Spinal injection procedures: volume,provider distribution,and reimbursement in the U.S. medicare population from 1993 to 1999

PURPOSE: To evaluate spinal injection procedures for trends in volume, reimbursement, and physician specialty participation. MATERIALS AND METHODS: By using the 1993, 1996, 1998, and 1999 Medicare Part B claims database, we studied Current Procedural Terminology revision 4 codes used for percutaneous spinal injection procedures, including cervical and lumbar discography, disk aspiration and/or injection, facet and/or perifacet joint injection, and epidural steroid injection. For each of these procedures, volume, reimbursement, and physician specialty participation (categorized as radiology, anesthesiology, surgery, physiatry, and other specialties) for each year were recorded. RESULTS: Despite an overall increase in spinal injection procedure volume and reimbursement from 1993 to 1999, nonradiologists performed most of these procedures. Epidural steroid and facet joint injections had the highest volume and reimbursement during this time period and were performed almost exclusively by nonradiologists (predominantly anesthesiologists). Radiologists performed more discography procedures than did other specialists in 1993, but participation decreased each year, while anesthesiologist participation increased; as of 1999, anesthesiologists performed more discography procedures than did radiologists. Although radiologists performed more disk aspiration procedures than did other specialists, procedure volume remained low during the period studied. CONCLUSION: Spinal injection volume and reimbursement have increased substantially in the Medicare population from 1993 to 1999. During this interval, radiologist participation has decreased. Nonradiologists perform most spinal injection procedures.     

Axial rotation of the lumbar spinal motion segments correlated with concordant pain on discography: a preliminary study

OBJECTIVE: One possible cause of back pain in patients with intervertebral disk degeneration is decreased stability of the motion segment. Axial rotations between lumbar spinal vertebrae can be measured noninvasively with CT. We tested the hypothesis that larger axial rotations are found in motion segments with disks that test positive for concordant pain, which is considered by some investigators to be a reasonable, accurate predictor of spinal instability. SUBJECTS AND METHODS: Between October 2002 and March 2004, all patients undergoing discography were evaluated for inclusion in the study, with the approval of the institutional review board. All patients in whom concordant pain was detected at discography were enrolled in the study. The patients were placed supine in the CT scanner on a table that rotated the pelvis 8 degrees clockwise and then counterclockwise with respect to the thorax. CT images were obtained with the patient in the two positions of rotation. An automated program calculated the amount of rotation between each lumbar vertebra as a result of the table rotations. Rotations were stratified by disk level and by disk classification (concordant pain, nonconcordant pain, no significant pain). RESULTS: We recorded the axial rotations of 94 disks in 16 consecutive patients (10 women, six men; age range, 26-53 years) after two disks were excluded because of a previous fusion. There were 68 normal disks by MRI and discography, six disks with nonconcordant pain, and 20 disks with concordant pain. Rotation averaged 0.6 degrees for the normal disks, 1.4 degrees for disks with nonconcordant pain, and 1.8 degrees for disks with concordant pain. The differences were significant (analysis of variance, p < 0.001). Disks at L3-L4 with concordant pain rotated on average 1.2 degrees , whereas disks classified as normal or nonconcordant pain rotated on average 0.7 degrees (significant at p = 0.005). Disks at L4-L5 with concordant pain rotated on average 1.9 degrees , and those without concordant pain rotated on average 1.4 degrees (significant at p = 0.05). Disks with concordant pain at L5-S1 had an average rotation of 2.2 degrees , whereas disks without concordant pain had an average rotation of 1.5 degrees (marginally significant difference at p = 0.07). CONCLUSION: Concordant pain at discography predicts increased axial rotation at a lumbar disk level.     

Can discoblock replace discography for identifying painful degenerated discs?

Objectives

The aim of the present study was to intra-individually compare provocative discography and discoblock (disc analgesia) of idiopathic degenerated discs (IDD) results to each other, to clinical parameters, and to MRI findings. By this the value of both diagnostic features should be critically reevaluated.

Methods

31 intervertebral IDD (Pfirrmann III°–IV°) of 26 patients were analyzed for surgery decision making by combined discoblock/discography procedure in an open MRI at 1 T. A correlation analysis was performed between the Dallas Discogram Scale, pain discrimination score (PDS: concordant/discordant/no pain), positive discoblock (Numerical Rating Scale [NRS] reduction by ≥3, 60 min after intervention), presence of Modic changes or high intensity zones (HIZ), patient sex and age, intervention level, injection pressure and discography endpoint analysis (pain/pressure/anatomic/volume).

Results

Concordant pain could be evoked in 35% of the IDDs whereas discoblock was positive in 64%. Patients’ age, sex, Dallas I, Dallas II, and Pfirrmann scores, as well as the presence of HIZ did not correlate to PDS or discoblock results. Discoblock correlated positively to concordant pain. Further positive correlation was found between PDS and intervention level/pressure, between discoblock and Modic changes/discography endpoint as well as between HIZ and discography endpoint.

Conclusions

We suggest discoblock to be an additional tool for surgery decision making in patients with IDD because it correlates to concordant pain evoked by provocative discography as well as to presence of Modic changes. Additionally, assessment of a release instead of provocation of pain can be of advantage.     

Percutaneous MR-guided discography in a low-field system using optical instrument tracking: a feasibility study

PURPOSE: To evaluate the feasibility of MRI-guided discography with optical tracking. MATERIAL AND METHODS: 12 consecutive patients who had a clinical suspicion of lumbar discogenic pain and/or suggestive finding of disc degeneration in imaging studies (MRI, CT, plain radiography) underwent MRI-guided discography in order to determine possible pain provocation during puncture and contrast injection. An 0.23 T open configuration MRI device with interventional tools (Outlook Proview, Philips Medical Systems, MR Technologies, Finland) was used in procedural imaging and instrument guidance. An optical guidance tool was attached to the MRI compatible needle (Chiba-type MReye, Cook, Bloomington, IN). After initial disc puncture, 1-2 mL of gadolinium contrast (Magnevist, 469 mg/mL, Schering AG, Germany) saline mixture (1:8) was injected into the disc. Immediately after injection, sagittal FE T1 weighted images were obtained to verify the final position of the needle and formation of the MRI discogram. On nine patients, additional noncontrast sagittal fast spin echo (FSE) T1, FSE T2, and axial 3D T1 gradient echo imaging was performed before and after contrast media injection to obtain MRI discograms. RESULTS: Overall, 35 disc punctures were initialized and 34 MRI discograms were obtained. In all punctures, a positive or negative pain response was obtained. The average time for performing a procedure for three discs was 1 hour 25 minutes (minimum 45 minutes, maximum 2 hours, 15 minutes), and the average number of imaging sequences used for a puncturing one disc was 12. On one disc, the puncture failed and a discogram was not acquired. There was one complication (disc collapse) reported during follow-up. CONCLUSION: Our results show that MRI guidance in performing discography is accurate and relatively safe. It is a technically comparable method to CT-guidance or fluoroscopy.     

Percutaneous tumor ablation: increased necrosis with combined radio-frequency ablation and intratumoral doxorubicin injection in a rat breast tumor model

PURPOSE: To investigate the predictive value of magnetic resonance (MR) imaging of abnormalities of the lumbar intervertebral disks, particularly with adjacent endplate changes, to predict symptomatic disk derangement, with discography as the standard. MATERIALS AND METHODS: Fifty patients aged 28-50 years with chronic low back pain and without radicular leg pain underwent prospective clinical examination and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging. Subsequently, patients underwent lumbar discography with a pain provocation test (116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity zone, and endplate abnormalities. Results of pain provocation at discography were rated independently of the image findings as concordant or as nonconcordant or painless. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the clinical relevance of MR abnormalities. RESULTS: Normal disks on MR images were generally not painful at provocative discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV, 63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%) were not helpful in the identification of symptomatic disk derangement. When only moderate and severe type I and type II endplate abnormalities were considered abnormal, all injected disks caused concordant pain with provocation (sensitivity, 38%; specificity, 100%; PPV, 100%). CONCLUSION: Moderate and severe endplate abnormalities appear be useful in the prediction of painful disk derangement in patients with symptomatic low back pain.     

Discography

Discography is an image-guided spine procedure that provides diagnostic information about the intervertebral disc. This procedure attempts to reproduce a patient's back or neck pain profile. Discography is used to confirm or refute the presence of a discogenic pain source. Additional morphologic information with post-discography computed tomography and manometric measurements of intradiscal pressure are further enhancements to this procedure. Copyright 2002, Elsevier Science (USA). All rights reserved.     

The role of discography in lumbar disc disease: a comparative study of magnetic resonance imaging and discography

This study reviews prospectively a series of 29 patients who were examined by magnetic resonance imaging (MRI) and discography for degenerative disc disease. All had persistent low-back pain and non-diagnostic initial investigations, including plain films, myelography and/or computed tomography (CT). The imaging characteristics for degenerative disc disease correlated in 65 out of 73 intervertebral levels. All symptomatic discs were degenerate on both MRI and discography. Features of degenerative disc disease on MRI were assessed retrospectively, with a view to identifying the symptomatic level as defined by discography. MRI could not reliably detect this level, particularly in those with multi-level degenerative disc disease. Positive reproduction of symptoms at discography was the criteria used for surgery. All 12 patients in this group had posterior spinal fusion performed. Nine improved and three were unchanged. Of the ancillary features associated with disc degeneration, only a bulging annulus fibrosis proved to be of any value on MRI. Nonetheless, MRI should be used as the primary investigation in this patient group as it can lead to a marked reduction in the number of disc levels requiring injection.     

Disc damage above a spondylolisthesis

Fifty-two patients with low back pain and spondylolisthesis at L5/S1 had discograms performed at the L4/L5 level. Retrolisthesis at L4/L5 occurred in 44%, but no direct relationship was demonstrated between the extent of retrolisthesis and either the grade of spondylolisthesis or the presence of disc damage. There was an inverse relationship between the degree of spondylolisthesis and L4/L5 disc damage. Thirty-six patients were assessed for symptomatic pain reproduction during discography. Fourteen (39%) had normal nuclear morphology and no pain induction on injection. Twenty-two patients had disc damage and 11 (50%) had symptomatic pain induced by injection. These results were correlated with the discographic appearances.     

Breast pain associated with mammographic compression.

Firm breast compression during film-screen mammography is necessary to achieve optimum image quality while minimizing radiation dose. Of 374 women who fully completed a questionnaire following mammography, 225 (60%) reported no pain, 115 (31%) moderate pain and only 3 (1%) reported severe pain. Only one patient stated that the pain from the procedure would prevent her from having a further mammogram. Underlying breast disease (usually fibrocystic disease) is associated with a greater incidence and severity of breast pain, but, no relationship has been demonstrated with regards to the patient's age, hormonal status, menstruation or caffeine intake. The high level of acceptance of firm compression by women in our study indicates that undue concern regarding patient discomfort should not deter people from referral for mammography or from the application of firm compression.     

MRI of the postoperative shoulder

Pain in the postoperative shoulder is difficult for all individuals involved. The patient has already undergone a surgical procedure and is presenting now with pain possibly relating to a complication of the procedure or reinjury. In addition, the patient typically has undergone a series of maneuvers, from physical therapy to cortisone injection, without relief of the symptoms. For the orthopaedic surgeon the possibility of a complication of the procedure is disheartening. Finally, for the radiologist the postoperative shoulder usually is more difficult to interpret because of a change in the normal anatomy, not knowing exactly what was accomplished at surgery or what techniques or types of equipment were used, and, more typically, the presence of artifact.     

Discogenic lumbar pain: association with MR imaging and CT discography

OBJECTIVE: To correlate MR and CT discography findings with pain response at provocative discography in patients with discogenic back pain. MATERIALS AND METHODS: Forty-seven patients aged 25-54 years who underwent MR imaging and subsequent CT discography (97 discs) were included in this study. MR images were retrospectively evaluated regarding disc degeneration, endplate abnormalities, facet joint osteoarthritis, and high intensity zone. During discography concordant pain was regarded as positive, whereas discordant pain and no pain were regarded as negative. MR and CT discographic findings were analyzed on the base of concordant pain using the Chi-square test. RESULTS:: Concordant pain was significantly common in the following (P < 0.05): grade 4 or 5 disc degeneration [88% (30/34) in concordant pain versus 48% (30/63) in discordant pain and no pain], high intensity zone [56% (19/34) versus 30% (19/63)], combination of above two findings [53% (18/34) versus 25% (16/63)], fissured and ruptured disc at discogram [94% (32/34) versus 57% (36/63)], and contrast beyond inner annulus at CT discogram [97% (33/34) versus 57% (36/63)]. CONCLUSION: Typical MR findings with concordant pain at discography include grade 4 or 5 disc degeneration and presence of a high intensity zone. Typical CT discography findings with concordant pain were fissured/ruptured discs and contrast extending into/beyond the outer annulus on CT.     

Plasma radio-frequency-based diskectomy for treatment of cervical herniated nucleus pulposus: feasibility, safety, and preliminary clinical results

BACKGROUND AND PURPOSE: Several techniques, including chymopapain, mechanical aspiration, laser-based disk decompression, and endoscopic keyhole surgery, have been proposed as minimally invasive alternatives to fusion for treating cervical disk herniation, though none has gained wide acceptance. The purpose of this study was to assess feasibility, safety, and preliminary clinical results of percutaneous plasma-mediated radio-frequency-based diskectomy for cervical disk herniation. METHODS: Patients (N = 55) with cervical soft disk protrusion were treated over a 29-month period. They had radicular pain; 3 patients also had moderate myelopathy. The procedure was performed with the Perc-DC SpineWand by using an anterior approach. Most cases were conducted with local anesthetic on an outpatient basis. Clinical outcomes were graded by using the Macnab criteria. RESULTS: At 2 months, outcomes were good or excellent in 44/55 (80%) patients; the success rate was similar at 6 months, when 44 (85%) patients (n = 52/55) had good or excellent results. One clinically relevant complication (infectious diskitis) occurred within the first month postprocedure and was successfully treated. One technical complication (in situ rupture of the device tip) was observed; however, the patient remained asymptomatic during the 2-year follow-up. The 3 patients with clinical myelopathy experienced regression of cord compression symptoms; MR imaging in 2 patients showed morphologic evidence of reduction of cord compression. CONCLUSIONS: Plasma radio-frequency-based diskectomy in the cervical spine appears to be a minimally invasive low-risk approach, which is easy to perform, associated with only minimal discomfort to the patient, and effective in the short term.     

椎间盘源性下腰痛的MRI和椎间盘造影的相关性研究

目的 探讨椎间盘源性下腰痛患者的MRI和椎间盘造影表现与椎间盘造影一致性诱发痛的相关性.方法 93例慢性下腰痛患者腰椎MR检查和256个腰椎椎间盘造影.椎间盘造影按照Adams等分级标准进行,MRI髓核退变按Pearce等分级标准,终板退变按Medic标准分级,疼痛诱发评价分为一致性诱发痛和无痛或非一致性诱发痛.分析MRI椎间盘退变分级、椎间盘造影分级与一致性诱发痛的相关性.获得的数据采用X2检验进行统计分析.结果 93例256个椎间盘造影,116个出现一致性诱发痛.椎间盘造影:Ⅰ型椎间盘17个(6.6%),Ⅱ型椎间盘25个(9.8%),Ⅲ型椎间盘91个(35.5%),Ⅳ型椎间盘77个(30.1%),Ⅴ型椎间盘46个(18.0%).MRI椎间盘退变分级:Ⅰ级23个(9.0%),Ⅱ级34个(13.3%),Ⅲ级84个(32.8%),Ⅳ级85个(33.2%),Ⅴ级30个(11.7%).椎间盘造影与MRl分级密切相关(r=0.62,X2=160.87,P<0.01);椎间盘造影Ⅳ-Ⅴ型椎间盘123个,104个出现一致性诱发痛,与一致性诱发痛密切相关(r=0.60,X2=144.08,P<0.01);MRI椎间盘Ⅳ-Ⅴ级退变115个,99个出现一致性诱发痛,与一致性诱发痛密切相关(r=0.59,X2=137.11,P<0.01);椎间盘后缘高信号区60个,52个出现一致性诱发痛,两者具有密切相关性(r=0.41,X2=51.93,P<0.01);椎间盘终板异常58个,51个出现一致性诱发痛,两者具有密切相关性(r=0.41,X2=52.76,P<0.01).结论 MRI显示髓核中、重度退变、椎间盘后缘高信号区、椎体终板退变,以及椎间盘造影表现为外纤维环破裂、后纵韧带复合体破裂和出现一致性诱发痛时,可高度提示椎间盘源性下腰痛.椎间盘造影显示的椎间盘纤维环破裂伴随造影时的一致性诱发痛,是椎间盘源性下腰痛诊断的重要依据.     

The causes of false-positive medial branch (facet joint) blocks in soldiers and retirees

OBJECTIVE: The purpose of this study was to determine the factors associated with false-positive medial branch blocks (MBB), the nerve blocks used to diagnose facet arthropathy, in soldiers and retirees. METHODS: The study subjects were 78 patients with chronic low back pain who underwent diagnostic MBB to determine whether or not the facet joints were pain generators. Radiofrequency denervation of these nerves was performed in all patients with positive responses. Patients who failed to obtain pain relief after the blocks (negative blocks) and those who obtained temporary pain relief after MBB but failed radiofrequency denervation (false-positive blocks) then proceeded to undergo discography. Based on patients' responses to diagnostic blocks, discography results, the presence of radicular pain, and previous back surgery, the data were analyzed to determine whether any of these variables correlated with false-positive MBB. RESULTS: The presence of discogenic or radicular pain was not associated with a higher false-positive response rate to MBB. Conversely, the absence of discogenic pain was associated with a higher percentage of false-positive blocks. There was also a trend for patients with previous back surgery to have a higher false-positive rate than those who had not undergone previous surgery. CONCLUSIONS: Although a high incidence of epidural and foraminal spread occurs during the performance of MBB, this is unlikely to be a significant cause of false-positive blocks.     

Can magnetic resonance imaging accurately predict concordant pain provocation during provocative disc injection?

Objective  To correlate magnetic resonance (MR) image findings with pain response by provocation discography in patients with discogenic low back pain, with an emphasis on the combination analysis of a high intensity zone (HIZ) and disc contour abnormalities. Materials and methods  Sixty-two patients (aged 17–68 years) with axial low back pain that was likely to be disc related underwent lumbar discography (178 discs tested). The MR images were evaluated for disc degeneration, disc contour abnormalities, HIZ, and endplate abnormalities. Based on the combination of an HIZ and disc contour abnormalities, four classes were determined: (1) normal or bulging disc without HIZ; (2) normal or bulging disc with HIZ; (3) disc protrusion without HIZ; (4) disc protrusion with HIZ. These MR image findings and a new combined MR classification were analyzed in the base of concordant pain determined by discography. Results  Disc protrusion with HIZ [sensitivity 45.5%; specificity 97.8%; positive predictive value (PPV), 87.0%] correlated significantly with concordant pain provocation (P < 0.01). A normal or bulging disc with HIZ was not associated with reproduction of pain. Disc degeneration (sensitivity 95.4%; specificity 38.8%; PPV 33.9%), disc protrusion (sensitivity 68.2%; specificity 80.6%; PPV 53.6%), and HIZ (sensitivity 56.8%; specificity 83.6%; PPV 53.2%) were not helpful in the identification of a disc with concordant pain. Conclusion  The proposed MR classification is useful to predict a disc with concordant pain. Disc protrusion with HIZ on MR imaging predicted positive discography in patients with discogenic low back pain. An erratum to this article can be found at     

Cervical radiculopathy: open study on percutaneous periradicular foraminal steroid infiltration performed under CT control in 30 patients

BACKGROUND AND PURPOSE: Cervical radiculopathy is a common entity that can become unremitting, seriously disrupting the patient's work and social activities. The purpose of our study was to evaluate the feasibility, tolerance, and efficacy of transforaminal periganglionic steroid infiltration under CT control. METHODS: Thirty patients with cervical radiculopathy, despite at least 1 month of appropriate medical treatment, underwent percutaneous periradicular foraminal steroid infiltration under CT control. Sixteen patients had foraminal degenerative stenosis, and 14 patients had disk herniation. The intensity of radicular pain was scored on an analogic visual scale (AVS). Pain relief was classified as excellent when the pain had diminished by 75% or more; good, by 50%-74%; fair by 25%-49%; or poor, by less than 25%. The patients were followed up at 2 weeks and at 6 months. RESULTS: No local complications occurred after the procedure. The mean AVS pain scores were 6.5 points before the procedure and 3.3 points 2 weeks after, with significant pain relief (P <.001). Pain relief was excellent in 11 patients (37%) and good in seven patients (23%). There was no rebound of pain at the 6-month follow-up. The duration of symptoms before infiltration and the intensity and cause of radiculalgia were not predictive of radicular pain relief. CONCLUSION: Intraforaminal cervical infiltration produced substantial sustained pain relief, whatever the cause of the radiculalgia. The CT approach ensures the safety of vital structures and allows the precise injection of a steroid specifically targeted to the ganglia.     

Radiating pain to the lower extremities caused by lumbar disk rupture without spinal nerve root involvement.

PURPOSETo locate the origin of the pain during lumbar diskography by means of a limited intradiskal injection of a local anesthetic.METHODSLumbar diskography by the direct central posterior approach was performed in 235 consecutive patients. In 17 patients, severe and persistent low back pain, with unilateral or bilateral radiation to the lower extremities, was provoked by contrast injection into only one disk. One milliliter of 1% lidocaine was then slowly injected in the center of these disks.RESULTSA 75% to 100% reduction of the low back pain was experienced by 13 patients, and a 75% to 100% reduction of the radiating pain was experienced by 16 patients within 60 seconds after the intradiskal injection of lidocaine. Radiographs demonstrated radial tears through the entire annulus thickness in 16 of 17 disks.CONCLUSIONOur results suggest that, in some patients with low back pain and unilateral or bilateral radiation to the lower extremities, the pain arises from within the disk. In these cases, pain radiating to the lower limb seems to be a referred type and seems unrelated to direct nerve root compression or irritation by a disk fragment in the epidural space.     

Lumbar degenerative disk disease

The sequelae of disk degeneration are among the leading causes of functional incapacity in both sexes and are a common source of chronic disability in the working years. Disk degeneration involves structural disruption and cell-mediated changes in composition. Mechanical, traumatic, nutritional, and genetic factors all may play a role in the cascade of disk degeneration, albeit to variable degree in different individuals. The presence of degenerative change is by no means an indicator of symptoms, and there is a very high prevalence in asymptomatic individuals. The etiology of pain as the symptom of degenerative disease is complex and appears to be a combination of mechanical deformation and the presence of inflammatory mediators. The role of imaging is to provide accurate morphologic information and influence therapeutic decision making. A necessary component, which connects these two purposes, is accurate natural history data. Understanding the relationship of etiologic factors, the morphologic alterations, which can be characterized with imaging, and the mechanisms of pain production and their interactions in the production of symptoms will require more accurate and reproducible stratification of patient cohorts.     

Pain improvement after intradiskal lidocaine administration in provocation lumbar diskography: association with diskographic contrast leakage

BACKGROUND AND PURPOSE: Our aim was to evaluate the relationship of pain reduction, after intradiskal lidocaine administration during provocation lumbar diskography, to the presence of contrast leakage on postdiskographic imaging. MATERIALS AND METHODS: Intradiskal lidocaine was injected at 182 significantly painful disk levels in 111 patients. The clinical records and imaging studies were reviewed for response to the lidocaine injection and for the presence/absence of diskographic contrast leakage on postdiskographic images and CT. Pain response was assigned the following grades: 1) complete or substantial improvement, 2) partial improvement, or 3) no significant improvement after lidocaine administration. Fluoroscopic imaging and postdiskographic CT were evaluated for the presence or absence of contrast leakage. RESULTS: Eighty-two (45%) significantly painful treated disks were contained, and 100 (55%) demonstrated contrast leakage. In leaking disks, 74 (74%) demonstrated complete or near-complete pain reduction after lidocaine administration, 15 (15%) demonstrated partial improvement, and 11 (11%) demonstrated no pain relief. In contained disks, 56 disks (69%) demonstrated no improvement after lidocaine administration, 9 (11%) demonstrating partial relief, and 17 (20%) demonstrated complete or substantial improvement. Results comparing leaking disks versus contained disks and complete versus no improvement were statistically significant (P<.001). CONCLUSION: Painful disks exhibiting diskographic leakage tend to be highly responsive to intradiskal lidocaine administration, whereas painful disks without diskographic leakage tend not to improve. This observation has implications with respect to targeting the origin of a patient's back pain and may have specific implications with respect to choice of treatment.     

Anulography

Despite new imaging modalities such as MRI, the discography remains useful, particularly as the first step of chemonucleolysis. The anulography corresponds to a technical error due to the wrong position of the needle during the procedure. We have noticed 32 anulographies on 1226 discographies done in our department, between 1985 and 1989. The anulography exhibits a typical pattern that must be diagnosed; if not, that can lead to a diagnosis mistake or a wrong therapeutic attitude. The needle of discography must then be repositioned.