Optimization of electronic prescription for parallel external fixator based on genetic algorithm.

PURPOSE: For the parallel external fixator, there are some defects, such as uneven distraction rate, unbearable pain and uncontrollable movement trajectory in practical clinical applications. In order to solve the problems, a new deformity correction algorithm, which is used to calculate the elongation of the six struts, is developed. Meanwhile, the corresponding computer software for getting the electronic prescription is developed. METHODS: First, the trajectory of the moving bone is planned by Cartesian coordinate path control. Next, the prescription is obtained from the trajectory by the inverse pose solution algorithm. Finally, the genetic algorithm is utilized to optimize the achieved prescription. From the year of 2015 to 2018, twenty-three patients with complicated tibia deformity are treated by using parallel external fixator and the developed computer software. All patients have standing, patella-forward, full-length post-operative AP and lateral radiographs of the lower limbs with the complete proximal ring for getting the deformity parameters and frame parameters. These parameters are input into the computer software to calculate a daily prescription schedule for strut adjustment. Radiographs are taken regularly to determine the effects of recovery during the correction process. RESULTS: The mean time of follow-up is 18 months (range 11-40 months). All patients reach the requirements for deformity correction, and their symptoms and appearance are improved significantly. No cases of wound infections or complications occur, and no severe pain came as well during the correction process. CONCLUSIONS: By using the computer-aided parallel external fixator for the correction of lower limb deformities, satisfactory outcomes can be achieved. Hence, this method greatly improved the treatment of these patients in a clinical application.

The computer-aided parallel external fixator for complex lower limb deformity correction.

PURPOSE: Since parameters of the parallel external fixator are difficult to measure and calculate in real applications, this study developed computer software that can help the doctor measure parameters using digital technology and generate an electronic prescription for deformity correction. METHODS: According to Paley's deformity measurement method, we provided digital measurement techniques. In addition, we proposed an deformity correction algorithm to calculate the elongations of the six struts and developed a electronic prescription software. At the same time, a three-dimensional simulation of the parallel external fixator and deformed fragment was made using virtual reality modeling language technology. From 2013 to 2015, fifteen patients with complex lower limb deformity were treated with parallel external fixators and the self-developed computer software. All of the cases had unilateral limb deformity. The deformities were caused by old osteomyelitis in nine cases and traumatic sequelae in six cases. A doctor measured the related angulation, displacement and rotation on postoperative radiographs using the digital measurement techniques. Measurement data were input into the electronic prescription software to calculate the daily adjustment elongations of the struts. Daily strut adjustments were conducted according to the data calculated. The frame was removed when expected results were achieved. Patients lived independently during the adjustment. RESULTS: The mean follow-up was 15 months (range 10-22 months). The duration of frame fixation from the time of application to the time of removal averaged 8.4 months (range 2.5-13.1 months). All patients were satisfied with the corrected limb alignment. No cases of wound infections or complications occurred. CONCLUSIONS: Using the computer-aided parallel external fixator for the correction of lower limb deformities can achieve satisfactory outcomes. The correction process can be simplified and is precise and digitized, which will greatly improve the treatment in a clinical application.

First aid protocols for severe pelvic fractures / 中华创伤骨科杂志

Objective To discuss diagnostic classification and emergency treatment protocols for complex pelvic fractures. Methods The first aid management of 23 cases of major pelvic fractures were analyzed retrospectively. Results 22 of the patients survived, but one died of hemorrhagic shock.Conclusions Correct classification of severe pelvic fractures is of guidance value to the first aid management. Cooperation among multiple departments, comprehensive application of various surgical methods, early stabilization of hemodynamics, rapid repair of injured organs, stabilization of pelvic ring with external fixator are effective techniques to enhance the survival rate of patients with severe pelvic fractures.