Bone marrow edema (BME) represents a reversible but highly painful finding in magnetic resonance imaging (MRI) of patients with knee osteoarthritis. The aim of this retrospective study was to evaluate the efficacy of extracorporeal shock wave treatment (ESWT) on painful BME in osteoarthritis of the knee.This study focuses on people who had early-to-mid stage osteoarthritis with knee pain and MRI findings of BME. Patients who underwent ESWT treatment or prescribed alendronate treatment in our department were analyzed. Knee pain and function were measured using the visual analog scale (VAS) for pain and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), respectively. The degree of BME was measured with MRI scans.A total of 126 patients who received ESWT treatment (Group A, n = 82) or alendronate treatment (Group B, n = 44) were included. All patients were followed up clinically and radiographically for a minimum of 12 months. The mean follow-up was 23.5 months (range, 12–38 months). The VAS and WOMAC score decreased more significantly after treatment in Group A than that in Group B (P <.01) within 3 months. In 6-month MRI follow-ups, there was higher incidence of distinct reduction and complete regression of BME of the affected knee in Group A than that in Group B (P <.01).ESWT is an effective, reliable, and noninvasive treatment in patients with painful BME in osteoarthritis of the knee followed by a rapid normalization of the MRI appearance. It has the potential to shorten the natural course of this disease.

Vapor-liquid-equilibrium (VLE) data for several copolymer + solvent systems at 298.15 K and 308.15 K have been obtained using the classical gravimetric-sorption method. The solvents studied were benzene and toluene. The copolymers studied were poly(styrene-co-methyl methacrylate), poly(styrene-cobutadiene), and poly(n-butyl methacrylate-co-N,N-dimethylaminoethyl methacrylate). The molecular thermodynamic model based on a close-packed lattice model developed by Hu et al. was used to correlate the experimental data.

This paper establishes four models of U-shaped flexure hinges with different notch shapes and structure parameters, and presents the close-form compliance equations for the four structure types of U-shaped flexure hinges. The compliance of the flexure hinges is developed based on the Castiglione’s second theorem and calculus theory. A relationship between compliances and structure parameters is deduced using the models. The influences of the notch structure parameters on the compliance of the flexure hinges are investigated. Moreover, fatigue life of U-shaped flexure hinges is studied by finite element analysis, the results show that the fatigue life of flexure hinge increases gradually with the increasing of flexure hinge center thickness t and hinge notch width m.  With the increasing of the major axis of the ellipse a and semi minor axis of the ellipse b, the fatigue life of flexure hinge fluctuates locally, the general trend is a gradual decrease. The stress and fatigue life of U-shaped flexure hinges and arc flexure hinge are compared. The results show that the reliability of U-shaped flexure hinge is higher than that of circular arc flexure hinge.