Is surgery more effective than non-surgical treatment for spinal stenosis and which non-surgical treatment is more effective? a systematic review

BACKGROUND: Spinal stenosis can be treated both conservatively and with decompression surgery. OBJECTIVES: To explore the effectiveness of surgery vs conservative treatment, and conservative interventions for spinal stenosis. DATA SOURCES: Medline, CINAHL, AMED, PEDro and Cochrane databases, as well as the reference lists of retrieved studies. STUDY SELECTION: The search included non-English studies, and all conservative interventions were included. STUDY APPRAISAL: The PEDro scale was used to assess quality, and levels of evidence were used to synthesise studies where possible. RESULTS: Thirty-one studies met the inclusion criteria, and 18 were high-quality studies. Decompression surgery was more effective than conservative care in four out of five studies, but only one of these was of high quality. In six high-quality studies, there was strong evidence that steroid epidural injections were not effective; in four out of five studies (two of which were of high quality), there was moderate evidence that calcitonin was not effective. There was no evidence for the effectiveness of all other conservative interventions. LIMITATIONS: Further research is needed to determine if decompression surgery is more effective than conservative care, and which conservative care is most effective. CONCLUSION AND IMPLICATIONS: At present, there is no evidence that favours the effect of any conservative management for spinal stenosis. There is an urgent need to see if any conservative treatment can change pain and functional outcomes in spinal stenosis.</p

3+1 Approach to the Long Wavelength Iteration Scheme

Large-scale inhomogeneities and anisotropies are modeled using the Long Wavelength Iteration Scheme. In this scheme solutions are obtained as expansions in spatial gradients, which are taken to be small. It is shown that the choice of foliation for spacetime can make the iteration scheme more effective in two respects: (i) the shift vector can be chosen so as to dilute the effect of anisotropy on the late-time value of the extrinsic curvature of the spacelike hypersurfaces of the foliation; and (ii) pure gauge solutions present in a similar calculation using the synchronous gauge vanish when the spacelike hypersurfaces have extrinsic curvature with constant trace. We furthermore verify the main conclusion of the synchronous gauge calculation which is large-scale inhomogeneity decays if the matter--considered to be that of a perfect-fluid with a barotropic equation of state--violates the strong-energy condition. Finally, we obtain the solution for the lapse function and discuss its late-time behaviour. It is found that the lapse function is well-behaved when the matter violates the strong energy condition.Comment: 21 pages, TeX file, already publishe

Bobcats Do Not Exhibit Rub Response Despite Presence at Hair Collection Stations

We evaluated the detection rate for hair snare sampling for bobcats (Lynx rufus) using colocated hair snares and infrared-triggered cameras at 20 locations on private property in eastern Texas. Hair snares and cameras were placed together at survey stations that included both visual and olfactory attractants. In 1,680 trap-nights we photographically documented 15 visits by bobcats but collected only one bobcat hair sample. Our observations suggested limited rubbing behavior by bobcats at hair snares despite presence at hair collection stations. The explanation for this behavior remains unclear but is consistent with observations of low and variable hair trap success for this species. Although presence of other carnivores, especially gray fox, may inhibit rub response of felids, we did not document gray foxes at our hair collection stations. Low rub frequency may limit the utility of these techniques for bobcats and we suggest that alternate techniques such as camera surveys or fecal DNA collection may be more suitable

A Home Exercise Programme Is No More Beneficial than Advice and Education for People with Neurogenic Claudication: Results from a Randomised Controlled Trial

Objective: To compare the effectiveness of a physiotherapy programme with a control treatment of advice and education in patients with neurogenic claudication symptoms. Design: Pragmatic randomised controlled clinical trial. Setting: Primary care-based musculoskeletal service. Patients: Adults aged 50 or over with neurogenic claudication symptoms causing limitation of walking. Interventions: Condition-specific home exercises combined with advice and education, or advice and education alone. Main outcome measures: The primary outcome was the difference in improvement of symptom severity scores on the Swiss Spinal Stenosis Scale at eight weeks. Secondary outcomes included measures of physical function, pain and general well-being at eight weeks and 12 months. Results: There was no significant difference between groups in the Swiss Spinal Stenosis symptom severity scale at eight weeks (t = 0.47, p = 0.643): mean change (SD) control group -0.18 (0.47), treatment group -0.10 (0.66), difference (95% CI) 0.08 (-0.19, 0.35); baseline-adjusted difference 0.06 (-0.19, 0.31)]. An unplanned subgroup analysis suggested that for patients with the top 25% of baseline symptom severity scores, the physiotherapy exercise programme resulted in an improvement in the primary outcome, and modest but consistently better secondary outcomes at both time-points compared to the control group. The effectiveness in different subgroups requires further direct evaluation. Conclusions: In the treatment of patients with neurogenic claudication symptoms, a physiotherapist-prescribed home exercise programme is no more effective than advice and education

Relativistic Two-stream Instability

We study the (local) propagation of plane waves in a relativistic, non-dissipative, two-fluid system, allowing for a relative velocity in the "background" configuration. The main aim is to analyze relativistic two-stream instability. This instability requires a relative flow -- either across an interface or when two or more fluids interpenetrate -- and can be triggered, for example, when one-dimensional plane-waves appear to be left-moving with respect to one fluid, but right-moving with respect to another. The dispersion relation of the two-fluid system is studied for different two-fluid equations of state: (i) the "free" (where there is no direct coupling between the fluid densities), (ii) coupled, and (iii) entrained (where the fluid momenta are linear combinations of the velocities) cases are considered in a frame-independent fashion (eg. no restriction to the rest-frame of either fluid). As a by-product of our analysis we determine the necessary conditions for a two-fluid system to be causal and absolutely stable and establish a new constraint on the entrainment.Comment: 15 pages, 2 eps-figure

Bedded Pack Management System Case Study

Agribusiness, Agricultural Finance, Farm Management,

Scaling of curvature in sub-critical gravitational collapse

We perform numerical simulations of the gravitational collapse of a spherically symmetric scalar field. For those data that just barely do not form black holes we find the maximum curvature at the position of the central observer. We find a scaling relation between this maximum curvature and distance from the critical solution. The scaling relation is analogous to that found by Choptuik for black hole mass for those data that do collapse to form black holes. We also find a periodic wiggle in the scaling exponent.Comment: Revtex, 2 figures, Discussion modified, to appear in Phys. Rev.