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    • Finite element analysis of the biomechanical effect of lateral wedge insole on foot and ankle
    杜 玮 瑾 , 陈 维毅 , 郭 媛
    Adopted date: April 25,2024
    [Abstract](9) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Lateral wedge insole (LWI) can improve lower limb alignment and relieve pain in patients with early to mid-stage knee osteoarthritis. However, its effect on biomechanics of foot and ankle remains to be elucidated. The aim of this study was to investigate the biomechanical effects of LWI on the internal tissues of the foot and ankle, including foot bones, joints, and ligaments. Methods The study developed and validated a three-dimensional finite element model of the foot-insole-ground and explored plantar pressure distributions, contact pressures on joints, and peak stresses on metatarsals and major ligaments in barefoot and insoles intervention models at three gait instants. Results The 5° LWI model reduced peak plantar pressure by 65.8% compared to the barefoot model. Insole interventions decreased the peak contact pressure at the cuneonavicular joint, but increased the peak contact pressure at the subtalar joint and peak stress at the fourth and fifth metatarsals. Conclusions This study quantitatively assessed the biomechanical effects of LWI on various parts of the foot and ankle, and suggested a design that could appropriately reduce the inclination angle of LWI at the fourth and fifth metatarsals.
    Progress of finite element study on anterior cervical surgery for cervical spondylosis
    TIAN Xue-Feng , LV Jun-Qiao , YU Zhe-Ming , LIU Yang , SUN Lin
    Adopted date: April 24,2024
    [Abstract](4) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    The impact of various anterior cervical surgeries on the biomechanical properties of cervical vertebrae varies depending on the specific surgical techniques employed. However, accurately measuring the mechanical characteristics of individual parts of the cervical vertebrae or the discs within them in a clinical setting can be challenging. As a result, the finite element method is commonly utilized in research on anterior cervical surgery, allowing for precise analysis of stress and strain distribution in different areas of interest through computer simulations. This method facilitates the study of biomechanical properties associated with different anterior cervical surgical approaches. This review article discusses the advancements in finite element analysis in the context of anterior cervical surgery, summarizing current research findings on fusion and non-fusion procedures, hybrid surgeries, and minimally invasive techniques. The aim is to offer a biomechanical perspective that can guide the selection of appropriate anterior cervical surgical interventions.
    Advances in Biomechanical Research on Single-Leg Drop Jump Following Anterior Cruciate Ligament Reconstruction
    赵建伟 , 刘艺 , 庄海英
    Adopted date: April 24,2024
    [Abstract](6) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Anterior cruciate ligament reconstruction is the preferred treatment to restore the original activity level of patients. The Single-leg drop jump can not only identify high-risk exercise strategies, but also provide a standard for the rehabilitation process of anterior cruciate ligament reconstruction. This paper conducted a combined search of " Single-leg drop jump, anterior cruciate ligament reconstruction, biomechanics" through CNKI, PubMed, Embase and other databases, summarized the biomechanical changes of Single-leg drop jump after anterior cruciate ligament reconstruction and related intervention methods, which will help anterior cruciate ligament reconstruction adjust rehabilitation strategies after surgery and avoid high-risk actions with secondary injuries. The analysis of Single-leg drop jump after anterior cruciate ligament reconstruction is of great significance for clinicians and rehabilitation therapists to guide the formulation and adjustment of rehabilitation treatment plan, improve the postoperative rehabilitation efficiency of anterior cruciate ligament reconstruction, and help patients return to sport as soon as possible.
    Effectiveness of Segmental Decompression Combined with Corrective Short-Segment Fusion Surgery in the Treatment of Degenerative Lumbar Scoliosis
    Zeng Hui
    Adopted date: April 24,2024
    [Abstract](4) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To investigate the effectiveness of utilizing segmental decompression combined with corrective short-segment fusion surgery in the treatment of degenerative lumbar scoliosis. Methods A total of 124 cases of degenerative lumbar scoliosis patients admitted to the Second People's Hospital of Fuyang City from February 2018 to February 2023 were selected. They were randomly divided into the short-segment fusion group and the long-segment fusion group using a random number table method, with 62 cases in each group. The short-segment fusion group underwent posterior short-segment decompression and fusion, with an average fused segment of adjacent lumbar vertebrae (2.36±0.75 segments). The long-segment fusion group underwent posterior long-segment decompression and fusion, with an average fused segment of multiple adjacent lumbar vertebrae (5.42±1.40 segments). The surgical time and intraoperative blood loss were recorded. At 6 months postoperatively, the coronal Cobb angle of lumbar convexity, sagittal Cobb angle of lumbar lordosis, intervertebral foramen height, intervertebral space height, intervertebral foramen area, spinal canal area, spinal canal diameter, Japanese Orthopedic Association score (JOA), Oswestry Disability Index (ODI), degree of pain in the lumbar and lower extremities, serum tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) levels, as well as postoperative complications were compared between the two groups. Results The intraoperative blood loss and surgical time in the short-segment fusion group were both lower than those in the long-segment fusion group (P＜0.05). At 6 months postoperatively, the coronal Cobb angle of lumbar convexity decreased and the sagittal Cobb angle of lumbar lordosis increased compared to preoperative measurements in both groups (P＜0.05), but there was no significant difference between the two groups (P＞0.05). At 6 months post-surgery, the intervertebral foramen height, intervertebral space height, intervertebral foramen area, spinal canal area, and spinal canal diameter all showed an increase in both groups of patients. The short segment fusion group exhibited higher measurements compared to the long segment fusion group (P<0.05). At 6 months postoperatively, the JOA scores of both groups improved compared to preoperative scores, with the short-segment fusion group showing higher improvement than the long-segment fusion group (P＜0.05); the ODI scores of both groups decreased compared to preoperative scores, with the short-segment fusion group showing greater improvement than the long-segment fusion group (P＜0.05). At 6 months postoperatively, the pain scores in the lumbar and lower extremities, as well as the levels of TNF-α and IL-1β, decreased compared to preoperative levels in both groups (P＜0.05), with no significant difference between the two groups (P＞0.05). In the long-segment fusion group, two cases experienced dural tearing during the decompression process due to adhesions between the lamina and dura mater, while no severe complications were observed in the short-segment fusion group. Conclusion Both short-segment decompression fixation fusion and long-segment decompression fixation fusion through a posterior approach can achieve good therapeutic effects in the treatment of degenerative lumbar scoliosis. However, compared to the long-segment fusion group, the short-segment fusion group undergoing short-segment decompression fixation fusion through a posterior approach has a shorter surgical time, lower intraoperative blood loss, better recovery of lumbar function, and lower risk of postoperative complications.
    Correlation analysis between sagittal orientation of lumbar pedicle screw and screw loosening
    ZHAN Xuqiang , YU Haixin , XI Xin , XIANG Qingzhi , YU Yan
    Adopted date: April 15,2024
    [Abstract](20) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To analyze the correlation between sagittal orientation of lumbar pedicle screw and screw loosening based on craniocaudal cyclic load and artificial vertebra, and to provide a reference for improvement of pedicle screw orientation during surgery thus reducing the incidence of screw loosening postoperatively. Methods The pedicle screws were inserted into artificial vertebra via cranial orientation, parallel orientation and caudal orientation respectively. After installation in the material testing machine, the model was subjected to a 100N preload and 166N cyclic load for 10,000 cycles. During the test, displacements were recorded and cycle-displacement curves were drawn. After test and removal of screw, the screw hole volume was measured, and the screw hole volume ratio (the ratio of screw hole volume to the volume of the screw inserted into the vertebra) was calculated. Results The cyclic-displacement curves showed that the cranial group had the largest displacement; parallel group was the second, and the last was the caudal group. Screw hole volume ratio result showed that cranial group had the highest ratio, and followed by parallel and caudal groups. Correlation analysis showed that negative relation was found between sagittal orientation of pedicle screw and the terminal displacement (the displacement corresponding to the 10,000th cycle) (p=-0.897, P=0.02) as well as screw hole volume ratio (p=-0.902, P=0.01). Conclusion Sagittal orientation of lumbar pedicle screw related negatively to the screw loosening, which indicated the adjustment of orientation from cranial to parallel and even caudal one at a certain angle would reduce the incidence of screw loosening.
    The effect of total knee arthroplasty on proprioception in patients with knee osteoarthritis
    张权# , 石静楠# , 张宽 , 张昊华 , 闫松华
    Adopted date: April 08,2024
    [Abstract](15) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective To explore the changes of proprioception in patients with knee osteoarthritis (KOA) before and after total knee arthroplasty (TKA). Methods Thirty-four KOA patients were selected as the experimental group and divided into posteriorly-cruciate-retaining TKA (CR-TKA) and posteriorly-stabilized TKA (PS-TKA) groups according to the surgical method, and the patients were followed up for three months after surgery, while 20 healthy subjects were included as the control group. Biodex system Ⅲ isokinetic training system, self-designed force sense test equipment and surface electromyography (sEMG) test system were used to collect proprioception (position sense, kinesthesia, force sense) of KOA patients before and after surgery and healthy subjects, and the data were processed and analyzed by applying SPSS26.0. Results Compared with healthy subjects, KOA patients had significantly worse position sense of 30°, 45°, and 60°, kinesthesia, and semitendinosus force sense of the affected knee and unaffected knee (p<0.05). At three months after surgery, there were significant differences in the force sense force of the affected biceps femoris and contralateral semitendinosus compared to healthy subjects (p<0.05). There were no statistically significant differences in deviation for position sense, kinesthetic, and force sense on the affected and contralateral knee joints between preoperative and three months postoperatively between the CR-TKA and PS-TKA groups (p>0.05). Conclusions Knee proprioception of KOA patients was significantly impaired compared with healthy subjects. No significant improvement in proprioception was seen at three months after TKA in CR-TKA and PS-TKA groups. There was no difference in the effect of different surgical types on proprioception at three months postoperatively. The results can provide certain data support for doctors' clinical diagnosis and treatment and determine a direction for subsequent rehabilitation programs.
    Study on the biomechanical factors of lower limbs affecting the mechanical energy of baseball batting based on factorial regression analysis
    王世坤 , 辛雷 , 杨晨 , 顾雪宋
    Adopted date: April 08,2024
    [Abstract](11) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective: To investigate the biomechanical factors of the lower limbs related to the mechanical energy in baseball batting skills. Methods: C3D data was collected using a motion capture system and imported into Visual 3D to establish a Hanavan multi-rigid-body human model and a rigid body model of the bat. Through a prepared pipeline command, the angular velocities and joint torques of the hip, knee, and ankle joints of the lower limbs, as well as the rotation of the trunk around the X, Y, and Z axes, were calculated and exported. A stepwise multiple linear regression analysis was performed between the independent variables and the dependent variable using SPSS, incorporating the factors and the dependent variable into the regression model. Results: The top four independent variables that have the greatest impact on the mechanical energy of the bat are as follows: x19 right ankle joint plantar flexion/dorsiflexion torque (β=91.97), x2 left ankle joint inversion/eversion torque (β=91.74), x25 right hip joint flexion/extension torque (β=91.58), and x3 left ankle joint internal rotation/external rotation torque (β=91.50). Conclusion: (1) There is a strong correlation between the right hip joint flexion/extension torque and the mechanical work of the bat. The batter generates energy transmission to the upper limbs by producing right hip joint extension torque to rotate the trunk and pelvis. (2) There is a close relationship between the adduction and abduction torque of the left ankle joint and the mechanical work of the bat, which are used for body braking in the early stage of batting and body rotation in the later stage. (3) It is necessary to conduct specific strength training for the adductors of the left ankle joint, extensors of the right hip joint, and plantar flexors of the right ankle joint to enhance batting power.
    Progress and Prospect of Small-Caliber Artificial Blood Vessels Research
    Wu Xin , Hou Lei , Xu Feng
    Adopted date: April 06,2024
    [Abstract](22) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    In recent years, the incidence of cardiovascular diseases has been gradually increasing, leading to a growing demand for regenerative blood vessels in clinical practice. Currently, large-caliber artificial blood vessels (caliber > 6 mm) have been successfully applied in clinical settings. However, small-caliber artificial blood vessels (caliber < 6 mm) still face challenges in long-term patency rates after transplantation due to reasons such as thrombosis, intimal hyperplasia, inflammatory reactions, and poor compliance which leading to hemodynamic changes.Achieving rapid endothelialization, inhibiting thrombus formation, and matching the compliance of autologous vessels remain key factors to be addressed. This article provides a brief overview of commonly used materials and techniques for preparing small-caliber artificial blood vessels, with a focus on discussing strategies to improve biocompatibility and compliance. Furthermore, future research directions are also discussed.
    Hemodynamics study of bi-leaflet mechanical heart valves at different implantation angles
    Liu Jingxin , Deng Xiaoyan , Ao Haiyong , Zhang Quanchao
    Adopted date: April 04,2024
    [Abstract](18) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Aim: To study comparatively the effects of different implantation angles of bi-leaflet mechanical valve on the swirling flow in the ascending aorta. Method: Based on the aortic CT images of a healthy volunteer, using a computational simulation, the effects of 4 different valve implantation orientations (0 ° , 45 ° , 90 ° and 135 o) on the aortic rotational flow were studied. Results: The results showed that the implantation of BMHV can seriously interfere with the aortic rotational flow, affecting the structure and helicity distribution of the rotational flow in the ascending aorta, and resulting in disturbed blood flows distal to the valve. For the case studied in this paper, the 135-degree implantation angle caused the most disruption to the swirling flow, leading to the largest areas of reversed rotational flows, while the 0-degree and 45-degree implantation angles caused relatively less damage to the swirling flow. The areas with low wall shear stress (WSS less than 0.5 Pa) was the smallest when the implantation angle of BMHV was 0 o. Conclusions: When the implantation angle was between 0 o and 45o, the disruption of BMHV to the swirling flow in the ascending aorta was relatively small. Therefore, for different patients, the choice of the implantation angle should be individualized according to the spatial geometry of their aorta, including the aortic sinuses.
    Photoplethysmography Pulse Wave Signal Detection and Pulse Rate Characteristics based on in Vitro Experiment
    HE Wei-jun , LIU Yong-tao , LIU Deng-ji , YIN Kai , HE Ying , CHI Qing-zhuo , MU Li-zhong
    Adopted date: April 04,2024
    [Abstract](12) [HTML](0) [PDF 0.00 Byte](0)
    Abstract:
    Objective Pulse rate variability has been widely used as a proxy for heart rate variability. However, studies have shown that a variety of factors, such as respiratory system and autonomic nervous regulation, can affect the consistency of the two. This study hopes to take advantage of the controllable parameters of the experimental system of cardiopulmonary bypass, and investigate whether the changes of blood flow parameters have an effect on pulse rate through a series of experiments. Methods In this study, a set of human circulatory system equipped with an in vitro wrist model was established. By changing the parameters of heart rate, wrist flow, pressure and system compliance, the photoplethysmography pulse wave signal was obtained from the wrist model and the time-domain and frequency domain indexes of pulse rate variability were extracted. Results The change of heart rate, pressure and system compliance will cause the change of pulse shape, but the time domain indexes NN50 and PNN50, which can indicate the pulse rate variability, are 0, and other indexes and frequency domain indexes are in the very low value category. Conclusions In the absence of heart rate variability, hemodynamic changes such as heart rate, wrist flow, blood pressure and system compliance did not produce significant pulse rate variability. This study can provide a reference for more studies on pulse rate variability and heart rate variability with more convenient wrist acquisition equipment.