all relevant lesion parameters , namely , horizontal diameter , vertical diameter , distal radius from tip , and maximal