Prediction of application scope of vertical fracture strike based on scattered wave fracture orientation function

Fracture system plays a very important role in the enrichment and accumulation of oil and gas in the reservoirs. Based on scattering wave information, Fracture Orientation Function （FOF） was built, which can be used to predict the fracture orientations. However, this method has only been verified by physical experiments without studies on the application scope. In this study, based on the linear sliding theory, F0F of the scattering wave was applied to the numerical simulation and the application scope was further studied according to fracture flexibility tensor. According to the fractures filled with gas and liquid, numerical simulation was conducted on the models with various fracture flexibilities. Numerical simulation results were used to inverse fracture orientation with the aid of the FOF of the scattering wave. The results show that it is workable to predict the vertical fracture orientation with the F0F of the scattering wave. Application of this method is more effective when the fractures are filled with gas than liquid. Moreover, the application scope can be predicted by the fracture flexibility.

Hidden blood loss after intertrochanteric fractures in elderly patients and its influence on the postoperative function recovery:a random controlled trial

Objective To investigate hidden blood loss after various types of intertrochanteric fractures and to determine whether oral iron supplementations is benefical for the postoperative functional recovery in elderly patients.Methods From

Effects of surgical and nonoperative treatment on wrist function of patients with distal radius fracture

Purpose： To study the effects of surgical and nonoperative treatment on wrist function in patients with distal radius fracture. Methods： In total, 97 patients treated for distal radius fracture in the Department of Orthopedic Trauma at the People＇s Hospital of Peking University from Jan. 2010 to Jun. 2016 were selected for outpatient follow-up, including manipulative reduction and dorsal splint fixation in 24 cases, bivalve cast fixation in 19 cases and open reduction and internal fixation in 54 cases. Evaluation was based on Sartiento＇s modification of the Gartland and Werley score. Efficacy was assessed with wrist pain as the focus. Results： The wrist function scores of the surgical group were better than nonoperative groups. There was no significant difference in wrist function scores between the dorsal splint group and the bivalve cast group. The ulnar wrist pain incidence had no significant difference in surgical and nonoperative groups. The displace rate in dorsal splint group was higher than other groups. Conclusion： The overall effect of surgical treatment of distal radius fracture is better than nonoperative treatment. The ulnar wrist pain incidence has no significant difference in these groups. Dorsal splint fixation is more prone to displace than bivalve cast fixation.

Tensile properties of phase interfaces in Mg Li alloy: A first principles study

Employing density functional theory, we study the tensile and fracture processes of the phase interfaces in Mg–Li binary alloy. The simulation presents the strain–stress relationships, the ideal tensile strengths, and the fracture processes of three phase interfaces. The results show that the α/α and α/β interfaces have larger tensile strength than that of β/β interface. The fractures of both α/α and β/β interfaces are ductile fractures, while the α/β fractures abruptly._Further analyses show that the fracture of the α/β occurs at the interface.

Outcome of distal end clavicle fractures treated with locking plates

Purpose： Fractures of the lateral end of the clavicle are relatively uncommon. These fractures are unstable due to the various deforming forces which act on the fragments as well as the small distal fracture fragment. At most times the deforming forces are not taken into consideration, and the fracture is not fixed securely. In this study, we assessed a fixation technique using the precontoured locking plates to find out whether it provided a stable fixation with good functional outcome. Methods： Totally, 32 patients with lateral end clavicle fracture （Neer＇s Type ll） were included in the study. After the informed consent and preoperative investigations were obtained, open reduction and intemal fixation was done using a 3.5 mm precontoured superior locking plate with lateral extension under general anesthesia. Postoperative X-rays were done on day I and every 6 weeks after operation, until radiological union was achieved. The postoperative pain was assessed using Visual Analogue Scale （VAS） on postoperative days 1, 2 and 10. Postoperatively arm pouch sling was given for 2 weeks followed by active mobilization. Patients were asked to do their daily routine work and avoid lifting heavy weights. The functional outcome was assessed at the end of 2nd and 6th months with the help of Disabilities of the Arm, Shoulder and Hand （DASH} scoring. Results： There were no intraoperative complications in the procedure. The mean VAS score on post- operative day 1 was found to be 5 which decreased to 3 on day 2 and 0 on day 10. The mean DASH score was calculated as 11.63 at the end of postoperative month 2 and then 4.6 at the end of month 6. There was one case of malunion in whom the overhead abduction was restricted but was not painful and was managed conservatively. Conclusion： The precontoured locking plates with lateral extension may be a good method to fix the fractures of the lateral end clavicle, which provide a stable fixation with good functional outcome with very few instances of stiffness and decreased range of motion of the shoulder with the hook plates and failure of fixation in screw and K-wire fixations. It may well be the answer to the fixation questions of the lateral clavicle fractures, although larger comparative studies between the surgical treatment methods are required to confirm the same.