ABSTRACT
<p><b>OBJECTIVE</b>To investigate the stress distribution and fracture mechanism of proximal femur under impact loads.</p><p><b>METHODS</b>The image data of one male's femur were collected by the Lightspeed multi-lay spiral computed tomography. A 3D finite element model of the femur was established by employing the finite element software ANSYS, which mainly concentrated on the effects of the directions of the impact loads arising from intense movements and the parenchyma on the hip joint as well as those of the femur material properties on the distribution of the Mises equivalent stress in the femur after impact.</p><p><b>RESULTS</b>The numerical results about the effects of the angle sigma of the impact loads to the anterior direction and the angle gamma of the impact loads to the femur shaft on the bone fracture were given. The angle sigma had larger effect on the stress distribution than the angle gamma, which mainly represented the fracture of the upper femur including the femoral neck fracture when the posterolateral femur was impacted. This result was consistent with the clinical one. The parenchyma on the hip joint has relatively large relaxation effect on the impact loads.</p><p><b>CONCLUSIONS</b>A 3D finite element analysis model of the femoral hip joint under dynamic loads is successfully established by using the impact dynamic theory.</p>
Subject(s)
Humans , Male , Femur , Physiology , Finite Element Analysis , Models, Biological , Stress, Mechanical , Weight-Bearing , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effects of hyperbaric oxygen (HBO) therapy on patients with postbrain injury neural status.</p><p><b>METHODS</b>Two to 4 courses of HBO therapy and/or medications were used to treat 320 patients who were randomly divided into two groups. Assessment was made with (99m)Tc-ethyl cysteinate dimer ( (99m)Tc-ECD) single photon emission computed tomography (SPECT) before and after treatment.</p><p><b>RESULTS</b>There was a significant difference between the HBO therapy group and the non-HBO therapy group. HBO therapy was superior to medication treatment alone in the recovery of clinical symptoms, control of epilepsy, and resolution of hydrocephalus (P<0.01).</p><p><b>CONCLUSIONS</b>HBO therapy has specific curative effects on patients with postbrain injury neural status, and (99m)Tc-ECD SPECT could play an important role in diagnosing postbrain injury neural status and monitoring the therapeutic effects of HBO.</p>