Showing papers in "Spine in 2000"

Guidelines for the process of cross-cultural adaptation of self-report measures.

Abstract: With the increase in the number of multinational and multicultural research projects, the need to adapt health status measures for use in other than the source language has also grown rapidly. 1,4,27 Most questionnaires were developed in English-speaking countries, 11 but even within these countries, researchers must consider immigrant populations in studies of health, especially when their exclusion could lead to a systematic bias in studies of health care utilization or quality of life. 9,11 The cross-cultural adaptation of a health status selfadministered questionnaire for use in a new country, culture, and/or language necessitates use of a unique method, to reach equivalence between the original source and target versions of the questionnaire. It is now recognized that if measures are to be used across cultures, the items must not only be translated well linguistically, but also must be adapted culturally to maintain the content validity of the instrument at a conceptual level across different cultures. 6,11‐13,15,24 Attention to this level of detail allows increased confidence that the impact of a disease or its treatment is described in a similar manner in multinational trials or outcome evaluations. The term “cross-cultural adaptation” is used to encompass a process that looks at both language (translation) and cultural adaptation issues in the process of preparing a questionnaire for use in another setting. Cross-cultural adaptations should be considered for several different scenarios. In some cases, this is more obvious than in others. Guillemin et al 11 suggest five different examples of when attention should be paid to this adaptation by comparing the target (where it is going to be used) and source (where it was developed) language and culture. The first scenario is that it is to be used in the same language and culture in which it was developed. No adaptation is necessary. The last scenario is the opposite extreme, the application of a questionnaire in a different culture, language and country—moving the Short Form 36-item questionnaire from the United States (source) to Japan (target) 7 which would necessitate translation and cultural adaptation. The other scenarios are summarized in Table 1 and reflect situations when some translation and/or adaptation is needed. The guidelines described in this document are based on a review of cross-cultural adaptation in the medical, sociological, and psychological literature. This review led to the description of a thorough adaptation process designed to maximize the attainment of semantic, idiomatic, experiential, and conceptual equivalence between the source and target questionnaires. 13 . Further experience in cross-cultural adaptation of generic and diseasespecific instruments and alternative strategies driven by different research groups 18 have led to some refinements

The Oswestry Disability Index.

Abstract: Study design The Oswestry Disability Index (ODI) has become one of the principal condition-specific outcome measures used in the management of spinal disorders. This review is based on publications using the ODI identified from the authors' personal databases, the Science Citation Index, and hand searches of Spine and current textbooks of spinal disorders. Objectives To review the versions of this instrument, document methods by which it has been validated, collate data from scores found in normal and back pain populations, provide curves for power calculations in studies using the ODI, and maintain the ODI as a gold standard outcome measure. Summary of background data It has now been 20 years since its original publication. More than 200 citations exist in the Science Citation Index. The authors have a large correspondence file relating to the ODI, that is cited in most of the large textbooks related to spinal disorders. Methods All the published versions of the questionnaire were identified. A systematic review of this literature was made. The various reports of validation were collated and related to a version. Results Four versions of the ODI are available in English and nine in other languages. Some published versions contain misprints, and many omit the scoring system. At least 114 studies contain usable data. These data provide both validation and standards for other users and indicate the power of the instrument for detecting change in sample populations. Conclusions The ODI remains a valid and vigorous measure and has been a worthwhile outcome measure. The process of using the ODI is reviewed and should be the subject of further research. The receiver operating characteristics should be explored in a population with higher self-report disabilities. The behavior of the instrument is incompletely understood, particularly in sensitivity to real change.

SF-36 health survey update.

Abstract: The SF-36 (Medical Outcomes Trust, Boston, MA) is a multipurpose, short-form health survey with only 36 questions. It yields an eight-scale profile of scores as well as physical and mental health summary measures. It is a generic measure, as opposed to one that targets a specific age, disease, or tr

A review of psychological risk factors in back and neck pain.

Abstract: STUDY DESIGN: The literature on psychological factors in neck and back pain was systematically searched and reviewed. OBJECTIVES: To summarize current knowledge concerning the role of psychological variables in the etiology and development of neck and back pain. SUMMARY OF BACKGROUND DATA: Recent conceptions of spinal pain, especially chronic back pain, have highlighted the role of psychological factors. Numerous studies subsequently have examined the effects of various psychological factors in neck and back pain. There is a need to review this material to ascertain what conclusions may be drawn. METHODS: Medical and psychological databases and cross-referencing were used to locate 913 potentially relevant articles. A table of 37 studies was constructed, consisting only of studies with prospective designs to ensure quality. Each study was reviewed for the population studied, the psychological predictor variables, and the outcome. RESULTS: The available literature indicated a clear link between psychological variables and neck and back pain. The prospective studies indicated that psychological variables were related to the onset of pain, and to acute, subacute, and chronic pain. Stress, distress, or anxiety as well as mood and emotions, cognitive functioning, and pain behavior all were found to be significant factors. Personality factors produced mixed results. Although the level of evidence was low, abuse also was found to be a potentially significant factor. CONCLUSIONS: Psychological factors play a significant role not only in chronic pain, but also in the etiology of acute pain, particularly in the transition to chronic problems. Specific types of psychological variables emerge and may be important in distinct developmental time frames, also implying that assessment and intervention need to reflect these variables. Still, psychological factors account for only a portion of the variance, thereby highlighting the multidimensional view. Because the methodologic quality of the studies varied considerably, future research should focus on improving quality and addressing new questions such as the mechanism, the developmental time factor, and the relevance that these risk factors have for intervention.

The Roland-Morris Disability Questionnaire and the Oswestry Disability Questionnaire.

Abstract: Condition-specific health status measures are commonly used as outcome measures in clinical trials and to assess patient progress in routine clinical practice. The expert panel that met to discuss this special issue of Spine recommended that, when possible, a condition-specific measure for back pain should be chosen from two widely used measures, the Roland–Morris Disability Questionnaire (RDQ) or the Oswestry Disability Index (ODI). These two measures have been used in a wide variety of situations over many years, and each is available in a number of languages. In this article, the authors describe these two instruments and provide evidence of their validity and reliability and some comparative results obtained with the use of the two questionnaires. The instruments themselves are included in the appendixes. When used in the forms reproduced in the appendixes, no permission is required from the authors or from Spine. Other back pain–specific health status measures are described by Kopec elsewhere in this edition of Spine.

Low back pain in relation to lumbar disc degeneration

Abstract: STUDY DESIGN: Cross-sectional magnetic resonance imaging (MRI) study. OBJECTIVES: To study the relation of low back pain (LBP) to disc degeneration in the lumbar spine. BACKGROUND DATA: Controversy still prevails about the relationship between disc degeneration and LBP. Classification of disc degeneration and symptoms varies, hampering comparison of study results. METHODS: Subjects comprised 164 men aged 40-45 years-53 machine drivers, 51 construction carpenters, and 60 office workers. The data of different types of LBP, individual characteristics, and lifestyle factors were obtained from a questionnaire and a structured interview. Degeneration of discs L2/L3-L5/S1 (dark nucleus pulposus and posterior and anterior bulge) was assessed with MRI. RESULTS: An increased risk of LBP (including all types) was found in relation to all signs of disc degeneration. An increased risk of sciatic pain was found in relation to posterior bulges, but local LBP was not related to disc degeneration. The risks of LBP and sciatic pain were strongly affected by occupation. CONCLUSIONS: Low back pain is associated with signs of disc degeneration and sciatic pain with posterior disc bulges. Low back pain is strongly associated with occupation.

Systematic review of psychosocial factors at work and private life as risk factors for back pain.

Abstract: Study Design. A systematic review of observational studies. Objectives. To assess whether psychosocial factors at work and in private life are risk factors for the occurrence of back pain. Summary of Background Data. Several reviews on risk factors for back pain have paid attention to psychosocial factors. However, in none of the published reviews was a strict systematic approach used to identify and summarize the available evidence Methods. A computerized bibliographical search of several databases was performed, restricted to studies with a cohort or case-control design. A rating system was used to assess the strength of the evidence for various factors, based on the methodologic quality of the studies and the consistency of the findings. Results. Eleven cohort and two case-control studies were included in this review. Strong evidence was found for low social support in the workplace and low job satisfaction as risk factors for back pain. Insufficient evidence was found for an effect of a high work pace, high qualitative demands, low job content, low job control, and psychosocial factors in private life. Conclusions. Evidence was found for an effect of low workplace social support and low job satisfaction. However, the result for workplace social support was sensitive to slight changes in the rating system, and the effect found for low job satisfaction may be a result of insufficient adjustment for psychosocial work characteristics and physical load at work. In addition, the combined evaluation of job content and job control, both aspects of decision latitude, led to strong evidence of a role for low job decision latitude. Thus, based on this review, there is evidence for an effect of work-related psychosocial factors, but the evidence for the role of specific factors has not been established yet.

Percutaneous vertebroplasty for pain relief and spinal stabilization

Abstract: Study Design. This was a retrospective review of 47 consecutive patients (1995–1998) in whom percutaneous intraosseous methylmethacrylate cement injection (percutaneous vertebroplasty) was used to treat osteoporotic vertebral compression fractures and spinal column neoplasms. Objectives. To present initial results regarding pain relief, spinal stabilization, and complications after treatment with percutaneous vertebroplasty. Summary of Background Data. Percutaneous vertebroplasty was developed in France in the late 1980s. Several European reports have described excellent results for treatment of compression fractures and neoplasms. The procedure was not performed in the United States until 1994. Only a single series of 29 patients treated in the United States has been reported. Methods. A retrospective review was conducted of 47 consecutive patients with 84 vertebrae treated with percutaneous vertebroplasty. Thirty-eight patients with 70 vertebrae had symptomatic, osteoporotic fractures and had failed medical therapy. Eight patients with 13 vertebrae had primary or metastatic neoplasms. One patient had a hemangioma. Immediate and long-term pain response, spinal stability, and complications were evaluated. Results. Among the 38 patients treated for osteoporotic fractures, 24 (63%) had marked to complete pain relief, 12 (32%) moderate relief and 2 (5%) no significant change. Only 4 of the 8 patients with malignancies had significant pain relief. In 7 of these patients, no further vertebral compression occurred, and spinal canal compromise was prevented. The patient with the hemangioma had no significant pain reduction. Minor complications occurred in 3 (6%) patients. Conclusions. Percutaneous vertebroplasty provided significant pain relief in a high percentage of patients with osteoporotic fractures. The procedure provided spinal stabilization in patients with malignancies but did not produce consistent pain relief. Complications were minor and infrequent. Percutaneous vertebroplasty is a promising therapy for patients with osteoporotic fractures and for selected vertebral column neoplasms.

Mechanical Initiation of Intervertebral Disc Degeneration

Abstract: volves gross structural disruption as well as cell-mediated changes in matrix composition, but there is little evidence concerning which comes first. Comparatively minor damage to a vertebral body is known to decompress the adjacent discs, and this may adversely affect both structure and cell function in the disc. Methods. In this study, 38 cadaveric lumbar motion segments (mean age, 51 years) were subjected to complex mechanical loading to simulate typical activities in vivo while the distribution of compressive stress in the disc matrix was measured using a pressure transducer mounted in a needle 1.3 mm in diameter. “Stress profiles” were repeated after a controlled compressive overload injury had reduced motion segment height by approximately 1%. Moderate repetitive loading, appropriate for the simulation of light manual labor, then was applied to the damaged specimens for approximately 4 hours, and stress profilometry was repeated a third time. Discs then were sectioned and photographed. Results. Endplate damage reduced pressure in the adjacent nucleus pulposus by 25% 6 27% and generated peaks of compressive stress in the anulus, usually posteriorly to the nucleus. Discs 50 to 70 years of age were affected the most. Repetitive loading further decompressed the nucleus and intensified stress concentrations in the anulus, especially in simulated lordotic postures. Sagittal plane sections of 15 of the discs showed an inwardly collapsing anulus in 9 discs, extreme outward bulging of the anulus in 11 discs, and complete radial fissures in 2 discs, 1 of which allowed posterior migration of nucleus pulposus. Comparisons with the results from tissue culture experiments indicated that the observed changes in matrix compressive stress would inhibit disc cell metabolism throughout the disc, and could lead to progressive deterioration of the matrix. Conclusions. Minor damage to a vertebral body end

Outcome assessments in the evaluation of treatment of spinal disorders: summary and general recommendations.

Abstract: Clinicians and researchers increasingly recognize the importance of the patient's perspective in the evaluations of the effectiveness of treatment. The rapid growth in the number and types of patient-based outcome measures can be confusing. This supplement provides a state-of-the-art review of the available tools. In this paper, the key recommendations from the participating authors are summarized. A core set of measures should include the following five domains: back specific function, generic health status, pain, work disability, and patient satisfaction. Two commonly used measures of back-specific function are recommended: the Roland-Morris Disability Questionnaire and the Oswestry Disability Index. Among the generic measures, the SF-36 strikes the best balance between length, reliability, validity, responsiveness, and experience in large populations of patients with back pain. Moreover, the SF-36 Bodily Pain Scale provides a brief measure of pain intensity and pain interference with activities. Health-related work disability should include at a minimum a measure of work status and work-time loss. For those who are still at work, new measures are being developed to measure health-related work limitations. No single measure of patient satisfaction is clearly preferred but guiding principles are provided to choose among available measures. In addition to the five recommended domains, preference-based health outcome measures, including patients utilities, may be useful when there is a need to value alternative health outcomes.

The use of rhBMP-2 in interbody fusion cages. Definitive evidence of osteoinduction in humans: a preliminary report.

Abstract: Study Design.A prospective randomized controlled human clinical pilot trial.Objectives.To determine the feasibility of using rhBMP-2/collagen as a substitute for autogenous bone graft inside interbody fusion cages to achieve arthrodesis in humans.Summary of Background Data.Preclinical studies have s

Lumbar spinal stenosis: conservative or surgical management?: A prospective 10-year study.

Abstract: Study design A cohort of 100 patients with symptomatic lumbar spinal stenosis, characterized in a previous article, were given surgical or conservative treatment and followed for 10 years. Objectives To identify the short- and long-term results after surgical and conservative treatment, and to determine whether clinical or radiologic predictors for the treatment result can be defined. Summary of background data Surgical decompression has been considered the rational treatment. However, clinical experience indicates that many patients do well with conservative treatment. Methods In this study, 19 patients with severe symptoms were selected for surgical treatment and 50 patients with moderate symptoms for conservative treatment, whereas 31 patients were randomized between the conservative (n = 18) and surgical (n = 13) treatment groups. Pain was decisive for the choice of treatment group. All patients were observed for 10 years by clinical evaluation and questionnaires. The results, evaluated by patient and physician, were rated as excellent, fair, unchanged, or worse. Results After a period of 3 months, relief of pain had occurred in most patients. Some had relief earlier, whereas for others it took 1 year. After a period of 4 years, excellent or fair results were found in half of the patients selected for conservative treatment, and in four fifths of the patients selected for surgery. Patients with an unsatisfactory result from conservative treatment were offered delayed surgery after 3 to 27 months (median, 3.5 months). The treatment result of delayed surgery was essentially similar to that of the initial group. The treatment result for the patients randomized for surgical treatment was considerably better than for the patients randomized for conservative treatment. Clinically significant deterioration of symptoms during the final 6 years of the follow-up period was not observed. Patients with multilevel afflictions, surgically treated or not, did not have a poorer outcome than those with single-level afflictions. Clinical or radiologic predictors for the final outcome were not found. There were no dropouts, except for 14 deaths. Conclusions The outcome was most favorable for surgical treatment. However, an initial conservative approach seems advisable for many patients because those with an unsatisfactory result can be treated surgically later with a good outcome.

Hematogenous pyogenic spinal infections and their surgical management.

Abstract: Study design Mainly a retrospective study of 101 cases of pyogenic spinal infection, excluding postoperative infections. Data were obtained through medical record review, imaging examination, and patient follow-up evaluation. Summary of background data Hematogenous pyogenic spinal infection has been described variously as spondylodiscitis, discitis, vertebral osteomyelitis, and epidural abscess. Recommended treatment options have included conservative methods (antibiotics and bracing) and surgical intervention. However, a comprehensive classification that would aid in diagnosis, treatment planning, and prognosis has not yet been devised. Objectives To analyze the bacteriology, pathologic entities, complications, and results of treatment options for pyogenic spinal infection. Method All patients received plain radiographs, gadolinium-enhanced magnetic resonance imaging scans, and bone/gallium radionuclide studies. All patients had tissue biopsies. Bacteriology, hematology, and predisposing factors were analyzed. All patients received intravenous and oral antibiotics. A total of 58 patients underwent surgery. Patient outcomes were correlated with clinical status, with treatment method and, where applicable, with location and nature of epidural compression. Statistical analyses were performed. Results Spondylodiscitis occurred most commonly with primary epidural abscess, spondylitis, discitis, and pyogenic facet arthropathy, all occurring rarely. Staphylococcus aureus was the main organism. Infection elsewhere was the most common predisposing factor. Leukocyte counts were elevated in 42.6% of spondylodiscitis cases. The erythrocyte sedimentation rate was elevated in all cases of epidural abscess. There were 35 cases of epidural abscess (frank abscess, 29; granulation tissue, 6). Epidural abscess complicating spondylodiscitis occurred most often in the cervical spine, followed by thoracic and lumbar areas. The rate of paraplegia or paraparesis also was highest in cervical and thoracic regions. There were no cases of quadriplegia. All patients with either epidural granulation tissue or paraparesis recovered completely after surgical decompression. Only 18% of patients with frank epidural abscess and 23% of patients with paralysis recovered completely after surgical decompression. Patients with spondylodiscitis who were treated nonsurgically reported residual back pain more often (64%) than patients treated surgically (26.3%). Conclusions Pyogenic spinal infection can be thought of as a spectrum of disease comprising spondylitis, discitis, spondylodiscitis, pyogenic facet arthropathy, and epidural abscess. Spondylodiscitis is more prone to develop epidural abscesses in the cervical spine (90%) than the thoracic (33.3%) or lumbar (23.6%) areas. Thecal sac neurocompression has a greater chance of causing neurologic deficit in the thoracic spine (81.8%). Treatment of neurologic deficit caused by epidural abscess is prompt surgical decompression, with or without fusion. Patients with frank abscess had less favorable outcomes than those with granulation tissue, and paraplegia responded to treatment more poorly than paraparesis. Surgery was preferable to nonsurgical treatment for improving back pain.

Assessing global pain severity by self-report in clinical and health services research.

Abstract: In this article, the assessment of global pain severity in clinical and health services research is considered. Specifically, the focus is on assessing pain during a defined period by retrospective self-report. Evidence is reviewed that indicates that it can be useful to regard pain severity as a global construct measured by pain intensity and interference with activities. In contrast, pain experience per se is more usefully regarded as multidimensional. Research on methods of assessing key dimensions of pain experience is reviewed, including pain intensity, affect, and chronicity. The authors suggest that global pain severity (made up of pain intensity and interference with activities) and pain persistence (chronicity) should be focal points for brief pain assessment. Two brief measures of pain severity are reviewed that provide practical, reliable, and valid approaches to pain assessment in clinical and health services research.

Exercise therapy for low back pain: A systematic review within the framework of the cochrane collaboration back review group

Abstract: Study design A systematic review of randomized controlled trials was performed. Summary of background data Exercise therapy is a widely used treatment for low back pain. Objectives To evaluate the effectiveness of exercise therapy for low back pain with regard to pain intensity, functional status, overall improvement, and return to work. Methods The Cochrane Controlled Trials Register, Medline, Embase, PsycLIT, and reference lists of articles were searched. Randomized trials testing all types of exercise therapy for subjects with nonspecific low back pain with or without radiation into the legs were included. Two reviewers independently extracted data and assessed trial quality. Because trials were considered heterogeneous with regard to study populations, interventions, and outcomes, it was decided not to perform a meta-analysis, but to summarize the results using a rating system of four levels of evidence: strong, moderate, limited, or none. Results In this review, 39 trials were identified. There is strong evidence that exercise therapy is not more effective for acute low back pain than inactive or other active treatments with which it has been compared. There is conflicting evidence on the effectiveness of exercise therapy compared with inactive treatments for chronic low back pain. Exercise therapy was more effective than usual care by the general practitioner and just as effective as conventional physiotherapy for chronic low back pain. Conclusions The evidence summarized in this systematic review does not indicate that specific exercises are effective for the treatment of acute low back pain. Exercises may be helpful for patients with chronic low back pain to increase return to normal daily activities and work.

Breast cancer mortality after diagnostic radiography: findings from the U.S. Scoliosis Cohort Study.

Abstract: Study design A retrospective cohort study was conducted in 5573 female patients with scoliosis who were referred for treatment at 14 orthopedic medical centers in the United States. Patients were less than 20 years of age at diagnosis which occurred between 1912 and 1965. Objectives To evaluate patterns in breast cancer mortality among women with scoliosis, with special emphasis on risk associated with diagnostic radiograph exposures. Summary of background data A pilot study of 1030 women with scoliosis revealed a nearly twofold statistically significant increased risk for incident breast cancer. Although based on only 11 cases, findings were consistent with radiation as a causative factor. Methods Medical records were reviewed for information on personal characteristics and scoliosis history. Diagnostic radiograph exposures were tabulated based on review of radiographs, radiology reports in the medical records, radiograph jackets, and radiology log books. Radiation doses were estimated for individual examinations. The mortality rate of the cohort through January 1, 1997, was determined by using state and national vital statistics records and was compared with that of women in the general U. S. population. Results Nearly 138,000 radiographic examinations were recorded. The average number of examinations per patient was 24.7 (range, 0-618); mean estimated cumulative radiation dose to the breast was 10.8 cGy (range, 0-170). After excluding patients with missing information, 5466 patients were included in breast cancer mortality analyses. Their mean age at diagnosis was 10.6 years and average length of follow-up was 40.1 years. There were 77 breast cancer deaths observed compared with the 45.6 deaths expected on the basis of U.S. mortality rates (standardized mortality ratio [SMR] = 1.69; 95% confidence interval [CI] = 1.3-2.1). Risk increased significantly with increasing number of radiograph exposures and with cumulative radiation dose. The unadjusted excess relative risk per Gy was 5.4 (95% CI = 1.2-14.1); when analyses were restricted to patients who had undergone at least one radiographic examination, the risk estimate was 2.7 (95% CI = -0. 2-9.3). Conclusions These data suggest that exposure to multiple diagnostic radiographic examinations during childhood and adolescence may increase the risk of breast cancer among women with scoliosis; however, potential confounding between radiation dose and severity of disease and thus with reproductive history may explain some of the increased risk observed.

The effect of disc degeneration and facet joint osteoarthritis on the segmental flexibility of the lumbar spine.

Abstract: STUDY DESIGN A biomechanical and imaging study of human cadaveric spinal motion segments. OBJECTIVE To investigate the effect of both disc degeneration and facet joint osteoarthritis on lumbar segmental motion. SUMMARY OF BACKGROUND DATA Spinal degeneration includes the osteoarthritic changes of the facet joint as well as disc degeneration. Disc degeneration has been reported to be associated with spinal motion. The association of facet joint osteoarthritis with lumbar segmental motion characteristics and the combined influence of disc degeneration and facet osteoarthritis has not yet been investigated. METHODS A total of 110 lumbar motion segments (52 female, 58 male) from 44 human lumbar spines were studied (mean age = 69 years). Magnetic resonance images were used to assess the disc degeneration from Grade I (normal) to Grade V (advanced) and the osteoarthritic changes in the facet joints in terms of cartilage degeneration, subchondral sclerosis, and osteophytes. Disc height, endplate size, and facet joint orientation and width also were measured from the computed tomographic images. Rotational movements of the motion segment in response to the flexion, extension, lateral bending, and axial rotational moments were measured using a three-dimensional motion analysis system. RESULTS Female motion segments showed significantly greater motion (lateral bending: P < 0. 001, flexion: P < 0.01, extension: P < 0.05) and smaller endplate size (P < 0.001) than male ones. The segmental motion increased with increasing severity of disc degeneration up to Grade IV, but decreased in both genders when the disc degeneration advanced to Grade V. In male segments, the disc degeneration-related motion changes were significant in axial rotation (P < 0.001), lateral bending (P < 0.05), and flexion (P < 0.05), whereas female segments showed significant changes only in axial rotation (P < 0.001). With cartilage degeneration of the facet joints, the axial rotational motion increased, whereas the lateral bending and flexion motion decreased in female segments. In male segments, however, motion in all directions increased with Grade 3 cartilage degeneration and decreased with Grade 4 cartilage degeneration. Subchondral sclerosis significantly decreased the motion (female: axial rotation, P < 0. 05; extension, P < 0.05 vs.- male:flexion,P < 0.05). Severity of osteophytes had no significant association with the segmental motion. CONCLUSION Axial rotational motion was most affected by disc degeneration, and the effects of disc degeneration on the motion were similar between genders. Facet joint osteoarthritis also affected segmental motion, and the influence differed for male and female spines. Further studies are needed to clarify whether the degenerative process of facet joint osteoarthritis differs between genders and how facet joint osteoarthritis affects the stability of the spinal motion segment.

Efficacy and validity of radiofrequency neurotomy for chronic lumbar zygapophysial joint pain

Abstract: Study design A prospective audit. Objective To establish the efficacy of lumbar medial branch neurotomy under optimum conditions. Summary of background data Previous reports of the efficacy of lumbar medial branch neurotomy have been confounded by poor patient selection, inaccurate surgical technique, and inadequate assessment of outcome. Methods Fifteen patients with chronic low back pain whose pain was relieved by controlled, diagnostic medial branch blocks of the lumbar zygapophysial joints, underwent lumbar medial branch neurotomy. Before surgery, all were evaluated by visual analog scale and a variety of validated measures of pain, disability, and treatment satisfaction. Electromyography of the multifidus muscle was performed before and after surgery to ensure accuracy of the neurotomy. All outcome measures were repeated at 6 weeks, and 3, 6, and 12 months after surgery. Results Some 60% of the patients obtained at least 90% relief of pain at 12 months, and 87% obtained at least 60% relief. Relief was associated with denervation of the multifidus in those segments in which the medial branches had been coagulated. Prelesion electrical stimulation of the medial branch nerve with measurement of impedance was not associated with outcome. Conclusions Lumbar medial branch neurotomy is an effective means of reducing pain in patients carefully selected on the basis of controlled diagnostic blocks. Adequate coagulation of the target nerves can be achieved by carefully placing the electrode in correct position as judged radiologically. Electrical stimulation before lesioning is superfluous in assuring correct placement of the electrode.

Muscle response pattern to sudden trunk loading in healthy individuals and in patients with chronic low back pain.

Abstract: Study Design.A quick-release method in four directions of isometric trunk exertions was used to study the muscle response patterns in 17 patients with chronic low back pain and 17 matched control subjects.Objectives.It was hypothesized that patients with low back pain would react to sudden load rele

Radiation exposure to the spine surgeon during fluoroscopically assisted pedicle screw insertion.

Abstract: Study Design. In vitro study to determine occupational radiation exposure during lumbar fluoroscopy. Objectives. To assess radiation exposure to the spine surgeon during fluoroscopically assisted thoracolumbar pedicle screw placement. Summary of Background Data. Occupational radiation exposure during a variety of fiuoroscopically assisted musculoskeletal procedures has been previously evaluated. No prior study has assessed fluoroscopy-related radiation exposure to the spine surgeon. Methods. Bilateral pedicle screw placement (T11-S1) was performed in six cadavers using lateral fluoroscopic imaging. Radiation dose rates to the surgeon's neck, torso, and dominant hand were measured with dosimeter badges and thermolucent dosimeter (TLD) rings. Radiation levels were also quantified at various distances from the dorsal lumbar surface using an ion chamber radiation survey meter. Results. The mean dose rate to the neck was 8.3 mrem/min. The dose rate to the torso was greatest when the surgeon was positioned ipsiiateral to the beam source (53.3 mrem/min, compared with 2.2 mrem/min on the contralateral side). The average hand dose rate was 58.2 mrem/min. A significant increase in hand dose rate was associated with placement of screws ipsilateral to the beam source (P = 0.0005) and larger specimens (P = 0.0007). Radiation levels significantly decreased as distance from the beam source and dorsal body surface increased. The greatest levels of radiation were noted on the side where the primary radiograph beam entered the cadaver. Conclusion. Fluoroscopically assisted thoracolumbar pedicle screw placement exposes the spine surgeon to significantly greater radiation levels than other, nonspinai musculoskeletal procedures that involve the use of a fluoroscope. In fact, dose rates are up to 10-12 times greater. Spine surgeons performing fluoroscopically assisted thoracolumbar procedures should monitor their annual radiation exposure. Measures to reduce radiation exposure and surgeon awareness of high-exposure body and hand positions are certainly called for.

Matrix metalloproteinases and aggrecanase: Their role in disorders of the human intervertebral disc

Abstract: Study Design. A comprehensive immunohistochemical study of matrix metalloproteinase activity in discs from patients with different disc diseases.— Objectives. To identify individual matrix metalloproteinase enzymes that could contribute to the degeneration of the matrix of the intervertebral disc, to identify the cells that produce matrix metalloproteinases (for example, the endogenous disc cells or invading cells associated with vascularisation), and to determine if “aggrecanase” contributes to degradation of proteoglycans in disc disorders. Summary of Background Data. Matrix disorganization and loss of substance are the most common findings in degenerate discs, and proteinase enzyme activity is one means of causing these changes. Methods. Forty-nine discs from 46 patients with degenerative disc disease, posterior anular tears, spondylolisthesis, or disc herniation were studied immunohistochemically to determine the presence of matrix metalloproteinases 1, 2, 3, 7, 8, 9 and 13, tissue metalloproteinases 1 and 2, and proteoglycan degradation products generated by either matrix metalloproteinases or aggrecanase activity. In addition, in situ zymography was used to confirm matrix metalloproteinase activity. Results. The most extensive staining was seen for matrix metalloproteinases 1, 2, 3, and 9, with 91%, 71%, 65%, and 72% of samples having some immunopositivity for the respective antibodies. In contrast, staining for matrix metalloproteinases 7 and 8 was much less (38% for both). Tissue inhibitor of metalloproteinases 1 and 2 were expressed in 34% and 79% of specimens, respectively. Matrix metalloproteinases were found particularly in cell clusters and blood vessels of degenerate discs, with staining correlating positively with macroscopic degenerative grade. For all of the enzymes, there was most staining in the herniation specimens and least in the autopsy samples. The opposite was true of staining for the matrix metalloproteinases inhibitor, tissue inhibitor of metalloproteinases 2, with most found in the autopsy specimens. Enzyme activity was confirmed by in situ zymography and staining for matrix metalloproteinase degradation products of proteoglycans. In addition, there was staining with antibodies demonstrating aggrecanase degradation products. Conclusions. Matrix metalloproteinase activity is more prevalent in herniated discs than in other disc disorders studied, although matrix metalloproteinases may have been more common earlier in the disease progression. Matrix metalloproteinases can be produced by invading blood vessels and associated cells, as well as by indigenous disc cells. Aggrecanase activity, although present in some samples, was not as obvious as that of matrix metalloproteinases. In addition to altered matrix metalloproteinase production, there appears to be a change in the balance between enzymes and endogenous inhibitors, tissue inhibitors of metalloproteinases. This study highlights specific matrix metalloproteinases that might be most efficient to target in developing therapeutics for minimizing degradation of the extracellular matrix of the disc.

Flexion and Rotation of the Trunk and Lifting at Work Are Risk Factors for Low Back Pain: Results of a Prospective Cohort Study

Abstract: Study Design: A 3-year prospective cohort study among workers of 34 companies in the Netherlands Objectives: To investigate the relation between flexion and rotation of the trunk and lifting at work and the occurrence of low back pain Summary of Background Data: Previous studies on work-related physical risk factors for low back pain either lacked quantification of the physical load or did not take confounding by individual and psychosocial factors into account Methods: The study population consisted of 861 workers with no low back pain at baseline and complete data on the occurrence of low back pain during the 3-year follow-up period Physical load at work was assessed by means of analyses of video-recordings Information on other risk factors and the occurrence of low back pain was obtained by means of self-administered questionnaires Results: An increased risk of low back pain was observed for workers who worked with the trunk in a minimum of 60°of flexion for more than 5% of the working time (RR 15, 95% Cl 10-21), for workers who worked with the trunk in a minimum of 30°of rotation for more than 10% of the working time (RR 13, 95% Cl 09-19), and for workers who lifted a load of at least 25 kg more than 15 times per working day (RR 16, 95% Cl 11-23) Conclusions Flexion and rotation of the trunk and lifting at work are moderate risk factors for low back pain, especially at greater levels of exposure

The role of paraspinal muscle spindles in lumbosacral position sense in individuals with and without low back pain.

Abstract: Study Design.A two-group experimental design with repeated measures on one factor was used.Objectives.To investigate the role of paraspinal muscle spindles in lumbosacral position sense in individuals with and without low back pain.Summary of Background Data.Proprioceptive deficits have been identif

Complications of pedicle screw fixation in reconstructive surgery of the cervical spine.

Abstract: Study Design. Retrospective evaluation of complications in 180 consecutive patients with cervical disorders who had been treated by using pedicle screw fixation systems.Objectives.To determine the risks associated with pedicle screw fixation in the cervical spine and to emphasize the importance of p

Increased fusion rates with cervical plating for three-level anterior cervical discectomy and fusion.

Abstract: Study design A retrospective review of all patients surgically treated with a two-level anterior cervical discectomy and fusion with and without anterior plate fixation by a single surgeon. Objectives To compare the clinical and radiographic success of two-level discectomy and the effect of anterior cervical plate fixation. Summary of background data Prior studies of multisegment fusions have shown decreased fusion rates correlating with the number of increased levels. The use of anterior plates for single-level cervical fusions is controversial. However, their use in multilevel fusions may be warranted because of the increased pseudarthrosis rates. Methods Over a 6-year period, 60 patients were treated surgically with a two-level anterior cervical discectomy and fusion by the senior author. Thirty-two patients had cervical plates, and 28 underwent fusions without plates. These patients were followed for an average of 2.7 years. Clinical and radiographic follow-up evaluations were performed. Results Of the 60 patients, 7 had a pseudarthrosis. The pseudarthrosis rates were 0% for patients with plating and 25% for those with no plating. This difference was statistically significant (P = 0.003). No correlation of pseudarthrosis with gender, age, level of surgery, history of tobacco use, or the presence of prior anterior surgery was found. There was significantly less graft collapse (P = 0.0001) in the patients without plates in whom pseudarthrosis developed (1.4 mm) than in those who had fusions with plates (0.3 mm). The amount of kyphotic deformity of the fused segment was 0.4 degree in patients with plating compared with 4.9 degrees in those without plating who developed a pseudarthrosis (P = 0.0001). Conclusions The addition of plate fixation for two-level anterior cervical discectomy and fusion is a safe procedure with no significant increase in complication rates. The pseudarthrosis rates are significantly higher in patients treated without plate fixation. No nonunions occurred in the patients treated with plate fixation. There was significantly less disc space collapse and kyphotic deformity with the plated fusions than with the nonplated fusions, in which a pseudarthrosis developed. The complication rates for plated fusions are extremely low and do not differ from those for nonplated fusions.

Behavioral Treatment for Chronic Low Back Pain : A Systematic Review Within the Framework of the Cochrane Back Review Group

Abstract: Study Design. A systematic review of randomized controlled trials. Summary of Background Data. The treatment of chronic low back pain is not primarily focused on removing an underlying organic disease but at the reduction of disability through the modification of environmental contingencies and cognitive processes. Behavioral interventions are commonly used in the treatment of chronic (disabling) low back pain. Objectives. To determine whether behavioral therapy is more effective than reference treatments for chronic nonspecific low back pain and which type of behavioral treatment is most effective. Methods. The authors searched the Medline and PsychLit databases and the Cochrane Controlled Trials Register up to April 1999. and Embase up to September 1999. Also screened were references of identified randomized trials and relevant systematic reviews. Methodologic quality assessment and data extraction were performed independently by two reviewers. The magnitude of effect was assessed by computing a pooled effect size for each domain (i.e., behavioral outcomes, overall improvement, back pain-specific and generic functional status, return to work, and pain intensity) using the random effects model. Results. Only six (25%) studies were high quality. There is strong evidence (level 1) that behavioral treatment has a moderate positive effect on pain intensity (pooled effect size 0.62; 95% confidence interval [CI] 0.25, 0.98), and small positive effects on generic functional status (pooled effect size 0.35; 95% CI: 0.04, 0.74) and behavioral outcomes (pooled effect size 0.40; 95% CI: 0.10, 0.70) of patients with chronic low back pain when compared-with waiting-list controls or no treatment. There is moderate evidence (level 2) that a addition of behavioral component to a usual treatment program for chronic low backpain has no positive short-term effect on generic functional status (pooled effect size 0.31; 95% Cl: 0.01, 0.64), pain intensity (pooled effect size 0.03; 95% CI: 0.30, 0.36), and behavioral outcomes (pooled effect size 0.19; 95% CI: 0.08, 0.45). Conclusions. Behavioral treatment seems to be an effective treatment for patients with chronic low back pain,but it is still unknown what type of patients benefitmost from what type of behavioral treatment.

Comparative results between conventional and computer-assisted pedicle screw installation in the thoracic, lumbar, and sacral spine.

Abstract: Study Design. A comparative study on the position of pedicle screws in patients treated surgically with and without computer assistance. Objectives. To evaluate the accuracy of computer-assisted pedicle screw installation, and to evaluate its clinical benefit as compared with conventional pedicle screw installation techniques. Summary of Background Data. In vitro and clinical studies have documented a significant rate of misplaced screws in the thoracolumbar area. Neurologic complications are recognized problems caused by screw misplacement. Methods. Patients treated surgically with computer assistance were compared with a historical control group of patients treated surgically with conventional techniques in the same hospital and by the same surgical team. All screw positions were measured with a postoperative magnetic resonance tomography, and cortical effractions were categorized in 2-mm increments. Patients' charts also were reviewed to assess individual neurologic outcomes. Results. The control cohort was composed of 100 patients, with 544 screws from T5 to S1. The computer-assisted cohort was composed of 50 patients, with 294 screws from T2 to S1. In the control cohort, 461 of 544 screws (85%) were found completely within their pedicles as compared with 278 of 294 screws (95%) correctly placed in the computer-assisted group (P < 0.0001). All 16 screws incorrectly placed with computer assistance were found 0.1 mm to 2 mm from the pedicle cortex. In the control cohort, 68 screws were found 0.1 mm to 2 mm, 10 screws 2.1 mm to 4 mm, and 5 screws more than 4 mm from the pedicle cortex. Seven patients in the control cohort were surgically retreated because of postoperative neurologic deficits, whereas no patients in the computer-assisted group were surgically retreated. Conclusions. Computer assistance can decrease the incidence of incorrectly positioned pedicle screws.

Cobb method or Harrison posterior tangent method: which to choose for lateral cervical radiographic analysis.

Abstract: STUDY DESIGN Thirty lateral cervical radiographs were digitized twice by three examiners to compare reliability of the Cobb and posterior tangent methods. OBJECTIVES To determine the reliability of the Cobb and Harrison posterior tangent methods and to compare and contrast these two methods. SUMMARY OF BACKGROUND DATA Cobb's method is commonly used on both anteroposterior and lateral radiographs, whereas the posterior tangent method is not widely used. METHODS A blind, repeated-measures design was used. Thirty lateral cervical radiographs were digitized twice by each of three examiners. To evaluate reliability of determining global and segmental alignment, vertebral bodies of C1-T1 were digitized. Angles created were two global two-line Cobb angles (C1-C7 and C2-C7), segmental Cobb angles from C2 to C7, and posterior tangents drawn at each posterior vertebral body margin. Cobb's method and the posterior tangent method are compared and contrasted with these data. RESULTS Of 34 intraclass and interclass correlation coefficients, 28 were in the high range (>0.7), and 6 were in the good range (0.6-0.7). The Cobb method at C1-C7 overestimated the cervical curvature (-54 degrees ) and, at C2-C7 it underestimated the cervical curve (-17 degrees ), whereas the posterior tangents were the slopes along the curve (-26 degrees from C2 to C7). The inferior vertebral endplates and posterior body margins did not meet at 90 degrees (C2: 105 degrees +/- 5.2 degrees, C3: 99.7 degrees +/- 5.2 degrees, C4: 99.9 degrees +/- 5.8 degrees, C5: 96.1 degrees +/- 4.5 degrees, C6: 97.0 degrees +/- 3.8 degrees, C7: 95.4 degrees +/- 4.1 degrees ), which caused the segmental Cobb angles to underestimate lordosis at C2-C3, C4-C5, and C6-C7. CONCLUSIONS Although both methods are reliable with the majority of correlation coefficients in the high range (ICC > 0.7), from the literature, the posterior tangent method has a smaller standard error of measurement than four-line Cobb methods. Global Cobb angles compare only the ends of the cervical curve and cannot delineate what happens to the curve internally. Posterior tangents are the slopes along the curve and can provide an analysis of any buckled areas of the cervical curve. The posterior tangent method is part of an engineering analysis (first derivative) and more accurately depicts cervical curvature than the Cobb method.

Surgical and nonsurgical management of lumbar spinal stenosis: Four-year outcomes from the maine lumbar spine study

Abstract: Study Design. A prospective cohort study of patients with lumbar spinal stenosis recruited from the practices of orthopedic surgeons and neurosurgeons throughout Maine. Objective. To assess 4-year outcomes for patients with lumbar spinal stenosis treated surgically or nonsurgically. Summary of Background Data. Surgery for lumbar spinal stenosis has increased dramatically despite the lack of randomized trials comparing surgical with nonsurgical treatments. Long-term evaluation of surgical series has documented deterioration in initial symptomatic improvement, but few studies have compared long-term outcomes of surgical and nonsurgical treatment. Methods. Eligible, consenting patients had baseline interviews with mailed follow-up questionnaires at 3, 6, and 12 months, then annually thereafter. Clinical data were obtained at baseline from a physician questionnaire. Outcomes included patient-reported symptoms of leg and back pain, functional status, and satisfaction. Results. Of 148 patients with lumbar spinal stenosis initially enrolled, 4-year outcomes were available on 119 patients (80.4%): 67 of 81 (83%) treated surgically and 52 of 67 (78%) treated nonsurgically. The surgically treated patients had more severe symptoms and worse functional status at baseline and better outcomes at 4-year evaluation than the nonsurgically treated patients. After 4 years, 70% of the surgically treated and 52% of the non-surgically treated patients reported that their predominant symptom, either leg or back pain, was better (P = 0.05). Satisfaction of patients with their current state at 4 years was reported by 63% of the surgically treated and 42% of the nonsurgically treated patients (P = 0.04). Surgical treatment remained a significant determinant of 4-year satisfaction, even after adjustment for other independent predictors (P = 0.001). For the nonsurgically treated patients, there was no significant change in outcomes over 4 years, whereas the initial improvement seen in the surgically treated patients modestly decreased over the subsequent 4 years. Conclusions. For the patients with severe lumbar spinal stenosis, surgical treatment was associated with greater improvement in patient-reported outcomes than nonsurgical treatment at 4-year evaluation, even after adjustment for differences in baseline characteristics among treatment groups. The relative benefit of surgery declined over time but remained superior to nonsurgical treatment. Outcomes for the nonsurgically treated patients improved modestly and remained stable over 4 years. Determining whether outcomes continue to converge will require longer-term evaluation.