79 research outputs found
Outcome after tantalum rod implantation for treatment of femoral head osteonecrosis: 26 hips followed for an average of 3 years
Background and purpose Tantalum rod implantation has recently been proposed for treatment of early stages of femoral head osteonecrosis. The purpose of our study was to report the early results of its use in pre- and post-collapse stages of the disease
Lesion aspirate culture for the diagnosis and isolation of Leishmania spp. from patients with cutaneous leishmaniasis
Quantifying intervertebral disc mechanics: a new definition of the neutral zone
<p>Abstract</p> <p>Background</p> <p>The neutral zone (NZ) is the range over which a spinal motion segment (SMS) moves with minimal resistance. Clear as this may seem, the various methods to quantify NZ described in the literature depend on rather arbitrary criteria. Here we present a stricter, more objective definition.</p> <p>Methods</p> <p>To mathematically represent load-deflection of a SMS, the asymmetric curve was fitted by a summed sigmoid function. The first derivative of this curve represents the SMS compliance and the region with the highest compliance (minimal stiffness) is the NZ. To determine the boundaries of this region, the inflection points of compliance can be used as unique points. These are defined by the maximum and the minimum in the second derivative of the fitted curve, respectively. The merits of the model were investigated experimentally: eight porcine lumbar SMS's were bent in flexion-extension, before and after seven hours of axial compression.</p> <p>Results</p> <p>The summed sigmoid function provided an excellent fit to the measured data (r<sup>2 </sup>> 0.976). The NZ by the new definition was on average 2.4 (range 0.82-7.4) times the NZ as determined by the more commonly used angulation difference at zero loading. Interestingly, NZ consistently and significantly decreased after seven hours of axial compression when determined by the new definition. On the other hand, NZ increased when defined as angulation difference, probably reflecting the increase of hysteresis. The methods thus address different aspects of the load-deflection curve.</p> <p>Conclusions</p> <p>A strict mathematical definition of the NZ is proposed, based on the compliance of the SMS. This operational definition is objective, conceptually correct, and does not depend on arbitrarily chosen criteria.</p
A biomechanical comparison of 360° stabilizations for corpectomy and total spondylectomy: a cadaveric study in the thoracolumbar spine
Accuracy of mucocutaneous leishmaniasis diagnosis using polymerase chain reaction: systematic literature review and meta-analysis
How nurses and their work environment affect patient experiences of the quality of care: a qualitative study
Primär und Sekundarstabilität einer neuen Technik zur Stabilisierung von osteoporotischen Kompressionsfrakturen der Wirbelsäule - eine in vitro Studie
Kombinierte En-bloc-Resektionen von Wirbelkörper und Thoraxwand bei primären Tumoren und solitären Metastasen: onkochirurgische Ergebnisse
Analyse der Muskelfunktion nach Unterschenkelfraktur: Einfluss des intramuskulären Perfusionsdruckes auf die posttraumatische Kraftminderung
Onkochirurgische Ergebnisse extremitätenerhaltender Tumorresektionen im Schultergürtelbereich bei primären Tumoren sowie Metastasen
- …