Degenerative lumbar disc and facet disease in older adults: prevalence and clinical correlates

E-learning module on chronic low back pain in older adults: evidence of effect on medical student objective structured clinical examination performance

The Institute of Medicine has highlighted the urgent need to close undergraduate and graduate educational gaps in treating pain. Chronic low back pain (CLBP) is one of the most common pain conditions, and older adults are particularly vulnerable to potential morbidities associated with misinformed treatment. An e-learning case-based interactive module was developed at the University of Pittsburgh Center of Excellence in Pain Education, one of 12 National Institutes of Health-designated centers, to teach students important principles for evaluating and managing CLBP in older adults. A team of six experts in education, information technology, pain management, and geriatrics developed the module. Teaching focused on common errors, interactivity, and expert modeling and feedback. The module mimicked a patient encounter using a standardized patient (the older adult with CLBP) and a pain expert (the patient provider). Twenty-eight medical students were not exposed to the module (Group 1) and 27 were exposed (Group 2). Their clinical skills in evaluating CLBP were assessed using an objective structured clinical examination (OSCE). Mean scores were 62.0 ± 8.6 for Group 1 and 79.5 ± 10.4 for Group 2 (P < .001). Using an OSCE pass-fail cutoff score of 60%, 17 of 28 Group 1 students (60.7%) and 26 of 27 Group 2 students (96.3%) passed. The CLBP OSCE was one of 10 OSCE stations in which students were tested at the end of a Combined Ambulatory Medicine and Pediatrics Clerkship. There were no between-group differences in performance on eight of the other nine OSCE stations. This module significantly improved medical student clinical skills in evaluating CLBP. Additional research is needed to ascertain the effect of e-learning modules on more-advanced learners and on improving the care of older adults with CLBP.

Establishing the diagnosis of low back pain: patient selection for interventional pain medicine

SUMMARY Low back pain is one of the most prominent healthcare problems but there is no gold standard for its diagnosis. Aspecific low back pain can be subdivided into radicular and mechanical pain. The diagnosis mainly relies on a combination of elements, such as medical history, physical examination, medical imaging and other possible additional tests. Once a working diagnosis has been established, confirmation of the causative structure and level is sought by means of diagnostic blocks. The use of the different diagnostic tests and blocks should be guided by the balance between the potential benefit (mainly in terms of improved treatment outcome, the possible burden for the patient and the chances of withholding potential effective treatment to patients) with false-negative test results.

Correlation of pain with objective quantification of magnetic resonance images in older adults with chronic low back pain

STUDY DESIGN

Cross sectional study.

OBJECTIVE

The goal of this study is to identify relationships between objectively measured and subjectively scored parameters and reported pain.

SUMMARY OF BACKGROUND DATA

Studies have demonstrated the unreliability of magnetic resonance imaging (MRI)-based parameters to identify pathological pain generators of chronic low back pain, but they were based on visual inspection and subjective assessment of lumbar disc features. Advancements in computer image analysis provide objective measurements of lumbar disc features.

METHODS

Two radiologists evaluated 39 axial and sagittal T1- and T2-weighted MR images of patients with chronic axial low back pain (age, >65 yr) and graded 4 subjective lumbar disc parameters (T2 signal intensity, nucleus shape, Modic changes, and osteophyte formation) whose sum is the cumulative MRI score. Objective parameter, MRI index, was calculated as the product of the measured lumbar disc area and total disc MRI signal intensity. Discs were sorted from least to the most degenerated relative to each parameter. Pearson correlation coefficient and multiple linear regression analysis were performed between the reported pain score and each parameter.

RESULTS

The most and least degenerated discs in each patient, as assessed by MRI index, had the highest negative and positive correlation coefficient and regression weight contribution, respectively. All subjective parameters had low correlation coefficients and regression goodness of fit.

CONCLUSION

Although limited by small sample size, the objective parameter, MRI index, can be a potential imaging biomarker used to identify possible pain generators. This study presents a potential new application of MR imaging in identifying pain generators of patients with chronic low back pain.

Coexisting lumbar spondylosis in patients undergoing TKA: how common and how serious?

BACKGROUND

Information on the coexistence of lumbar spondylosis and its influence on overall levels of pain and function in patients with advanced knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA) would be valuable for patient consultation and management.

QUESTIONS/PURPOSES

The purposes of this study were to document the prevalence and severity of coexisting lumbar spondylosis in patients with advanced knee OA undergoing TKA and to determine whether the coexisting lumbar spondylosis at the time of TKA adversely affects clinical scores in affected patients before and 2 years after TKA.

METHODS

Radiographic lumbar spine degeneration and lumbar spine symptoms including lower back pain, radiating pain at rest, and radiating pain with activity were assessed in 225 patients undergoing TKA. In addition, the WOMAC score and the SF-36 scores were evaluated before and 2 years after TKA. Potential associations of radiographic lumbar spine degeneration and lumbar spine symptom severities with pre- and postoperative WOMAC subscales and SF-36 scores were examined.

RESULTS

All 225 patients had radiographic degeneration of the lumbar spine, and the large majority (89% [200 of 225]) had either moderate or severe spondylosis (72% and 17%, respectively). A total of 114 patients (51%) had at least one moderate or severe lumbar spine symptom. No association was found between radiographic severity of lumbar spine degeneration and pre- and postoperative clinical scores. In terms of lumbar spine symptoms, more severe symptoms were likely to adversely affect the preoperative WOMAC and SF-36 physical component summary (PCS) scores, but most of these adverse effects improved by 2 years after TKA with the exception of the association between severe radiating pain during activity and a poorer postoperative SF-36 PCS score (regression coefficient = -5.41, p = 0.015).

CONCLUSIONS

Radiographic lumbar spine degeneration and lumbar spine symptoms are common among patients with advanced knee OA undergoing TKA. Severe lumbar spine symptoms (visual analog scale score of ≥ 7) were likely to adversely affect the preoperative clinical scores of patients undergoing TKA; however, most of the adverse effects were not found 2 years after TKA. Nevertheless, because preexisting severe radiating pain during activity may be a source of a poorer outcome after TKA, careful patient consultation regarding this potential poorer prognosis after TKA needs to be provided to the patient with this symptom.

Occult neural foraminal stenosis caused by association between disc degeneration and facet joint osteoarthritis: demonstration with dedicated upright MRI system

PURPOSE

The aim of our study was to evaluate the presence of dynamic foraminal stenosis using a new low-field dedicated magnetic resonance (MR) unit with a balancing system that allows images to be acquired both in the recumbent and upright position. Imaging of lumbar spine with the patient in a supine, nonweight-bearing position is likely to misrepresent the degree and potential risk of spinal stenosis.

MATERIALS AND METHODS

In the period between September 2008 and May 2011, we selected 630 symptomatic patients aged 40-65 years (mean age 56) who underwent conventional MR in clinostatic position. The study only included selected patients (total 160) who underwent clinostatic and orthostatic evaluation using a dedicated MR system (G-scan). The biomechanical parameters were also considered. Changes in the dimension of the neural foramina were compared using the presence of disc and facet degeneration by statistical analysis.

RESULTS

Stenosis of the intervertebral foramen was never found in the presence of normal intervertebral discs either in the presence or in the absence of facet disease, in either clinostatic or orthostatic position. Sixty-one stenotic levels were detected which were visualised exclusively in scans obtained under weight-bearing conditions. We named this dynamic condition "occult stenosis". In all of these cases, disc disease was associated with facet pathology.

CONCLUSION

Our data show that the association between disc pathology and facet osteoarthrosis can cause occult foraminal stenosis. Strategies to image the spine under physiological load conditions may improve the clinical diagnosis of radicular pain.

Lumbar disc degenerative disease: disc degeneration symptoms and magnetic resonance image findings

Study Design

Cross sectional and observational.

Purpose

To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms.

Overview of Literature

Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration are lower back pain and sciatica which may be aggravated by standing, walking, bending, straining and coughing.

Methods

This study was conducted from January 2012 to June 2012. Study was conducted on the diagnosed patients of lumbar disc degeneration. Diagnostic criteria were based upon abnormal findings in MRI. Patients with prior back surgery, spine fractures, sacroiliac arthritis, metabolic bone disease, spinal infection, rheumatoid arthritis, active malignancy, and pregnancy were excluded.

Results

During the targeted months, 163 patients of lumbar disc degeneration with mean age of 43.92±11.76 years, came into Neurosurgery department. Disc degeneration was most commonly present at the level of L4/L5 105 (64.4%).Commonest types of disc degeneration were disc herniation 109 (66.9%) and lumbar spinal stenosis 37 (22.7%). Spondylolisthesis was commonly present at L5/S1 10 (6.1%) and associated mostly with lumbar spinal stenosis 7 (18.9%).

Conclusions

Results reported the frequent occurrence of lumbar disc degenerative disease in advance age. Research efforts should endeavor to reduce risk factors and improve the quality of life.

Twenty-year perspective of randomized controlled trials for surgery of chronic nonspecific low back pain: citation bias and tangential knowledge

BACKGROUND CONTEXT

After decades of clinical research, the role of surgery for chronic nonspecific low back pain (CNLBP) remains equivocal. Despite significant intellectual, human, and economic investments into randomized controlled trials (RCTs) in the past two decades, the role of surgery in the treatment for CNLBP has not been clarified.

PURPOSE

To delineate the historical research agenda of surgical RCTs for CNLBP performed between 1993 and 2012 investigating whether conclusions from earlier published trials influenced the choice of research questions of subsequent RCTs on elucidating the role of surgery in the management of CNLBP.

STUDY DESIGN

Literature review.

METHODS

We searched the literature for all RCTs involving surgery for CNLBP. We reviewed relevant studies to identify the study question, comparator arms, and sample size. Randomized controlled trials were classified as "indication" trials if they evaluated the effectiveness of surgical therapy versus nonoperative care or as "technical" if they compared different surgical techniques, adjuncts, or procedures. We used citation analysis to determine the impact of trials on subsequent research in the field.

RESULTS

Altogether 33 technical RCTs (3,790 patients) and 6 indication RCTs (981 patients) have been performed. Since 2007, despite the unclear benefits of surgery reported by the first four indication trials published in 2001 to 2006, technical trials have continued to predominate (16 vs. 2). Of the technical trials, types of instrumentation (13 trials, 1,332 patients), bone graft materials and substitutes (11 trials, 833 patients), and disc arthroplasty versus fusion (5 trials, 1,337 patients) were the most common comparisons made. Surgeon authors have predominantly cited one of the indication trials that reported more favorable results for surgery, despite a lack of superior methodology or sample size. Trials evaluating bone morphogenic protein, instrumentation, and disc arthroplasty were all cited more frequently than the largest trial of surgical versus nonsurgical therapy.

CONCLUSIONS

The research agenda of RCTs for surgery of CNLBP has not changed substantially in the last 20 years. Technical trials evaluating nuances of surgical techniques significantly predominate. Despite the publication of four RCTs reporting equivocal benefits of surgery for CNLBP between 2001 and 2006, there was no change in the research agenda of subsequent RCTs, and technical trials continued to outnumber indication trials. Rather than clarifying what, if any, indications for surgery exist, investigators in the field continue to analyze variations in surgical technique, which will probably have relatively little impact on patient outcomes. As a result, clinicians unfortunately have little evidence to advise patients regarding surgical intervention for CNLBP.

Temporal patterns of the trunk muscles remain altered in a low back-injured population despite subjective reports of recovery

OBJECTIVE

To compare temporal activation patterns from 24 abdominal and lumbar muscles between healthy subjects and those who reported recovery from recent low back injury (LBI).

DESIGN

Cross-sectional comparative study.

SETTING

University neuromuscular function laboratory.

PARTICIPANTS

Healthy adult volunteers (N=81; 30 LBI, 51 asymptomatic subjects).

INTERVENTIONS

Trunk muscle electromyographic activity was collected during 2 difficulty levels of a supine trunk stability test aimed at challenging lumbopelvic control.

MAIN OUTCOME MEASURES

Principal component (PC) analysis was applied to determine differences in temporal and/or amplitude electromyographic patterns between groups. Mixed-model analyses of variance were performed on PC scores that explained more than 89% of the variance (α=.05).

RESULTS

Four PCs explained 89% and 96% of the variance for the abdominal and back muscles, respectively, with both muscle groups having similar shapes in the first 3 PCs. Significant interactions or group main effects were found for all PC scores except PC4 for the back extensors. Overall activation amplitudes for both the abdominal and back muscles (PC1 scores) were significantly (P<.05) higher for the LBI group, with both abdominal and back muscles of the LBI group demonstrating an increased response to the leg-loading phase (PC2 scores) compared with the asymptomatic group. Differences were also found between groups in their preparatory activity (PC3 scores), with the LBI group having a higher early relative amplitude of abdominal and back extensor activity.

CONCLUSIONS

Despite perceived readiness to return to work and low pain scores, muscle activation patterns remained altered in this LBI group, including reduced synergistic coactivation and increased overall amplitudes as well as greater relative amplitude differences during specific phases of the movement. Electromyographic measures provide objective information to help guide therapy and may assist with determining the level of healing and return-to-work readiness after an LBI.

Axial lumbar interbody fusion: a 6-year single-center experience

Introduction

Methods

Results

Conclusion

Controlled release of simvastatin from in situ forming hydrogel triggers bone formation in MC3T3-E1 cells

Simvastatin (SIM), a drug commonly administered for the treatment of hypercholesterolemia, has been recently reported to induce bone regeneration/formation. In this study, we investigated the properties of hydrogel composed of gelatin-poly(ethylene glycol)-tyramine (GPT) as an efficient SIM delivery vehicle that can trigger osteogenic differentiation. Sustained delivery of SIM was achieved through its encapsulation in an injectable, biodegradable GPT-hydrogel. Cross-linking of the gelatin-based GPT-hydrogel was induced by the reaction of horse radish peroxidase and H(2)O(2). GPT-hydrogels of three different matrix stiffness, 1,800 (GPT-hydrogel1), 5,800 (GPT-hydrogel2), and 8,400 Pa (GPT-hydrogel3) were used. The gelation/degradation time and SIM release profiles of hydrogels loaded with two different concentrations of SIM, 1 and 3 mg/ml, were also evaluated. Maximum swelling times of GPT-hydrogel1, GPT-hydrogel2, and GPT-hydrogel3 were observed to be 6, 12, and 20 days, respectively. All GPT-hydrogels showed complete degradation within 55 days. The in vitro SIM release profiles, investigated in PBS buffer (pH 7.4) at 37°C, exhibited typical biphasic release patterns with the initial burst being more rapid with GPT-hydrogel1 compared with GPT-hydrogel3. Substantial increase in matrix metalloproteinase-13, osteocalcin expression levels, and mineralization were seen in osteogenic differentiation system using MC3T3-E1 cells cultured with GPT-hydrogels loaded with SIM in a dose-dependent manner. This study demonstrated that controlled release of SIM from a biodegradable, injectable GPT-hydrogel had a promising role for long-term treatment of chronic degenerative diseases such as disc degenerative disease.

Degenerative changes at the lumbar spine--implications for bone mineral density measurement in elderly women

Degenerative changes of the lumbar spine may lead to misinterpretation of bone mineral density (BMD) measurements and cause underdiagnosis of osteoporosis. This longitudinal study of 1,044 women, 75 years at inclusion and followed for 10 years, shows that identification of apparent degenerative changes on the dual energy X-ray absorptiometry (DXA) scan can increase the proportion diagnosed.

INTRODUCTION

In the elderly, degenerative manifestations in the lumbar spine may result in falsely elevated BMD values, consequently missing a large proportion of those with osteoporosis. Our aim was to determine the distribution and impact of degenerative changes on lumbar spine DXA over time and its clinical implications.

METHODS

Participants were 1,044 women from the population-based Osteoporosis Risk Assessment cohort. All women were 75 years old at invitation and followed up after 5 years (n=715) and 10 years (n=382). Degenerative changes were evaluated visually on the DXA image for each vertebra L1 to L4 (intraobserver precision kappa values of 0.66-0.70).

RESULTS

At baseline, apparent degenerative changes were more frequent in the inferior segments of the lumbar spine [5% (L1), 15% (L2), 26% (L3), and 36% (L4)] and increased over time. At 10 years, the prevalences were 20% (L1), 39% (L2), 59% (L3), 72% (L4), resulting in a significant increase in overall BMD. In women without apparent degenerative changes, BMD remained stable between 75 and 85 rather than an expected bone loss. At baseline, 37% had osteoporosis (BMD<-2.5) at L1-L4; exclusion of women with apparent degenerative changes increased this proportion to 47%. Using L1-L2, which was less prone to degenerative changes, 46% of women were classified as osteoporotic regardless of degenerative changes.

CONCLUSION

Degenerative changes were very common in elderly women, accelerated disproportionately over time, were increasingly frequent from vertebrae L1 to L4, and had significant impact on diagnosing osteoporosis. This suggests that routine reporting of spine BMD at L1-L2 would add valuable information for reassessment and monitoring.

New treatments and imaging strategies in degenerative disease of the intervertebral disks

Magnetic resonance (MR) imaging in patients with persistent low back pain and sciatica effectively demonstrates spine anatomy and the relationship of nerve roots and intervertebral disks. Except in cases with nerve root compression, disk extrusion, or central stenosis, conventional anatomic MR images do not help distinguish effectively between painful and nonpainful degenerating disks. Hypoxia, inflammation, innervation, accelerated catabolism, and reduced water and glycosaminoglycan content characterize degenerated disks, the extent of which may distinguish nonpainful from painful ones. Applied to the spine, "functional" imaging techniques such as MR spectroscopy, T1ρ calculation, T2 relaxation time measurement, diffusion quantitative imaging, and radio nucleotide imaging provide measurements of some of these degenerative features. Novel minimally invasive therapies, with injected growth factors or genetic materials, target these processes in the disk and effectively reverse degeneration in controlled laboratory conditions. Functional imaging has applications in clinical trials to evaluate the efficacy of these therapies and eventually to select patients for treatment. This report summarizes the biochemical processes in disk degeneration, the application of advanced disk imaging techniques, and the novel biologic therapies that presently have the most clinical promise.

Association between spinal morning stiffness and lumbar disc degeneration: the Rotterdam Study

OBJECTIVE

To explore the associations between spinal morning stiffness and lumbar disc degeneration (LDD).

DESIGN

Data from a cross-sectional general population-based study (Rotterdam Study-I) were used. Intervertebral disc spaces and osteophytes of people aged ≥55 years were scored on lumbar lateral radiographs (L1-2 through L5-S1 was scored). Logistic regression analysis was used to explore associations between spinal morning stiffness and two definitions of LDD (i.e., 'narrowing' and 'osteophytes'). Spinal morning stiffness combined with low back pain and its association with LDD was also analyzed. Similar analyses were performed for knee and hip pain, morning stiffness in the legs, and radiographic knee and hip osteoarthritis (OA) in order to compare these associations with those of LDD. All analyses were adjusted for age, gender, and body mass index (BMI).

RESULTS

Lumbar lateral radiographs were scored for 2,819 participants. Both definitions of LDD were associated with spinal morning stiffness: adjusted odds ratio (aOR) 1.3; 95% confidence interval (CI): 1.1-1.6 for 'osteophytes' and aOR 1.8; 95% CI: 1.4-2.2 for 'narrowing'. Both the odds ratios increased when spinal morning stiffness was combined with low back pain: aOR 1.5; 95% CI: 1.1-2.0 for 'osteophytes' and aOR 2.5; 95% CI: 1.9-3.4 for 'narrowing'. When morning stiffness in the legs was combined with knee or hip pain, the associations with radiographic knee or hip OA were: aOR 3.0; 95% CI: 2.1-4.1 for knee OA and aOR 3.1; 95% CI: 1.9-5.0 for hip OA.

CONCLUSIONS

Reported spinal morning stiffness is associated with LDD. The associations increased when we combined spinal morning stiffness with low back pain. The magnitude of the association for the definition 'narrowing' is similar to the association between morning stiffness in the legs and knee or hip OA.

Imaging-guided lumbar facet injections: is there a difference in outcomes between low back pain patients who remember to return a postal questionnaire and those who do not?

Objectives

To determine whether data obtained from patients returning postal questionnaires accurately reflect how patients receiving imaging-guided lumbar facet injections respond.

Methods

Seventy-eight patients receiving lumbar facet joint injections who returned an outcomes questionnaire (responders) were age and gender matched with 78 patients who did not return the postal questionnaire (non-responders) after facet joint injections. Baseline numerical rating scale (NRS) pain data were collected. NRS and Patients’ Global Impression of Change (PGIC) data were collected 1 month after injection by postal questionnaire or telephone interview.

Differences in NRS scores were calculated using the unpaired t-test. One level injection patients were compared to patients having ≥2 levels injected using the paired and unpaired t-test. The proportion of patients reporting significant improvement in each group was calculated.

Results

NRS scores were significantly improved compared to baseline (p = 0.0001). Thirty-eight percent of responders were significantly improved compared to 50 % of non-responders. Patients having ≥2 levels injected reported significantly higher baseline NRS scores, but by 1 month there was no difference in NRS scores between groups.

Conclusions

Patients returning postal questionnaires report a less favourable outcome. Telephone interview patients having injections at more than one level have better outcomes.

Main messages

• Patients returning postal questionnaires report worse outcomes after facet injection.

• Method of data collection should be considered when reporting treatment outcomes.

• Patients receiving facet injections at more than one level report greater levels of pain reduction.

Fear avoidance beliefs predict disability in older adults with chronic low back pain

OBJECTIVES

To determine whether fear avoidance beliefs (FABs) in older adults with chronic low back pain (CLBP) are significantly associated with gait speed decline and/or self-report of greater disability.

DESIGN

Cross-sectional analysis.

SETTING

An academic medical center (single site).

PARTICIPANTS

Two hundred English-speaking participants aged 65 years and older with CLBP every day or almost every day of moderate or greater intensity for ≥3 months.

MAIN OUTCOME MEASUREMENTS

The physical activity portion of the FAB questionnaire assessed FABs. Disability was measured with gait speed and the Roland Morris Questionnaire. Covariates measured included age, gender, body mass index, chronic disease (Cumulative Illness Rating Scale), depression (Geriatric Depression Scale), and pain (McGill Pain Questionnaire Short Form).

RESULTS

FABs were significantly associated with the Roland Morris Questionnaire (P < .0001) and gait speed (P = .002) after controlling for all covariates.

CONCLUSION

FABs related to physical activity in older adults with CLBP were significantly associated with both self-reported and performance-based disability after controlling for known confounders. Previous studies have reported similar associations between self-reported measures of disabling back pain and FABs. Ours is the first study to examine the relationship between FAB and gait speed, a powerful predictor of morbidity and mortality. Future work should examine whether targeting fear avoidance in addition to other psychosocial measures in older adults with CLBP improves gait speed and functional independence.

Low back pain

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization’s International Classification of Functioning, Disability, and Health (ICF). The purpose of these low back pain clinical practice guidelines, in particular, is to describe the peer-reviewed literature and make recommendations related to (1) treatment matched to low back pain subgroup responder categories, (2) treatments that have evidence to prevent recurrence of low back pain, and (3) treatments that have evidence to influence the progression from acute to chronic low back pain and disability.

Square-cut: a segmentation algorithm on the basis of a rectangle shape

We present a rectangle-based segmentation algorithm that sets up a graph and performs a graph cut to separate an object from the background. However, graph-based algorithms distribute the graph's nodes uniformly and equidistantly on the image. Then, a smoothness term is added to force the cut to prefer a particular shape. This strategy does not allow the cut to prefer a certain structure, especially when areas of the object are indistinguishable from the background. We solve this problem by referring to a rectangle shape of the object when sampling the graph nodes, i.e., the nodes are distributed non-uniformly and non-equidistantly on the image. This strategy can be useful, when areas of the object are indistinguishable from the background. For evaluation, we focus on vertebrae images from Magnetic Resonance Imaging (MRI) datasets to support the time consuming manual slice-by-slice segmentation performed by physicians. The ground truth of the vertebrae boundaries were manually extracted by two clinical experts (neurological surgeons) with several years of experience in spine surgery and afterwards compared with the automatic segmentation results of the proposed scheme yielding an average Dice Similarity Coefficient (DSC) of 90.97±2.2%.

Low back pain in the United States: incidence and risk factors for presentation in the emergency setting

BACKGROUND CONTEXT

Low back pain is prevalent in the United States. At the present time, no large longitudinal study is available characterizing the incidence of this condition in the US population or identifying potential risk factors for its development.

PURPOSE

To characterize the incidence of acute low back pain requiring medical evaluation in the emergency department and establish risk factors for its development.

STUDY DESIGN

Cross-sectional study.

PATIENT SAMPLE

United States population estimates.

OUTCOME MEASURES

Incidence rate ratios were calculated to determine the influence of age, sex, and race on the development of low back pain requiring emergent medical evaluation.

METHODS

The National Electronic Injury Surveillance System was queried for all cases of low back pain presenting to emergency departments between 2004 and 2008. Incidence rate ratios were then calculated with respect to age, sex, and race. The chi-square statistic was used to identify statistically significant differences in the incidence of low back pain requiring emergent medical evaluation between subgroups.

RESULTS

An estimated 2.06 million episodes of low back pain occurred among a population at risk of over 1.48 billion person-years for an incidence rate of 1.39 per 1,000 person-years in the United States. Low back pain accounted for 3.15% of all emergency visits. Injuries sustained at home (65%) accounted for most patients presenting with low back pain. Low back pain demonstrates a bimodal distribution with peaks between 25 and 29 years of age (2.58/1,000 person-years) and 95 to 99 years of age (1.47/1,000) without differentiation by underlying etiology. When compared with females, males showed no significant differences in the rates of low back pain. However, when analyzed by 5-year age group, males aged 10 to 49 years and females aged 65 to 94 years had increased risk of low back pain than their opposite sex counterparts. When compared with Asian race, patients of black and white race were found to have significantly higher rates of low back pain. Older patients were found to be at a greater risk of hospital admission for low back pain.

CONCLUSION

Age, sex, and race are significant risk factors for the development of low back pain necessitating treatment in an emergency department.

Facet joints arthrosis in normal and stenotic lumbar spines

STUDY DESIGN

A descriptive CT study of lumbar facet joint (FJ) arthrosis in general and spinal stenosis populations.

OBJECTIVE

To reveal the prevalence of FJ arthrosis in general and stenosis populations and to establish its relationship to age and sex.

SUMMARY OF BACKGROUND DATA

FJ arthrosis is a common radiographic finding and has been suggested as a cause of low back and lower extremity pain. It is also considered a dominant player in the genesis of lumbar spinal stenosis. Although it is well accepted that FJ arthrosis is an age dependent phenomenon, controversies still exist as to its association with sex and its prevalence at different spine levels. In addition, data on FJ arthrosis frequency in spinal stenosis population are missing.

METHODS

Two groups were studied. The first included 65 individuals with LSS (mean age = 66 ± 10 yr) and the second, 150 individuals (mean age = 52 ± 19 yr) without LSS related symptoms. Both left and right FJ arthrosis for each vertebral level (L3-S1) were evaluated on CT images (Brilliance 64, Philips Medical System, Cleveland, OH). Chi-square, Linear-by-Linear Association and McNemar test were carried out to reveal the correlation between FJ arthrosis and demographic factors (age, sex) and prevalence at different lumbar levels in both stenosis and nonstenosis groups. In addition, a two-way analysis of variance (ANOVA) was used to determine the association between body mass index (BMI) and FJ arthrosis.

RESULTS

The rate of FJ arthrosis at L3-L4 and L4-L5 were significantly higher (P < 0.001) in the stenotic group compared to the control. In the control group the prevalence of FJ arthrosis increases cephalocaudally (L3-L4 = 16%, L4-L5 = 28%, L5-S1 = 55%), whereas in the stenotic group there is a sharp increase from L3-L4 (27%) to L4-L5 (58%), but not from L4-L5 to L5-S1 (55%). No association between FJ arthrosis and sex was noted. Although, mean BMI was significantly smaller in the control group compared to the stenotic group, no association between BMI and facet arthrosis was found. In the general population the prevalence of FJ arthrosis at all three levels was greater for the right side; however, significant difference (P = 0.004) was obtained only for L3-L4. In all joints studied, the prevalence of FJ arthrosis increases considerably from the young age cohort (18-39) to the old age cohort (>60). Nevertheless, 10% of the young individuals (18-39) have already manifested FJ arthrosis at L5-S1. No arthrosis at that age was observed at L3-L4.

CONCLUSION

FJ arthrosis is an age-dependent and BMI and sex independent phenomenon. In the general population, the prevalence of FJ arthrosis increases cephalocaudally with the highest frequency at L5-S1. In the stenotic group, the highest frequency was observed at the two caudal levels; L4-L5 and L5-S1. The prevalence of FJ arthrosis was greater for the right side.

Minimally invasive axial presacral L5-S1 interbody fusion: two-year clinical and radiographic outcomes

STUDY DESIGN

Retrospective case series.

OBJECTIVE

The primary aim of this study was to evaluate and report the 2-year clinical and radiographic outcomes associated with a L5-S1 interbody fusion procedure that employs an axial presacral surgical approach.

SUMMARY OF BACKGROUND DATA

There are a number of lumbar interbody fusion procedures used to treat painful, degenerated discs. However, despite their procedural differences (e.g., anterior vs. posterior), all of the current surgical approaches are undertaken in the same anatomical plane that requires disruption of musculoligamentous and osseous support structures as well as vascular and neurologic tissue to gain access the intervertebral disc space. The presacral procedure is distinct in that it uses an approach along an axis essentially perpendicular to the anatomical plane of traditional fusion procedures.

METHODS

One hundred fifty-six patients from four clinical sites were selected for inclusion if they underwent a L5-S1 interbody fusion via the presacral approach with the AxiaLIF system (TranS1, Wilmington, NC) and had both presurgical and 2-year radiographic or clinical follow-up. Back pain and functional impairment were evaluated with an 11-point numeric scale and the Oswestry Disability Index (ODI), respectively, preoperatively and at 2 years. Standard radiographic imaging techniques were used to determine fusion status.

RESULTS

Marked clinical improvements were realized in back pain severity and functional impairment through 2 years of follow-up. Mean pain scores improved from 7.7 ± 1.6 (n = 155) preoperatively to 2.7 ± 2.4 (n = 148) at 24 months, reflecting an approximate 63% overall improvement (P < 0.001). Mean ODI scores improved from 36.6 ± 14.6% (n = 86) preoperatively to 19.0 ± 19.2% (n = 78) at 24 months, or approximately 54% (P < 0.001). Two-year clinical success rates on the basis of change relative to baseline of at least 30% were 86% (127 of 147) and 74% (57 of 77) for pain and function, respectively. The overall radiographic fusion rate at 2 years was 94% (145 of 155).

CONCLUSION

Findings from this clinical series of patients treated with a presacral interbody fusion procedure, stabilized with the AxiaLIF rod, reflect favorable and durable outcomes through 2 years of follow-up.

Total number and severity of comorbidities do not differ based on anatomical region of musculoskeletal pain

STUDY DESIGN

Secondary analysis, cross-sectional study.

OBJECTIVES

To (1) compare differences in individual comorbidity rates among patients with cervical, lumbar, and extremity pain complaints and (2) compare rates based on total number and severity in these same patient groups.

BACKGROUND

Comorbidities can impact recovery, prognosis, and potentially hinder participation in rehabilitation. Few studies have compared comorbidity rates among patients with different anatomical region of pain, to determine whether specific screening is warranted in physical therapy settings.

METHODS

Included in the analyses were 2375 patients who reported complete demographic, clinical, and comorbidity information using Patient Inquiry software. Comorbidity data were collected from the Functional Comorbidity Index (18 items) and 6 additional comorbidities, to assess the presence of medical disease across multiple body systems. Comorbidities were further classified as "nonsevere" or "severe," based on inclusion in the Charlson Comorbidity Index. Chi-square analyses investigated differences in the rates of total number and severe comorbidities. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated on rates with statistically significant differences (P<.001), using the lumbar spine as the reference group.

RESULTS

Of the 24 comorbid conditions included in this analysis, 3 nonsevere medical conditions (degenerative disc disease, obesity, and headache) had different rates among anatomical region. A lower rate for degenerative disc disease was associated with the extremity conditions (χ2 = 66.3; OR = 0.40; 95% CI: 0.32, 0.50). Higher rate of headache (χ2 = 115.3; OR = 3.01; 95% CI: 2.45, 3.70) and lower rate of obesity (χ2 = 16.2; OR = 0.64; 95% CI: 0.51, 0.80) were associated with cervical conditions. There were no differences among the 3 anatomical regions for total number or severe comorbidities.

CONCLUSION

Focused screening for degenerative disc disease, obesity, and headache may be warranted. However, the same strategy was not supported for total number or severe comorbidities, at least when considering comparative rates from this cohort. Physical therapists should consider the potential influence of total number and severe comorbidities equally for all anatomical regions of musculoskeletal pain.

LEVEL OF EVIDENCE

Differential diagnosis/symptom prevalence, level 3b.

12. Pain originating from the lumbar facet joints

Although the existence of a "facet syndrome" had long been questioned, it is now generally accepted as a clinical entity. Depending on the diagnostic criteria, the zygapophysial joints account for between 5% and 15% of cases of chronic, axial low back pain. Most commonly, facetogenic pain is the result of repetitive stress and/or cumulative low-level trauma, leading to inflammation and stretching of the joint capsule. The most frequent complaint is axial low back pain with referred pain perceived in the flank, hip, and thigh. No physical examination findings are pathognomonic for diagnosis. The strongest indicator for lumbar facet pain is pain reduction after anesthetic blocks of the rami mediales (medial branches) of the rami dorsales that innervate the facet joints. Because false-positive and, possibly, false-negative results may occur, results must be interpreted carefully. In patients with injection-confirmed zygapophysial joint pain, procedural interventions can be undertaken in the context of a multidisciplinary, multimodal treatment regimen that includes pharmacotherapy, physical therapy and regular exercise, and, if indicated, psychotherapy. Currently, the "gold standard" for treating facetogenic pain is radiofrequency treatment (1 B+). The evidence supporting intra-articular corticosteroids is limited; hence, this should be reserved for those individuals who do not respond to radiofrequency treatment (2 B±).

Appropriateness of lumbar spine referrals to a neurosurgical service

BACKGROUND

Patients with lumbar spine complaints are often referred for surgical assessment. Only those with clinical and radiological evidence of nerve root compression are potential candidates for surgery and appropriate for surgical assessment. This study examines the appropriateness of lumbar spine referrals made to neurosurgeons in Edmonton, Alberta.

METHODS

Lumbar spine referrals to a group of ten neurosurgeons at the University of Alberta were reviewed over three two month intervals. Clinical criteria for "appropriateness" for surgical assessment were as follows: •"Appropriate" referrals were those that stated leg pain was the chief complaint, or those that described physical exam evidence of neurological deficit, and imaging reports (CT or MRI) were positive for nerve root compression. •"Uncertain" referrals were those that reported both back and leg pain without specifying which was greater, without mention of neurologic deficit, and when at least possible nerve root compression was reported on imaging. •"Inappropriate" referrals contained no mention of leg symptoms or signs of neurological deficit, and/or had no description of nerve root compression on imaging.

RESULTS

Of the 303 referrals collected, 80 (26%) were appropriate, 92 (30%) were uncertain and 131 (44%) were inappropriate for surgical assessment.

CONCLUSIONS

Physicians seeking specialist consultations for patients with lumbar spine complaints need to be better informed of the criteria which indicate an appropriate referral for surgical treatment, namely clinical and radiological evidence of nerve root compression. Avoiding inappropriate referrals could reduce wait-times for both surgical consultation and lumbar spine surgery for those patients requiring it.

Reduction in segmental flexibility because of disc degeneration is accompanied by higher changes in facet loads than changes in disc pressure: a poroelastic C5-C6 finite element investigation

BACKGROUND CONTEXT

Nerve fiber growth inside the degenerative intervertebral discs and facets is thought to be a source of pain, although there may be several other pathological and clinical reasons for the neck pain. It, however, remains difficult to decipher how much disc and facet joints contribute to overall degenerative segmental responses. Although the biomechanical effects of disc degeneration (DD) on segmental flexibility and posterior facets have been reported in the lumbar spine, a clear understanding of the pathways of degenerative progression is still lacking in the cervical spine.

PURPOSE

To test the hypothesis that after an occurrence of degenerative disease in a cervical disc, changes in the facet loads will be higher than changes in the disc pressure.

STUDY DESIGN

To understand the biomechanical relationships between segmental flexibility, disc pressure, and facet loads when the C5-C6 disc degenerates.

METHODS

A poroelastic, three-dimensional finite element (FE) model of a normal C5-C6 segment was developed and validated. Two degenerated disc models (moderate and severe) were built from the normal disc model. Biomechanical responses of the three FE models (normal, moderate, and severe) were further studied under diurnal compression (at the end of the daytime activity period) and moment loads (at the end of 5 seconds) in terms of disc height loss, angular motions, disc pressure, and facet loads (average of right and left facets).

RESULTS

Disc deformation under compression and segmental rotational motions under moment loads for the normal disc model agreed well with the corresponding in vivo studies. A decrease in segmental flexibility because of DD is accompanied by a decrease in disc pressure and an increase in facet loads. Biomechanical effects of degenerative disc changes are least in flexion. Segmental flexibility changes are higher in extension, whereas changes in disc pressure and facet loads are higher in lateral bending and axial rotation, respectively.

CONCLUSIONS

The results of the present study confirmed the hypothesis of higher changes in facet loads than in disc pressure, suggesting posterior facets are more affected than discs because of a decrease in degenerative segmental flexibility. Therefore, a degenerated disc may increase the risk of overloading the posterior facet joints. It should be clearly noted that only after degeneration simulation in the disc, we recorded the biomechanical responses of the facets and disc. Therefore, our hypothesis does not suggest that facet joint osteoarthritis may occur before degeneration in the disc. Future cervical spine-based experiments are warranted to verify the conclusions presented in this study.

Association of catechol-O-methyltransferase genetic variants with outcome in patients undergoing surgical treatment for lumbar degenerative disc disease

BACKGROUND CONTEXT

Surgical treatment for lumbar degenerative disc disease (DDD) has been associated with highly variable results in terms of postoperative pain relief and functional improvement. Many experts believe that DDD should be considered a chronic pain disorder as opposed to a degenerative disease. Genetic variation of the catechol-O-methyltransferase (COMT) gene has been associated with variation in human pain sensitivity and response to analgesics in previous studies.

PURPOSE

To determine whether genetic variation of COMT is associated with clinical outcome after surgical treatment for DDD.

STUDY DESIGN

Prospective genetic association study.

PATIENT SAMPLE

Sixty-nine patients undergoing surgical treatment for lumbar DDD. Diagnosis was based on documentation of chronic disabling low back pain (LBP) present for a minimum of 6 months and unresponsive to supervised nonoperative treatment, including activity modification, medication, physical therapy, and/or injection therapy. Plain radiographs and magnetic resonance imaging revealed intervertebral disc desiccation, tears, and/or collapse without focal herniation, nerve root compression, stenosis, spondylolisthesis, spondylolysis, or alternative diagnoses.

OUTCOME MEASURES

Oswestry Disability Index (ODI) and visual analog score (VAS) for LBP.

METHODS

Surgical treatment included 65 instrumented fusions and four disc arthroplasty procedures. All patients completed preoperative and 1-year postoperative ODI questionnaires. DNA was extracted from a sample of venous blood, and genotype analysis was performed for five common COMT single nucleotide polymorphisms (SNPs). Potential genetic association between these COMT SNPs and the primary outcome variable, 1-year change in ODI, was investigated using both single-marker and haplotype association analyses. Association with VAS scores for LBP was analyzed as a secondary outcome variable.

RESULTS

Single-marker analysis revealed that the COMT SNP rs4633 was significantly associated with greater improvement in ODI score 1 year after surgery (p=.03), with individuals homozygous for the less common "T" allele demonstrating the largest improvement in ODI. Haplotype analysis of four COMT SNPs, rs6269, rs4633, rs4818, and rs4680, also identified a common haplotype "ATCA" (haplotype frequency of 39.3% in the study population) associated with greater improvement in ODI (p=.046). The greatest mean improvement in ODI was observed in patients homozygous for the "ATCA"COMT haplotype. A nonsignificant trend was observed between SNP rs4633 and greater improvement in VAS score for LBP.

CONCLUSIONS

This is the first study to report an association between surgical treatment success in DDD patients and genetic variation in the putative pain sensitivity gene COMT. These findings require replication in other DDD populations but suggest that genetic testing for pain-relevant genetic markers such as COMT may provide useful clinical information in terms of predicting outcome after surgery for patients diagnosed with DDD.

In vivo and in vitro analysis of rat lumbar spine mechanics

BACKGROUND

Rodent lumbar and caudal (tail) spine segments provide useful in vivo and in vitro models for human disc research. In vivo caudal models allow characterization of the effect of static and dynamic loads on disc mechanics of individual animals with time, but the lumbar models have required sacrifice of the animals for in vitro mechanical testing.

QUESTIONS/PURPOSES

We therefore developed a novel displacement controlled in vivo lumbar spine noninvasive induced angular displacement (NIAD) test; data obtained with NIAD were used to compare angular displacement between segmental levels (L4/L5, L5/L6 and L6/S1), interobserver radiograph measurement agreement, and intraobserver radiograph measurement repeatability. Measurements from NIAD were compared with angular displacement, bending stiffness, and moment to failure measured by an in vitro test.

METHODS

Anesthetized Lewis rats were xrayed in a 90° angled fixture, and NIAD was measured at lumbar levels L4 to S1 by two independent and blinded observers. After euthanasia, in vitro angular displacement (IVAD), stiffness, and failure moment were measured for the combined L4-L6 segment in four-point bending.

RESULTS

NIAD was greater at L4/L5 and L5/L6 than at L6/S1. Combined coronal NIAD for L4-L6 was 42.8° ± 5.3° and for IVAD was 61.5° ± 3.8°. Reliability assessed by intraclass correlation coefficient (ICC) was 0.905 and 0.937 for intraobserver radiograph measurements, and interobserver ICCs ranged from 0.387 to 0.653 for individual levels. The interobserver ICC was 0.911 for combined data from all levels. Reliability for test-retest NIAD measurements had an ICC of 0.932. In vitro failure moment correlated with NIAD left bending.

CONCLUSIONS

The NIAD method yielded reproducible and reliable rat lumbar spine angular displacement measurements without required euthanasia, and allows repetitive monitoring of animals with time. For lumbar spine research studies performed during a course of time, the NIAD method may reduce animal numbers required by providing serial angular displacement measurements without euthanasia.

CLINICAL RELEVANCE

Improved methods to assess comparative models for disease or aging may permit enhanced clinical treatments and improved patient care.

Laser-guided lumbar medial branch kryorhizotomy

The authors describe a modification of the medial branch kryorhizotomy technique for the treatment of lumbar facet joint syndrome using a fluoroscopy-based laser-guided method. A total of 32 patients suffering from lumbar facet joint syndrome confirmed by positive medial nerve block underwent conventional or laser-guided kryorhizotomy. The procedural time (20.6 ± 1.0 vs 16.3 ± 0.9 minutes, p < 0.01), fluoroscopy time (54.1 ± 3.5 vs 28.2 ± 2.4 seconds, p < 0.01), radiation dose (407.5 ± 32.0 vs 224.1 ± 20.3 cGy/cm2, p < 0.01), and patient discomfort during the procedure (7.1 ± 0.4 vs 5.2 ± 0.4 on the visual analog scale, p < 0.01) were significantly reduced in the laser-guided group. There was a tendency for a better positioning accuracy when the laser guidance method was used (3.0 ± 0.3 vs 2.2 ± 0.3 mm of deviation from the target points, p > 0.05). No difference in the outcome was observed between the 2 groups of patients (visual analog scale score 3.5 ± 0.2 vs 3.3 ± 0.3, p > 0.05). This improved minimally invasive surgical technique offers advantages to conventional fluoroscopy-based kryorhizotomy.

Effects of etiology on inpatient rehabilitation outcomes in 65- to 74-year-old patients with incomplete paraplegia from a nontraumatic spinal cord injury

OBJECTIVE

To examine differences in rehabilitation outcomes for older patients with a nontraumatic spinal cord injury (NT-SCI) for 5 etiologic diagnoses: degenerative spinal disease (DSD), malignant spinal tumor, benign spinal tumor, vascular ischemia, and spinal abscess.

DESIGN

Retrospective cohort study that used Medicare claims and assessment data.

SETTING

A total of 479 inpatient rehabilitation hospitals and units.

PATIENTS

A total of 1780 Medicare beneficiaries (65-74 years old) with incomplete paraplegia attributable to NT-SCI who were discharged from inpatient rehabilitation facilities from 2002 through 2005.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Length of stay, discharge Functional Independence Measure (FIM) instrument motor item and subscale scores, and discharge destination.

RESULTS

Demographic characteristics varied by etiology group. Mean +/- SD rehabilitation stays ranged from 13.3 +/- 7.7 days for DSD to 26.4 +/- 13.4 days for vascular ischemia. Adjusted data showed stays differed (P < .001) across etiology groups. Adjusted discharge mean self-care and mobility subscores revealed that patients with DSD and benign tumor were more independent (P < .001) than patients with a malignant tumor or spinal abscess. Patients with vascular ischemia were more dependent (P < .01) in mobility than the DSD and benign tumor groups. Etiologic differences (P < .01) in independence in discharge FIM modifiers for walking (FIM > or = 4), bladder (FIM > or = 6) and bowel management (FIM > or = 6) and bowel accidents/continence (FIM > or = 6), but not bladder accidents (FIM > or = 6), were present. The percent of patients discharged to a community residence ranged from 59.3% to 92.6%. Adjusted data showed that significantly larger percentages (P < .01) of patients in the DSD and malignant tumor groups than in the spinal abscess group were discharged to a community residence (versus nursing home).

CONCLUSION

There are etiologic differences in demographics, rehabilitation length of stay, functional outcomes, and discharge destination in elderly patients with NT-SCI.

Vitamin C deficiency is an under-diagnosed contributor to degenerative disc disease in the elderly

The human aging process is often accompanied by significant increases in degenerative spine disease. The pathophysiology of intervertebral disc degeneration has been extensively studied, but the etiology of this aging-related problem remains poorly understood. The elderly often have lower daily vitamin C intakes and circulating ascorbic acid values than younger people because of problems with poor dentition or mobility, and also are more likely to have underlying sub-clinical diseases that can reduce plasma ascorbate concentrations. Ascorbate is essential for collagen production, and vitamin C deficiency will result in defective connective tissue, including reductions in collagen synthesis and structural stability. It is hypothesised that vitamin C deficiencies may be a key contributing factor in the development of degenerative disk disease (DDD) in the elderly. Once degenerative disc disease has begun, the tissue inflammation that accompanies DDD may further increase vitamin C requirements in the affected patient, thereby creating a cascade of positive feedbacks that potentially accelerates and contributes to further disc degeneration and low-back pain. Aggressive monitoring of patient ascorbate status, as well as more finely-calibrated RDAs for vitamin C that explicitly take into account the patient's age, may be required if aging-related degenerative disk disease is to be minimised.