Relationship between alterations of the lumbar spine, visualized with magnetic resonance imaging, and occupational variables

Association between facet joint orientation/tropism and lumbar intervertebral disc degeneration

Background: The aim of this study was to understand how facet joint orientation (FJO) and facet joint tropism (FJT) affected severe intervertebral disc degeneration (IVDD) process at lower lumbar levels in patients with LBP.Methods: This study is a cross-sectional analysis of a retrospective database. Patients were evaluated in terms of IVDD, FJO, and FJT at all lumbar levels on magnetic resonance imaging.Results: In this study (n: 123) facet joints were aligned more coronal in men than in women at upper lumbar levels. Men had less FJT compared to women, significantly at L2-L3 and L3-L4 levels. Severe IVDD at L4-L5 was associated with more coronal aligned L1-L2 (29.0 ± 2.5° vs. 23.3 ± 2.3°, p = 0.006) and misaligned L5-S1 (8.3 ± 1.9° vs. 4.5 ± 1.7°, p = 0.008). Besides, severe IVDD at L3-L4 was associated with more coronal aligned L4-L5 (49.1 ± 3.2° vs. 41.4 ± 2.8°, p = 0.014).Conclusion: There is a close association between FJO/FJT with lumbar IVDD. Facet joint orientation and FJT do not affect the disc at only the corresponding level; the lumbar spine should be evaluated as a whole.

Factors Predisposing to The Formation of Degenerative Spondylolisthesis-A Narrative Review

The relationship between various factors predisposing to the formation of spondylolisthesis, including degenerative spondylolisthesis, has been analyzed by many authors. However, not all observations are consistent. In this review, we identified factors whose impact on the prevalence of spondylolisthesis was most often mentioned in the literature. These included gender, age, bone mineral density, ethnic origin, and oophorectomy. The results were inclusive in terms of physical activity, pregnancy status, and use of hormone replacement therapy. Associations between diabetes and smoking were very poorly marked. The literature so far has identified a number of factors significantly affecting the incidence of degenerative spondylolisthesis. These include age, gender, body weight, ethnic origin, bone mineral density, and hormonal balance. Radiological parameters, which include iliac crest, pelvic tilt, pelvic incidence, sacral slope, and lumbar lordosis, may also be of great importance for assessing changes in the occurrence and progression. However, the authors do not agree on the real significance of individual factors. The aim of this review was to identify the factors predisposing to the formation of degenerative spondylolisthesis, the importance of which has been suggested in the current literature. The systematization of knowledge in this field can allow a more accurate adjustment of the treatment plan for each patient affected by this condition.

An Objective Assessment of Lumbar Spine Degeneration/Ageing Seen on MRI Using An Ensemble Method-A Novel Approach to Lumbar MRI Reporting

STUDY DESIGN

Retrospective, randomized, radiographic study assessing age-related changes (ARCs) on lumbar magnetic resonance imaging (MRI) using an ensemble method.

OBJECTIVES

This study proposed to develop a novel reporting method to calculate a predicted "age estimate" for the ARC seen on lumbar MRI.

SUMMARY OF BACKGROUND DATA

Lumbar MRI reports include pathological findings but usually not the prevalence data of common findings which has been shown to decrease the need for narcotics in the management of non-specific lower back pain (NSLBP). Comparing the normal age estimation for lumbar spine degenerative changes/ARC on MRI and comparing this to the patient's real age may improve patient outcome in the management of NSLBP.

METHODS

A total of 60 lumbar MRI were taken from patients aged between 0 and 100 years. Lumbar MRI features reported as associated with age on review of the literature were measured on each MRI and statistically evaluated for correlation with age. Factors found to be associated were then entered into an ensemble model consisting of several machine learning techniques. The resulting ensemble model was then tested to predict age for a further 10 random lumbar MRI scans. One further lumbar MRI was then assessed for observer variability.

RESULTS

Features that correlated with age were disc signal intensity, the appearance of paravertebral and psoas muscle, disc height, facet joint size, ligamentum flavum thickness, Schmorl nodes, Modic changes, vertebral osteophytes, and high-intensity zones. With the ensemble model, 80% of estimated spinal age were within 11 years of the subjects' physical age.

CONCLUSION

It would appear that the intervertebral discs, and many other structures that are subjected to loading in and around the lumbar spine change their lumbar MRI appearance in a predictable way with increasing age. ARC on lumbar MRI can be assessed to predict an "expected age" for the subject.Level of Evidence: 2.

Obesity could be associated with poor paraspinal muscle quality at upper lumbar levels and degenerated spine at lower lumbar levels: Is this a domino effect?

Vertebral end-plate changes and paraspinal muscles are recently getting much more attention, since they could be associated with intervertebral disc degeneration (IVDD) and low back pain (LBP). Even though obesity is known as a risk factor for LBP, the role of obesity in the process of LBP is still controversial. In this study, we aimed to identify whether increased body mass index (BMI) was associated with IVDD, vertebral end-plate changes and paraspinal muscle quality. Consecutive women and men, aged between 20 and 50 years, presented with chronic LBP to the outpatient clinics were included. Patients were evaluated in terms of IVDD, vertebral end-plate changes, fatty infiltration in the paraspinal muscles at all lumbar levels on magnetic resonance imaging. Severe IVDD was more common in obese patients than in non-obese patients (73.5% vs. 50.4%, p = 0.017). When we compared the groups level by level, the significant difference for severe IVDD was present only at L4-L5 disc level (50% vs. 27.4%, p = 0.013). There was a higher trend of harboring Modic change at any lumbar level in obese patients, significantly in women (35.9% vs. 16.4%, p = 0.026). More severe fatty infiltration in the paraspinal muscles was seen at upper lumbar levels of the obese patients, particularly in women. Patients with higher BMI and suffering from LBP, had more fatty infiltration in the paraspinal muscles at the upper lumbar levels, more severe IVDD, and Modic changes at the lower lumbar levels; particularly women.

Is radiographic lumbar spondylolisthesis associated with occupational exposures? Findings from a nested case control study within the Wakayama spine study

Background

To explore the relationship between radiographic spondylolisthesis and occupational factors in a case-control study nested within the Wakayama Spine Study (WSS).

Methods

The WSS is a cross-sectional observational study amongst Japanese adults. All participants completed a lifetime occupational history and underwent X-rays of the lumbar spine (L1-S1) according to a pre-defined protocol. One trained surgeon graded the presence of a spondylolisthesis based upon ≥5% anterior or posterior slip at one or more levels. Cases, with lumbar spondylolisthesis, were compared with controls without, for their principal occupation and occupational exposures.

Results

In total, data were available for 722 adults (245 men and 477 women), mean age 70.1 (range 53–93) years. According to the pre-defined radiographic criteria, 117 were defined with spondylolisthesis (cases), leaving 605 controls. Cases were not significantly different from controls for age, gender, BMI, smoking or alcohol intake. However, cases were more than twice as likely to report occupational driving ≥4 h/day (OR 2.39, 95% CI 1.08–5.27) after adjustment for age, gender and BMI. Additionally, after stratification by age using 75 years as a cut-point, cases were more than 3-fold more likely to report having worked in the agricultural/ fishing industries (OR 3.47, 95% CI 1.29–9.29) among those aged < 75 years. A reduced risk of being a case was associated with climbing slopes/steps and walking.

Conclusions

A history of occupational driving and working in the agricultural/fishing industry were associated with radiographic spondylolisthesis in this cross-sectional population study. This finding requires further evaluation in longitudinal studies.

The association between occupational loading and spine degeneration on imaging - a systematic review and meta-analysis

Background

There are inconsistencies in findings regarding the relationship of occupational loading with spinal degeneration or structural damage. Thus, a systematic review was conducted to determine the current state of knowledge on the association of occupational loading and spine degeneration on imaging.

Methods

We performed electronic searches on MEDLINE, CINAHL and EMBASE. We included cross-sectional, case control and cohort studies evaluating occupational loading as the exposure and lumbar spine structural findings on imaging as the outcomes. When possible, results were pooled.

Results

Seventeen studies were included in the review. Ten studies evaluated the association of occupational loading with disc degeneration (signal intensity), four of which were pooled into a meta-analysis. Of the 10 studies, only two did not identify a relationship between occupation loading and disc degeneration. A meta-analysis including four of the studies demonstrated an association between higher loading and degeneration for all spinal levels, with odds ratios between 1.6 and 3.3. Seven studies evaluated disc height narrowing and seven evaluate disc bulge, with six and five identifying an association of loading and with imaging findings respectively. Three studies evaluated modic changes and one identified and association with occupational load.

Conclusions

There was moderate evidence suggesting a modest association between occupational loading and disc degeneration (signal intensity), and low-quality evidence of an association between occupational loading and disc narrowing and bulging.

Is age more than manual material handling associated with lumbar vertebral body and disc changes? A cross-sectional multicentre MRI study

OBJECTIVE

Conflicting evidence exists to what extent manual material handling (MMH) causes lumbar disc disease, lack of evidence exist that this effect takes place especially at L5-S1 level, where the greatest moment occurs. The aim was to assess if lumbar vertebral body and disc changes are more common in people whose job involves significant MMH and, if so, to evaluate if lumbar vertebral body and disc changes are more prevalent in the lower part of the lumbar spine (L4-L5 and L5-S1).

DESIGN

Observational, cross-sectional, with quasi-random recruitment.

SETTING

Outpatient radiology units of three large hospitals in northern (Bologna and Brescia) and southern (Bari) Italy.

PARTICIPANTS

183 consecutive adult subjects (89 males, 94 females) aged 20-70 years referred by the general practitioner or a specialist for MRI of the lumbar spine.

PRIMARY AND SECONDARY OUTCOME MEASURES

Neuroradiologists (blind to clinical assessment) evaluated the prevalence of intervertebral disc and vertebral body changes in standardised MRI examinations. History of personal and family musculoskeletal diseases and injuries, current and previous MMH at work and during leisure time were assessed by interview and self-administered questionnaire.

RESULTS

Participants were classified according their occupational exposure to MMH. No association was found between MMH and vertebral body and intervertebral disc changes, whereas age over 45 years was consistently associated with more disc extension beyond the interspace changes, Pfirrmann changes, osteophytes and Modic changes: the association was statistically significant at the conventional 5% level.

CONCLUSIONS

Age, and not MMH, seems to primarily affect the presence of intervertebral disc changes; prospective studies are needed to better explore the relationship between MMH and the possible presence (and level) of lumbar vertebral body and/or disc changes.

Occupational lifting predicts hospital admission due to low back pain in a cohort of airport baggage handlers

Purpose

To examine if occupational lifting assessed as cumulative years as a baggage handler is associated with first-time hospital diagnosis or treatment for low back disorders.

Methods

This study is based on the Copenhagen Airport Cohort consisting of male baggage handlers performing heavy lifting every day and a reference group of unskilled men from the greater Copenhagen area during the period 1990–2012. We followed the cohort in the National Patient Register and Civil Registration System to obtain information on diagnoses, surgery, mortality, and migration. The outcomes were first-time hospital diagnosis or surgery for (1) lumbar disc herniation or (2) low back pain (LBP).

Results

Baggage handlers (N = 3473) had a higher incidence rate of LBP, but not of lumbar disc herniation, compared to the reference group (N = 65,702). Baggage handlers with longer employment had a higher incidence of LBP compared to baggage handlers with shorter employment. The linear association of cumulative years as a baggage handler on LBP was significantly increased with an incidence rate ratio of 1.16 (95% CI 1.07–1.25) for a 5-year increase of employment as baggage handler.

Conclusions

In this large cohort study, we found an increased incidence of LBP among baggage handlers compared to the reference group with indications of a dose–response relationship between years of employment and the outcome. For baggage handlers working on the apron, the incidence was particularly increased before introduction of technical lifting equipment, suggesting that preventive measures to reduce cumulative work load may have a positive effect.

Factory and construction work is associated with an increased risk of severe lumbar spinal stenosis on MRI: A case control analysis within the wakayama spine study

BACKGROUND

To explore the association of MRI-diagnosed severe lumbar spinal stenosis with occupation.

METHODS

Occupational data were collected by questionnaire and all participants underwent spine MRI scans using the same protocol. Central lumbar spinal stenosis (LSS) was graded qualitatively. Those with severe LSS (>two-thirds narrowing) were compared with the controls with lesser degrees of stenosis or no stenosis.

RESULTS

Data were available for 722 subjects, mean age 70.1 years. 239 (33%) cases with severe LSS were identified. Factory/construction workers had an almost four-fold increased risk of severe LSS after adjustment for age, sex, smoking, and walking speed amongst those aged <75 years (OR 3.97, 95%CI 1.46-10.85). Severe LSS was also associated with squatting ≥1 h/day (OR 1.76, 95%CI 1.01-3.07) but this association became non-significant after adjustment.

CONCLUSION

Further research is needed but this study adds more evidence that occupational factors are associated with an increased risk and/or severity of degenerative disease of the lumbar spine.

Radiographic Classification for Degenerative Spondylolisthesis of the Lumbar Spine Based on Sagittal Balance: A Reliability Study

STUDY DESIGN

Inter- and intraobserver reliability study.

OBJECT

To assess the reliability of a new radiographic classification of degenerative spondylolisthesis of the lumbar spine (DSLS).

SUMMARY OF BACKGROUND DATA

DSLS is a common cause of chronic low back and leg pain in adults. To this date, there is no consensus for a comprehensive analysis of DSLS. The reliability of a new DSLS classification system based on sagittal alignment was assessed.

METHODS

Ninety-nine patients admitted to our spinal surgery department for surgical treatment of DSLS between January 2012 and December 2015 were included. Three observers measured sagittal alignment parameters with validated software: segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Full body low-dose lateral view radiographs were analyzed and classified according to three main types: Type 1A: preserved LL and SL; Type 1B: preserved LL and reduced SL (≤5°); Type 2A: PI-LL ≥10° without pelvic compensation (PT <25°); Type 2B: PI-LL ≥10° with pelvic compensation (PT ≥25°); Type 3: global sagittal malalignment (SVA ≥40 mm). The three observers classified radiographs twice with a 3-week interval for intraobserver reproducibility. Interobserver reproducibility was calculated using Fleiss κ and intra-class coefficient. Intraobserver reproducibility was calculated using Cohen κ.

RESULTS

Mean age was 68.8 ± 9.8 years. Mean sagittal alignment parameters values were the following: PI: 60.1° ± 12.7°; PI-LL was 12.2° ± 13.9°, PT: 24.7° ± 8.5°; SVA: 44.9 mm ± 44.6 mm; SL: 16.6° ± 8.4°. Intraobserver repeatability showed an almost perfect agreement (ICC > 0.92 and Cohen κ > 0.89 for each observer). Fleiss κ value for interobserver reproducibility was 0.82, with percentage agreement among observers between 88% and 89%.

CONCLUSION

This new classification showed an excellent inter- and intraobserver reliability. This simple method could be an additional sagittal balance tool helping surgeons improve their preoperative DSLS analysis.

Effects of the weight configuration of hand load on trunk musculature during static weight holding

The performance of manual material handling tasks is one major cause of lower back injuries. In the current study, we investigated the influence of the weight configuration of hand loads on trunk muscle activities and the associated spinal stability. Thirteen volunteers each performed static weight-holding tasks using two different 9 kg weight bars (with medial and lateral weight configurations) at two levels of height (low and high) and one fixed horizontal distance (which resulted in constant spinal joint moment across conditions). Results of the current study demonstrated that holding the laterally distributed load significantly reduced activation levels of lumbar and abdominal muscles by 9-13% as compared with holding the medially distributed load. We believe such an effect is due to an elevated rotational moment of inertia when the weight of the load is laterally distributed. These findings suggest that during the design and assessment of manual material handling tasks, such as lifting and carrying, the weight configuration of the hand load should be considered. Practitioner summary: Elevated trunk muscle activities were found when holding a medially distributed load vs. a laterally distributed load (with an equivalent external moment to the spine), indicating a reduced spinal stability due to the reduced rotational moment of inertia. The configuration of the hand load should be considered when evaluating manual material handling tasks.

Do Occupational Risks for Low Back Pain Differ From Risks for Specific Lumbar Disc Diseases?: Results of the German Lumbar Spine Study (EPILIFT)

STUDY DESIGN

A multicenter, population based, case-control study.

OBJECTIVE

The aim of the present analysis is to clarify potential differences in the "occupational risk profiles" of structural lumbar disc diseases on the one hand, and low back pain (LBP) on the other hand.

SUMMARY OF BACKGROUND DATA

Physical workplace factors seem to play an important etiological role.

METHODS

We recruited 901 patients with structural lumbar disc diseases (disc herniation or severe disc space narrowing) and 233 control subjects with "low-back-pain." Both groups were compared with 422 "low-back pain free" control subjects. Case history, pain data, neurological deficits, and movement restrictions were documented. LBP was recorded by the Nordic questionnaire on musculoskeletal symptoms. All magnetic resonance imaging, computed tomography, and X-rays were inspected by an independent study radiologist. The calculation of cumulative physical workload was based on a computer-assisted interview and a biomechanical analysis by 3-D-dynamic simulation tool. Occupational exposures were documented for the whole working life.

RESULTS

We found a positive dose-response relationship between cumulative lumbar load and LBP among men, but not among women. Physical occupational risks for structural lumbar disc diseases [odds ratio (OR) 3.7; 95% confidence interval (95% CI) 2.3-6.0] are higher than for LBP (OR 1.9; 95% CI 1.0-3.5).

CONCLUSION

Our finding points to potentially different etiological pathways in the heterogeneous disease group of LBP. Results suggest that not all of the structural disc damage arising from physical workload leads to LBP.

LEVEL OF EVIDENCE

4.

Sagittal spinopelvic parameters in 2-level lumbar degenerative spondylolisthesis: A retrospective study

The purpose of our study is to evaluate sagittal parameters in 2-level lumbar degenerative spondylolisthesis (DS) (TLDS).A total of 15 patients with TLDS, 40 patients with single-level DS (SLDS), and 30 normal volunteers as control were included in our study. All subjects performed on full spine X-ray. Two categorized data were analyzed: patient characteristics-age, sex, body mass index, radiographic parameters-pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), sacral slope (SS), PI-LL, Cobb between the fifth thoracic vertebral and 12th thoracic vertebral (T5-T12), sagittal vertical axis (SVA) Cobb angle of spondylolisthesis level (CSL), ratio of PT to SS (PT/SS), CSL/LL, variation trend of SS over PI, and LL over PI.The PI (73.1° vs 52.9°), SS (50.8° vs 32.2°), LL (53.1° vs 46.9°), SVA (66.1 vs 22.0 mm), PI-LL (20.0° vs 6.0°), and CSL (23.6° vs 20.0°) in TLDS were significantly larger than these in SLDS. The PI (73.1° vs 40.6°), PT (22.3° vs 17.1°), SS (50.8° vs 23.5°), LL (53.1° vs 32.5°), PI-LL (20.0° vs 8.1°), and SVA (66.1 vs 17.0 mm) in TLDS were significantly larger than those in the normal group (NG). The PI (52.9° vs 40.6°), PT (21.0° vs 17.1°), SS (32.2° vs 23.5°), LL (46.9° vs 32.5°), and SVA (22.0 vs 17.0 mm) in SLDS were significantly higher than those in NG. However, PT/SS (44.0%), LL over PI (y = 0.39x + 24.25), SS over PI (y = 10.79 + 0.55x) were lower in TLDS than these in SLDS (63.8%, y = 0.41x + 25, y = 0.65x - 2.09, respectively), and the similar tend between SLDS and NG (74.0%, y = 0.49x + 13.09, y = 0.67x - 3.9, respectively).Our results showed that 2-level lumbar DS, which was caused by multiple-factors, has a severe sagittal imbalance, but single-level has not any. When we plan for surgical selection for 2-level lumbar DS, global sagittal balance must be considered.

A comparison of two methods to evaluate a narrow spinal canal: routine magnetic resonance imaging versus three-dimensional reconstruction

BACKGROUND CONTEXT

In routine clinical practice, the presence of lumbar spinal stenosis (LSS) is assessed on axial magnetic resonance images (MRI) typically acquired using a preselected spine sagittal angle. Given the natural lordosis of the lumbar spine, not all axial slices will be parallel to the disc and perpendicular to the spinal canal and, thus, are not optimal for the assessment of dural sac cross-sectional area (DCSA).

PURPOSE

The objective of this study was to compare DCSA measurements from routinely acquired clinical images with three-dimensional (3D)-reconstructed images.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

The sample consists of 390 patients referred for lumbar imaging with some aspect of anatomical LSS found, with no prior back surgery, 40 years of age or older, and with available volumetric MR images to allow 3D reconstruction of the spine.

OUTCOME MEASURES

The outcome of interest in this study was dural sac cross sectional area.

METHODS

Spine images were 3D reconstructed at the level of the disc, perpendicular to the spinal canal. Dural sac cross-sectional area was measured for both 3D-reconstructed and routinely acquired clinical images using the slice orientation captured.

RESULTS

Dural sac cross-sectional area for the lower lumbar levels (L4-L5 and L5-S1) was significantly different between routinely acquired clinical images and 3D-reconstructed images, with a standard error of measurement of 12.98 and 19.73 mm(2), respectively.

CONCLUSIONS

When canal size is of interest, particularly when LSS affecting the lower lumbar levels is of concern, 3D reconstruction of clinical images should be considered.

An analysis of permanent work disability among construction sheet metal workers

BACKGROUND

Causes of permanent work disability in the sheet metal industry are not well characterized.

METHODS

Pension records were used to compare causes of disability among sheet metal workers and the U.S. working population. Subgroup analysis examined the major causes of sheet metal worker disability.

RESULTS

Musculoskeletal disorders (MSDs), circulatory disease, and injuries were leading causes of sheet metal worker disability (47.2%, 13.7%, 10.9% of awards, respectively). Award distribution differed from the U.S. working population (P < 0.0001); MSDs and injuries accounted for higher proportions of sheet metal worker awards, particularly at spine, shoulder, and knee.

CONCLUSIONS

Higher proportions of awards caused by MSD or injury among sheet metal workers may reflect higher rates of work-related injuries and MSDs, a high likelihood of disability with construction work given the same impairment, or higher prevalence of other conditions in the general population. Prevention requires task-specific ergonomic innovations and proven participatory interventions.

An epidemiological surveillance network of lumbar disc surgery to help prevention of and compensation for low back pain

BACKGROUND

In the context of the establishment of a new surveillance system, the aim was to assess the proportion of cases of lumbar disc surgery (LDS) attributable to work according to occupation category and industry sector.

METHODS

The sociodemographic and socioeconomic data of 3150 inpatients living in a French region discharged in 2007-2008 from spine centers of the region following LDS were compared with those of the regional population. Occupational history was gathered using a mailed questionnaire. The attributable fraction of risk for exposed individuals (AFE) and population attributable fraction of risk (PAF) were calculated in relation to occupations and industries.

RESULTS

Three occupational subcategories presented an AFE >50% for men (police and armed forces, unskilled agricultural and skilled craft blue-collar workers). There were eight subcategories for women, including material handlers and related equipment workers, and skilled industrial and unskilled agricultural blue-collar workers. The PAF for men was highest for construction and for women it was highest for wholesale and retail trades.

CONCLUSION

The AFE and PAF are valuable for public policy. Although PAF could be used to help public health policy makers to implement preventive measures, the AFE could assist expert tribunals who take decisions about compensation for occupational diseases.

Low back pain, intervertebral disc and occupational diseases

Nonspecific low back pain and sciatica are prevalent diseases among working adults and have become a worrying occupational health issue because they sometimes affect continuation or resumption of employment. Epidemiological studies that based questionnaires on workers' healthcare consumption have shown a higher prevalence of these disorders in certain industrial sectors. Thus, low back disorders are usually more prevalent among workers exposed to cumulative lumbar load such as manual handling, awkward postures of the trunk and whole-body vibrations. In addition, morphological and biomechanical studies have compared disc space narrowing and the intensity of lumbar workload. Although debated, the relationship between disc degeneration and biomechanical work exposures seems to be usually accepted by most authors. In response to a considerable need of prevention and compensation for workers, low back pain and/or disc disease can be recognized as an occupational diseases in several countries but the criteria of recognition remains heterogeneous from one country to another.

Pelvic retroversion is the key protective mechanism of L4-5 degenerative spondylolisthesis

PURPOSE

To explore the role of spinopelvic sagittal alignment in the pathological mechanism of degenerative spondlylolisthesis (DS) development.

METHOD

A total of 52 asymptomatic volunteers, 32 single segment L4-5 DS and 29 lumbar spinal stenosis (LSS) without spondylolisthesis patients were enrolled. All subjects had standard lumbar spine X-ray films with standard position along with lumbar spine magnetic resonance image. Comparative analysis of sagittal parameters and disc degeneration grades among asymptomatic volunteers and patients with the two disorders were performed.

RESULTS

Compared to normal population (NP) and LSS, DS showed significantly greater pelvic incidence (PI), sacral slope (SS) and lumbar lordosis (LL), while LSS showed significantly smaller PT and PT/SS. DS showed significantly greater L5 slope than NP and LSS. In both Great-PI group and Small-PI group, all above differences between DS and LSS remained. LSS showed significantly higher degenerative grade of each adjacent disc than DS. Population with adjacent segment degeneration showed higher incidence of pelvic retroversion (PT/SS ≥1), and LSS showed greater proportion of adjacent segment degeneration than DS.

CONCLUSIONS

Lumbar spine morphology of great LL determined by great PI is a risk factor of L4-5 DS. L5 slope is a parameter that can be used to predict the risk of L4-5 DS. Pelvic retroversion is the key protective mechanism from DS. Adjacent segment degeneration is a driving factor of pelvic retroversion for compensation of lumbar sagittal malalignment.

Do more MRI findings imply worse disability or more intense low back pain? A cross-sectional study of candidates for lumbar disc prosthesis

OBJECTIVE

To examine whether combined magnetic resonance imaging (MRI) findings are related to the degree of disability and low back pain (LBP) in candidates for lumbar disc prosthesis surgery.

MATERIALS AND METHODS

This cross-sectional study included 170 disc prosthesis candidates (mean age 41 years; 88 women) with chronic non-radicular LBP and localized disc degeneration. Experienced radiologists rated Modic changes and disc findings at L4-S1 on pre-treatment MRIs. An MRI total score (0-10) for findings at L4/L5 plus L5/S1 was calculated for Modic type I and/or II changes, a posterior high intensity zone (HIZ) in the disc, dark/black nucleus pulposus signal, and ≥40 % disc height decrease. We analyzed the relationship of the MRI total score to the Oswestry Disability Index (ODI) (n = 170) and LBP intensity scores (0-100 visual analogue scale, n = 165) using multiple linear regression and adjusting for age, gender, body mass index, smoking, and anxiety/depression.

RESULTS

The MRI total score was not related to ODI (regression coefficient 0.12, p = 0.79) or LBP intensity (regression coefficient 0.64, p = 0.37). When individual MRI findings were analyzed, patients with HIZ at L5/S1 had slightly lower ODI scores (4.7 points, p = 0.02). In post hoc analyses, results remained unchanged after adding facet arthropathy to the MRI total score and adjusting also for physical workload and physical leisure-time activity.

CONCLUSIONS

The combined MRI findings were not related to the degree of disability or the intensity of LBP. These degenerative MRI findings cannot explain variation in pre-treatment disability and pain in patients with chronic LBP accepted for disc prosthesis surgery.

Prevalence and risk factors of lumbar spondylolisthesis in elderly Chinese men and women

OBJECTIVE

A screening survey for osteoporotic fractures in men and women in Hong Kong represents the first large-scale prospective population-based study on bone health in elderly (≥65 years) Chinese men and women. This study aims to identify the prevalence and potential risk factors of lumbar spondylolisthesis in these subjects.

METHODS

The lateral lumbar radiographs of 1,994 male and 1,996 female patients were analysed using the Meyerding classification.

RESULTS

Amongst the men, 380 (19.1%) had at least one spondylolisthesis and 43 (11.3%) had slips at two or more levels; 283 had anterolisthesis, 85 had retrolisthesis, whereas 12 subjects had both anterolisthesis and retrolisthesis. Amongst the women, 499 (25.0%) had at least one spondylolisthesis and 69 (13.8%) had slips at two or more levels; 459 had anterolisthesis, 34 had retrolisthesis, whereas 6 subjects had both anterolisthesis and retrolisthesis. Advanced age, short height, higher body mass index (BMI), higher bone mineral density (BMD) and degenerative arthritis are associated with spondylolisthesis. Lower Physical Activity Scale for the Elderly (PASE) score was associated with spondylolisthesis in men; higher body weight, angina and lower grip strength were associated with spondylolisthesis in women.

CONCLUSION

The male/female ratio of lumbar spondylolisthesis prevalence was 1:1.3 in elderly Chinese. Men are more likely to have retrolisthesis.

KEY POINTS

• The prevalence of spondylolisthesis is 19.1% in elderly Chinese men. • The prevalence of spondylolisthesis is 25.0% in elderly Chinese women. • Men are more likely to have retrolisthesis. • Anterolisthesis is most commonly seen at the L4/L5 level. • Retrolisthesis is most commonly seen at the L3/L4 level.

The sedimentation sign for differential diagnosis of lumbar spinal stenosis

STUDY DESIGN

Cross-sectional cohort study.

OBJECTIVE

To evaluate the diagnostic value of the sedimentation sign further by assessing its performance on the differential diagnosis of patients with lumbar spinal stenosis (LSS) and other lumbar conditions with similar clinical presentations.

SUMMARY OF BACKGROUND DATA

Recently, a new test using MR imaging, the sedimentation sign, was introduced to aid in the diagnosis of LSS. The initial testing demonstrated that the sign was positive in 100% of patients with LSS with decreased walking ability and dural sac cross-sectional areas (CSA) less than 80 mm, and negative in 94% of patients with nonspecific low back pain, no leg pain or claudication and dural sac CSA greater than 120 mm.

METHODS

Fifty patients with central or combined LSS, 22 with lateral stenosis only and 43 with posterolateral disc herniation with unilateral radiculopathy were included. Using axial MR images of the lumbar spine, the sedimentation sign was assessed by 2 observers independently, without knowledge of participant clinical history or diagnosis. Frequencies of a positive sign in each patient group were calculated.

RESULTS

The sedimentation sign was positive in 2% of patients with disc herniation, 23% with lateral stenosis, and 54% with central or combined stenosis. When the analysis included only patients with LSS with dural sac CSA less than 80 mm and walking limitations similar to the original study introducing the sedimentation sign (n = 17), the proportion of patients presenting with a positive sign increased to 82%.

CONCLUSION

The sedimentation sign is more prevalent in patients with the clinical diagnosis of central or combined LSS than in patients with lateral stenosis only or posterolateral disc herniation. Yet, whether it enhances current diagnostic practices remains undetermined.

Risk factors for degenerative spondylolisthesis: a systematic review

STUDY DESIGN

 Systematic literature review.

RATIONALE

 Many authors have postulated on various risk factors associated with the pathogenesis of degenerative spondylolisthesis (DS), yet controversies regarding those risk factors still exist.

OBJECTIVE

 To critically appraise and summarize evidence on risk factors for DS.

METHODS

 Articles published before October 15, 2011, were systematically reviewed using PubMed and bibliographies of key articles. Each article was subject to quality rating and was analyzed by two independent reviewers.

RESULTS

 From 382 citations, 30 underwent full-text review. Fourteen studies met inclusion criteria. All but two were considered poor quality. Female gender and higher facet joint angle were consistently associated with an increased risk of DS across multiple studies. Multiple studies also consistently reported no association between back pain and prolonged occupational sitting. Associations between age, parity, lumbosacral angle, lumbar lordosis, facet joint tropism, and pelvic inclination angles were inconsistent.

CONCLUSIONS

 There appears to be consistent evidence to suggest that the risk of DS increases with increasing age and is greater for females and people with a greater facet joint angle.

Modic changes and associated features in Southern European chronic low back pain patients

BACKGROUND CONTEXT

Conflicting reports exist regarding the prevalence of Modic changes among low back pain (LBP) patients and factors associated with their existence.

PURPOSE

To assess the prevalence of Modic changes and other findings on lumbar magnetic resonance imaging (MRI) among Spanish adult chronic LBP patients and the patient characteristics and radiological findings associated with Modic changes.

STUDY DESIGN

A cross-sectional imaging study among chronic LBP patients.

PATIENT SAMPLE

Four hundred eighty-seven patients (263 women and 224 men) undergoing lumbar spine MRI examination for chronic LBP.

OUTCOME MEASURES

Gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, and image features (disc degeneration, type and extension of Modic changes, disc contour, annular tears, spinal stenosis, and spondylolisthesis).

METHODS

Ten radiologists from six hospitals across six cities in Spain consecutively recruited adult patients in whom lumbar MRI had been prescribed for LBP lasting ≥3 months. Patients' characteristics and imaging findings were assessed through previously validated instruments. A multivariate logistic regression model was developed to assess the features associated with Modic changes.

RESULTS

Modic changes were found in 81% of the patients. The most common was Type II (51.3%), affecting only the end plate. Variables associated with Type I changes were disc contour abnormalities, spondylolisthesis, and disc degeneration. The same variables were associated with a higher risk of Type II or any type of Modic changes, as well as being male, and having a higher BMI.

CONCLUSIONS

Modic changes are found in 81% (95% confidence interval, 77-85) of adult Spanish patients in whom an MRI is prescribed for chronic LBP. Modic changes are more likely to be found in males with a high BMI, who also show disc contour abnormalities, spondylolisthesis, or disc degeneration.

Deconditioning in chronic low back pain: might there be a relationship between fitness and magnetic resonance imaging findings?

The presence of persistent low back pain leads to avoidance of daily activities, contributes to further exercise intolerance and subsequent further loss of functional capacity. We sought to search for the relationship between lumbar magnetic resonance imaging findings and deconditioning in a homogeneous subset of patients with low back pain. We studied 20 sedentary, nonsmoking patients with chronic low back pain using symptom-limited cardiopulmonary exercise testing using treadmill breath-by-breath analysis using modified Bruce protocol. Lumbar facet and disc degeneration involving L1-S1 levels were assessed using 1.5 Tesla MRI. The total number of levels involved was positively correlated with age (r = 0.478, P = 0.033). The Pfirrmann grading of lumbar disc degeneration was positively correlated with Weishaupt grading of facet degeneration (r = 0.502, P = 0.024); however, VO(2) peak was only negatively correlated with facet degeneration (r = -0.5, P = 0.025). Facet joint-mediated pain is a significant problem in all patients suffering from chronic low back pain. Since in this study, aerobic fitness level was negatively correlated with facet degeneration, we suggest that degeneration of facet joints might better reflect the chronicity of low back pain when compared to intervertebral disc degeneration.

Lumbar spondylolisthesis among elderly men: prevalence, correlates, and progression

STUDY DESIGN

Prospective cohort study. OBJECTIVE.: Estimate the prevalence of spondylolisthesis and determine the factors associated with higher or lower prevalence among men aged 65 years or older.

SUMMARY OF BACKGROUND DATA

Spondylolisthesis prevalence is reported to increase with age and to be higher among women than men. Among women aged > or =65 years, prevalence was estimated to be 29%, but no estimates among men of this age have been reported. METHODS.: Lateral lumbar spine radiographs were obtained at baseline and a follow-up visit in the Osteoporotic Fractures in Men (MrOS) study, a cohort of community dwelling men ages > or =65 years. Average time between radiographs was 4.6 (+/-0.4) years. For the present study, 300 men were sampled at random at baseline. Of these, 295 had a usable baseline radiograph; 190 surviving participants had a follow-up radiograph. Spondylolisthesis was defined as a forward slip > or =5%. Progression was defined as a 5% increase in slip severity on the follow-up radiograph. Associations of spondylolisthesis prevalence with baseline characteristics were estimated with age-adjusted prevalence ratios and 95% confidence intervals from log binomial regression models.

RESULTS

The mean (SD) age of the men studied was 74 (+/-6) years. Prevalence of lumbar spondylolisthesis was 31%. Spondylolisthesis was observed at the L3/4, L4/5, and L5/S1 levels. In 96% with spondylolisthesis, only one vertebral level was involved. The degree of slip ranged from 5% to 28%, and nearly all listhesis was classified as Meyerding grade I. During follow-up, 12% of men with prevalent spondylolisthesis had progression; 12% without baseline spondylolisthesis had new onset. Prevalence did not vary by height, BMI, smoking history, diabetes, or heart disease. However, men with spondylolisthesis more often reported higher levels of physical activity or walking daily for exercise than men without spondylolisthesis.

CONCLUSION

Spondylolisthesis may be more common among older men than previously recognized.

Does multilevel lumbar stenosis lead to poorer outcomes?: a subanalysis of the Spine Patient Outcomes Research Trial (SPORT) lumbar stenosis study

STUDY DESIGN

A subanalysis study.

OBJECTIVE

The purpose of this study was to determine the impact of multilevel lumbar stenosis with or without degenerative spondylolisthesis compared to single level disease on patients' baseline symptoms and clinical outcomes over time.

SUMMARY OF BACKGROUND DATA

Previous studies have demonstrated better clinical outcomes with surgery than nonoperative treatment in patients with spinal stenosis with or without degenerative spondylolisthesis. However, the impact of multilevel stenosis has not been studied in these patients.

METHODS

The results from a multicenter randomized and observational study, the Spine Patient Outcomes Research Trial (SPORT) comparing surgical versus nonoperative treatment for spinal stenosis with or without spondylolisthesis, were analyzed. The primary outcomes measures were the Bodily Pain and Physical Function scales of the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 6 weeks, 3 months, 6 months, 1 year, and 2 years. Secondary outcome measures included the stenosis bothersomeness index, leg pain bothersomeness, low back pain bothersomeness, and patient satisfaction.

RESULTS

In this subanalysis of SPORT data, multilevel spinal stenosis did not demonstrate worse baseline symptoms or worse treatment outcomes in isolated spinal stenosis; however, if concomitant degenerative spondylolisthesis existed, patients with only single level stenosis tended to improve more than those with multilevel stenosis, particularly after surgery.

CONCLUSION

Patients with spinal stenosis without associated degenerative spondylolisthesis or scoliosis can be managed nonoperatively irrespective of the number of levels involved. If surgery is performed, the number of levels treated does not predict outcome. In contrast, patients with concomitant degenerative spondylolisthesis and single level stenosis do better surgically than those with additional levels of stenosis. This study emphasizes the importance of shared decision-making between the physician and patient when considering treatment for spinal stenosis.

Frequency and clinical meaning of long-term degenerative changes after lumbar discectomy visualized on imaging tests

The aim of this retrospective controlled study was to evaluate radiographic degeneration in the lumbar spine of patients who had undergone lumbar discectomy minimum 21 years earlier and its clinical meaning. Indeed, no previous investigation on degenerative changes occurring after lumbar discectomy with a comparable long follow-up has been published. The study participants consisted of 50 patients who had undergone discectomy for lumbar disc herniation. The mean length of follow-up was 25.3 +/- 3.0 years. Patients were assessed by Short Form-36 Health Survey (SF-36), Oswestry Disability Index, and a study-specific questionnaire. Radiographic views of the lumbar spine were obtained from all patients and compared to those of 50 asymptomatic controls. A five-step published classification was used to assess the increasing severity of radiographic changes. CT or MRI scans were also available for 27 patients who had undergone discectomy. Moderate to severe radiographic changes were present in 45 patients (90%) and 34 controls (68%), respectively (P = 0.013). The most prevalent MRI/CT changes were loss of disc height (89%), facet joint arthritis (89%), and endplate changes (57%). Thirty-two of 33 subjects (97%) reporting pain during the last 12 months had significant degeneration on their radiographs, and the frequency of changes was higher with respect to subjects without pain (P = 0.040). In conclusion, standard lumbar discectomy frequently leads to long-term degenerative changes on imaging tests. The presence of moderate to severe degeneration is associated with self-reported pain.

A porcine model of intervertebral disc degeneration induced by annular injury characterized with magnetic resonance imaging and histopathological findings. Laboratory investigation

OBJECT

Appropriate animal models of disc degeneration are critical for the study of proposed interventions as well as to further delineate the degenerative process. The purpose of this study was to characterize a porcine model for disc degeneration confirmed on magnetic resonance (MR) imaging studies and histological analysis.

METHODS

Twelve miniature pigs were used (weight 48-65 kg) to study degeneration in the lumbar spine. Under fluoroscopic guidance, the disc was percutaneously punctured with a 3.2-mm-diameter trephine to a 5-mm depth into the annulus fibrosus. Control and experimental levels were randomized among 6 levels in the lumbar spine. The unlesioned spinal levels were used as controls and were compared with lesioned levels. Magnetic resonance imaging grading and disc height were serially recorded preoperatively, and at 5, 8, 19, 32, and 39 weeks postoperatively. The animals were killed in groups of 3 at 7, 18, 32, and 41 weeks postinjury, and the discs were examined histopathologically.

RESULTS

Consistent, sequential, and progressive degeneration of the annular injury was observed on MR imaging and histopathological studies from the time of injury to the final time point. The disc height and the disc height index also sequentially decreased from the time of the injury in a consistent manner. The uninjured control levels did not show any progressive degeneration and maintained their normal state.

CONCLUSIONS

Based on MR imaging and histopathological findings, the authors demonstrated and characterized a reliable model of sequential disc degeneration in miniature pigs with percutaneous injury to the annulus fibrosus. In the early stages, as soon as 5 weeks after injury, significant disc degeneration was seen on MR imaging grading with decreases in disc height. This degeneration did not improve by the final time point of 39 weeks.