Development and clinical application of grading and classification criteria of lumbar disc herniation

This study aimed to develop new grading and classification criteria for lumbar disc herniation (LDH). First, from January 1993 to January 2003, we collected the detailed information of 1127 patients with LDH and, based on that information, developed a new grading classification termed the 6-score-V-type criteria wherein conservative treatment is recommended for patients with type I, II, or IIIA, surgical treatment is recommended for type IIIC, IV, and V, and 3 months of conservative followed by surgery if no improvements are obtained during the conservative treatment period is recommended for type IIIBe. The distribution of types among the 1,127 patients was: type I (7.9%), type II (22.9%), type III (34.1%), type IV (22.2%), and type V (12.6%). Type III cases were subdivided into type IIIA (9.9%), type IIIB (13.3%), and IIIC (10.8%). Second, from February 2003 to December 2009, we treated a separate group of 1130 patients with LDH according to this 6-score-V-type classification rubric and monitored them for 24 months. Therapeutic efficacy was assessed in 1130 patients with a standard evaluation for leg pain. Overall, 85.3% of the patients in the first year and 84.1% in the second year had good or excellent response ratings. The inter-examiner reliability was 98%. Assignment of therapeutic protocols according to the 6-score-V-type classification yielded satisfactory outcomes, indicating that the 6-score-V-type criteria are straightforward and practical.

[Expert Assessment of Traumatic Disc Herniations]

In numerous legal areas, expert assessments are needed to clarify the causality of herniated discs: Was the damage caused by an accident? The literature mentions specific requirements regarding the trauma mechanism as well as temporal criteria, which prescribe the causality test. These are essentially high-energy traumas with immediate functional impairments. Accident-related MRI examinations are of paramount importance in the expert assessment process to confirm the primary body harm. In examining the causality constituting liability, competitive causes must be assessed. Since the legal requirements of the causality test differ in civil and social law, legal norms need to be taken into account. We present a test scheme that supports the assessment process through entry, implementation and decision-making levels.

[Relationship between effect of sacral canal injection and different sections, types, courses of lumbar intervertebral disc herniation]

OBJECTIVE

To observe the effects of sacral canal injection in treating lumbar intervertebral disc herniation with different sections, types and courses, in order to provide selective basis for clinical indications.

METHODS

From March 2007 to May 2011, 329 patients with lumbar intervertebral disc herniation were treated with sacral canal injection and their data were retrospectively analyzed. There were 178 males and 151 females,ranging in age from 16 to 78 years old with an average of 45 years; ranging in course of disease from 2 days to 41 years with an average of 4.1 years. All the protrusions were simple segment, and L3,4 of 51 cases, L4,5 of 142 cases, L5S1 of 136 cases including central protrusion of 137 cases, posterolateral of 145 cases, extreme posterolateral of 47 cases. According to different sections, types, courses (more than or less than 6 months ) of lumbar intervertebral disc herniation, the patients were divided into several groups, clinical effects of the groups were compared and analyzed.

RESULTS

Clinical effect of protrusion in L5S1 group was better than that of L3,4, L4,5 group; the effect of patients with course less than 6 months was better than with course more than 6 months; effect of posterolateral protrution was better than that of central and extreme posterolateral protrusion. Clinical effect of corresponding the three conditions was better than that of others no corresponding the three conditions,the three conditions included the course less than 6 months, protrusion in L5S1 section, with type of posterolateral protrusion. No complications were found in all patients and cured patients were followed up for 1 year with the recurrence rate of 0.05%.

CONCLUSION

The patients with short course, lower protrusion, type of posterolateral protrusion can obtained better effects, while the patients who meets the three conditions is appropriate mostly to sacral canal injection therapy.

[Clinical classification and surgical options of the far-lateral lumbar disc herniation]

OBJECTIVES

To suggest the clinical classification of the far-lateral lumbar disc herniation and offer the considerations for clinical choice of different surgical procedures.

METHODS

According to the locations of the herniated disc and relevant clinical symptoms, the far-lateral lumbar disc herniation was divided into three types: Type I: posterolateral and foraminal herniation(double herniations); Type II: foraminal disc herniation and Type III: extraforaminal herniation. From January 2002 to January 2007, 38 patients with far lateral lumbar disc herniation underwent surgery in the institute. The surgical options were decided by means of the classification. The surgical procedures included (1) discectomy by inter-TP (transverse process) approach, (2) discectomy with partial facetectomy and (3) discectomy with facetectomy and PLIF (posterior lumbar interbody fusion). Among the 38 patients, there were 25 males and 13 females. The mean age was 58.4 years old. The herniated discs located at L(3-4) in 17, L(4-5) in 13, and 8 cases at L(5)S(1). Twenty-three patients were simple disc herniation, 15 cases with concomitant lumbar spinal stenosis. The symptoms and signs of exiting root compression at herniated disc level were presented in all patients and passing root compression presented in 7 Type I cases as well; while intermittent claudication being presented in 15 and low back pain in 21 patients. The VAS (visual analog pain scale) of radicular leg pain was taken before and after the operation. The postoperative outcomes were evaluated through the MacNab's method in all the patients.

RESULTS

By using the new classification system, the 38 patient were divided into Type I 10 cases, Type II 19 cases and Type III 9 cases. The adopted surgeries included discectomy by intertransverse approach in 5, discectomy with partial facetectomy in 7, and discectomy with facetectomy and PLIF in the rest 26 cases. The mean follow-up period was ranging from 6 months to 4 years and 10 months, average 2 years and 11 months. The mean VAS scores of radicular pain was 7.4 preoperatively, 2.7 at 2 weeks after the operation and 3.1 at final follow-up. The final clinical outcomes by MacNab's method were as follow: excellent results in 20 cases, good in 12, fair in 5 and poor in 1 case. The overall improvement ratio was 84.2%. The postoperative complications included superficial wound infection in 1 case, insufficient decompression in 1 case and leakage of cerebrospinal fluid in 1 case respectively. No breakage and loosening of internal fixation were detected.

CONCLUSIONS

A new clinical classification of far lateral lumbar disc herniation was suggested, which is significant to understanding the relevant pathology and choosing the surgical procedures.

[Feasibility of endoscopic surgery by paravertebral approach in far lateral lumbar disc herniation]

OBJECTIVE

To evaluate the feasibility of endoscopic paravertebral approach surgery in the far lateral lumbar disc herniation.

METHODS

Fifty sets of integral lumbar vertebral specimens were selected, and the anatomical data of lumbar intervertebral foramina and its adjacent structures were measured. Twenty specimens are randomly divided into a traditional group and an endoscopic group, then the traditional and endoscopic operations by paravertebral approach were used to dissect every strata of soft tissues in order to expose the intervertebral foramen. At last,the relationship between the intervertebral foramen and its adjacent structures was observed, and the 2 procedures were compared.

RESULTS

The sagittal diameter of lumbar intervertebral foramina became shorter from the top to bottom,while the diameter of cross section of relative nerve roots became longer. The depth of the line which connected the middle point of the 2 adjacent transverse process roots and the anterior branch of lumber nerve root in L1,L3 and L5 was (1.03+/-0.30), (1.71+/-0.29), and (1.99+/-0.34) mm respectively, with the increasing tendency; the depth of L3 to L5 was mostly less than 2 cm. The distance of the middle points of the 2 adjacent transverse process roots from L1 to L5 was long enough, but the distance between L5 and S1 was only (10.14+/-1.71) mm. The surgery by paravertebral approach had a relative safe operation area,which was similar to a triangle.

CONCLUSION

The technique of endoscopic surgery by paravertebral approach is feasible in the treatment of far lateral lumbar disc herniation. However, it is difficult to perform this surgery in the treatment of L5/S1 far lateral lumbar disc herniation, which is often conducted with endoscopy, after 18 to approximately 20 mm of the partial sacrum is eliminated by conventional method.

The risk of disc prolapses with complex loading in different degrees of disc degeneration - a finite element analysis

BACKGROUND

Disc prolapses can result from various complex load situations and degenerative changes in the intervertebral disc. The aim of this finite element study was to find load combinations that would lead to the highest internal stresses in a healthy and in degenerated discs.

METHODS

A three-dimensional finite element model of a lumbar spinal segment L4-L5 in different grades of disc degeneration (healthy, mild, moderate, and severe) were generated, in which the disc height reduction, the formation of osteophytes and the increasing of nucleus' compressibility were considered. The intradiscal pressure in the nucleus, the fiber strains, and the shear strains between the annulus and the adjacent endplates under pure and complex loads were investigated.

RESULTS

In all grades of disc degeneration the intradiscal pressure was found to be highest in flexion. The shear and fiber strains predicted a strong increase under lateral bending+flexion for the healthy disc and under axial rotation and lateral bending+axial rotation for all degenerated discs, mostly located in the postero-lateral annulus. Compared to the healthy disc, the mildly degenerated disc indicated an increase of the intradiscal pressure and of the fiber strains, both of 25% in axial rotation. The shear strains showed an increase of 27% in axial rotation+flexion. As from the moderately degenerated disc all measurement parameters strongly decreased.

INTERPRETATION

The results support how specifically changes associated with disc degeneration might contribute to risk of prolapse. Thus, the highest risk of prolapses can be found for healthy and mildly degenerated discs.

Nomenclature and Standard Reporting Terminology of Intervertebral Disk Herniation

Spine pathology is ubiquitous and is encountered by nearly all medical specialties. The anatomy of the spine is complex, but the language used to describe pathology may be even more complex. Many of the common references differ in their nomenclature used to report intervertebral disk herniation. This article summarizes and relates the standard recommendations for reporting terminology in regard to herniation of the intervertebral disk. This standard reporting terminology may be used with CT or MR imaging and is useful to report the location and size of the disk herniation. Recommendations are to report abnormalities in zones on axial images and in levels on the sagittal and coronal images. The diagnostician must also be aware of the various pitfalls associated with disk herniation to avoid the scenario of surgical intervention at the incorrect spinal level.

Percutaneous endoscopic lumbar discectomy for migrated disc herniation: classification of disc migration and surgical approaches

Percutaneous endoscopic lumbar discectomy (PELD) for migrated disc herniations is technically demanding due to the absence of the technical guideline. The purposes of this study were to propose a radiologic classification of disc migration and surgical approaches of PELD according to the classification. A prospective study of 116 consecutive patients undergoing single-level PELD was conducted. According to preoperative MRI findings, disc migration was classified into four zones based on the direction and distance from the disc space: zone 1 (far up), zone 2 (near up), zone 3 (near down), zone 4 (far down). Two surgical approaches were used according to this classification. Near-migrated discs were treated with "half-and-half" technique, which involved positioning a beveled working sheath across the disc space to the epidural space. Far-migrated discs were treated with "epiduroscopic" technique, which involved introducing the endoscope into the epidural space completely. The mean follow-up period was 14.5 (range 9-20) months. According to the Macnab criteria, satisfactory results were as follows: 91.6% (98/107) in the down-migrated discs; 88.9% (8/9) in the up-migrated discs; 97.4% (76/78) in the near-migrated discs; and 78.9% (30/38) in the far-migrated discs. The mean VAS score decreased from 7.5 +/- 1.7 preoperatively to 2.6 +/- 1.8 at the final follow-up (P < 0.0001). There were no recurrence and no approach-related complications during the follow-up period. The proposed classification and approaches will provide appropriate surgical guideline of PELD for migrated disc herniation. Based on our results, open surgery should be considered for far-migrated disc herniations.

The value of T2 relaxation times to characterize lumbar intervertebral disks: preliminary results

BACKGROUND AND PURPOSE

The present standard for staging intervertebral disk degeneration is a discrete scale, consisting usually of 5 stages. The purpose of this pilot study was to investigate the use of T2 measurements as a continuous measure of intervertebral disk degeneration.

METHODS

We obtained images in 5 volunteers with a 3D fast spin-echo sequence modified for the purpose of calculating T2 relaxation times from multiple echoes in the echo train. Disks were classified on the basis of conventional criteria into one of the 5 stages of disk degeneration. Average T2 values were calculated for stage II, III, and V disks, which were identified in the volunteers. Differences between the disk levels were analyzed with analysis of variance and differences between stages tested with a Student t test with significance set at the 0.01 level.

RESULTS

In the 5 volunteers, 20 stage II, 4 stage III, and a single stage V disk were found. Contour plots showed the highest T2 values in the nucleus pulposus near the vertebral endplates and lower T2 values in the intranuclear cleft region and peripheral annulus fibrosus. Average T2 values were significantly lower in the type III and V disks than in the normal disks.

CONCLUSIONS

The study suggests that intervertebral disks can be characterized and classified accurately by means of T2 values. More studies are warranted to determine the range of T2 values for normal disks.

The influence of subdiagnosis on radiographic and clinical outcomes after lumbar fusion for degenerative disc disorders: an analysis of the literature from two decades

STUDY DESIGN

A critical review of published literature from 2 decades.

OBJECTIVE

To critically analyze the literature from 1979 to 2000 in order to examine the influence of subdiagnosis on outcome after fusion for lumbar degenerative disc disorders.

SUMMARY OF BACKGROUND DATA

Numerous diagnostic subgroups of degenerative disc disorders exist. Although it is commonly believed that surgical outcomes after lumbar fusion are influenced by these subdiagnoses, there is a paucity of literature demonstrating differences in clinical outcomes or fusion rates among them. As the indications for fusion have been under greater scrutiny recently, this information would be useful in prognosticating outcomes and optimizing patient selection.

METHODS

A computer search of the English literature using the keywords "degenerative," "lumbar," and "fusion" was performed. Disorders were organized according to the following subdiagnostic groups: degenerative spondylolisthesis (DDDsp), herniated disc (DH), degenerative scoliosis (DDDsc), stable DDD (DDDs), dynamically unstable DDD (DDDu), and DDD that was not specified as either DDDu or DDDs (DDDn). For each group, the type of instrumentation, fusion location, fusion rate, clinical outcome, and complication rate were recorded in a computer database. Data were pooled by simple summation and statistically analyzed using a chi test or Fisher exact test.

RESULTS

Of 244 articles identified, 78 satisfied inclusion criteria with data from 4454 patients recorded. The most common diagnosis was DDDn (50%), followed by DDDsp (25%), DH (14%), DDDu (6%), DDDs (3%), and DDDsc (2%). The DDDn group had a higher fusion rate than DDDsp (P = 0.025), but a lower clinical outcome (P = 0.051). Complication rates were highest in DDDsc, whereas this subdiagnosis also had the best reported clinical outcomes. In comparing individual subgroups, a trend towards higher fusion rate and better clinical outcome was noted in DDDsp cases with instrumentation compared to noninstrumented cases. This trend was reversed for patients in the DDDn group, in whom better clinical outcomes were noted after noninstrumented fusions regardless of a lower fusion rate.

CONCLUSIONS

The present data indicate that clinical outcomes and fusion rates statistically differ among the various subgroups of degenerative disc disease. Concerning the use of instrumentation, it appears that it may have greater clinical benefit in patients with DDDsp than DDDn. These findings underscore the importance of delineating specific clinical diagnoses when documenting results of lumbar fusion. This information might also be useful for both selecting surgical candidates and discussing anticipated operative outcomes.

[Thoracic and thoraco-lumbar discs herniations: diagnosis and therapeutic management]

Summary Management of symptomatic thoracic disc hemiations is difficult because of their polymorphic symptomatology and hardness to join the intervertebral thoracic disc surgically. The objective of this study was first to show the difficult diagnosis of these discal herniations and their posterior approach particularities; secondly, to analyse our results and compare them with those of the literature. This retrospective study analyses a four patients series operated between January 1997 and march 2003 using intraoperative somatosensory evoked potentials. All of them had before surgical management, a lumbar Xray or a MRI. The average postoperative follow-up was seven months. All patients were males with a mean age of 39.5 years old (extremes: 22-59). They had systematisation of their lumboradiculalgia, leading to an average delayed diagnosis of 10 months. The disc herniation was paramedian in three cases, median in one,. It was in T10-T11 in one case, in T11-T12 in two and in T12-L1 in one. All the patients were operated on with a posterior approach, recording the intraoperative somatosensory evoked potentials. Disc herniation was resected in three cases. Functional results were satisfactory (no pains for three patients) in the follow-up period of seven months. Every patient presenting with an atypical lumboradiculalgia must have a spine MRI to diagnose the symptomatic thoracic disc herniation. Surgery has good results if technical details are used respecting the threatened spinal cord.

Clinical application of a new three-dimensional radiological classification of lumbar disc herniations

The results after lumbar discectomy are usually satisfactory. However, there is a group of patients with less favorable result. The predictive factors affecting the result are not fully understood. In this paper a new radiological classification for lumbar disc herniations has been used in order to study the predictive value of the type and location of the herniation for the postoperative result. 142 patients operated with standard lumbar discectomy were included in the study. The preoperative CT-scans were used to classify the disc herniations in the transverse, sagittal and longitudinal directions and the size of the herniations were calculated. At a mean of 7.7 years postoperatively a patient administrated questionnaire was used to compare the clinical results to the radiological findings. A significantly smaller size of the lumbar disc herniation was found with increasing age, which could reflect the increased degeneration of the disc. Patients with a wide transverse distribution of the herniation seem to have a less favorable postoperative outcome in terms of higher rate of repeat surgery (p = 0.056). No other correlations were found.

Degenerative Veränderungen der zervikalen Facettengelenke sowie der medialen und lateralen atlantoaxialen Gelenke - eine paläopathologische Studie

AIM

This article describes the prevalence of degenerative changes of the upper cervical spine (C1-C2) and cervical facet joints found during investigations of spinal column remains.

MATERIALS AND METHODS

This study was conducted on a sample of 196 cervical spines from southwestern Germany which derive from the 6th to 8th centuries AD. The degenerative lesions were classified into grades 1 (marginal osteophytes), 2 (uneven joint surfaces), or 3 (osseous ankylosis).

RESULTS

Of the skeletons examined, 19.4 % (n = 38) showed degenerative changes of the cervical facet joints and/or upper cervical spine (mean age at death was 44 years). The medial (6.1 %) and lateral (0.6 %) atlanto-axial joints were rarely involved in degenerative changes. The facet joints from C3-C4 to C6-C7 showed degenerative changes in 8.0-11.7 % of cases (usually grade 1 and 2). The C2-C3 facet joints were significantly involved in degenerative changes in 19.7 % of cases, one fourth of which were osseous ankylosis (grade 3).

CONCLUSION

The C2-C3 facet joints showed a high rate of degenerative changes.

MR Image–based Grading of Lumbar Nerve Root Compromise due to Disk Herniation: Reliability Study with Surgical Correlation

A system for grading lumbar nerve root compromise (no compromise, contact of disk material with nerve root, deviation of nerve root, and compression of nerve root) was tested in the interpretation of routine magnetic resonance images of 500 lumbar nerve roots in 250 symptomatic patients. Intra- and interobserver reliability was assessed for three independent observers. In the 94 nerve roots evaluated at surgery, surgical grading was correlated with image-based grading. kappa statistics indicated substantial agreement between different readings by the same observer and between different observers (for intraobserver agreement, kappa = 0.72-0.77; for interobserver agreement, kappa = 0.62-0.67). Correlation of image-based grading with surgical grading was high (r = 0.86). The image-based grading system enabled reliable evaluation and reporting of nerve root compromise.

Adjacent two-level lumbar discectomy: outcome and SF-36 functional assessment

STUDY DESIGN

A retrospective outcomes study.

OBJECTIVES

To examine the outcome following adjacent two-level lumbar discectomy using both surgeon-based evaluation criteria and validated patient-based quality of life instrument (SF-36).

SUMMARY OF BACKGROUND DATA

Lumbar discectomies have documented success rates between 49% and 98% for single-level procedures. However, no prior study has specifically examined the outcome following adjacent two-level lumbar discectomy in a large series of patients.

METHODS

This study analyzed 55 patients with a minimum 2-year follow-up. All patients underwent adjacent two-level lumbar discectomy for radicular pain attributable to nerve root impingement at the corresponding levels. The patients were divided into two diagnostic groups based on their preoperative radiographic studies. Patients with two-level adjacent posterolateral lumbar disc herniations without concomitant osseous degenerative changes at the same levels constituted Group 1 (22 patients). Patients with associated osseous degenerative changes at the same levels made up Group 2 (33 patients). The patients' clinical outcome was assessed using the MacNab classification and SF-36 questionnaire.

RESULTS

The average duration of follow-up was 41 months (range 24-96 months). The group consisted of 35 males and 20 females with average age of 49 years (range 19-82 years). Excellent results were observed in 49%, good in 20%, fair in 15%, and poor in 16%. However, patients in Group 1 have 86% excellent/good results, whereas patients in Group 2 have 57% excellent/good results. Overall, 15% of the patients required reoperation and subsequent spinal fusion. Analysis of the SF-36 scores revealed significant differences based on patient's diagnostic grouping as well. Patients in Group 1 have physical and mental summary scores comparable with age- and sex-adjusted population norms and significantly higher than those in Group 2 (P < 0.01).

CONCLUSIONS

Two-level discectomy is an effective treatment with clinical outcome comparable with single-level discectomy. Patients with posterolateral disc herniations and definitive radiculopathy without osseous degenerative changes at the same levels have better clinical outcome and quality of life scores compared with those patients having concomitant degenerative arthritis at the same levels. Patients having two-level discectomy may be at increased risk of requiring subsequent lumbar fusion compared with those with single-level discectomy.

Courses of cervical disc herniation causing myelopathy or radiculopathy: an analysis based on computed tomographic discograms

STUDY DESIGN

The courses of protruded masses in cervical disc herniations were traced on preoperative computed tomography discograms of patients with myelopathy or radiculopathy.

OBJECTIVE

To characterize the courses of protruded masses in cervical disc herniation.

SUMMARY OF BACKGROUND DATA

No studies have been reported on the varied courses of protruded masses in cervical disc herniation.

METHODS

This study investigated the preoperative CT discograms of 150 patients with myelopathy and 50 patients with radiculopathy who had undergone anterior cervical discectomy and fusion for disc herniation. The courses of herniations were traced from the penetration sites on the deep layer of the posterior longitudinal ligament through their locations in the spinal canal, and were divided into one median, two paramedian, and two lateral sections.

RESULTS

Of the 150 discs in the patients with myelopathy, 87% had a median penetration and 13% had a paramedian one. No discs had a lateral penetration. It was found that 45% of the median penetrations led to median herniation through a straight course and 55% to paramedian herniation through an oblique course, and that 95% of the paramedian penetrations led to paramedian herniation through a straight course. Of the 50 discs in the patients with radiculopathy, 70% had a median penetration, 26% a paramedian penetration, and 4% a lateral penetration. Lateral penetration was observed only at C7-T1. All of the median penetrations led to the paramedian or lateral herniation, and 92% of the paramedian penetrations led to lateral herniation through oblique courses.

CONCLUSIONS

In the cervical spine, most herniated masses penetrate the deep layer of the posterior longitudinal ligament in the middle, where the posterior intervertebral space is widest. Oblique courses to paramedian or lateral herniation are common. Only at C7-T1, where there are no Luschka joints, lateral penetration was observed. The narrow space of the Luschka joint may prevent fragments from penetrating laterally. Preoperative information from the CT discograms on the characteristic courses of the herniation may facilitate the complete removal of herniated mass in anterior decompressive surgery.

[Guidelines for the sociomedical assessment of performance in patients suffering from discopathy or associated diseases]

The following guidelines were developed for the medical assessment services of the German Federal Insurance Institute for Salaried Employees (BfA). Starting from day-to-day practice, criteria and attributes to guide decisions for a systemisation of the sociomedical assessment of performance in discopathy or associated diseases were compiled. The guidelines aim at standardising the sociomedical assessment of performance and help to make the decision-making process more transparent -- e. g. for the assessment of applications for decreased earning capacity benefits. The guidelines summarise typical manifestations of discopathy or associated diseases and describe the necessary medical information for the sociomedical assessment of performance. Relevant assessment criteria for the medical history, clinical examination, and for diagnostic tests are illustrated. The assessment of the individual's capacity is outlined, taking occupational factors into account. Following the determination of dysfunctions the remaining abilities and disabilities, respectively, are deduced and compared with occupational demands. Finally, inferences are drawn regarding the occupational capacity of the individual. Guidelines for the sociomedical assessment of performance in coronary heart disease (CHD) have been published in Gesundheitswesen 2002, 64: 451-465.

A new method for lumbar herniated inter-vertebral disc diagnosis based on image analysis of transverse sections

This paper describes an image analysis method that uses automatic algorithms for the evaluation of herniation classification and geometry in the diagnosis of lumbar herniated inter-vertebral disc (HIVD). The method uses boundary approximation that uses a B-spline curve to approximate circle-like disc boundary and excludes the herniation from other normal parts of the disc boundary and, feature recognition that classifies the herniation, and herniation shape reconstruction that infers the 3D geometry from one or more transverse sections. This method can be used as a qualitative and quantitative tool for the diagnosis of lumbar HIVD using transverse sections.

Gadolinium diethylenetriaminepentaacetic acid enhancement in magnetic resonance imaging in relation to symptoms and signs among sciatic patients: a cross-sectional study

STUDY DESIGN

A cross-sectional descriptive study.

OBJECTIVES

Gadolinium enhancement in lumbar magnetic resonance imaging is not used routinely. The current study explored the possible intercorrelations of enhancement patterns with clinical symptoms and signs.

SUMMARY OF BACKGROUND DATA

Rim enhancement has been reported to occur in the periphery of disc herniations, and it is thought to represent neovascularization. To the authors' knowledge, the significance of the enhancement in relation to clinical symptoms has not been studied.

METHODS

Magnetic resonance imaging of the lumbar spine with intravenous gadolinium diethylenetriaminepentaacetic acid was performed in each patient. Various contrast enhancement parameters and volume of herniation were evaluated, and their correlations with clinical signs and symptoms (straight leg raising, motor defect, Achilles reflex, leg and back pain, disability) were analyzed.

RESULTS

The extent of rim enhancement correlated highly significantly with the degree of disc displacement, being most pronounced in the case of sequesters. The duration of sciatic symptoms correlated negatively with enhancement. The clinical symptoms did not correlate significantly with the different enhancement parameters or disc herniation volume. Straight leg raising correlated only slightly with the extent of rim enhancement (P = 0.04) when bulges were excluded. Achilles reflex abnormality correlated significantly with all enhancement parameters for lesions at L5-S1. In the final stepwise logistic regression model, contrast enhancement extent correlated most significantly with abnormal Achilles reflex (P = 0.0002).

CONCLUSIONS

Although rim enhancement of disc herniation is thought to represent a beneficial phagocytotic phenomenon, it may also have a harmful effect on the adjacent nerve root.

Video-assisted thoracoscopic surgery for thoracic disc disease: Classification and outcome study of 100 consecutive cases with a 2-year minimum follow-up period

STUDY DESIGN

Prospectively collected data from regular clinical follow-up evaluations were tabulated, analyzed, reviewed using a patient self-reported questionnaire.

OBJECTIVE

To develop a classification system and present the long-term functional outcome of video-assisted thorascopic surgery for refractory thoracic disc disease.

SUMMARY OF BACKGROUND DATA

Recent studies have found an 11.1% to 14.5% prevalence of thoracic disc herniations. Surgical approaches have included laminectomy, pediculectomy, costotransversectomy, lateral extracavitary, transverse arthropediculectomy, transthoracic-transpleural thoracotomy, and thoracoscopy. Recent reports have documented encouraging early results with video-assisted thorascopic surgery for thoracic disc herniations. Comparisons between thoracoscopy and open thoracotomy have demonstrated improvement in postoperative pain and morbidity with the use of endoscopic techniques.

METHODS

This study included 100 consecutive patients (45 women and 55 men) with an average follow-up evaluation of 4 years (range, 2-6 years). The average age of the patients was 42 years (range, 22-76 years). The average duration of symptoms was 26 months (range, 6-96 months), and 18 patients had undergone prior spine surgery. Patients were graded as follows according to the presenting symptoms (Table 1): Grade 1 (pure axial; n = 28), Grade 2 (pure radicular; n = 5), Grade 3A (axial and thoracic radicular; n = 38), Grade 3B (axial with lower leg pain; n = 19), Grade 4 (myelopathic; n = 8), or Grade 5 (paralytic = 2).

RESULTS

A total of 117 discs were excised in 100 patients. Of the 40 patients who underwent fusion, 27 had autologous rib struts and 13 had threaded fusion. The mean operative time was 173 minutes, blood loss 259 mL, average ICU stay less than 1 day, and average hospital stay 4 days. Minor complications occurred in 21 patients, all of which resolved with no untoward effect. No patient's neurologic status worsened. Four patients underwent a secondary fusion, and a pseudarthrosis developed in one patient. Clinical success was defined objectively as an improvement in Oswestry score of 20% or more at 2 years and at final follow-up assessment, as compared with the preoperative Oswestry score. Overall, objective clinical success was observed at 2 years in 73% of the patients, and at final follow-up assessment in 70% of patients. The average percentage of improvement in Oswestry scores was most marked in Grade 4 patients (myelopathy; 60%), followed by Grade 3A patients (axial and thoracic radicular pain; 37%), Grade 3B patients (axial with leg pain; 28%), and Grade 1 patients (pure axial; 24%). The Oswestry disability score (Table 2) and back pain visual analog score (Table 3) also were significantly improved (P < 0.05) at 2 years and at final follow-up assessment in these patients. In the Grade 2 patients, those pure thoracic radicular pain, Oswestry scores initially improved significantly up to 1 year (P < 0.05). At 2 years, no significant improvement could be shown, and four of the five Grade 2 patients reported increased axial pain as their main symptom at the final follow-up assessment. Significant improvement also was seen in patients with no prior spine surgery and patients with preoperative Oswestry disability scores greater than 50. Of the 68 patients who responded to the final questionnaire, 12 rated the procedure as excellent, 37 as good, 11 as fair, and 8 as poor. Also, 57 (83.8%) of these 68 patients were satisfied and indicated they would recommend the surgery. Of the 36 patients at the final follow up assessment who had severe disability, 34 (94%) were satisfied, as compared with 23 of the 32 patients (72%) who had presented with milder disability.

CONCLUSIONS

The clinical classification system helps in differentiating different presentations of thoracic disc disease and their final outcome. Video-assisted thorascopic surgery appears to be a safe and efficacious method for the treatment of refractory symptomatic thoracic disc herniations. The current data suggest that the procedure has an acceptable long-term outcome, with an 84% overall subjective patient satisfaction rate, and with objective long-term clinical success achieved in 70% of patients.

Comparison of the prevalence of inflammatory cells in subtypes of disc herniations and associations with straight leg raising

STUDY DESIGN

The prevalence of inflammatory cells in 205 disc herniations (DHs) and nine macroscopically normal discs for comparison was studied immunohistochemically. Inflammatory cells were separately analyzed in subtypes of DH. Immunohistochemical data were related to clinical parameters, the straight leg raising test (SLR) in particular.

OBJECTIVES

The objectives of the study were to compare the occurrence of inflammatory cells in various subtypes of DH and to determine the association between clinical data and inflammatory cell occurrence in a more extensive sample of DH, with separate analysis of DH subtypes.

SUMMARY OF BACKGROUND DATA

Previous studies have suggested a common occurrence of inflammation and inflammatory cells, particularly macrophages, in DHs. No studies on any larger material comprising different subtypes of DH have been done.

METHODS

For immunohistochemistry the alkaline phosphatase antialkaline phosphatase method was used. Monoclonal antibodies to T cells in general (CD2), activated T cells (CD25), B cells (CD22), and macrophages (CD68) were used. Obtained immunostaining results were then compared with clinical data, e.g., duration of pain, SLR, and type of DH (sequesters 86, extrusions 103, protrusions 16). Associations were studied by the chi2 test or Fisher's exact test, as applicable (level of significance P < 0.05).

RESULTS

Abundant T cells were seen in 17% of the 205 DHs, activated T cells in 17%, B cells in 16%, and macrophages in 37%. All cell types were 2-3 times more prevalent in sequestrated discs than in extrusions. In protrusions macrophages were abundantly seen in 25% (4 of 16) and no other inflammatory cells. In patients with positive SLR and a sequestrated disc abundant lymphocytes were seen three times more often than in extrusions. When patients with bilaterally negative SLR were compared with those with tight SLR (< or =30 degrees ) with respect to inflammatory cell occurrence, some significant differences were noted (CD68, P < 0.025; CD25, P = 0.04). A comparison between SLR bilaterally positive and bilaterally negative also showed associations for all four inflammatory cell types (P = 0.016 to P = 0.029). There was no correlation between inflammatory cells and duration of pain. Abundant inflammatory cells were never seen in control discs.

CONCLUSIONS

When SLR was positive and the DH type was sequestered, inflammatory cells were most commonly seen. Our results showed some statistically significant associations between inflammatory cells and SLR, most clearly when comparing bilaterally positive and negative SLR. Interestingly, a bilaterally positive SLR showed an association with all four inflammatory cell types analyzed. Tight SLR also showed an association, particularly with macrophages. In addition to tissue resorption, they may participate in sciatic pain. Even though lymphocytes were less prevalent, they may have some role in sequestered discs and bilaterally positive SLR.

Intraradicular disc herniations in the lumbar spine and a new classification of intradural disc herniations

STUDY DESIGN

A case report of intraradicular disc herniation. Intraradicular disc herniation is a special type of intradural disc herniations. In this report, we present the tenth case of intraradicular lumbar disc herniation and suggest a new classification for intradural disc herniations.

CASE REPORT

A 32-year-old male was admitted to hospital having experienced pain in the lower back and right leg for 1 month prior to admission. Neurological examination revealed weakness of the extensor hallucis longus, positive Laségue's sign, decreased ankle reflex in his right lower extremity, and bilateral paravertebral muscle spasm. Magnetic resonance imaging (MRI) revealed a disc herniation with a posterolateral extruded fragment on the right at the level of the L5-S1 space. He underwent L5 laminectomy. During the operation, the right S1 root was found to be swollen and immobile. A longitudinal incision was made in the dura of the right S1 root and an intradural free disc fragment was removed, and the S1 root was relieved. The patient was free of pain postoperatively.

CONCLUSION

We suggest a new classification for intradural disc herniations with this unusual case presentation and review the literature for pathogenesis, clinical picture, diagnosis and treatment.

Magnetic resonance classification of lumbar intervertebral disc degeneration

STUDY DESIGN

A reliability study was conducted.

OBJECTIVES

To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system.

SUMMARY OF BACKGROUND DATA

A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations. The reliability of the assessment has a crucial influence on the validity of the data. Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse.

METHODS

A grading system for lumbar disc degeneration was developed on the basis of the literature. An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations. The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years). All scans were analyzed independently by three observers. Intra- and interobserver reliabilities were assessed by calculating kappa statistics.

RESULTS

There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs. The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 0.84-0.90) and interobserver (kappa range, 0.69-0.81). Complete agreement was obtained, on the average, in 83.8% of all the discs. A difference of one grade occurred in 15.9% and a difference of two or more grades in 1.3% of all the cases.

CONCLUSION

Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.

[Clinical classification and the operative curative effects of microendoscopic discectomy in the elderly lumbar disc herniation]

OBJECTIVE

To study the value of the classification of the elderly lumbar disc herniation(LDH) as an indication of microendoscopic discectomy(MED).

METHODS

Based on the pathological features of the elderly LDH, eighty-one patients over fifty years old (Group A) were proved to be intraspinal complications by traditional operation and were divided into I and II types which were compared with what were seen in the operation. Sixty-two patients over 50 years old (Group B) were treated with MED and reviewed retrospectively, and their curative effects were compared with their types.

RESULTS

A general intraspinal narrowness rate of Group A was 62.07% in Type I, 107.69% in Type II (P < 0.01). Group B was all followed up (mean 10 months). According to the macnnab criterion, the satisfactory rate was 100% in Type I, 75% in Type II (P < 0.05).

CONCLUSION

The clinical classification of the elderly LDH makes a significant effect on the treatment of MED, can be used as an indication of MED, and can be popularized in clinic.

Relationships between outcomes of conservative treatment and magnetic resonance imaging findings in patients with mild cervical myelopathy caused by soft disc herniations

STUDY DESIGN

A retrospective follow-up study of conservatively treated patients with mild cervical myelopathy caused by cervical soft disc herniation.

OBJECTIVE

To investigate the outcome of conservative treatment for patients with mild myelopathy caused by cervical soft disc herniation and to evaluate usefulness of magnetic resonance findings in the prediction of the outcomes.

SUMMARY OF BACKGROUND DATA

Recent studies on conservative treatment for cervical soft disc herniation have focused mainly on radiculopathy, and not on myelopathy.

METHODS

Twenty-seven patients with mild cervical myelopathy secondary to cervical soft disc herniation were treated conservatively for more than 6 months by cervical bracing and restriction of daily activities. Of the 27 patients, 17 patients (Group A) underwent conservative treatment only and it was associated with improvement in their neurologic deficits, while the other 10 patients (Group B) ultimately underwent decompression surgery because of neurologic deterioration. Comparisons between the two groups were made in regard to JOA scores, patient satisfaction, and magnetic resonance findings, including location of the disc herniation (focal or diffuse in the sagittal plane, median or paramedian in the axial plane).

RESULTS

The JOA scores were 13.6 +/- 1.6 in Group A and 14.1 +/- 1.6 in Group B before treatment, 14.9 +/- 1.0 and 12.9 +/- 2.1, respectively, at 3 months, and 16.2 +/- 0.8 and 16.0 +/- 1.2, respectively, at the final follow-up. The JOA scores at 3 months were significantly lower in Group B than in Group A. Satisfaction with the results of treatment at the final follow-up was reported by 77% of the patients in Group A and 90% in Group B. Focal-type herniation was present in 47% of the patients in Group A and 70% in Group B, while median-type herniation was diagnosed in 77% in Group A and 30% in Group B. Follow-up magnetic resonance imaging of the patients in Group A showed spontaneous regression of a herniated mass in 10 patients (59%). Diffuse-type herniations were more likely to regress spontaneously than focal-type herniations (78% vs. 37%).

CONCLUSIONS

Conservative treatment is an effective treatment option for mild cervical myelopathy caused by cervical soft disc herniation. A good outcome can be expected in patients with a median-type and/or diffuse-type herniation on magnetic resonance imaging.

Central lumbar disc herniation

A follow-up study which describes the experience of the Department of Neurosurgery in Berne in the treatment of patients with central lumbar disc herniation (CLDH).

BACKGROUND DATA

The anatomical position of lumbar disc herniation, in general, does not seem to affect postoperative outcome. However, according to other studies a subgroup of patients with central lumbar disc herniations appears to have poorer results.

OBJECTIVES

The aim of the present study was to assess clinical outcome in a recent cohort of patients, to investigate whether there is a difference in outcome with regard to the surgical approach (unilateral vs bilateral) and to compare the postoperative results between the subcategories of CLDH: central massprolaps (CMP) and central contained disc herniation (CCDH).

METHODS

Between 1990 and 1997, 40 out of 3150 patients operated on for lumbar disc herniation were diagnosed with CLDH (1.2%). The patients were operated on through unilateral or bilateral fenestrations with microdiscectomy. Recent follow-up studies were obtained by standardized questionnaires. The retrospective investigation was performed by an unbiased observer.

RESULTS

Long-term follow-up was available for 34 of the 40 patients (85%) at a mean of 3.3 years. Eight patients had an excellent result (24%), 15 patients a good result (44%), 8 patients a fair (24%) and 3 patients had a poor result (9%). Overall, the operation was considered successful in 68% of patients. There was no statistically significant difference in outcome in patients with CMP as compared with those with CCDH (75% versus 64%). There was also no significant difference for better outcome between bilateral as compared with unilateral approaches.

CONCLUSIONS

Postoperative outcome of central lumbar disc herniation (CLDH) is poorer as compared with other types of lumbar disc herniation. The reason seems to be the anatomical position of the disc herniation with a peculiar derangement of the disc architecture. The surgical approach itself or the subcategories of CLDH appear to have only minor impact on postoperative outcome. Interlaminar fenestrations, in general, are appropriate for removal of the disc fragments.

[Use of modified lateral nucleus pulposus herniation classification in low back pain]

Nucleus pulposus herniation is one of frequent causes in spinal pains. The necessity of undertaking of appropriate treatment, often surgical, requires early establishing of precise diagnosis. The traditional classification of herniations into central, centrolateral and lateral seems to be insufficiently precise, especially from the surgical point of view. For that purpose, the authors, following the classification of Volle et al., applied in their analysis the new classification into central and lateral nucleus pulposus herniae and discerning among the latter ones four types with strictly defined localisation: mediolateral, lateral with recess involvement, intervertebral foramen hernia, outside intervertebral foramen hernia. Seventy-two cases were analysed. Hernia was diagnosed by means of CT. Particular attention was given to the most external hernias, that is into and outside the intervertebral foramen. The more accurate method for the assessment of hernias and bone changes was in CT the Reconstruction in sagittal and frontal planes and also in oblique projections. The authors believe that the diagnosis of lateral nucleus pulposus hernias in low spinal area, particularly those with herniation into and outside the intervertebral foramen should be based on CT in appropriate reconstructions.

Classification, diagnostic imaging, and imaging characterization of a lumbar herniated disk

The absence of universal nomenclature standardization with respect to the definition of a disk herniation and its different categories, especially regarding type and location, is still a major problem that will only be overcome when major national or international scientific societies join efforts to support a particular scheme. Meanwhile, it is important to realize that the two models that are currently most used are based on a different [figure: see text] perspective. Trying to straddle the two by opposing, for instance, bulging disk and herniation is doomed to failure because this exercise defies formal logic. MR imaging is currently the most accurate noninvasive imaging modality to diagnose a disk herniation and to determine its exact location. The determination of some pathoanatomic characteristics of herniated disks (type and composition) may require the use of CT, diskography, or CT diskography.

[Giant cervical disc herniation: case report]

Disc herniation occurs commonly in neurosurgery. The Neurosurgery Department of Santa Casa de Belo Horizonte in 1997 had 17% of all surgeries for disc herniation and 7% of those were of cervical spine. We report a giant cervical disc herniation C4-C5 in a 72-year-old male patient, presenting with tetraparesis, sensory loss below C5 and urinary retention, who underwent microsurgical anterior decompression and internal fixation with iliac bone graft without plate fixation according Cloward. The patient had a satisfactory outcome. We propose a new classification for disc herniation according the dural compression: small (until 12%), medium (12 to 25%), big (25 to 50%) and giant (more than 50%).

[Neurosurgical treatment of complications of intra-disk injections of triamcinolone hexacetonide. Value of a radio-clinical classification]

Epidural granulomas following intra-discal injection of triamcinolone hexacetonide are a well-known complication of this procedure, which is still encountered, even if its utilization was discontinued several years ago. According to the results of their experience, the authors propose a new radio-clinical grading system: grade I: disc calcification with aspect of "sub-ligamentar hernia" on CT scan; grade II: ascendant or descendant retrosomatic migration of distal content; grade III: pseudotumoral epidural infiltrate producing progressive narrowing of the spinal canal with neurological disturbance. Surgical indications in these cases can be drawn from their evolution: posterior approach can be used, with or without laminectomy, for excision as complete as possible of the involved disc (grades I and II); anterior approach should be preferred in cases of multiples recurrences after medical treatment and failure of classical posterior approach, or in case of necrotico-inflammatory proliferation with narrowing of the spinal canal (grade III).

Contrast-enhanced magnetic resonance imaging in conservative management of lumbar disc herniation

STUDY DESIGN

This study was designed to investigate the morphologic changes in contrast-enhanced magnetic resonance imaging that occur during conservative treatment of patients with unilateral leg pain resulting from herniated nucleus pulposus without significant lumbar canal stenosis.

OBJECTIVES

To compare the morphologic results with clinical outcomes to ascertain whether enhanced magnetic resonance imaging contributes to the management of lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

Contrast-enhanced magnetic resonance imaging has already been reported to be useful in the postoperative examination of the lumbar spine and in visualization of symptomatic nerve roots. However, there have been few reports about its usefulness in the conservative management of herniated nucleus pulposus or about the correlation between herniated nucleus pulposus regression and enhanced effect. The study population consisted of 48 patients with radiculopathy. All patients primarily reported unilateral leg pain, and 94% had positive tension signs. Additionally, 38% exhibited muscle weakness corresponding to the symptomatic nerve root.

METHODS

All patients were studied twice or more using gadolinium-magnetic resonance imaging during conservative therapy, at a mean interval of 191 days. Changes in the size of the herniated nucleus pulposus on precontrast images fell into four categories, with changes in enhancement on postcontrast images classified into two categories: "enlargement" and "no change."

RESULTS

In all cases of migrating type herniated nucleus pulposus, circular enhancement was seen on postcontrast images. In 17 of 22 cases, the enhanced area gradually thickened and intruded into the migrated disc materials as the size of the herniated nucleus pulposus decreased; the herniated nucleus pulposus disappeared in nine cases and showed a marked decrease in seven cases. These cases showed good clinical courses of sciatica. In the other five patients, in whom there were no changes in the enhanced area, there was less of a tendency for the herniated nucleus pulposus to decrease in size, and there were poorer clinical results. In six cases of extruding-type herniated nucleus pulposus, no enhanced effects were observed throughout the follow-up period. The other 20 cases showed enhancement that was relatively weaker than that of migrating disc herniation. Extension or expansion of the enhanced area was observed in the follow-up images of 15 cases, though only four showed obvious changes in the size of the herniated nucleus pulposus. These 15 cases had better clinical results than the other cases, in which enhanced effects did not change or were not observed.

CONCLUSION

Contrast-enhanced magnetic resonance imaging is a useful prognostic parameter, and multiple use contributes to the proper management of lumbar disc herniation.

Imaging of the spine. Techniques of MR imaging

Recently, magnetic resonance (MR) imaging has become the preferred method of evaluation for spinal disorders. The vertebrae, intervertebral disks, ligaments, spinal canal, and neural foramen may all be evaluated using current MR imaging techniques. MR imaging with paramagnetic contrast has developed into a valuable technique for diagnosing a tumor, an infection, or a degenerative disease. Computed tomography remains the procedure of choice for examining fine cortical bone detail including evaluation of spine fractures and assessing neural foraminal size, but it is not sensitive for detecting marrow-infiltrating disorders.

[Significance of revision of the occupational illness legislation for evaluating intervertebral disk damage]

QUESTION

Are there any radiological criterions which are able to indicate the profession related disease No. 2108?

METHODS

The medical documents and x-rays of the whole spine of 390 back pain patients who applied for a profession related disease of the spine were evaluated. Those patients who fulfilled the professional claims for acknowledgement of the profession related disease were compared to those who didn't fulfill these conditions.

RESULTS

Concerning the segmental alterations of the cervical and the lumbal spine specific allocation frequencies were found. The dominance of L3/4 in the comparison group was conspicuous. Looking at the allocation frequencies of the cervical and lumbal disc alterations in view of affection heaviness it was obvious, that the predominating slight alterations mainly were located in the central parts of the cervical and the lumbal spine whereas bad alterations mainly were found in the lower parts. Regarding this matter test and comparison groups behaved the same way. Looking at the allocation frequencies concerning single respectively multiple alterations it was found that in the comparison group single respectively bisegmentale alterations could be recognized even in duplicate than in the test group in which the multiple alterations were dominant. The comparison of the cervical and the lumbal spine regarding chondrotic? spondylotic, slight and bad alterations in all mentioned features the next deeper located segment was affected particularly in the test group. Therefore a distal shift of the chondrotic alterations could be recognized. In case of the spondylotic affections it was the other way round: a cranial shift was conspicuous.

CONCLUSION

After doing heavy labour for years only a few isolated multiple affections of the lumbal spine are found. On the strength of this fact the proof of exclusively in the lumbal spine located alterations doesn't allow the acknowledgement of a profession related disease. However, a distal shift of osteochondrotic alterations respectively a cranial shift of spondylotic affections in the lumbal spine is suspicous for being job-related. L3/4 takes a very special place in the differential diagnosis of profession related disease of the spine. In the test group this part of the lumbal spine showed bad alterations much more frequent. The affection of L3/4 pleads against a considerable participation of mechanical influences and therefore against a profession related disease. Singular or bisegmental disc affections are out of question for being a profession related disease because these alterations are seen much more frequent in the comparison than in the test group.

[The validation of a procedure for the surgical treatment of intervertebral disk hernias of the cervical spine]

Thirty-four consecutive patients with cervical disc herniation underwent surgical treatment at Burdenko Neurosurgical Institute. The clinical signs and diagnostic findings as well as surgical results were analyzed. Predominance of direct spinal cord involvement, characteristic changes in the anterior spinal artery and afferent vessels confirm the fact that cervical disk herniation causes vascular changes to take place, which in turn affect neural structures. Microsurgical techniques with maximum preservation of bone structures and vertebral endplates is mandatory. If multiple disk herniations are present, the most prominent compressing disk fragment should be removed. Stabilization following the surgery is considered effective.

[Foraminal and extraforaminal lumbar disc herniations]

The severity of the clinical presentations of the foraminal or extraforaminal lumbar disc herniation (FLDH or EFLDH) and its response to conservative treatment were different. In order to make clear the reasons for that and then chose the best method of treatment, two types of FLDH or EFLDH were classified in a group of 23 cases according to the location of the protruded disc shown in the films of CT or MRI. Type I: the disc protruded up to the superior pedicle closely. Type II: the disc protruded laterally mainly with slight moving up. Then two subtypes were made, subtype a: symple FLDH or EFLDH: subtype b: if combined with posterior lateral disc herniation. In total of 23 cases there were 10 of type (I a: 8, I b: 2) and 13 of type II (II a: 7, II b: 6), among of which there were 14 FLDHs and 9 EFLDHs. The clinical presentations and the results of conservative treatment were compared between the two types. The results of statistical analysis showed that the severity of damage to the nerve root and its response to conservative treatment were mainly related to the location of the protruded disc to the superior pedicle rather than the protruded disc in the foramen or extraforamen. All of cases of type I had more severe symptoms and signs, poorer results of conservative treatment and were operated on finally. However some cases of type II only had slight or even no symptoms and signs at all, 50% of the patients in the type II were cured by nonsurgical methods. So it was suggested that the cases of type I be treated surgically mainly, whereas the type II initially be treated conservatively and if failed, go to operation. The approach lateral to the pars interarticularis for the discectomy had more advantages than the other methods and could be applied in most of cases. If combined posterior lateral disc herniation was the main pathologic change in the cases of type II laminectomy with partial facetectomy might be used. The classification is reliable as it is well consisten with the findings of operations. So it is valuable for the guidance of determining the method of nonsurgical or surgical treatment.

Concordance between ANSI occupational back injury codes and claim form diagnoses and a lower bound estimate of the fraction associated with disc displacement/herniation

The current BLS Annual Survey of Occupational Illnesses and Injuries and several recent analyses of factors affecting missed worktime in occupational back injuries rely on ANSI-based injury codes derived from injury narratives to classify occupational injuries and estimate incidence and outcome. No population-based studies of the concordance between back injury codes and clinical diagnoses have been reported. Back injury cases were identified in two large work-injured populations totaling almost 80,000 cases in the states of Michigan and Minnesota. In both populations, cases had been coded by the single nature-of-injury and part-of-body-injured codes assigned by an ANSI-based injury-coding system and by as many as four (Michigan) or three (Minnesota) clinical diagnoses according to the International Classification of Diseases-Clinical Modification, 9th Revision. Concordance was measured by the sensitivity and predictive value positive (PVP, aka PV+ or PPA) of the injury coding scheme for related diagnostic groups. We also used an algorithm based on the limited clinical information available to corroborate the diagnosis of displaced/herniated disc for cases that underwent spinal surgery. Cases identified by the algorithm were then used to obtain a lower bound estimate of the fraction with disc injury. The injury coding scheme had PVPs of 82.9-90.1% and overall sensitivities of 69.7-75.9%. Sensitivities for individual diagnostic groups show that their distribution in ANSI-coded injury groups is skewed slightly toward cases with sprain and disc displacement/herniation, but these shifts are modest. The lower bound estimate of the fraction of cases with disc displacement/herniation in a population of cases with back injuries producing at least 1 day of missed worktime is 5.8%. The demographic comparisons indicate that, as the time between injury and cohort ascertainment increases during the first 8 days of missed worktime following injury, the proportion of younger workers in an injury cohort decreases. The relationship between increasing age and increasing missed worktime disability, reported in various outcome studies, is also present during the first few days following injury. The use of ANSI injury codes underestimates the contribution of back injuries to missed worktime because 24-30% of cases are missed by the ANSI coding system. However, the distribution of diagnostic groups in the injury-coded groups approximates that observed with all diagnosed cases and supports the use of such data to study outcome. Our estimate, and one from Quebec, suggest that disc displacement/herniation occurs more frequently in the subset of occupational back injuries compared to the set of back injuries from all sources.

Interreader reliability for a new classification of lumbar disk disease

RATIONALE AND OBJECTIVES

The nomenclature that divides disk herniations into protrusions and extrusions may increase the specificity of magnetic resonance (MR) imaging for clinically important lesions. Our goal was to determine this terminology's interreader reliability.

METHODS

Three readers who were unaware of patients' histories independently read MR images of 34 consecutive patients with back pain. Readers classified disks at the lowest three lumbar levels as normal, bulging, protruded, or extruded. Kappa and weighted kappa values were the primary measures of agreement.

RESULTS

Weighted kappa values showed fair-to-moderate agreement. Kappas for the dichotomous decision of extrusion present or absent were more variable, ranging from 0 to .78. Major disagreements (greater than a single category) occurred with 6.2% of all comparisons and in 10 of 34 volunteers; five involved extrusions.

CONCLUSION

Overall, readers achieved moderate agreement for this new nomenclature. However, agreement for the presence or absence of an extrusion was less reliable.

Pain and pathology in lumbar disc hernia

The authors analyzed pain drawings of patients having lumbar disc surgery and tried to correlate pain pattern to disc pathology and level. Preoperatively, patients having spinal surgery were asked to draw on a standardized form the localization, postural variation, and modality of their pain. In this study, 185 consecutive patients with unilateral and unisegmental L4-L5 and L5-S1 hernias were analyzed. The pain drawings were coded and read blindly; each drawing was divided operationally into anatomic areas, and the type of pain symbol in each pixel was recorded, digitized, and analyzed by stepwise discriminant analysis. For predicting the level of the lesion, the most important variables were pain on the anterolateral aspect of the leg (L4-L5) and pain radiating to the posterior aspect of the foot (L5-S1). For predicting the grade of herniation, the most discriminative factors were pain radiating to the foot (sequestrated hernia) and bilateral back pain (protruded hernia). Pain drawing facilities communication and documentation. In addition, it is an aid to diagnose the level and degree of the hernia, and therefore is useful for selecting patients who might benefit from disc surgery. For scientific purposes, data are digitized easily, allowing analyses of large populations.