354 research outputs found

    Valuation of public investment to support bicycling (FV-09)

    Get PDF
    In this paper we develop a framework to value public investments with the purpose of increasing bicycling that explicitly accounts internal costs of bicycling, which are typically neglected in current established approaches that value bicycle spending by means of gross health benefits alone, as are inframarginal benefits to existing cyclists. By monetizing internal costs independent of health benefits, we can assess the degree of internalization of private benefits and/or the internalization of external benefits such as environmental improvements due to altruistic preferences by cyclists. Our framework further conceptualizes the complementarity between “hard” (investments in infrastructure) and “soft” measures (informational campaigns) in bicycle policy. Finally, we propose an empirical method for identifying internal costs using a latent variable approach and apply it to eight Swiss cities. Our results imply that Swiss cyclists internalize more than mortality-based benefits. However, because data for some important bicycle mode choice determinants are not available, our results cannot inform policy directly at the current stage. Instead, the contributions of our paper are the development of an economically consistent framework to value public bicycle investments and the identification of crucial data needs for the development of comprehensive assessments informing bicycle policy decisions

    Predictive value of immediate pain relief after lumbar transforaminal epidural injection with local anesthetics and steroids for single level radiculopathy

    Full text link
    Objective: To assess the predictive value of immediate pain-relief after CT-guided transforaminal epidural steroid injection (TFESI) including local anesthetics for longer-term pain relief and patients' global impression of change (PGIC) after 4 weeks. Materials and methods: One hundred ninety-three patients (age 55.4 ± 14.9) with single-level discogenic lumbar radiculopathy and subsequent TFESI were included. Pain scores were recorded before (NRS0), 15 min (NRS15min), and 4 weeks (NRS4w) after treatment using a numerical-rating-scale (NRS; 0, no pain; 10, intolerable pain). Additionally, the PGIC was assessed after 4 weeks. Two fellowship-trained musculoskeletal radiologists evaluated nerve compression of the injected level and contrast dispersion. Spearman's rank and point-biserial correlation were applied to assess associations between outcome variables and demographics/imaging findings. A p-value < 0.05 was considered to be statistically significant. Results: There was a significant positive correlation between immediate pain-relief and longer-term pain-reduction (r = 0.24, p = 0.001) with an odds ratio of 2.0 (CI: 1.1-3.6). A good short-term response (NRS15min ≥ 50% reduction) was associated with a persistent longer-term good response (NRS4w ≥ 50% reduction) in 59.7% (CI: 50.9-68.0%) of patients. There was no association between short-term pain-relief and PGIC after 4 weeks (p = 0.18). Extent and location of nerve compression and contrast dispersion during TFESI did not correlate with longer-term pain-relief (all p ≥ 0.07). Conclusion: Our results indicate a significant positive correlation between immediate post-procedural and longer-term pain relief after TFESI in patients with lumbar radiculopathy; however, no effect of short-term pain relief is seen on PGIC after 4 weeks. Patients with good longer-term outcome (≥ 50% pain reduction) are twice as likely to have already shown good immediate pain reduction after TFESI. Keywords: Anesthetics; Injections; Radiculopathy; Steroids; Treatment outcom

    How is spinal range of motion affected by disc- and facet degeneration and spinopelvic anatomy

    Full text link
    Background: We aimed to investigate how disc- and facet joint degeneration relate to ROM and spinopelvic alignment parameters. Their interrelation, however, is not yet understood, although eminent in patient specific modeling approaches and surgical decision making. Further is not yet sufficiently understood whether spinal alignment parameters relate to the degenerative states. Methods: The ROM of lumbar spinal segments was quantified using flexion/extension radiographs of 90 patients. The grades of degeneration of discs (IDD, Pfirrmann grades, n=440) and facet joints (FJD, Weishaupt classification, n=406) were assessed in CT and MRI scans. Results: The grade of IDD was significantly related to changes in ROM (p<0.01) whereas no association was observed with the amount of FJD. Grade V IDD was associated with a significant decrease in motion (p<0.01) compared to all other IDD grades (II-IV), which did not differ significantly among each other. The combined occurrence of IDD and FJD revealed the largest angular segmental ROM in segments with the lowest IDD (II) and lowest FJD (0). The lowermost ROM was present in fused segments (control), followed by those with severe IDD (V). In combination with FJD, the destabilizing effect of initial IDD was only observed if FJD was already in an advanced state. Conclusions: While the degree of facet joint degeneration seems not significantly associated with limitations in spinal motion, severe lumbar disc degeneration limits segmental motion, nearly equal to spinal fusion. This should affect counseling patients undergoing spinal fusion with questions on the probability of adjacent segment degeneration compared to the natural course. Keywords: Degenerative Disease; Facet Joint Degeneration; Facet Joint Osteoarthritis; Intervertebral Disc Degeneration; Kinematics; Sagittal Alignment

    Investigation of the relationship between tensile viscoelasticity and unloaded ultrasound shear wave measurements in ex vivo tendon

    Full text link
    Mechanical properties of biological tissues are of key importance for proper function and in situ methods for mechanical characterization are sought after in the context of both medical diagnosis as well as understanding of pathophysiological processes. Shear wave elastography (SWE) and accompanying physical modelling methods provide valid estimates of stiffness in quasi-linear viscoelastic, isotropic tissue but suffer from limitations in assessing non-linear viscoelastic or anisotropic material, such as tendon. Indeed, mathematical modelling predicts the longitudinal shear wave velocity to be unaffected by the tensile but rather the shear viscoelasticity. Here, we employ a heuristic experimental testing approach to the problem to assess the most important potential confounders, namely tendon mass density and diameter, and to investigate associations between tendon tensile viscoelasticity with shear wave descriptors. Small oscillatory testing of animal flexor tendons at two baseline stress levels over a large frequency range comprehensively characterized tensile viscoelastic behavior. A broad set of shear wave descriptors was retrieved on the unloaded tendon based on high frame-rate plane wave ultrasound after applying an acoustic deformation impulse. Tensile modulus and strain energy dissipation increased logarithmically and linearly, respectively, with the frequency of the applied strain. Shear wave descriptors were mostly unaffected by tendon diameter but were highly sensitive to tendon mass density. Shear wave group and phase velocity showed no association with tensile elasticity or strain rate-stiffening but did show an association with tensile strain energy dissipation. The longitudinal shear wave velocity may not characterize tensile elasticity but rather tensile viscous properties of transversely isotropic collagenous tissues

    Malunion deformity of the forearm: Three-dimensional length variation of interosseous membrane and bone collision

    Full text link
    It remains unclear to what extent the interosseous membrane (IOM) is affected through the whole range of motion (ROM) in posttraumatic deformities of the forearm. The purpose of this study is to describe the ligament- and bone-related factors involved in rotational deficit of the forearm. Through three-dimensional (3D) kinematic simulations on one cadaveric forearm, angular deformities of 5° in four directions (flexion, extension, valgus, varus) were produced at two locations of the radius and the ulna (proximal and distal third). The occurrence of bone collision in pronation and the linear length variation of six parts of the IOM through the whole ROM were compared between the 32 types of forearm deformities. Similar patterns could be observed among four groups: 12 types of deformity presented increased bone collision in pronation, 8 presented an improvement of bone collision with an increase of the mean linear lengthening of the IOM in neutral rotation, 6 had an increased linear lengthening of the IOM in supination with nearly unchanged bone collision in pronation and 6 types presented nearly unchanged bone collision in pronation with a shortening of the mean linear length of IOM in supination or neutral rotation. This kinematic analysis provides a better understanding of the ligament- and bone-related factors expected to cause rotational deficit in forearm deformity and may help to refine the surgical indications of patient-specific corrective osteotomy

    Prognostic value of clinical and MRI features in the screening of lipomatous lesions

    Full text link
    BACKGROUND AND OBJECTIVES: Differentiation of lipomatous tumors mostly requires diagnostic biopsy but is essential to decide for the most adequate therapy. This study aims to investigate the prognostic value of available clinical and radiological features with regard to malignancy of the lesion, recurrence and survival. METHODS: In this retrospective cohort study, 104 patients with a biopsy-proven lipomatous tumor between 2010 and 2015 and a minimum clinical follow-up of two years were enrolled. Next to clinical features (age, gender, location of the lesion, histopathologic diagnosis, stage of disease, time to recurrence and death), MRI parameters were recorded retrospectively and blinded to the histological diagnosis. RESULTS: Malignant lipomatous tumors were associated with location in the lower extremities and MRI features like thick septation (>2 mm), presence of a non-adipose mass, foci of high T2/STIR signal and contrast agent enhancement. A non-adipose mass was a predictor for recurrence and inferior overall survival, while lesions with high T2/STIR signal showed higher risk of recurrence only. In combination, clinical and radiological features (lower extremities, septation > 2 mm, existence of non-adipose mass, contrast enhancement, and foci of high T2/STIR signal) predicted a malignant lipomatous tumor with an accuracy of 0.941 (95% CI of 0.899-0.983; 87% sensitivity, 86% specificity). CONCLUSION: Localization and characteristic MR features predict malignancy in most lipomatous lesions. Non-adipose masses are a poor prognostic factor, being associated with tumor recurrence and disease-related death

    Contrasts in active transport behaviour across four countries: how do they translate into public health benefits?

    Get PDF
    OBJECTIVE: Countries and regions vary substantially in transport related physical activity that people gain from walking and cycling and in how this varies by age and gender. This study aims to quantify the population health impacts of differences between four settings. METHOD: The Integrated Transport and Health Model (ITHIM) was used to estimate health impacts from changes to physical activity that would arise if adults in urban areas in England and Wales adopted travel patterns of Switzerland, the Netherlands, and California. The model was parameterised with data from travel surveys from each setting and estimated using Monte Carlo simulation. Two types of scenarios were created, one in which the total travel time budget was assumed to be fixed and one where total travel times varied. RESULTS: Substantial population health benefits would accrue if people in England and Wales gained as much transport related physical activity as people in Switzerland or the Netherlands, whilst smaller but still considerable harms would occur if active travel fell to the level seen in California. The benefits from achieving the travel patterns of the high cycling Netherlands or high walking Switzerland were similar. CONCLUSION: Differences between high income countries in how people travel have important implications for population health.The work was undertaken under the auspices of the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence which is funded by the British Heart Foundation, Cancer Research UK, the Economic and Social Research Council, the Medical Research Council, the National Institute for Health Research, and the Wellcome Trust (RG69032). James Woodcock is funded by an MRC Population Health Scientist fellowship (RG68972). Anna Goodman's contribution to this research was funded by a postdoctoral fellowship from the National Institute for Health Research (NIHR) (PDF-2010-03-130). The views expressed in this paper are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health or those of other study funders.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.ypmed.2015.02.00

    No difference in long-term outcome between open and arthroscopic rotator cuff repair: a prospective, randomized study

    Full text link
    Background: Arthroscopic rotator cuff repair techniques have almost replaced open repairs. Short- and mid-term studies have shown comparable outcomes, with no clear superiority of either procedure. The aim of this study was to compare the long-term clinical and imaging outcomes following arthroscopic or open rotator cuff repair. Methods: Forty patients with magnetic resonance imaging (MRI)-documented, symptomatic supraspinatus or supraspinatus and infraspinatus tears were randomized to undergo arthroscopic or open rotator cuff repair. Clinical and radiographic follow-up was obtained at 6 weeks, 3 months, 1 year, 2 years, and >10 years postoperatively. Clinical assessment included measurement of active range of motion, visual analog scale score for pain, functional scoring according to the Constant-Murley score (CS), and assessment of the Subjective Shoulder Value. Imaging included conventional radiography and MRI for the assessment of cuff integrity and alteration of the deltoid muscle. Results: We enrolled 20 patients with a mean age of 60 years (range, 50-71 years; standard deviation [SD], 6 years) in the arthroscopic surgery group and 20 patients with a mean age of 55 years (range, 39-67 years; SD, 8 years) in the open surgery group. More than 10 years' follow-up was available for 13 patients in the arthroscopic surgery group and 11 patients in the open surgery group, with mean follow-up periods of 13.8 years (range, 11.9-15.2 years; SD, 1.1 years) and 13.1 years (range, 11.7-15 years; SD, 1.1 years), respectively. No statistically significant differences in clinical outcomes were identified between the 2 groups: The median absolute CS was 79 points (range, 14-84 points) in the arthroscopic surgery group and 84 points (range, 56-90 points) in the open surgery group (P = .177). The median relative CS was 94% (range, 20%-99%) and 96% (range, 65%-111%), respectively (P = .429). The median Subjective Shoulder Value was 93% (range, 20%-100%) and 93% (range, 10%-100%), respectively (P = .976). MRI evaluation showed a retear rate of 30% equally distributed between the 2 groups. Neither fatty infiltration of the deltoid muscle, deltoid muscle volume, nor the deltoid origin were different between the 2 groups. Conclusion: In a small cohort of patients, we could not document any difference in clinical and radiographic outcomes at long-term follow-up between arthroscopic and open rotator cuff repair. The postulated harm to the deltoid muscle with the open technique could not be confirmed

    Clinical relevance of occult infections in spinal pseudarthrosis revision

    Full text link
    BACKGROUND Occult infections in spinal pseudarthrosis revisions have been reported in the literature, but the relevance of such an infection on patient outcomes is unknown. We aimed to elucidate clinical outcomes and re-revision risks between patients with and without occult infections in spinal revision surgery for pseudarthrosis. METHODS In this matched case-control study, we identified 128 patients who underwent thoracolumbar revision surgery from 2014-2019 for pseudarthrosis of the spine. Among them, 13 (10.2%) revealed an occult infection (defined by at least two positive intraoperative tissue samples with the same pathogen), and nine of these 13 were available for follow-up. We selected 18 of the 115 controls using a 2:1 fuzzy matching based on fusion length and length of follow-up. The patients were followed up to assess subsequent re-revision surgeries and the following postoperative patient-reported outcome measures (PROMs): overall satisfaction, Oswestry Disability Index, 5-level EQ-5D, and Short Form 36. RESULTS Patient characteristics, surgical data, and length of follow-up were equal between both study groups. The rate of re-revision free survival after the initial pseudarthrosis revision surgery was higher in the occult infection group (77.8%) than the non-infectious controls (44.4%), although not significantly (0.22). The total number of re-revision surgeries, including re-re-revisions, was thirteen (in ten patients) in the control and two (in two patients) in the occult infection group (p = 0.08) after a median follow-up of 24 months (range 13-75). Four cases in the control group underwent re-revision for pseudarthrosis compared to none in the infected group. Satisfactory scores were recorded in all PROMs, with similar scores between the two groups. CONCLUSIONS The presence of an occult infection accompanying spinal pseudarthrosis revision was not inferior to non-infected pseudarthrosis revisions in a matched, small sample size cohort study. This may be explained due to the possibility of targeted treatment of the identified cause of pseudarthrosis
    • …
    corecore