In vitro measurement of pressure in intervertebral discs and annulus fibrosus with and without annular tears during discography

BACKGROUND CONTEXT: Discogram studies have shown that pain reproduction correlates with the extent of annular disruption. However, it has not been assessed if pressure changes in the annulus fibrosus vary incrementally with intradiscal pressure. PURPOSE: To determine the relationship between intradiscal pressure and outer annular pressure during discography in intervertebral discs with and without annular tears. STUDY DESIGN: Intradiscal and periannular pressures were measured simultaneously in vitro during intradiscal injection in porcine cadaver spines. METHODS: Twenty fresh porcine cadaver lumbar spines with intervening discs were tested. Intradiscal and periannular pressures were measured simultaneously using two pressure sensors during intradiscal contrast injection. The tip of a 25-gauge needle connected with a pressure manometer was placed in the center of the nucleus pulposus. A second pressure transducer was located at the outer third of the annulus fibrosus. Needle and transducer locations were confirmed by fluoroscopy. To compare the intact and torn annulus fibrosus, annular disruptions were created with a 20-gauge needle and confirmed by fluoroscopy. RESULTS: During intradiscal injections of discs with an intact annulus, annulus fibrosus pressure remained low and a sharp increase in intradiscal pressure was observed. Significantly higher pressures were noted in the outer annulus in discs with annular tears (p<.01). Mean pressures at the central nucleus pulposus, the outer third of intact annuli and torn annuli were 93.4+/-40.9 psi, 14.8+/-1.9 psi and 85.7+/-24.8 psi, respectively. CONCLUSIONS: Volumetric injection of intervertebral discs with a torn annulus fibrosis during discography may increase intra-annular pressure similar to the increase in pressure that may occur during spinal loading activities. This effect may not occur in discs with an intact annulus fibrosus.     

Provocative discography in patients after limited lumbar discectomy: A controlled, randomized study of pain response in symptomatic and asymptomatic subjects

STUDY DESIGN: This was a prospective observational study of patients with low back pain and those without after laminotomy and discectomy. OBJECTIVES: To determine, using a strict experimental design, the relative pain intensity response to provocative discography in symptomatic and asymptomatic subjects after lumbar discectomy for intervertebral disc herniation. BACKGROUND: Provocative discography frequently is used to evaluate persistent or recurrent low back pain syndromes in patients who have undergone posterior discectomy. The validity of interpreting painful injections during this procedure has not been critically assessed. The prevalence of significantly painful disc injections in a group with good outcomes after surgery is not known. Knowing the rates of significantly painful injections in asymptomatic patients after lumbar discectomy may clarify the meaning of painful injections in symptomatic patients. METHODS: From a cohort of 240 patients who had undergone single-level limited discectomy for sciatica, 20 asymptomatic volunteers were recruited for experimental three-level lumbar discography. Inclusion criteria required nearly perfect scores on standardized back pain rating instruments, no other spinal pathology, and normal psychometric screening. A control group of 27 symptomatic patients, after single-level discectomy with intractable low back pain syndrome, and without other spinal pathology, underwent discography. Seven patients in the control group had normal psychometric tests. Experienced raters who were blinded to control versus experimental status of the subjects scored the magnetic resonance imaging, discogram, psychometric tests, and discography videotapes of the subjects' pain behavior. RESULTS: There were 8 of 20 (40%) positive injections of discs that had previous surgery in the asymptomatic group and 17 of 27 (63%) positive injections in the symptomatic group. Specifically with regard to the symptomatic group, there were 3 of 7 (43%) positive injections (all concordant) in patients with normal psychometric scores, as compared with 14 of 20 (70%) positive injections (12 concordant) in patients with abnormal psychometric scores. Injections of discs that had previous surgery resulted in a mean pain score of 2.1 of 5 in the asymptomatic group, 2.1 in the symptomatic group with normal psychometric scores, and 3.4 in the symptomatic group with abnormal psychometric scores. Of the discs not treated with surgery, 2 were positive in the asymptomatic group (10%), 3 in 2 symptomatic subjects with normal psychological testing (29), and 18 in 13 symptomatic subjects with abnormal psychometric testing (76%). CONCLUSIONS: A high percentage of asymptomatic patients with normal psychometric testing who previously have undergone lumbar discectomy will have significant pain on injection of their discs that had previous surgery (40%). This is not significantly different from the experience of symptomatic patients with normal psychometric testing undergoing discography on discs that had previous surgery. Patients with abnormal psychological profiles have significantly higher rates of positive disc injections than either asymptomatic volunteers or symptomatic subjects with normal psychological screening.     

椎间盘造影阴性在椎间盘源性腰痛诊断中的分析评价

[目的]通过对一组有典型椎间盘源性下腰痛症状和影像学表现但椎间盘造影阴性的患者进行前瞻性分析,观察椎间盘造影阴性是否能完全排除椎间盘源性下腰痛的诊断.[方法] 2008年6月～2011年2月连续诊治的具有典型椎间盘源性疼痛症状和影像学表现(Dallas V型)但椎间盘造影阴性的一组患者共59例,其中男16例,女43例;年龄36～ 51岁,平均43.8岁;病史6个月～4年,平均1.8年.将59例患者随机分为两组,实验组(29例)于造影剂注射完后于椎间隙再给予注射利多卡因10 mg和地塞米松2.5 mg的混悬液,对照组(30例)则不注射药物并结束造影.两组患者于椎间盘造影术术前、术中、术后行VAS及ODI评分并观察结果.[结果]实验组术后2周内可见VAS评分下降,与对照组相比有统计学意义(P＜0.01),术后第3周随访时两组间VAS评分无明显差别(P＞0.05).实验组中18例VAS评分下降的患者在术后第1、4、8周时进行VAS评分及ODI评分时均较术前明显改善(P＜0.01),在第12周随访时总体上VAS评分及ODI评分与术前比较无明显差别(P＞0.05),对照组患者VAS评分及ODI评分与术前比较均无明显差别(P＞0.05).[结论]本研究结果表明椎间盘造影阴性,但同时合并典型的症状和影像学表现时,并不能完全排除椎间盘源性疼痛的诊断.     

Bony vibration stimulation: A new,non-invasive method for examining intradiscal pain

Summary Fifty-seven patients with low-back pain were evaluated immediately prior to a discography examination by means of an electrical tool which produced bony vibration to the lumbar spinal processes. The vibrator was composed of a standard electric toothbrush shaft (Braun) with a blunt head instead of the brush. The lumbar spinal processes were compressed one by one for a few seconds with this blunt, vibrating tool. The patient's pain experience provoked by vibration was compared with that from injections during discography. A good correlation was found between these two examinations when patients with previously operated backs and painful, prolapsed discs were excluded: sensitivity was 0.96 and specificity 0.72. Prolapsed, but discographically painful discs were always painless in the vibration examination. The local, non-invasive bony vibration stimulation test is an easy, quick, safe, inexpensive and reliable method for examining intradiscal pain.     

Discitis after discography

Infection after intradiscal injections has been recognised as a distinct entity, but discitis after discography has often been attributed to an aseptic process or a chemical reaction to the contrast material. We examined the hypothesis that discitis after discography is always due to infection, and report a clinical review and an experimental study. Part I. We reviewed the case records and radiographs of 432 patients who had undergone lumbar discography. When an 18-gauge needle without a stilette had been used, discitis was diagnosed in 2.7% of 222 patients but stiletted needles and a two-needle technique at each level reduced the incidence to 0.7%. Seven patients with discitis after discography had undergone anterior discectomy and fusion; in them the histopathological findings were of a chronic inflammatory response. Bacteria were isolated from the discs of three of the four patients who had open biopsy less than six weeks from the time of discography. These findings suggest that bacteria were initiators rather than promoters of the response. Part II. Multiple level lumbar discography was carried out in mature sheep, injecting contrast material with or without various concentrations of bacteria. Radiographs were taken and the discs and end-plates were examined histologically and cultured for bacteria at intervals after injection. None of the controls showed any evidence of discitis but all sheep injected with bacteria had typical radiological and histopathological changes by six weeks, though cultures were almost all negative. However, at one and two weeks after injection, but usually not after three weeks, bacteria could be isolated. We suggest that all cases of discitis after discography are initiated by infection, and that a very strict aseptic technique should be used for all injections into intervertebral discs.     

Effects on the vertebral end-plate of uncomplicated lumbar discography: an MRI study

The study aimed to identify and characterise changes occurring in the vertebral end-plate on MRI following uncomplicated lumbar discography. MRI was performed immediately before and within 2 h after uncomplicated lumbar discography in 20 consecutive patients undergoing the study as a precursor to possible spinal fusion. Of these, seven patients underwent a further MRI study at a mean of 72 days after discography (range 19–183 days). The MRI scans were assessed for the presence of any changes in the end-plates prior to and following discography. End-plate changes were identified in eight patients (40%) prior to discography. No new changes in end-plate signal intensity (SI) were identified in either the immediate or delayed MRI studies. The study suggests that any changes occurring in the vertebral end-plate following discography should be considered due to infectious discitis. There is no support for the concept of chemical discitis, chemical irritation of bone or microfracture of subchondral trabeculae as a cause of pain at discography. Received: 13 May 1997 Revised: 15 August 1997 Accepted: 14 October 1997     

MRI and discography of annular tears and intervertebral disc degeneration. A prospective clinical comparison.

We attempted to correlate the findings of MRI and discography in patients with low back pain, examining 108 lumbar intervertebral discs in 33 consecutive patients. MRI results were assessed from the intensity and shape of the signal obtained from the central part of the disc. Discography was classified according to the pattern of contrast material, the pressure accepted and the pain reproduced. All discs which were abnormal on MRI had altered patterns on discography, but 18 of the 60 discs with normal MRI had abnormal discograms. Of 39 asymptomatic discs, 33 had normal MRI signals and 24 had normal discograms. None of the 15 discs showing severe degeneration on MRI sustained high levels of intradiscal pressure, but only six of the 60 discs giving normal MRI had low pressure. With current techniques, discography is more accurate than MRI for the detection of annular pathology: a normal MRI does not exclude significant changes in the peripheral structure of the intervertebral disc which can produce low back pain.     

椎间盘封闭术对纤维环破裂型椎间盘源性腰痛的诊治价值

 目的 探讨椎间盘封闭术对纤维环破裂型椎间盘源性腰痛的诊治价值。方法 临床高度怀疑椎间盘源性腰痛行椎间盘造影及单个椎间盘封闭术且有完整随访资料的患者120例,男72例,女48例;年龄25～60岁,平均48岁。根据造影术中纤维环破裂Dallas分级将患者分为0级组7例、1级组36例、2级组48例、3级组29例。采用疼痛视觉模拟评分(visual analogue scale,VAS)及罗兰莫里斯功能评分表(Roland Morris Disability Questionnaire,RMDQ)对术前及术后2周、2个月、6个月、12个月及24个月的疗效进行评估。结果 对高度怀疑的“责任椎间盘”进行封闭阻滞后患者腰痛症状明显改善,术后疼痛VAS和RMDQ评分与术前比较差异有统计学意义;Dallas 3级组中期疗效优于Dallas 1级组及2级组,差异有统计学意义;重度纤维环破裂患者(Dallas分级3级)术后各时间点腰痛症状复发率均低于其他各组患者。结论 椎间盘封闭术能有效缓解椎间盘源性腰痛的症状,并有一定的诊断价值,可作为造影术不能复制疼痛病例的补充诊断依据;纤维环破裂型椎间盘源性腰痛患者,特别是重度纤维环破裂患者,接受椎间盘局部封闭术后缓解疼痛的效果确切。     

Roentgenographic evaluation of ossification and calcification of the lumbar spinal canal after intradiscal betamethasone injection

There have been reports of lumbar spinal canal ossification and calcification after triamcinolone intradiscal injection therapy. Our objective was to observe the roentgenographic changes after betamethasone intradiscal injection therapy for lumbar disc diseases. The subjects were 183 patients (498 discs; 130 men and 53 women) who underwent discography and betamethasone intradiscal injection therapy and were followed for a mean of 5 years and 7 months. Ossification and calcification appeared de novo (three patients, three discs) or enlarged (four patients, five discs) in the outer layer of the posterior annulus fibrosus or posterior longitudinal ligament in eight discs among seven patients (3.8%). The incidence and degree of ossification and calcification in our patients were significantly lower than those reported in previous studies, and a long time elapsed before ossification and calcification appeared or enlarged. Intradiscal injection of betamethasone did not appear to confer any incremental relative risk for lumbar spinal canal ossification and calcification based on review of follow-up roentgenographs.     

Treatment of multilevel degenerative disc disease with intradiscal electrothermal therapy

Intradiscal electrothermal therapy is a frequently performed procedure for the pain of internal disc disruption. It is typically performed on one to two discs; the discal treatment is followed by a long period of rest and rehabilitation. In patients with multilevel disc disease, intradiscal electrothermal therapy is either not contemplated or only one to two discs are treated at a time. This approach therefore either denies these patients the potential benefits of intradiscal electrothermal therapy or significantly prolongs the period of pain and disability. A 25-year-old female patient presented with internal disc disruption at four lumbar disc levels, diagnosed by provocative discography and post discography CT scan. All these discs were treated simultaneously by intradiscal electrothermal therapy. The patient tolerated the procedure well and responded favourably with significant and prolonged decrease in her symptoms. She reported sustained reduction in her pain and showed no clinical evidence of early neurological or infectious complications during 18 months of follow-up. This report indicates that intradiscal electrothermal therapy can be performed at multiple levels at a single sitting, compared to intradiscal electrothermal therapy performed at one to two discs at a time, this approach may obviate the need for surgery and may reduce the duration of pain and disability incurred. However, the influence of multilevel intradiscal electrothermal therapy on long-term complications or outcome is not known.     

Psychophysical measurements during lumbar discography: a heart rate response study

STUDY DESIGN: Prospective clinical data analysis. OBJECTIVE: To determine if heart rate (HR) response correlates with positive discography results. SUMMARY OF BACKGROUND DATA: Lumbar discography is a controversial tool for the diagnosis of discogenic low back pain. The subjective nature of discography can make data interpretation difficult, leading to false-positive and false-negative results. HR changes have been found in numerous studies to be a reliable and valid indicator of acute pain. To date, there is no study analyzing the HR response to discography-induced pain. METHODS: The HR measurements were recorded immediately preceding and after contrast injection into the each disc, and statistically correlated with the provocation of concordant pain, nonconcordant pain, and nonpainful discs. RESULTS: Discography was performed in 26 subjects with low back pain. Among 75 discograms, 26 discs elicited concordant pain, 9 provoked nonconcordant pain, and 40 elicited no pain response. There was no significant change in HR during disc stimulation for negative [no pain response (P=0.19) and nonconcordant (P=0.26)] discograms, whereas positive discograms [concordant pain (numerical rating scale> or =6/10)] were associated with a statistically significant increase in HR (P=0.000002). CONCLUSIONS: Lumbar discography induces positive HR response only in positive discograms. Although there is no immediate practical application of these results, 2 implications may deserve future research: (a) correlation of HR response with surgical and intradiscal electrotherapy treatment outcomes; (b) evaluation of HR measurement in cases of false-positive results (concordant pain on discography but no HR response).     

False-positive findings on lumbar discography. Reliability of subjective concordance assessment during provocative disc injection

STUDY DESIGN: Experimental disc injections in subjects with no history of low back symptoms. OBJECTIVE: To determine in an experimental model the reliability of patients' subjective interpretation of pain concordancy during provocative disc injection. BACKGROUND: Discography in the evaluation of low back pain relies on a patient's subjective assessment of pain magnitude and quality during disc injection. Reproduction of significant pain on disc injection, which is similar to patients' usual pain, is believed to prove that the disc injected is the source of the patient's low back pain. In the current study, this hypothesis was tested in a controlled setting on patients with known nonspinal pain in a common referral area of discogenic pain. METHODS: Patients with no history of low back pain were recruited to participate in a study of discography. Patients scheduled to undergo posterior iliac crest bone graft harvesting for nonthoracolumbar procedures were evaluated with lumbar radiography, magnetic resonance imaging, and psychometric testing. Two to 4 months after bone graft harvesting, patients underwent lumbar discography by strict blinded protocol. Patients were asked to compare the sensations elicited at discography to their usual back/buttock pain since bone graft harvesting. Pain was rated as 0-5 on a pain thermometer and concordancy was rated as none, dissimilar, similar, or exact. RESULTS: Eight subjects completed the study, and 24 discs were injected. Of the 14 disc injections causing some pain response, 5 were believed to be "different" (nonconcordant) pains (35.7%); 7 were "similar" (50.0%), and 2 were "exact" pain reproductions (14.3%). The presence of anular disruption predicted concordant pain reproduction (P < 0.05). Of 10 discs with anular tears, injection of 5 elicited pain that was similar to or an exact reproduction of pain at the iliac crest bone graft harvest sites. By the usual criteria for positive discography, 4 of the 8 patients (50%) would have been classified as positive. In these patients, the pain on a single disc injection was very painful, and the pain quality was noted to be exact or similar to the usual discomfort. All subjects had a negative control disc. CONCLUSIONS: The findings of this study demonstrate that patients with no history of low back pain who had undergone posterior iliac bone graft harvesting for nonlumbar procedures often experienced a concordant painful sensation on lumbar discography with their usual gluteal area pain. Thus, the ability of a patient to separate spinal from nonspinal sources of pain on discography is questioned, and a response of concordant pain on discography may be less meaningful than often assumed.     

In vitro measurement of pressure differences using manometry at various injection speeds during discography.

BACKGROUND CONTEXT: Lumbar discography has been widely used to evaluate discogenic low back pain. Anecdotal evidence suggests that pain reproduction during discography is more closely correlated with peak dynamic pressure than with static postinjection pressure. Although there can be a significant difference between dynamic and static pressures, to date most discographic evaluations use static pressure recorded postinjection (which is stable and easily measured). The use of readings taken after injection, rather than readings of maximum dynamic peak pressure recorded during injection, appear to increase false positives in lumbar discography. High-speed intradiscal injections also appear to have potentially confounding effects that may increase the rate of false-positive responses during lumbar discography. To date there has been no study for the evaluation of peak dynamic intradiscal pressures or for differentiating dynamic from static pressures in the nucleus pulposus (NP) in response to various speeds of intradiscal injection. PURPOSE: The goal of this study was to obtain additional data on potential confounding factors that could affect discographic results by assessment of pressures within the NP during discography at various injection speeds. The purpose of data collection was to more precisely evaluate pressure differences between dynamic and static pressure within the NP, evident during discography. STUDY DESIGN: In vitro laboratory study. SAMPLES: A total of 82 trials were performed on intervening discs of 82 porcine cadaver lumbar spines. METHODS: Dynamic and static intradiscal pressures were measured with manometry, using two pressure sensors simultaneously during intradiscal injection of contrast media at various speeds. The tip of a 25-gauge needle was placed in the center of the NP and connected with a pressure manometer, which recorded the pressure and therefore the speed of injection. A second pressure reading was obtained using a sensor tip connected to a transducer; the sensor tip was located separately in the same NP tissue. The needle and transducer locations were confirmed by fluoroscopy. OUTCOME MEASURES: At low controlled injection speeds (below 0.08 mL/s), the mean peak pressure difference in the NP was 4.06 (+/-1.52) psi. With high-speed injections of 0.08 mL/s or greater, the mean increased abruptly up to 14.52 (+/-4.11) psi (p<.05). The data indicate that injections applied slowly resulted in smaller differences in pressure within the NP, registered by both manometry and the needle sensor tip. Additional samples were taken using both devices to confirm this threshold level. RESULTS: With low injection speeds, especially those below 0.08 mL/s, differences between dynamic and static pressures on both pressure sensors were minor. These differences increased as injection speed became faster. However, at fast injection speeds of 0.08 mL/s and above, those differences were significantly higher. CONCLUSION: Dynamic and static intradiscal pressures are of similar value when measured by manometer and by needle sensor at slow injection speeds during discography. However, the pressure differences appeared to rapidly increase in response to incremental increases in injection speed. The data from these 82 samples suggest that uncontrolled high speeds of intradiscal injections are a potential confounding factor, which may increase false-positive responses during lumbar discography.     

Patterns of lumbar disc degeneration are different in degenerative disc disease and disc prolapse magnetic resonance imaging analysis of 224 patients

Background contextExisting research on lumbar disc degeneration has remained inconclusive regarding its etiology, pathogenesis, symptomatology, prevention, and management. Degenerative disc disease (DDD) and disc prolapse (DP) are common diseases affecting the lumbar discs. Although they manifest clinically differently, existing studies on disc degeneration have included patients with both these features, leading to wide variations in observations. The possible relationship or disaffect between DDD and DP is not fully evaluated.PurposeTo analyze the patterns of lumbar disc degeneration in patients with chronic back pain and DDD and those with acute DP.Study designProspective, magnetic resonance imaging–based radiological study.MethodsTwo groups of patients (aged 20–50 years) were prospectively studied. Group 1 included patients requiring a single level microdiscectomy for acute DP. Group 2 included patients with chronic low back pain and DDD. Discs were assessed by magnetic resonance imaging through Pfirmann grading, Schmorl nodes, Modic changes, and the total end-plate damage score for all the five lumbar discs.ResultsGroup 1 (DP) had 91 patients and group 2 (DDD) had 133 patients. DP and DDD patients differed significantly in the number, extent, and severity of degeneration. DDD patients had a significantly higher number of degenerated discs than DP patients (p<.000). The incidence of multilevel and pan-lumbar degeneration was also significantly higher in DDD group. The pattern of degeneration also differed in both the groups. DDD patients had predominant upper lumbar involvement, whereas DP patients had mainly lower lumbar degeneration. Modic changes were more common in DP patients, especially at the prolapsed level. Modic changes were present in 37% of prolapsed levels compared with 9.9% of normal discs (p<.00). The total end-plate damage score had a positive correlation with disc degeneration in both the groups. Further the mean total end-plate damage score at prolapsed level was also significantly higher.ConclusionThe results suggest that patients with disc prolapse, and those with back pain with DDD are clinically and radiologically different groups of patients with varying patterns, severity, and extent of disc degeneration. This is the first study in literature to compare and identify significant differences in these two commonly encountered patient groups. In patients with single-level DP, the majority of the other discs are nondegenerate, the lower lumbar spine is predominantly involved and the end-plate damage is higher. Patients with back pain and DDD have larger number of degenerate discs, early multilevel degeneration, and predominant upper lumbar degeneration. The knowledge that these two groups of patients are different clinically and radiologically is critical for our improved understanding of the disease and for future studies on disc degeneration and disc prolapse.     

Provocative discography in volunteer subjects with mild persistent low back pain.

BACKGROUND CONTEXT: Whether discographic injections would be positive in subjects with benign persistent "backache" who are not seeking treatment is unknown. This information is important, because benign backache undoubtedly co-exists in patients with chronic low back pain (CLBP) illness that is not discogenicin origin. If these subjects had a high rate of positive discography, the high background incidence of common backache would allow many positive tests in patients in whom discogenic processes were unrelated to their severe CLBP illness. Conversely, if subjects with benign low back pain rarely if ever had significant concordant pain reproduction on disc injections, the basic tenet of discographic diagnosis would be strengthened. PURPOSE: To compare, using a strict experimental design, the relative pain and concordancy response to provocative discography in subjects with clinically insignificant "backache" and clinical subjects with CLBP illness considering surgical treatment. STUDY DESIGN: Comparison of experimental disc injections in subjects with persistent mild backache and those with chronic low back pain (CLBP) illness. PATIENT SAMPLE: Twenty-five subjects with mild persistent low back pain (LBP) were recruited for an experimental discography study. Subjects were recruited from a clinical study of patients having had cervical spine surgery. Inclusion criteria required that subjects not be receiving or seeking medical treatment for LBP, be taking no medications for backache, have no activity restrictions because of LBP, and have normal psychometric scores. To more closely approximate the pain behavior in CLBP illness, 50% (12) of the "backache" group were recruited with a chronic painful condition (neck/shoulder) unrelated to the low back. CLBP subjects, patients coming to discography for consideration of surgical treatment, were used as control subjects. OUTCOME MEASURES: Results of discography were determined using the criteria of Walsh et al.: pain response of 3 or greater, two or more pain behaviors, a negative "control" discographic injection, and a similar or exact concordancy rating. METHODS: Discography was performed on experimental subjects and control patients. Experienced raters, who were blinded to control versus experimental status of the subjects, scored the magnetic resonance image, discogram, psychometric tests and discography videotapes of the subjects' pain behavior. RESULTS: Thirteen of 25 volunteer subjects had pain rated as "bad" or worse with disc injection. There were 12 painful and fully concordant disc injections in 9 of these 25 "backache" subjects (36%). These injections met all the Walsh et al. criteria for a positive diagnosis of discogenic pain. All positive discs had annular disruption to or through the outer annulus. Of the 9 subjects with positive discograms, 3 had no chronic pain states and 6 did. All subjects with positive injections had negative control discs. In comparison, in 52 subjects with CLBP illness 38 (73%) had at least one positive disc injection. CONCLUSIONS: In a group of volunteer subjects with persistent "backache," 36% were found to have significant pain on disc injection, which is reported to be concordant with their usual pain. The presence of positive concordant pain responses and negative control discs in 33% of subjects without CLBP illness seriously challenges the specificity of provocative discography in identifying a clinically relevant spinal pathology.     

The stress lumbar discogram

Stress discography is that done during the time in which the subject's pain is present at a significant level of intensity. This prospective study examines the findings in 200 patients who were evaluated for low-back pain. A standardized injection technique was used and the contrast pattern within the disc was studied radiographically and with CT scanning. Pain response was recorded. Familiar low-back pain was reproduced in all cases, and familiar leg pain in 46% of cases. Of 549 discs studied, 319 reproduced familiar pain, an average of 1.6 discs per patient. Pain reproduction occurred in 69% of the L5 discs, 62% of the L4 discs, and 25% of the L3 discs. Internal disc disruption was present in 302 discs, but extruded annular material was found in only 19. Stress discography is a useful diagnostic study in evaluating patients with low-back pain.     

CT引导下腰椎间盘造影的临床应用

目的探讨CT引导下椎间盘造影的临床应用价值。方法回顾性分析55例慢性腰痛或腰腿痛患者的CT引导下椎间盘造影表现及临床资料,依据对比剂在椎间盘内、外的弥散范围,对椎间盘破裂、椎间盘退行性变及椎间盘退行性变合并椎间盘破裂进行分级。结果 55例中,2例穿刺失败,53例造影成功。造影椎间盘132个;根据达拉斯CT椎间盘造影评价法,51个椎间盘形态正常,81个椎间盘形态异常。阳性椎间盘73个,其中椎间盘纤维环撕裂30个,包括Ⅰ级3个、Ⅱ级15个、Ⅲ级12个,椎间盘纤维环退行性变24个,包括Ⅰ级2个、Ⅱ级12个、Ⅲ级10个,椎间盘退行性变并合椎间盘破裂19个。CT引导下椎间盘造影同时可激发再现原有腰痛或腰腿痛,证实腰痛或腰腿痛的病因。结论依据CT引导下椎间盘造影表现可准确对椎间盘退行性变和破裂程度及椎间盘退行性变合并破裂进行分级,有助于临床诊断和治疗。     

Cytokine evaluation in individuals with low back pain using discographic lavage

Background contextThe pathophysiology underlying degenerative disc disease and its implication in painful syndromes remain unclear. However, spine magnetic resonance imaging (MRI) can demonstrate changes in disc water content and the annulus; provocative discography purportedly identifies degenerate discs causing serious low back pain; and biochemical assays have identified local inflammatory markers. No study to date has correlated pain on disc injection during discography evaluation with relevant MRI findings and biochemical markers.PurposeThe purpose of this study was to correlate concordant pain on during discography to biochemical markers obtained by disc lavage and MRI findings.Study designThis is a Phase 1 Diagnostic Test Assessment Cohort Study (Sackett and Haynes).Patient sampleThe patient sample included 21 symptomatic patients with suspected discogenic pain and three Phase 1 control subjects.Outcome measuresThe outcome measures included discography pain scores, MRI degenerative grades, and immunoreactivity to various inflammatory cytokine concentrations present in disc lavage samples.MethodsTwenty-one symptomatic patients with lumbar degenerative disc disease and three control subjects underwent discography, MRI, and biochemical analysis of disc lavage fluid. Lumbar MRI was scored for Pfirrmann grading of the lumbar discs, and annular disruption was identified by nuclear disc lavage. Disc lavage samples were analyzed for biochemical markers by high-sensitivity immunoassay.ResultsEighty-three discs from 24 patients were studied: 67 discs from 21 patients with axial back pain (suspected discogenic pain group) and 16 discs from 3 scoliosis patients without back pain (Phase 1 control subjects). Among the biochemical markers surveyed, interferon gamma (IFN-γ) immunoreactivity was most consistently identified in patients with axial back pain. Discs with annular disruption and concordant pain reproduction at a visual analog scale of 7 to 10/10 had greater IFN-γ immunoreactivity than those without this finding (p=.003); however, at least some IFN-γ immunoreactivity was found in all but one disc in the symptomatic group.ConclusionsAmong the potential inflammatory markers tested in this Phase 1 study, IFN-γ immunoreactivity was most commonly elevated in discogram “positive” discs but absent in asymptomatic controls. However, this marker was also frequently elevated in degenerative but “negative” discography discs. From these findings, Phase 2 and Phase 3 validity studies are reasonable to pursue. Phase 4 utility studies may be performed concurrently to assess this method's predictive value in outcome studies.