The European multicenter trial on the safety and efficacy of guided oblique lumbar interbody fusion (GO-LIF)

Background: Because of the implant-related problems with pedicle screw-based spinal instrumentations, other types of fixation have been tried in spinal arthrodesis. One such technique is the direct trans-pedicular, trans-discal screw fixation, pioneered by Grob for spondylolisthesis. The newly developed GO-LIF procedure expands the scope of the Grob technique in several important ways and adds security by means of robotic-assisted navigation. This is the first clinical trial on the GO-LIF procedure and it will assess safety and efficacy. Methods/Design: Multicentric prospective study with n = 40 patients to undergo single level instrumented spinal arthrodesis of the lumbar or the lumbosacral spine, based on a diagnosis of: painful disc degeneration, painful erosive osteochondrosis, segmental instability, recurrent disc herniation, spinal canal stenosis or foraminal stenosis. The primary target criteria with regards to safety are: The number, severity and cause of intra-and perioperative complications. The number of significant penetrations of the cortical layer of the vertebral body by the implant as recognized on postoperative CT. The primary target parameters with regards to feasibility are: Performance of the procedure according to the preoperative plan. The planned follow-up is 12 months and the following scores will be evaluated as secondary target parameters with regards to clinical improvement: VAS back pain, VAS leg pain, Oswestry Disability Index, short form - 12 health questionnaire and the Swiss spinal stenosis questionnaire for patients with spinal claudication. The secondary parameters with regards to construct stability are visible fusion or lack thereof and signs of implant loosening, implant migration or pseudarthrosis on plain and functional radiographs. Discussion: This trial will for the first time assess the safety and efficacy of guided oblique lumbar interbody fusion. There is no control group, but the results, the outcome and the rate of any complications will be analyzed on the background of the literature on instrumented spinal fusion. Despite its limitations, we expect that this study will serve as the key step in deciding whether a direct comparative trial with another fusion technique is warranted

Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

BACKGROUND: Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. METHODS: A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block) and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. RESULTS: Our main findings in the experiments with an anterior interbody cage support are as follows: 1) large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2) polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3) polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. CONCLUSION: Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment is set at large lordotic angles. Polyaxial pedicle screw fixation performs nearly equal percentages of vertebra-cage contact among all constructs with different sagittal alignments, therefore enhances the stabilization effect of interbody cages in the lumbosacral area

Life Course Offending Pathways Across Gender and Race/Ethnicity

Purpose This paper aims to refine our understanding of life course offending patterns across gender and race/ethnicity and to advance work in this area by examining how gender and race/ethnicity interact to influence life course offending patterns. Methods We use criminal justice system data to construct a longitudinal offending cohort that includes all individuals born in 1983/1984 with at least one court finalization for a criminal offense in the state of Queensland between the ages of 10 and 25 years. The data include 41,280 offenders (25.6 % female; 8.9 % Indigenous Australian) responsible for 209,872 offenses (M?=?5.08, SD?=?12.31). Coupling these data with state-level census data for those born in 1983/1984 (N?=?129,782), we estimate cohort offending rates overall and disaggregated by gender and race/ethnicity both independently and jointly. Focusing on the offenders, we use semiparametric group-based modeling to identify the number and longitudinal distributions of offending trajectories within the cohort and compare how subgroups defined by gender, Indigenous status, and their combination sort into these trajectories. Results Most of the birth cohort has little to no contact with the criminal justice system through age 25. However, patterns are not uniform across gender or race/ethnicity, with males and Indigenous Australians most likely to fit the serious and chronic offending trajectories. Gender and race/ethnicity also interact to influence offending patterns with non-Indigenous females significantly more likely than any other group to avoid system contact, while Indigenous males have comparatively exaggerated rates of contact. Moreover, Indigenous females offend in ways more similar to non-Indigenous males than females and, in some instances, evidence even more serious offending. Conclusions Developmental and life course models should highlight not just the operant developmental dynamics across key life stages or the relevant age-graded risk and protective factors at play, but also how gender and race/ethnicity condition these processes both independently and jointly.Arts, Education & Law Group, School of Criminology and Criminal JusticeNo Full Tex

A model for homeopathic remedy effects: low dose nanoparticles, allostatic cross-adaptation, and time-dependent sensitization in a complex adaptive system

BACKGROUND: This paper proposes a novel model for homeopathic remedy action on living systems. Research indicates that homeopathic remedies (a) contain measurable source and silica nanoparticles heterogeneously dispersed in colloidal solution; (b) act by modulating biological function of the allostatic stress response network (c) evoke biphasic actions on living systems via organism-dependent adaptive and endogenously amplified effects; (d) improve systemic resilience. DISCUSSION: The proposed active components of homeopathic remedies are nanoparticles of source substance in water-based colloidal solution, not bulk-form drugs. Nanoparticles have unique biological and physico-chemical properties, including increased catalytic reactivity, protein and DNA adsorption, bioavailability, dose-sparing, electromagnetic, and quantum effects different from bulk-form materials. Trituration and/or liquid succussions during classical remedy preparation create “top-down” nanostructures. Plants can biosynthesize remedy-templated silica nanostructures. Nanoparticles stimulate hormesis, a beneficial low-dose adaptive response. Homeopathic remedies prescribed in low doses spaced intermittently over time act as biological signals that stimulate the organism’s allostatic biological stress response network, evoking nonlinear modulatory, self-organizing change. Potential mechanisms include time-dependent sensitization (TDS), a type of adaptive plasticity/metaplasticity involving progressive amplification of host responses, which reverse direction and oscillate at physiological limits. To mobilize hormesis and TDS, the remedy must be appraised as a salient, but low level, novel threat, stressor, or homeostatic disruption for the whole organism. Silica nanoparticles adsorb remedy source and amplify effects. Properly-timed remedy dosing elicits disease-primed compensatory reversal in direction of maladaptive dynamics of the allostatic network, thus promoting resilience and recovery from disease. SUMMARY: Homeopathic remedies are proposed as source nanoparticles that mobilize hormesis and time-dependent sensitization via non-pharmacological effects on specific biological adaptive and amplification mechanisms. The nanoparticle nature of remedies would distinguish them from conventional bulk drugs in structure, morphology, and functional properties. Outcomes would depend upon the ability of the organism to respond to the remedy as a novel stressor or heterotypic biological threat, initiating reversals of cumulative, cross-adapted biological maladaptations underlying disease in the allostatic stress response network. Systemic resilience would improve. This model provides a foundation for theory-driven research on the role of nanomaterials in living systems, mechanisms of homeopathic remedy actions and translational uses in nanomedicine

Complications of pedicle screws in lumbar and lumbosacral fusions in 105 consecutive primary operations

Pedicle screw fixation is technically demanding and associated with high complication rates. The aim of this study was to identify and quantify the pedicle screw-related complications in 105 consecutive operations. We retrospectively analysed 105 consecutive primary operations. We found complications of varying severity in 54% of the patients. Deep infections were found in 4.7%, all successfully cured by debridement and antibiotics. There were no permanent neurological complications related to the screws. One serious neurological sequela, a T10 paraplegia, was unrelated to screw placement between L3 and S1. Screw misplacement was found in 6.5% of the screws. Screw breakage occurred in 12.4% of the patients, inevitably leading to loss of correction. Reduced spondylolisthesis L5-S1 without anterior support was found to be especially prone to screw breakage. The study confirmed that pedicle screw placement is a technically demanding procedure with a high complication rate. Fortunately, most complications are not severe. Infections can be dealt with by thorough debridement and parenteral antibiotics. Neurological sequelae can be minimised by careful tactile technique. To avoid screw breakage and subsequent loss of correction, anterior support should be provided, through either posterior or anterior lumbar interbody fusion (PLIF or ALIF) techniques, in reduced spondylolisthesis L5-S1

Chemotherapeutic treatment for spinal tuberculosis

AIM: To evaluate whether 6 months of chemotherapy for patients with spinal tuberculosis prevents relapse as effectively as more than 6 months of chemotherapy. METHOD: Literature review. Medline search including references, from January 1978 to November 2000. Inclusion criteria for publications: diagnosis of spinal tuberculosis confirmed bacteriologically and/or histologically, or probable on the basis of clinical and radiological parameters; treatment regimen (whether or not in combination with surgery) included isoniazid (H), rifampicin (R) and pyrazinamide (Z); follow-up period after completion of treatment of 12 months or more. Exclusion criteria: patients with relapse who had previously been treated adequately for tuberculosis. OUTCOME PARAMETERS: Relapse rate. RESULTS: Four publications were found with HRZ regimens of 6 months' duration and 10 publications with HRZ regimens of >6 months' duration. A number of patients had received HRE (E = ethambutol) for > or = 9 months. In the results, no distinction was made between treatment groups. HRZ for 6 months led to a relapse rate of 0% (0/56, 95%CI 0.0-6.4); follow-up after surgical intervention ranged from 6 to 108 months. HRZ for > or = 9 months (> or = 119 patients) or HRE for > or = 9 months (< or = 71 patients) led to a relapse rate of 2% (4/218, 95%CI 0.6-5.0); follow-up after surgical intervention was 6-168 months. Despite the small number of studies, 6 months of therapy is probably sufficient for patients with spinal tuberculosis