Emerging technology in spine: should we rethink the past or move forward in spite of the past?
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Humans↗
Biomedical subjects
James N Weinstein
Publications and source records attributed to James N Weinstein.
Rates of advanced spinal imaging and spine surgery.
STUDY DESIGN: Small area analysis. OBJECTIVES: To determine the association between the rates of advanced spinal imaging and spine surgery across geographic areas. SUMMARY OF BACKGROUND DATA: The rates of spine surgery in the United States have increased along with a concurrent rise in the use of advanced spinal imaging: CT and MRI. Spine surgery rates vary six-fold across geographic areas of the United States. Differences in patient populations and health care supply have explained only about 10% of this variation. METHODS: We used a random 5% sample of Medicare's National Claims History Part B files for 1996 and 1997 to determine procedure rates across 306 Hospital Referral Regions. We analyzed the association between spinal imaging and spine surgery using linear regression. Main outcome measures were rates of procedures and coefficients of determination (R2). RESULTS: The rates of advanced spinal imaging (CT and MRI combined) varied 5.5-fold across geographic areas. Areas with higher rates of MRI had higher rates of spine surgery overall (r = 0.46) and spinal stenosis surgery specifically (r = 0.37). The rates of advanced spinal imaging accounted for 22% of the variability in overall spine surgery rates (R2 = 0.22, P < 0.001) and 14% of the variability in lumbar stenosis surgery rates (R2 = 0.14, P < 0.001). A simulation model showed that MRIs obtained in the patients undergoing surgery accounted for only a small part of the correlation between MRI and total spine surgery rates. CONCLUSIONS: A significant proportion of the variation in rates of spine surgery can be explained by differences in the rates of advanced spinal imaging. The indications for advanced spinal imaging are not firmly agreed on, and the appropriateness of many of these imaging studies has been questioned. Improved consensus on the use and interpretation of advanced spinal imaging studies could have an important effect on variation in spine surgery rates.
Aged↗
Is a condition-specific instrument for patients with low back pain/leg symptoms really necessary? The responsiveness of the Oswestry Disability Index, MODEMS, and the SF-36.
STUDY DESIGN: Analysis of longitudinal data collected prospectively from patients seen in 27 National Spine Network member centers across the United States. OBJECTIVE: To evaluate the responsiveness of the Oswestry Disability Index, MODEMS scales, and all scales and summary scales of the MOS Short-Form 36 (SF-36) for patients with low back pain/leg symptoms. SUMMARY OF BACKGROUND DATA: The responsiveness of general and condition-specific health status instruments is a key concept for clinicians and scientists. Various authors have explored responsiveness in common surveys used to assess spine patients. Although it is generally believed that condition-specific measures are more responsive to change in the condition under study, in the case of low back pain, most authors agree that further exploration is necessary. METHODS: Patients with diagnoses of herniated disc, spinal stenosis, and spondylosis from the National Spine Network database who completed baseline and 3-month follow-up surveys were analyzed. Patient-provider consensus regarding improvement, worsening, or no change in the condition was selected as the external criterion. Responsiveness was evaluated using ROC curve analysis and effect size calculations. RESULTS: Nine hundred and seventy patients had complete data at baseline and 3 months. At follow-up, 68% of the patients had consensus improvement. Based on ROC analysis, scales assessing pain were significantly more responsive than scales assessing function. There were no significant differences between the condition-specific scales and their equivalent general-health counterpart. The scales with the highest probabilities of correctly identifying patient's improvement were: the condition-specific pain scale from MODEMS (PAIN, ROC = 0.758); the combined pain and function scale from MODEMS (MPDL, ROC = 0.755); the general pain scale from the SF-36 (BP, ROC = 0.753); the combined pain and function scale from the SF-36 (PCS, ROC = 0.745); the condition-specific function measure from the Oswestry (ODI, ROC = 0.723); and the physical function measure from the SF-36 (PF, ROC = 0.721). A similar rank order was typically maintained with effect size calculations. Results were nearly identical in patients with multiple non-spine-related comorbidities and in patients with high degrees of perceived disability. The BP scale was most responsive to worsening of symptoms. CONCLUSION: For studies of patients with low back problems, the general SF-36 may be a sufficient measure of health status and patient function, without the need for additional condition-specific instruments. Pain scales appear to be the most responsive measures in patients with low back pain.
Cohort Studies↗
Health professional's guide to rehabilitation of the patient with osteoporosis.
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Aged↗
Computerized questionnaires and the quality of survey data.
STUDY DESIGN: A retrospective data quality analysis was conducted. OBJECTIVE: To compare missing response rates and internal consistency between computerized and paper surveys administered to spine patients. SUMMARY OF BACKGROUND DATA: Computerized patient surveys have been shown to offer numerous advantages over traditional paper surveys. It has been assumed that computerized surveys also improve data quality, but quantitative comparisons have not been made. METHODS: Between January 1998 and December 2000, approximately 3500 computerized questionnaires and 15,000 paper questionnaires containing the MOS 36-Item Short-Form Health Survey (SF-36) and the Oswestry Low Back Pain Disability Questionnaire were administered in the National Spine Network. Missing response rates and the Response Consistency Index (RCI) were compared between computerized and paper questionnaire data. RESULTS: Computer surveys had approximately half the missing response rate of paper surveys. For the SF-36, the computer survey had 1.7% missing, as compared with 3.3% missing on paper (P < 0.001). For the Oswestry, the computer survey had 2.9% missing, as compared with 6% missing on paper (P < 0.001). Whereas 84% of the SF-36 surveys and 85% of the Oswestry surveys collected by computer were completely filled out (no missing responses), only 68% of the SF-36 surveys (P < 0.001) and 77% of the Oswestry surveys (P < 0.001) collected on paper were completely filled out. The SF-36 data collected by computer had better internal consistency than the paper-form data, with average Response Consistency Index scores of 0.12 and 0.16, respectively (P = 0.001). CONCLUSIONS: Superior response rates and higher internal consistency suggest that computerized survey systems improve data quality, and may enhance instrument validity for commonly used measures of spine patient health.
Cohort Studies↗
Design of the Spine Patient outcomes Research Trial (SPORT).
SUMMARY OF BACKGROUND DATA: The Spine Patient Outcomes Research Trial (SPORT) was designed to assess the relative efficacy and cost-effectiveness of surgical and nonsurgical approaches to the treatment of common conditions associated with low back and leg pain. OBJECTIVES: To describe the rationale and design of the SPORT project and to discuss its strengths and limitations. STUDY DESIGN: Descriptive. METHODS: First, the authors explain the rationale for embarking on SPORT, i.e., deficiencies in the existing scientific knowledge base for treatment of these conditions. Second, the authors describe the design of SPORT, including topics such as specific aims, participating sites, study population, recruitment and enrollment, study interventions, follow-up, outcomes, statistical analysis, and study governance and organization. Finally, issues that complicate the performance of randomized trials in surgery as they relate to the design and conduct of SPORT are discussed. RESULTS: The SPORT project is being conducted at 11 clinical centers around the United States. It involves the simultaneous conduct of three multicenter, randomized, controlled clinical trials. The study includes patients with the three most common diagnoses for which spine surgery is performed: intervertebral disc herniation, spinal stenosis, and degenerative spondylolisthesis, and it compares the most commonly used standard surgical and nonsurgical treatments for patients with these diagnoses. By the end of enrollment the authors anticipate a total of 500 patients with intervertebral disc herniation, 370 patients with spinal stenosis, and 300 patients with degenerative spondylolisthesis in the randomized trials. Patients who meet the eligibility criteria but decline to be randomized are invited to participate in an observational cohort study. Patients are being followed for a minimum of 24 months with visits scheduled at 6 weeks and at 3, 6, 12, and 24 months. CONCLUSIONS: The results of this study will provide high-quality scientific evidence to aid clinical decision-making and improve treatment outcomes for these common, costly, and, in some instances, debilitating conditions.
Cost-Benefit Analysis↗
Dorsal root sensitivity to interleukin-1 beta, interleukin-6 and tumor necrosis factor in rats.
The release of inflammatory cytokines caused by a disrupted disc may play a critical role in pain production at nerve endings, axons, and nerve cell bodies. Herniated disc tissue has been shown to release inflammatory cytokines such as interleukin-1 beta (IL-1beta), interleukin-6 (IL-6), tumor necrosis factor (TNF), and other algesic chemicals. This study was designed to characterize the effects of these proinflammatory cytokines on the somatosensory neural response at the dorsal root level in rats. It is hypothesized that their effects on nerve endings in disc and adjacent tissue contribute to low-back pain, and the effects on dorsal root axons and ganglia contribute to radiculopathy and sciatica. Surgically isolated sacral dorsal roots were investigated by electrophysiologic techniques. IL-1beta, IL-6, or TNF (100 ng, each) were applied onto the dorsal roots. Neural responses and mechanosensitivity of the receptive fields were evaluated over time. The results showed that 3 h after each cytokine application, the neural activity was statistically decreased. The mechanical sensitivity of the receptive fields increased at 90 min following IL-1beta or TNF application, and returned to normal more than 3 h after IL-1beta application. IL-1beta, IL-6, and TNF may be neurotoxic to dorsal root axons. Furthermore IL-1beta and TNF may sensitize the peripheral receptive fields. This study suggests that dorsal roots may be impaired by these proinflammatory cytokines.
Action Potentials↗
Association between obesity and functional status in patients with spine disease.
STUDY DESIGN: A cross-sectional study of 15,974 patients with spine disease from 26 members of the National Spine Network. OBJECTIVES: To use functional status measures and clinical parameters to evaluate the association between obesity and health status among patients with spine conditions. SUMMARY OF BACKGROUND DATA: With 22.5% of Americans overweight, obesity is a significant health concern. However, the functional impact caused by obesity in spine patients remains unknown. METHODS: Functional status was measured on 15,974 patients on an initial visit using a general physical health measure (SF-36 Physical Component Summary score) and a disease-specific measure (Oswestry Disability Index). Obesity was measured using body mass index (kg/m2). Patients were categorized into four groups according to body mass index: normal range (<25.0 kg/m2, n = 5732), Grade 1 obesity (25.0-29.9 kg/m2, n = 5845), Grade 2 obesity (30.0-39.9 kg/m2, n = 3836), and Grade 3 obesity (>/=40.0 kg/m2, n = 561). The associations between SF-36 Physical Component Summary and Oswestry Disability Index scores and body mass index were evaluated in a multivariate linear regression model. Clinical presentation data were derived from patient and clinician reports and were compared across body mass index categories. RESULTS: In the four obesity categories, the PCS scores were 32.6 (normal range body mass index), 30.8 (Grade 1), 28.2 (Grade 2), and 25.9 (Grade 3) (P < 0.001). The SF-36 Physical Component Summary score of the general U.S. population is 50.0. The Oswestry Disability Index scores across the four body mass index groups were 39.0, 41.6, 46.6, and 52.2, respectively (P < 0.001). Compared with nonobese patients, obese patients were more likely to have radicular pain and neurologic signs (P < 0.01). Furthermore, obese patients had more comorbidities and were more likely to be receiving worker's compensation. After adjusting for clinical and demographic factors, each increased level of obesity was associated with a 1-1.5-point worsening in both the SF-36 Physical Component Summary and Oswestry Disability Index scales (P < 0.05). CONCLUSIONS: General and disease-specific functional health status was significantly worse for patients with a higher body mass index. Obese patients also displayed more severe pain symptoms than nonobese spine patients.
Body Mass Index↗
An observational study on the prevalence and pattern of opioid use in 25,479 patients with spine and radicular pain.
STUDY DESIGN: A cross-sectional analysis of data obtained from patients with spinal and radicular pain and their spine center treating physicians was performed. OBJECTIVES: To identify characteristics of patients treated with opioids that distinguish them from similar patients not treated with opioids in a large population of patients with spine and radicular pain, and to determine the prevalence of opioid use. SUMMARY OF BACKGROUND DATA: The use of opioids with patients who have chronic pain remains controversial. The long-term risks and benefits are poorly described. The efficacy of this treatment has not been proved, yet the large majority of pain specialist physicians manage chronic pain with opioids. METHODS: Descriptive data from the initial visits of 25,479 patients with spinal pain were reviewed. Patients were grouped according to whether or not opioids were recommended, prescribed, or continued. The prevalence of opioid use and patient characteristics were compared using standard statistical tests. RESULTS: Overall, 3.4% of the patients had opioids included in their plan of care. There was no difference in age, gender, education, or compensation status between the two groups. Patients were more likely to be treated if the duration of their symptoms had been less than 3 months. However, 75% of the patients with opioids in their plan had experienced symptoms longer than 3 months. A greater incidence of objective findings was identified in the opioid group. CONCLUSIONS: The authors cannot comment on the prevalence of opioid use because, to the best of their knowledge, no other similar studies are available for comparison.
Cross-Sectional Studies↗
Editorial: Happy holidays. Where do we go from here? Turn right !!
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Empathy↗
Editorial conflict of interest: art or science? The hippocratic solution.
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Conflict of Interest↗
The role of mechanical deformation in lumbar radiculopathy: an in vivo model.
STUDY DESIGN: In vivo strain techniques were used in an animal radiculopathy model. OBJECTIVE: To quantify the severity of compressive nerve root injury and characterize its effect on resultant mechanical allodynia in a lumbar radiculopathy model. SUMMARY OF BACKGROUND DATA: Clinical and experimental work indicate many factors contributing to radicular pain mechanisms, including mechanical injury. Although it has been suggested that the degree of mechanical injury to the nerve root affects the nature of the pain response, no study has quantified local in vivo injury biomechanics, nor have such measures been linked with the resulting magnitude of mechanical allodynia or other clinical symptoms. METHODS: Male Holtzman rats were divided into a sham group with only nerve root exposure or a ligation group in which the nerve root was tightly ligated with a single silk suture. Using image analysis, nerve root radial strains were calculated at the time of injury and after surgery. The animals were grouped according to ligation strain for analysis. Mechanical allodynia was continuously assessed throughout the study. RESULTS: Compressive strains in the nerve root ranged from 7.8% to 61% (mean, 30.8% +/- 14.5%). Animals undergoing larger ligation strains exhibited heightened mechanical allodynia after injury. This was significant using a 12-g von Frey filament (P = 0.05). After surgery, the nerve roots displayed tissue swelling, which was relatively uniform in the low-strain group and less so in the high-strain group. CONCLUSIONS: For the first time, in vivo biomechanical analysis of tissue deformations was used to investigate the role of mechanics in radicular pain. Overall mechanical allodynia was greater for more severe nerve root injuries (greater strains) in an animal model, suggesting that mechanical deformation plays an important role in the pain mechanism. Continued work is underway to understand the complex interplay between mechanics and the physiology of radicular pain.
Animals↗
Prophylactic pinning of the contralateral hip in slipped capital femoral epiphysis : evaluation of long-term outcome for the contralateral hip with use of decision analysis.
BACKGROUND: The risk of a contralateral slip in patients who are first seen with a unilateral slipped capital femoral epiphysis has been reported to be 2335 times higher than the risk of an initial slip. The overall prevalence of bilaterality varies widely throughout the literature, with some reports indicating rates as high as 80%. This finding has led many authors to recommend prophylactic pinning of the contralateral asymptomatic hip in patients presenting with a unilateral slipped capital femoral epiphysis. METHODS: A decision analysis model with probabilities for the occurrence of contralateral slip and for the severity of slip at different intervals of follow-up was used in the present study. These probabilities were compared with those for various outcomes when the contralateral hip is prophylactically pinned. Scores representing long-term outcome, according to the Iowa hip-rating system, were used in the model as a measure of utility. The probabilities of contralateral slip and the rates of slip severity were taken from large retrospective series. All meaningful clinical scenarios with regard to long-term outcome for the hip were considered in the model. Variables of uncertainty were subjected to sensitivity analyses in order to explore the effect on outcome over the range of plausible values for variables of interest. RESULTS: The results showed a benefit in the long-term outcome for patients who had prophylactic pinning of the contralateral hip. The threshold level at which a benefit is obtained with prophylactic pinning is expressed according to the rates of sequential slip, rates of slips overlooked at follow-up, and complications associated with prophylactic pinning of the contralateral hip. CONCLUSIONS: The decision model shows that, when pooled data are used to predict probabilities of sequential slip, treatment of the contralateral hip with prophylactic pinning is beneficial to the long-term outcome for that hip. When considering prophylactic pinning of the contralateral hip, the clinician should use sound clinical judgment with respect to the age, sex, and endocrine status of the patient. Long-term follow-up studies are needed to establish the efficacy of prophylactic pinning, but the predictions in the present study, which are based on findings in the literature, support the safety of this procedure.
Bone Nails↗
Central administration of methotrexate reduces mechanical allodynia in an animal model of radiculopathy/sciatica.
We have recently reported that injury to a lumbar root in a rat model of radiculopathy produces spinal glial activation associated with elevated proinflammatory cytokines. Based on our hypothesis that central neuroinflammatory processes may manifest clinically as radicular pain, we undertook pharmacological intervention using the immunosuppressive agent methotrexate (MTX). The L5 lumbar spinal root (central to the dorsal root ganglia) was exposed unilaterally and loosely constricted with chromic gut. In the prevention (phase I) study, MTX was administered intrathecally (1 mg/kg) and around the spinal root (1 mg/kg) at surgery and at days 2 and 4 postsurgery (group A). Saline injection was employed for the control group (group B). Sham operated animals were administered MTX to determine the potential for behavioral/neural side effects (group C). In the existing pain paradigm (phase II) study, the experiment was extended to day 14 with three additional groups. The same dose and method of delivery of MTX or saline was administered as in phase I in the first week on days 0, 2, and 4 and in the second week on days 7, 9, and 11 postsurgery. To measure the effects of MTX on existing behaviors saline was administered in the first week and MTX during the second (group D; Saline:MTX). The control group received saline during both weeks (group E; Saline:Saline). To examine the possible recurrence of radicular pain after MTX termination, MTX was given in the first week and saline in the second (group F; MTX:Saline). Gait disturbance and mechanical allodynia (using von Frey filaments) were assessed up to day 7 in the prevention study (Phase I) and day 14 in the existing pain paradigm (Phase II). The L5 spinal cord segments were harvested for assessment of immunohistochemical glial activation using the antibodies OX-42 (microglial marker) and glial fibrillary acidic protein (GFAP: astrocytic marker) and for the presence of Major Histocompatibility Complex (MHC) Class II expression. Group C (Sham+MTX) did not demonstrate any evidence of gait disturbance or mechanical allodynia after MTX administration. The rats in group B (Surgery+Saline) demonstrated mechanical allodynia from one day postsurgery to the time of euthanization. When allodynia was assessed using the 12 g von Frey filament, the MTX treated rats in group A showed significantly decreased mechanical allodynia as compared to the saline treated rats (group B) (repeated measured ANOVA, P<0.0001). In the phase II study, the rats in group D (Saline:MTX) and E (Saline:Saline) showed robust allodynia in the first week after the surgery. In the second week, mechanical allodynia significantly decreased in group D, while mechanical allodynia continued in the saline treated group (repeated measured ANOVA, P=0.0121). Allodynia was significantly attenuated in group F (MTX: Saline) as compared to the response in groups D and E at day 7 (one-way ANOVA, P<0.0001) and remained significantly lower as compared to group E up to day 11 postsurgery (one-way ANOVA, P9=0. 0013: P11=0.0048). OX-42 and GFAP expression were elevated in the gray matter of the L5 spinal section in all groups that underwent the root ligature with chromic gut (Groups A, B, D-F). There were no significant differences in glial activation between the groups. However, spinal expression of MHC II was markedly reduced in the MTX treated group as compared with the saline treated group. The exact mechanism of action of MTX in attenuating mechanical allodynia has not yet been elucidated. The present results indicate that MTX administration may offer a new treatment modality for radicular pain with or without disc herniation as well as directing new research into the development of novel immunomodulators for the treatment of chronic neuropathic and radicular pain.
Animals↗
The effectiveness of psychological interventions for the rehabilitation of low back pain: a randomized controlled trial evaluation.
Forty-five low back pain patients were randomly assigned to either a standard inpatient rehabilitation program or the standard program with additional psychological components. The standard program emphasized education, support, and physical reconditioning through exercise. Patients receiving the psychological program were given additional training in relaxation and other coping skills and received contingent reinforcement for exercise. Both programs included reduction of medication intake and an emphasis on family involvement after discharge. Measures of functional status were taken prior to the program, at discharge from the 3-week inpatient program, and at a 6-month follow-up appointment. These data revealed that patients improved their overall functioning at discharge and maintained these gains at the follow-up assessment. A similar pattern of findings was obtained for self-reported pain and interference. Furthermore, 81% of the patients had returned to work or were engaged in active job retraining by the follow-up. Using a conservative measure of full-time return to the same or an equivalent job, 57% were employed by the follow-up. Patient improvement, however, was not differentially affected by treatment group assignment, suggesting that the psychological treatment failed to add to the effectiveness obtained by the standard rehabilitation program. Results are discussed in the context of improving patient outcomes from rehabilitation for low back pain.
Adaptation, Psychological↗