Capillary-scale hydrogel microchannel networks by wire templating

Microvascular networks are essential for the efficient transport of nutrients, waste products, and drugs throughout the body. Wire-templating is an accessible method for generating laboratory models of these blood vessel networks, but it has difficulty fabricating microchannels with diameters of ten microns and narrower, a requirement for modeling human capillaries. This study describes a suite of surface modification techniques to selectively control the interactions amongst wires, hydrogels, and world-to-chip interfaces. This wire templating method enables the fabrication of perfusable hydrogel-based rounded cross-section capillary-scale networks whose diameters controllably narrow at bifurcations down to 6.1 ± 0.3 microns in diameter. Due to its low cost, accessibility, and compatibility with a wide range of common hydrogels of tunable stiffnesses such as collagen, this technique may increase the fidelity of experimental models of capillary networks for the study of human health and disease

Scoliotic posture as the initial symptom in adolescents with lumbar disc herniation: its curve pattern and natural history after lumbar discectomy

<p>Abstract</p> <p>Background</p> <p>There have been few studies focusing on the curve pattern of scoliosis caused by lumbar disc herniation (LDH) in adolescents and the natural history of scoliosis after discectomy. The current study was carried out to identify the curve pattern of scoliosis and investigate the effect of posterior discectomy on the curve improvement in adolescents with LDH.</p> <p>Methods</p> <p>This review focused on a group of 26 adolescents with LDH who initially presented to our clinic for evaluation of scoliosis, followed by posterior discectomy between 2000 and 2009. Radiographic measurements included curve pattern, specific curve features, trunk shift, and sagittal profile. The correlation between the side of disc herniation and the direction of lumbosacral curve and the trunk shift was evaluated.</p> <p>Results</p> <p>A typical curve pattern was initially identified in all of the patients as a short lumbosacral curve accompanied with a long thoracic or thoracolumbar curve toward the opposite side. 23 of 26 patients (88.5%) had a trunk shift more than 2.0 cm away from the midline, showing a poor coronal balance. A relatively straight sagittal profile was noted in all the patients. 84.6% (22/26) patients had a disc herniation at the convex side of lumbosacral curve. Similarly, 73.1% (19/26) patients showed a trunk shift toward the opposite side of disc herniation. All of the patients had an marked curve improvement immediately after discectomy. In the 17 patients with a more than 2-year follow-up, only two had a residual lumbosacral curve greater than or equal to 20 degrees. The mean ODI improved from 21.4% before surgery to 7.3% at the final follow-up.</p> <p>Conclusions</p> <p>A short lumbosacral curve accompanied with a long thoracic or thoracolumbar curve toward the opposite side, and a relatively straight sagittal profile have been noted in all the patients. The direction of lumbosacral curve and trunk shift was related to the side of disc herniation. A majority of patients have a small curve size while assosiated with a significant coronal imbalance. Earlier decompression can provide a greater opportunity for spontaneous correction of scoliosis.</p

The contribution of RCTs to quality management and their feasibility in practice

The randomized controlled trial (RCT) is generally accepted as the most reliable method of conducting clinical research. To obtain an unbiased evaluation of the effectiveness of spine surgery, patients should be randomly assigned to either new or standard treatment. The aim of the present article is to provide a short overview of the advantages and challenges of RCTs and to present a summary of the conclusions of the Cochrane Reviews in spine surgery and later published trials in order to evaluate their contribution to quality management and feasibility in practice. From the searches, 130 RCTs were included, 95 from Cochrane Reviews and systematic reviews, and 35 from additional search. No study comparing surgery with sham surgery was identified. The first RCT in spine surgery was published in 1974 and compared debridement and ambulatory treatment in tuberculosis of the spine. The contribution of RCTs in spinal surgery has markedly increased over the last 10 years, which indicates that RCTs are feasible in this field. The results demonstrate missing quality specifications. Despite the number of published trials there is conflicting or limited evidence to support various techniques of instrumentation. The only intervention that receives strong evidence is discectomy for faster relief in carefully selected patients due to lumbar disc prolapse with sciatica. For future trials, authors, referees, and editors are recommended to follow the CONSORT statement. RCTs provide evidence to support clinical opinions before implementation of new techniques, but the individual clinical experience is still important for the doctor who has to face the patient

The effect of an intramedullary implant with a static magnetic field on the healing of the osteotomised rabbit femur

Static magnetic fields are a type of electromagnetic fields used in clinical practice. To ascertain what effect a static magnetic intramedullary device implanted in the rabbit femur had on fracture healing, 20 male New Zealand white rabbits with magnetic/nonmagnetic intramedullary implants were examined histologically, radiologically and for bone mineral density. Three groups were constituted according to the poles of the magnets. During surgery the intramedullary device was driven into the medulla. A femoral osteotomy was created with a mini Gigli wire at the centre point of the rod. Radiographs were obtained at the second and fourth weeks. Histological examination and bone mineral density were evaluated at the fourth week. The results of this study verified that an intramedullary implant with a static magnetic field improves bone healing in the first two weeks radiologically and that the configuration difference in magnetic poles has an effect on bone quality. Static magnetic fields have minor effects on bone mineral density values