wire tension
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Abstract Objective: To investigate the method, technique and clinical efficacy of double-row anchor suture bridge technique in the treatment of inferior pole fractures of patella, and to compare it with traditional Kirschner wire tension band internal fixation. Methods: General information A total of 62 patients were enrolled in this study, including 35 males and 27 females, aged 31-80 years old, with an average of (53.2±4) years old. All the patients were divided into two groups by a random double-blind method: Group A (double-row anchor suture bridge technique group) and Group B (Kirschner wire tension band internal fixation group), with 32 cases and 30 cases in each group, respectively. The two techniques were performed by the same group of doctors to fix the fracture respectively, and the intraoperative bleeding, operation time, incidence of postoperative complications, knee function score, etc., were compared between the two techniques. Results: Group A (double-row anchor suture bridge technique group): operation time 56-80min, with an average of (60±10) min; intraoperative blood loss 30-56ml, with an average of (43±10) ml. All incisions healed in one stage and stitches were removed after 2 weeks. No complications such as incision infection, flap necrosis and nerve injury occurred. The average healing time of the fracture was 12 weeks. At the last follow-up, the Bostman score was (28.5±3.3), and the excellent rate was 93.7%. Group B (Kirschner wire tension band internal fixation group): operation time 54-76min, with an average of (56±10) min; intraoperative blood loss 31-50ml, with an average of (43±80) ml. One patient developed delayed incision healing postoperatively. Four patients experienced Kirschner wire withdrawal, one of which was accompanied by infection. Two patients were found to have mild separation of distal fracture fragments, despite the fracture being fine. The average healing time of the fracture was 13 weeks. At the last follow-up, the Bostman score was (23.5±3.3), and the excellent rate was 86.7%. Conclusion: Double-row anchor suture bridge technique is applied to inferior pole fractures of patella by virtue of its various effects, such as the complete preservation of the inferior pole fragments during the operation, satisfactory fracture reduction, firm fixation, and meeting patients’ requirements for early postoperative ambulation. This technology is superior to traditional Kirschner wire tension band internal fixation owing to its advantages of no need to take out the internal fixation, firm fixation, no need to worry about Kirschner wire withdrawal and fewer complications, and its clinical efficacy satisfaction rate is also better than traditional surgical methods. In short, double-row anchor suture bridge technique is an ideal surgical procedure for the treatment of the inferior pole fracture of patella with safety, reliability and high satisfaction.

Abstract The wire bow angle is an important factor that affects the shape precision of an ingot after the diamond wire sawing process. In this research, the wire bow angles of the inside and outside of an ingot were recorded with a high-speed camera. The effects of the processing parameters such as the wire tension force, feed speed, and wire speed on the wire bow angles inside and outside the ingot were analyzed. A numerical simulation model of the wire bow in the wire sawing process is presented in this paper to describe the wire bow angle inside the ingot. It was shown that the wire bow angle inside the ingot was smaller than that of outside the ingot for all of the processing parameters. The wire bow angles improved with the increase of the feed speed and decrease of the wire speed and the wire tension force. The results of the wire bow angle measurement of the inside ingot and the simulation calculation were similar for the process parameters.

Abstract A non-iterative analytical approach is investigated to plan the safe wire tension distribution along with the cables in the redundant cable-driven parallel robots. The proposed algorithm considers not only tracking the desired trajectory but also protecting the system against possible failures. This method is used to optimize the non-negative wire tensions through the cables which are constrained based on the workspace conditions. It also maintains both actuators’ torque and cables’ tensile strength boundary limits. The pseudo-inverse problem solution leads to an n-dimensional convex problem, which is related to the robot degrees of redundancy. In this paper, a comprehensive solution is presented for a 1–3 degree(s) of redundancy in wire-actuated robots. To evaluate the effectiveness of this method, it is verified through an experimental study on the RoboCab cable robot in the infinity trajectory tracking task. As a matter of comparison, some standard methods like Active-set and sequential quadratic programming are also presented and the average elapsed time for each method is compared to the proposed algorithm.

Abstract Background: This study evaluates the effects of wire tension band ventral compression wiring technology paired with artificial femoral head replacement according to the different types of intertrochanteric fractures of the greater trochanter in elderly patients. Methods: Thirty-eight patients with unstable intertrochanteric fractures of the femur treated with artificial femoral head replacement between January 2015 and August 2019 were included. According to the fracture line of the greater trochanter, a new classification system was proposed. Type A fractures include transverse fractures from the greater trochanter tip to the base (2 patients). Type B fractures include oblique fractures from the greater trochanter tip to the base (according to the fracture line direction, type B was further divided into types B1 [4 patients], and B2 [24 patients]). the fracture line of type C fractures runs from the greater trochanter to near the femur end (8 patients). Different wire tension belt ventral compression wiring technologies were used for each fracture type. The Harris hip function score, Parker activity score, and hip pain were evaluated during the follow-up period. Fracture healing and prosthesis positioning, loosening, and dislocation were evaluated using radiographs. Results: The average follow-up period was 28.6 ± 5.8 months. Deep vein embolism was noted in one patient, heterotopic ossification in another, and steel wire fractures in another. All patients had satisfactory fracture healing and femoral prosthesis positioning and no chronic pain. The mean Harris hip function score was 7.21 ± 2.58 preoperatively and 84.74 ± 3.82 at the final follow-up (F = -48.13, P < 0.001).Conclusion: The use of different wire tension band ventral compression wiring technology based on different types of femoral rotation fractures combined with artificial femoral head replacement in elderly patients with unstable intertrochanteric fractures results in favorable clinical outcomes.

Abstract The work investigated the effect on wire offset and surface morphology, with input process parameters as peak current, pulse on time, wire tension over Die Steel D3. Some of experiments were performed by using response surface methodology (RSM) as the design of experiment with central composite design (CCD) technique for the analysis. The ANOVA results annotate that the model is significant. Wire Tension and peak current are observed to have major impact on wire offset during machining operation and surface morphology. The scanning electron microscope (SEM) images confirmed that the thermal stresses produced during the machining of the workpiece resulted in the development of microcracks, craters and spherical module. Due to higher thermal gradient i.e., higher peak current and pulse on-time larger cracks and melted deposits were observed.

Dropper is the key component of in a catenary system and it is prone to fatigue fracture. Dropper stress directly affects the operation safety of high-speed railway. In this paper, a span of dropper in a catenary system is modeled to investigate the effects of contact wire tension on dropper stress. The response equation of contact wire and the theoretical equation of dropper stress are deduced. The initial and boundary conditions of each dropper are determined, and then the stress of each dropper is calculated by the finite difference method using a MATLAB program. The results show that the stress amplitude and the maximum tensile stress of the dropper decrease significantly with the increase of contact wire tension. When the tension is low, the stress changes of dropper near the load location experience three stages: instant rebound, attenuated vibration, and bending compression. However, the attenuation vibration stage disappears when the tension is increased to a certain extent. Therefore, the control of the vibration response of the contact wire can effectively reduce the stress amplitude and the maximum tensile stress of the dropper, so as to improve the working reliability of the dropper.

Variants of the electrode tension mechanism in an electric erosion machine are considered in order to ensure a quick change of the electrode thread and the required degree of tension.