腰椎间盘MRI高信号区的组织病理学特点和临床意义

目的研究椎间盘源性下腰痛患者腰椎间盘纤维环后方MRI高信号区的组织病理学特征及其临床意义。方法对52例经保守治疗无效、CT片显示无腰椎间盘突出的下腰痛患者行腰椎MR检查及腰椎间盘造影术。男39例,女13例;平均年龄38.8岁。选择纤维环后方出现高信号区的部分病例行腰椎后路椎间盘切除、椎体间融合、椎弓根螺钉内固定术,术中收集包括高信号区部位的椎间盘。对标本行矢状面连续组织学切片,光镜下观察高信号区椎间盘组织的组织病理学结构,并分析其临床意义。结果在行腰椎间盘造影的52例142个椎间盘中,17例17个椎间盘显示高信号区,且在椎间盘造影过程中全部呈现2或3级的纤维环破裂和疼痛复制反应。敏感性和特异性均为100%。高信号区与纤维环破裂程度分级呈正相关,说明纤维环破裂程度分级越高,越易出现高信号区(R=0.462,P<0.01)。共收集11例患者11个椎间盘,组织学研究发现对应高信号区的椎间盘组织表现为沿纤维环裂隙形成的不同程度的血管化肉芽组织,有成熟的瘢痕化胶原组织。结论症状性下腰痛患者的腰椎MRI上有椎间盘高信号区,可以作为椎间盘源性下腰痛诊断的重要征象。     

腰椎间盘MRI高信号区在诊断椎间盘源性下腰痛中的意义

目的:探讨腰椎间盘MRI高信号区(HIZ)在诊断椎间盘源性下腰痛中的作用。方法:对52例经保守治疗无效、CT影像上无腰椎间盘突出的下腰痛患者行腰椎MRI检查和腰椎间盘造影术,分析腰椎间盘MRI高信号区与腰椎间盘造影诱发的下腰痛之间的关系。结果:在行腰椎间盘造影的142个椎间盘中,共有38个椎间盘呈现疼痛复制反应,其中17个椎间盘显示高信号区。这17个有高信号区的椎间盘在椎间盘造影过程中全部呈现2～3级的纤维环破裂和疼痛复制反应。结论:无椎间盘突出的下腰痛患者在腰椎MRI上存在椎间盘内高信号区,可表明该椎间盘是产生腰痛的破裂椎间盘。     

MRI对腰椎纤维环后部破裂的诊断价值

目的明确腰椎MRI对诊断疼痛性纤维环破裂的敏感性。方法收集近 2年因腰椎间盘退变伴下肢放射痛而手术的患者47例,所有患者腰椎 MRI均有高信号区 (high-intensity zone, HIZ)表现。通过比较手术结果与 MRI影像学资料,对 MRI诊断纤维环后部破裂的敏感性作出评价。结果共研究 47例,手术探查 105个椎间盘。其中 HIZ椎间盘 56个,手术证实阳性率 85.7％,假阳性率 14.3％;无 HIZ椎间盘 49个,手术证实阴性率 87.8％,假阴性率 12.2％。结果表明 MRI诊断纤维环后部破裂的敏感性为 88.9％,特异性为 84.3％。结论 HIZ是诊断疼痛性腰椎纤维环后部破裂的特异性和敏感性较高的影像学标准。     

MRI高信号区与椎间盘造影在椎间盘源性腰痛诊断中的相关性研究

目的 研究腰椎间盘MRI高信号区(HIZ)与椎间盘造影诱发疼痛反应之间的关系,为椎间盘源性下腰痛诊断和治疗提供参考.方法 对37例长期慢性下腰痛、无典型的神经根性症状和体征,且CT证实无椎间盘突出的患者行MRI检查和腰椎间盘造影.分析造影后的X线片和CT片,并结合造影时诱发的疼痛反应,比较其与腰椎间盘MRI高信号区之间的关系.结果 37例患者共行98个腰椎间盘造影,21个椎间盘疼痛反应阳性,其中有HIZ的间盘10个,占47.6%.77个疼痛反应阴性的椎间盘中,有HIZ的间盘29个,占37.6%.纤维环破裂程度分级越高,MRI出现高信号区的比例也越高,说明有高信号区的纤维环破裂程度高,无高信号区的纤维环破裂程度低(P＜0.01);而高信号区与造影疼痛反应阳性之间并无明显一致性(P＞0.05).结论 MRI高信号区在诊断椎间盘源性腰痛中仅为提示性和筛选性的影像学征象,不能替代椎间盘造影的金标准.     

椎间盘源性下腰痛的发病机制

目的探讨椎间盘源性下腰痛的发病机制。方法收集腰椎后路切除的17例椎间盘源性下腰痛患者的19个经腰椎间盘造影术证实的疼痛腰椎间盘;同时收集12个在MRI T2加权像上信号强度明显减弱、无腰痛症状的生理老化椎间盘和10个正常对照椎间盘,行组织学检查和P物质、神经丝蛋白和血管活性肠肽的免疫组织化学染色检查。结果椎间盘源性下腰痛患者的疼痛椎间盘在组织学上的显著特征表现为,一条从髓核至纤维环外层的血管化肉芽组织条带区,其间伴有1个或多个裂隙;肉芽组织条带区与椎间盘造影术后CT上显示的纤维环裂隙一致,肉芽组织之外的纤维环结构基本正常。生理老化椎间盘和正常对照椎间盘表现为与年龄相关的改变。免疫组织化学染色显示,疼痛椎间盘中P物质、神经丝蛋白和血管活性肠肽3种神经肽阳性神经纤维分布数量和比例,较正常对照椎间盘和生理老化椎间盘明显增多;神经纤维主要沿伴有裂隙的肉芽组织条带区分布;疼痛椎间盘髓核中可见P物质和神经丝蛋白的阳性神经纤维分布。结论椎间盘后方神经分布广泛的肉芽组织条带区是椎间盘造影术疼痛和椎间盘源性下腰痛的起源部位。肉芽组织条带可能起源于椎间盘的创伤修复过程。生理老化椎间盘和疼痛椎间盘的差异是后者形成组织学上的肉芽组织条带区。     

The pathogenesis of discogenic low back pain

Discogenic low back pain is a common cause of disability, but its pathogenesis is poorly understood. We collected 19 specimens of lumbar intervertebral discs from 17 patients with discogenic low back pain during posterior lumbar interbody fusion, 12 from physiologically ageing discs and ten from normal control discs. We investigated the histological features and assessed the immunoreactive activity of neurofilament (NF200) and neuropeptides such as substance P (SP) and vasoactive-intestinal peptide (VIP) in the nerve fibres. The distinct histological characteristic of the painful disc was the formation of a zone of vascularised granulation tissue from the nucleus pulposus to the outer part of the annulus fibrosus along the edges of the fissures. SP-, NF- and VIP-immunoreactive nerve fibres in the painful discs were more extensive than in the control discs. Growth of nerves deep into the annulus fibrosus and nucleus pulposus was observed mainly along the zone of granulation tissue in the painful discs. This suggests that the zone of granulation tissue with extensive innervation along the tears in the posterior part of the painful disc may be responsible for causing the pain of discography and of discogenic low back pain.     

腰椎椎间盘后方高信号区的临床意义

 目的 通过 CT、MRI及组织学分析,探讨腰椎间盘后方高信号区（high-intensity zone,HIZ）的病理学性质。 方法 选取下腰痛患者中其 MRI T2 加权像存在局限性 HIZ患者 41例,男 23例,女 18例;年龄 33~50岁,平均年龄 38岁。按照 MRI T1 加权像 HIZ的特点分为两组,T1 加权非高信号组（29例）即 T2 加权像呈高信号,T1 加权像呈低或等信号;T1 加权高信号组（12例）即 T1、T2 加权像均呈高信号。所有病例均同时进行 X线和 CT检查,T1 加权非高信号组中 26例进行了椎间盘造影以及疼痛激发试验。T1 加权非高信号组 15例、T1 加权高信号组 7例接受了手术治疗,手术方式分别为经椎间孔椎体间融合术或后路椎体间减压融合术,并对术中切取的 HIZ区域标本进行 HE染色和（或）免疫组织化学染色进行观察。 结果 T1 加权非高信号组患者 X线、CT及 MR检查均显示椎间盘退变,26例进行椎间盘造影以及疼痛激发试验者中 21例造影阳性及疼痛复制,并显示纤维环破裂,其中 15例阳性者接受手术治疗;5例阴性。术中切取的 HIZ区域标本 HE染色显示为纤维环破裂伴随肉芽组织长入,CD34染色可见 HIZ区域内新生毛细血管,CD68见 HIZ区域内多量染色阳性的巨噬细胞,而 HIZ外区域表达较弱。而 T1 加权高信号组患者椎间盘在 CT上显示为后方纤维环钙化或骨化,HE染色可见明显的钙化灶和钙化的潮汐线形成。结论 腰椎间盘后方 HIZ,在 T2 加权像的局限性高信号、T1 加权像呈局限性较低或等信号意味着通常所指的纤维环破裂伴随肉芽组织长入;而 T2、T1 加权像均呈高信号可能是钙化或骨化灶,因此,传统 HIZ 的概念可能需要进行一定的修正,结合 CT 检查可能更有意义。     

Lumbar disc high-intensity zone: the value and significance of provocative discography in the determination of the discogenic pain source

Disagreement still exists in the literature as to the significance of the high-intensity zone (HIZ) demonstrated on magnetic resonance imaging (MRI) as a potential pain ¶indicator in patients with low back pain. A prospective blind study was therefore conducted to evaluate the lumbar disc high-intensity zone with the pain provocation response of lumbar discography. Consecutive patients with low back pain unresponsive to conservative treatment and being considered for spinal fusion were subjected to MRI followed by lumbar discography as a pre-operative assessment. The discographer was blinded to the results of the MRI scans. We used the chi-squared test to analyse our results. Ninety-two HIZs were identified in 73 patients, mainly occurring at L4/5 (48%) and L5/S1 (35%). Significant correlation was found between abnormal disc morphology and the HIZ (P < 0.001). In morphologically abnormal discs (grades 3, 4 and 5), there was a significant correlation between the HIZ and exact or similar pain reproduction (P < 0.001). The sensitivity, specificity and positive predictive value for pain reproduction were high, at 81%, 79% and 87% respectively. The nature of the HIZ remains unknown, but it may represent an area of secondary inflammation as a result of an annular tear. We conclude from our study that the lumbar disc HIZ observed on MRI in patients with low back pain is likely to represent painful internal disc disruption.     

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.     

腰椎间盘造影一致性疼痛反应和纤维环破裂程度的相关性研究

目的: 研究椎间盘源性下腰痛病人纤维环破裂程度和腰椎间盘造影一致性疼痛之间的关系。方法: 105例慢性下腰痛且无椎间盘突出的病人, 行腰椎间盘造影术。询问造影时病人疼痛反应, 分析造影后的X线片和造影后的CT片, 比较纤维环破裂程度与腰椎间盘造影一致性疼痛之间的相关性。结果: 105例病人中的 285个造影的腰椎间盘中, 67个腰椎间盘诱发一致性疼痛反应, 且全部呈现 2级以上的纤维环破裂。纤维环破裂分级越高, 椎间盘造影时一致性疼痛比例越大, 两者之间有显著的正相关性。结论: 椎间盘造影诱发的一致性疼痛反应比例和纤维环外层破裂程度呈正相关, 研究结果表明纤维环外层撕裂是疼痛复制的起源部位。     

Pathophysiology,diagnosis, and treatment of discogenic low back pain

Discogenic low back pain is a serious medical and social problem, and accounts for 26%-42% of the patients with chronic low back pain. Recent studies found that the pathologic features of discs obtained from the patients with discogenic low back pain were the formation of the zones of vascularized granulation tissue, with extensive innervation in fissures extending from the outer part of the annulus into the nucleus pulposus. Studies suggested that the degeneration of the painful disc might originate from the injury and subsequent repair of annulus fibrosus. Growth factors such as basic fibroblast growth factor, transforming growth factor β1, and connective tissue growth factor, macrophages and mast cells might play a key role in the repair of the injured annulus fibrosus and subsequent disc degeneration. Although there exist controversies about the role of discography as a diagnostic test, provocation discography still is the only available means by which to identify a painful disc. A recent study has classified discogenic low back pain into two types that were annular disruption-induced low back pain and internal endplate disruption-induced low back pain, which have been fully supported by clinical and theoretical bases. Current treatment options for discogenic back pain range from medicinal anti-inflammation strategy to invasive procedures including spine fusion and recently spinal arthroplasty. However, these treatments are limited to relieving symptoms, with no attempt to restore the disc’s structure. Recently, there has been a growing interest in developing strategies that aim to repair or regenerate the degenerated disc biologically.     

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.     

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.     

An analysis of radiating pain at lumbar discography

This study aimed to identify the morphological abnormalities of the intervertebral disc, as demonstrated by lumbar discography, that are associated with pain radiation to the hip, groin, buttock or lower limb. We carried out a retrospective review of 99 consecutive lumbar discogram reports. The association of disc degeneration, annular tears (partial or full thickness) and the level of disc injected was determined with respect to the presence and pattern of radiating pain. A total of 260 discs were injected, of which 179 were considered abnormal. Posterior annular tears were demonstrated in 84 discs, anterior annular tears in 15 discs and 45 discs had both anterior and posterior tears. A significant association was identified between isolated posterior tears and the production of concordant radiating pain (P = 0.0041). No difference was identified between partial thickness posterior tears and full thickness posterior tears associated with leak of contrast medium, with regard to radiating pain. Similarly, there was no significant association between disc level injected and the pattern of pain radiation. The results indicate that pain experienced in the buttock, hip, groin or lower limb can arise from the posterior annulus of the intervertebral disc without direct involvement of the nerve root. Received: 29 November 1997 Revised: 20 March 1998 Accepted: 6 April 1998     

Side of symptomatic annular tear and site of low back pain: is there a correlation?

STUDY DESIGN: A retrospective chart review. OBJECTIVES: To report the correlation between the side of a concordantly painful, post-discography computer tomography (CT) visualized, annular tear, and the side of a patients' low back pain. SUMMARY OF BACKGROUND DATA: An annular fissure extending from the nucleus to the outer one-third of the annulus is thought to be the nociceptive source stimulated during provocative lumbar discography. To our knowledge, there are no studies that have attempted to delineate whether the side of the annular tear correlates with the side of the patient pain. METHODS: One hundred and one post-discography CT scans, performed on patients with single level, concordantly painful, and fissured discs identified during lumbar discography, were randomly obtained from the archived and current files of the Penn Spine Center's film library. These were reviewed by both the lead author and a spine radiologist, both of who were blinded to the side of the patients pain, to determine which scans demonstrated clearly definable tears extending to the outer one-third of the annulus. Statistical analysis via the exact method was used to determine the correlation between the side of the patients tear and the side of the patients pain. RESULTS: Forty post-discography CT scans met the inclusion criteria. There was a random correlation between the side of the patients concordantly painful annular tear and the side of the patients pain. CONCLUSIONS: The results of this study raise several questions regarding the embryologic development of the intervertebral disc and its somite, neurologic transmission of discogenic pain, distribution of chemical inflammagens, validity of discography, technique of ESI, and technique and validity of IDET.     

Korrelation degenerativer Bandscheibenveränderungen im MRT mit dem Befund der Diskographie bei Rückenschmerzpatienten

BACKGROUND: MRI can be too sensitive for detecting degenerative changes and commonly displays pathology that is not necessarily responsible for the patient's symptoms. METHODS: Retrospectively, we investigated MRI findings and results of discography in 23 patients with lower back pain. MRI investigations were performed with a 1.0 and 1.5 Tesla device using T1-weighted and T2-weighted sagittal plane imaging and T2-weighted transverse plane imaging. RESULTS: Of the 35 degenerated discs, 16 were detected on MRI as having a high intensity zone (HIZ). Eleven of the 35 segments had previous lumbar disc surgery with a HIZ rate of 81.8%, whereas the HIZ rate for unoperated segments was only 29.2%. CONCLUSIONS: HIZ is known to be a common lesion found using MRI in lower back pain patients. In operated segments, we found an incidence of 81.8% and in unoperated segments of 28.2%. Discography can discriminate between painful and non-painful discs. With the help of additional parameters such as contrast mean volume and pain characteristics during puncture, the number of false positive discograms can be reduced.     

青年士兵盘源性下腰痛CT椎间盘造影与MRI表现的相关性

目的探讨CT椎间盘造影(CTD)诱发青年士兵盘源性下腰痛患者一致性疼痛与腰椎间盘MRI表现的相关性。方法对54例盘源性下腰痛青年士兵行MR检查后,共对152个腰椎间盘进行CTD,分析CTD分型、对比剂剂量、诱发一致性疼痛与MRI表现的相关性。结果青年士兵盘源性下腰痛患者椎间盘内破裂类型主要为CTDⅡ型和Ⅳ型,其分型、对比剂注射剂量与诱发一致性疼痛具有相关性(P0.01),腰椎间盘MRI表现与CTD诱发一致性疼痛存在明显相关性(P0.01)。结论 CTD能够定性诊断腰椎间盘内破裂,进一步确定责任椎间盘;MRI改变可能与青年士兵盘源性下腰痛的病因相关。     

Intervertebral disc degeneration

Summary Disc degeneration in the human spine is a complex phenomenon characterised by biochemical change in the nucleus pulposus and inner annulus and the formation of clefts and fissures radiating from the central area of the disc towards the periphery. In addition, and probably independent of these phenomena, discrete defects in the outer annular attachement are seen which are likely to be due to mechanical stress and failure. The presence of stress tears in disc tissue and their failure to heal can initiate or accelerate the degeneration of the central component of the intervertebral disc. We postulate that discogenic pain may be linked to damage to the outer portion of the annulus fibrosus. Although it would seem logical to assume that discs with sustained high intradiscal pressure would be more prone to pain referred in the outer annular layers because of higher tensile strain, analysis of prospective studies has failed to confirm a relationship between typical pain reproduction at discography and high pressure values. It is concluded that, at present, the only consistent morphological changes present in patients with pain reproduction at discography are the presence of various annular defects involving the outer layers. Whether nerve ingrowth during attempts at repair of these defects is a consistent feature remains to be established.     

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.