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28 October 2024, Volume 28 Issue 30 Previous Issue   

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Finite element analysis of effect of proximal fibular fracture on knee joint stress in an extended state Wang Jiaqi, Tang Jiangan, Huang Guohua, Kong Dece, Zhao Yiding, Gong Lulu, Pan Hongyuan, Kong Dewei, Liu Yue, Yang Tieyi 2024, 28 (30):  4757-4762.  doi: 10.12307/2024.635 Abstract ( 99 )   PDF (1332KB) ( 29 )   Save BACKGROUND: The traditional view is that proximal fibular fractures do not require fixation. Others and our research suggest that the proximal fibular structure plays an important role in the stability of the posterolateral structure of the knee joint, and its mechanism of action is worth studying. OBJECTIVE: To investigate the biomechanical effects of proximal fibular fractures on various structures of the knee joint in an extended state. METHODS: Finite element method was used to conduct simulated biomechanical experiments. A healthy young male volunteer was selected to establish a finite element model of the knee joint in an extended state using MRI and CT image data, and four proximal fibular shapes were simulated (Model A: intact, Model B: 1 cm fracture below the fibular head, Model C: 1 cm tip defect fracture from the proximal end of the fibula to the distal end, and Model D: 2 cm bone defect from the proximal end of the fibula). A longitudinal concentrated load of 1 500 N was applied to the femoral shaft to compare and analyze the distribution and changing trend of the maximum equivalent stress and maximum first principal stress of each structure of the knee joint in an extended state under four working conditions.  RESULTS AND CONCLUSION: (1) In Model A, the maximum equivalent stress in the tibial cartilage and lateral compartment of the meniscus was greater than that in the medial compartment, while the maximum first principal stress in the tibial plateau and medial compartment of the meniscus was greater than that in the lateral compartment. The maximum equivalent stress of the medial condyle of the femoral cartilage was greater than that of the lateral condyle, and the maximum first principal stress of the medial condyle of the femoral cartilage was greater than that of the medial condyle. (2) Compared to Model A, there was no significant difference in the magnitude and distribution of the maximum equivalent stress and maximum first principal stress in the cartilage and meniscus of Model C. (3) Compared to Model A, the maximum equivalent stress increase amplitude of Model B was in the order of medial tibial cartilage (14.9%), medial condyle of femoral cartilage (13.6%), and medial meniscus (6.6%). The maximum first principal stress increase amplitude was the medial meniscus (11.06%), the medial tibial cartilage (8.65%), and the medial condyle of the femoral cartilage (7.46%). The maximum equivalent stress increase amplitude of the ligament was as follows: popliteal arch ligament (33.2%)>anterior cruciate ligament (21.3%)>fibular collateral ligament (17%)>posterior cruciate ligament (14.3%)>anterior lateral collateral ligament (13.2%)>medial collateral ligament (10.1%). (4) Compared to Model A, the maximum equivalent stress increasing trend of Model D followed the medial tibial cartilage (19.5%), femoral cartilage medial condyle (17.9%), and medial meniscus (9.9%). The maximum first principal stress in sequence was the medial meniscus (14.04%), the medial tibial cartilage (13.03%), and the medial condyle of the femoral cartilage (11.37%). The increasing trend of maximum equivalent stress in ligaments was as follows: anterior cruciate ligament (25.2%)>posterior cruciate ligament (18.9%)>medial collateral ligament (18.5%)>anterior lateral collateral ligament (12.7%). (5) It is suggested that when the knee joint is extended, a 1 cm fracture below the fibular head and a 2 cm fibular tip bone defect have a significant impact on the structure of the medial ventricular cartilage, anterior cruciate ligament, and posterior lateral ligament complex.   Figures and Tables | References | Related Articles | Metrics

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Three internal fixation devices used for finite element analysis of Pauwels type III femoral neck fractures Qi Yuanbo, Li Jiantao, Liu Daohong, Tao Sheng, Wang Daofeng, Wu Jie 2024, 28 (30):  4763-4769.  doi: 10.12307/2024.645 Abstract ( 113 )   PDF (1423KB) ( 23 )   Save BACKGROUND: At present, there is still controversy in clinical practice about the choice of internal fixation of Pauwels type III femoral neck fracture, and the selection of internal fixation that provides stable fixation strength is the key basis for achieving Pauwels type III fracture fixation. OBJECTIVE: The three-dimensional finite element analysis method was used to test the difference in biomechanical strength of three types of internal fixation in Pauwels type III femoral neck fracture, which provided a reference for its clinical treatment. METHODS: Using the CT data of the left femur of a healthy male volunteer, a complete femur and its cancellous bone were reconstructed in Mimics software, and Geomagic studio software was used for reverse modeling. Cannulated compression screw, dynamic hip screw, and femoral neck system were created in UG-NX software. Three kinds of internal fixation models were assembled on the femur model, and Pauwels type III femoral neck fracture was simulated by Hypermesh software. Finally, Abaqus software was used to carry out finite element experimental analysis to analyze and compare the stress distribution, stress peak, strain, and displacement distribution caused by fixed femoral neck fracture of different internal fixation systems. RESULTS AND CONCLUSION: (1) The stress of the proximal femur bone mass was mainly distributed in the area below the femoral neck near the fracture end, with the highest stress peak in the dynamic hip screw group and the smallest in the femoral neck system group. (2) The stress distribution of the internal fixation device was mainly concentrated on the screw surface near the fracture line, with the highest stress peak in the femoral neck system group and the smallest in the dynamic hip screw group. (3) The main strain field of the proximal femur bone mass was distributed in the upper surface area where the bone and screw contacted, and the yield strain was the smallest in the femoral neck system group and the largest in the cannulated compression screw group. (4) The main strain field of the internal fixation device model was distributed on the upper surface of the femoral neck screw, with the yield strain being the smallest in the femoral neck system group and the largest in the cannulated compression screw group. (5) The displacement distribution values of femur, proximal bone mass, distal bone block, internal fixation device and internal fixation with the femur as a whole in the three femoral neck fracture internal fixation models decreased gradually from proximal to distal, and the peak displacement of the femoral neck system group was the largest and the lowest in the dynamic hip screw group. (6) The results showed that when the Pauwels type III femoral neck fracture was fixed, the stress distribution of femoral neck system was more uniform, the mechanical conduction characteristics were better, and it was subjected to lower yield strain, higher stress and higher displacement. It has relatively better biomechanical stability and can provide a superior mechanical environment for fracture healing. Figures and Tables | References | Related Articles | Metrics

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Finite element analysis of reamed versus undreamed proximal femoral nail antirotation-II in treatment of 31-A3 intertrochanteric femur fracture Liu Zemin, Wang Dong, Li Yan, Liu Min, Chen Bin, Wang Caoqi, Lyu Xin, Zhang Yonghong 2024, 28 (30):  4770-4776.  doi: 10.12307/2024.624 Abstract ( 103 )   PDF (1373KB) ( 21 )   Save BACKGROUND: There is controversy regarding the need for marrow reaming in intertrochanteric fractures of the femur. Some believe that unreaming shortens operative time, reduces bleeding, and decreases intraoperative risk in elderly patients, but there is no basis for whether this move reduces the effectiveness of intramedullary nail support. Others believe that reaming allows for the selection of thicker diameter intramedullary nails for better mechanical support, but basic studies have shown that this approach carries risks such as fat embolism and destruction of bone (especially in elderly patients with osteoporosis).  OBJECTIVE: To analyze the mechanical distribution characteristics of reamed and unreamed proximal femoral nail antirotation-II in the treatment of type 31-A3 intertrochanteric fractures by finite element analysis.  METHODS: A healthy volunteer was included, and CT scans of his femur were obtained in DICOM format, and the files were sequentially imported into Mimics, Geomagic Wrap, SolidWorks, Hypermesh, and Ansys software for processing. The A3.1, A3.2, and A3.3 intertrochanteric fracture models were obtained and assembled with 9 mm, 11 mm diameter, and 170 mm length intramedullary nails, respectively, followed by assigning material properties, setting the interaction relationship of each contact surface and defining the load and boundary conditions, and then solved. The femoral stress distribution, internal fixation stress distribution, femoral displacement, and internal fixation displacement were observed in different models.  RESULTS AND CONCLUSION: (1) The femoral stress was less than that of unreamed intramedullary nail fixation for each type of fracture, and the maximum stress value of the femur for A3.3 fracture was greater than that of A3.1 and A3.2. (2) The internal fixation stress was greater than that of unreamed intramedullary nail fixation for each type of fracture, and the maximum stress value of internal fixation for A3.3 fracture was greater than that of A3.1. (3) Reamed versus unreamed intramedullary nailing has less effect on femoral and internal fixation displacement and more effect on stress. (4) It is indicated that the use of reamed intramedullary nail fixation results in a reduction in femoral stress, an increase in the stress borne by the internal fixation as a whole, and a reduction in the stress borne by the distal locking nail. The use of reamed intramedullary nail fixation may provide better treatment results compared to unreamed intramedullary nail fixation. Figures and Tables | References | Related Articles | Metrics

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Finite element method predicts the effect of screw placement position in anterior cervical discectomy and fusion on stability of internal fixation Ji Xinghua, Wei Jinzheng, Hao Shuai, Xing Zejun 2024, 28 (30):  4777-4782.  doi: 10.12307/2024.636 Abstract ( 81 )   PDF (1186KB) ( 17 )   Save BACKGROUND: The angle of screw placement in anterior cervical discectomy and fusion plays a crucial role in determining the stability of the internal fixation system.  OBJECTIVE: To predict the impact of different screw placement angles on the stress experienced by the internal fixation system in anterior cervical discectomy and fusion utilizing finite element analysis, with the ultimate goal of identifying the optimal screw placement angle.  METHODS: A three-dimensional reconstruction method was employed to establish a mechanical model of the cervical spine, enabling the simulation of three distinct working conditions: scoliosis, uprightness, and forward flexion. In SolidWorks 2017, the anterior cervical plate and screw models were built according to different placement angles of the screws, with a as the inward offset, b as the ideal position, c as the outward offset, d as the downward offset, and e as the upward offset. The stress distribution of internal fixation system at different screw placement angles was observed, and the stress and displacement were recorded. RESULTS AND CONCLUSION: (1) By constructing a finite element model of the entire cervical spine and incorporating an anterior titanium plate, it was found that the biomechanical changes in the spine did not significantly differ based on the various angles of screw insertion on the titanium plate under the same working conditions. (2) However, microscopic analysis revealed that the outward offset (c) screw position exhibited the most effective resistance against side bending, while the downward offset (d) screw demonstrated optimal load-bearing capacity in the upright condition. Additionally, the outward deviation (c) screw displayed superior anti-bending effects in the reverse buckling condition. (3) The fixation effect of the internal fixation device remained relatively stable across different motion conditions. Although there was a 10% variation in the internal fixation effect under the three working conditions when the screw was placed inward, outward, downward, or upward, the displacement changes were minimal. These findings suggest that the requirements of load bearing, bending resistance, and flexion resistance could be simultaneously met without a specific optimal screw location in clinical practice. (4) The placement direction of titanium plate screw in anterior cervical disc-resection and fusion has little effect on the mechanical stability of the cervical spine. The screw angles in different directions have little influence on the stability of the internal fixation device in the lateral, upright, and forward flexion movements of the cervical spine. There is no need to pursue the direction of screw placement in clinical operations. Figures and Tables | References | Related Articles | Metrics

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Finite element modal analysis of whole spine in adolescent idiopathic scoliosis Zhang Yufang, Li Shuai, Liu Ning, Guo Haiwei, Qi Xiaohua, Lyu Meng 2024, 28 (30):  4783-4787.  doi: 10.12307/2024.627 Abstract ( 89 )   PDF (1487KB) ( 60 )   Save BACKGROUND: Vibration environment can cause spinal injury, especially in patients with scoliosis. At present, there is no information about the inherent mode of the whole spine from T1 to the pelvis in scoliosis patients in the free state.  OBJECTIVE: To analyze the dynamic characteristics of the whole spine in patients with scoliosis by the finite element method.  METHODS: Based on CT scan images, a three-dimensional finite element model of the T1-pelvic total spine of an 11-year-old patient with thoracolumbar biflexion scoliosis was established, and the Cobb angles of thoracolumbar scoliosis were 36° and 24°, respectively. The mode analysis in the free state of the whole spine was carried out by the finite element method.  RESULTS AND CONCLUSION: The fifteen-order free modes of the spine were extracted, and the dynamic characteristics of the scolio-curved spine were obtained. The resonance frequency distribution of the spine was concentrated. The thoracic vertebra was the most deformed in the whole spine model, and the amplitude of the thoracic vertebra was larger than that of the lumbar vertebra. Modal analysis was used to analyze the vibration characteristics of scoliosis patients in the vibration environment. It is of great significance to determine the natural frequency, vibration mode, and amplitude of scoliosis patients for analyzing the vibration characteristics of scoliosis.  Figures and Tables | References | Related Articles | Metrics

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Effect of positioning and non-positioning cervical rotatory manipulation on tensile mechanical properties of internal carotid artery with different degrees of atherosclerosis Zhang Shaoqun, Zheng Chuanjiang, Liu Jiafu, Jiang Shunwan 2024, 28 (30):  4788-4794.  doi: 10.12307/2024.630 Abstract ( 78 )   PDF (960KB) ( 20 )   Save BACKGROUND: Cervical rotatory manipulation is widely used in the treatment of neck-related diseases with a clear curative effect, but it also has some risks in clinical practice. The previous study of our group found that cervical rotatory manipulation can reduce the tensile mechanical properties of the atherosclerotic carotid artery, but it is not clear about the effects of different cervical rotatory manipulations (positioning/non-positioning) and different degrees (mild/moderate/severe) of atherosclerosis on the tensile mechanical properties of the carotid artery.  OBJECTIVE: To explore the effects of different cervical rotatory manipulations and different degrees of atherosclerosis on the tensile mechanical properties of the internal carotid artery.  METHODS: The 120 male New Zealand rabbits were randomly divided into eight experimental groups with different degrees of atherosclerosis and different cervical rotatory manipulations: severe atherosclerosis + positioning/non-positioning cervical rotatory manipulation, moderate atherosclerosis + positioning/non-positioning cervical rotatory manipulation, mild atherosclerosis + positioning/non-positioning cervical rotatory manipulation, and normal rabbit + positioning/non-positioning cervical rotatory manipulation, as well as three model control groups: mild/moderate/severe atherosclerosis + non-cervical rotatory manipulation, and the blank control group. Two-factor analysis of variance was used to explore the main effects and interactive effects of different cervical rotatory manipulations and different degrees of atherosclerosis on the tensile mechanical properties of the internal carotid artery. One-way analysis of variance was applied to explore the influence of different cervical rotatory manipulations on the tensile mechanical properties of the internal carotid artery under the same degree of atherosclerosis.   RESULTS AND CONCLUSION: (1) Both different cervical rotatory manipulations and different degrees of atherosclerosis were the main effect factors affecting the tensile mechanical properties of the internal carotid artery. (2) For both mild and severe atherosclerosis, both positioning and non-positioning cervical rotatory manipulations reduced the maximum stress of the internal carotid artery (P < 0.05) and also increased the physiological elastic modulus of the internal carotid artery (P < 0.05). (3) For moderate atherosclerosis, positioning and non-positioning cervical rotatory manipulations also increased the physiological elastic modulus of the internal carotid artery (P < 0.05). Non-positioning cervical rotatory manipulation reduced the maximum strain of the internal carotid artery (P < 0.05), and its maximum strain was also less than the internal carotid artery of the positioning cervical rotatory manipulations (P < 0.05). (4) For the normal internal carotid artery, in addition to the maximum strain, both positioning and non-positioning cervical rotatory manipulations had no statistically significant effects on other tensile mechanical indicators of the internal carotid artery (P > 0.05). (5) The results suggest that both positioning and non-positioning cervical rotatory manipulations may increase the stiffness of the atherosclerotic internal carotid artery, reducing its elasticity and brittleness. Therefore, both positioning and non-positioning cervical rotatory manipulations may increase the risk of cardiovascular events in mild/moderate/severe atherosclerotic internal carotid artery, and the more severe the atherosclerosis is, the greater the risk of positioning/non-positioning cervical rotatory manipulation treatment, but the risk of positioning cervical rotatory manipulation is not lower than that of non-positioning cervical rotatory manipulation.  Figures and Tables | References | Related Articles | Metrics

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Establishing equivalent model to verify the precision of personalized bone model rapidly Zhang Aili, Huang Jiazheng, Fan Wen, Li Yihuan, Li Shuang, Gan Xuewen, Xiong Ying 2024, 28 (30):  4795-4799.  doi: 10.12307/2024.650 Abstract ( 67 )   PDF (1240KB) ( 16 )   Save BACKGROUND: Currently, the verification of the precision of personalized bone models is usually performed by methods such as paired t-tests or intraclass correlation coefficient, but such methods often require the production of large batches of models, which do not satisfy the need for immediate use of personalized models. OBJECTIVE: To study the feasibility of establishing the equivalent model to verify the precision of the personalized bone model rapidly. METHODS: Bone CT images of three adults were randomly obtained for reconstruction. 3D printing was used to create personalized bone models, and then the personalized bone models were scanned using CT and reconstructed. Mimics was used to compare the reconstructed models of bone CT images with the bone CT images. Geomagic Studio was used to analyze the fitting deviation between the reconstruction model of personalized bone model CT image and the reconstruction model of skeletal CT image. The 3D-printed personalized bone model was measured against the measurement positions and dimensions marked on the reconstruction model of skeletal CT image, and the error was calculated. RESULTS AND CONCLUSION: (1) By comparing the reconstructed bone CT image model with the bone CT scan image, the two were compatible in terms of anatomical structure and morphology, and the contours almost overlapped. (2) By fitting bias analysis, the standard bias was 0.176, 0.226, and 0.143 mm in order, and all the results were < 0.25 mm. (3) By measuring and calculating the model, the mean relative errors were 0.44%, 0.21%, and 0.13%, and all the results were within 5% error. (4) The constructed equivalent model was in line with the basic conditions for making personalized bone models. The established equivalent model met the clinical needs and design requirements, and it was feasible to use the method of the equivalent model to verify the precision of the personalized bone model quickly. (5) This method could provide a targeted and rapid way to verify the precision of personalized bone models. It could achieve the goal of providing immediate clinical use without the need to produce large batches of models compared to conventional methods such as paired t-tests or intraclass correlation coefficient.  Figures and Tables | References | Related Articles | Metrics

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Reverse design of a new type of low-profile lateral malleolus steel plate assisted by computer bioengineering technology Wang Xiao, Zhang Fan, Lin Lupan, Qi Tianxu, Lin Fuqing 2024, 28 (30):  4800-4805.  doi: 10.12307/2024.637 Abstract ( 72 )   PDF (1477KB) ( 17 )   Save BACKGROUND: Poor incision healing and infection often occur in elderly patients with lateral malleolar fractures after traditional lateral plate fixation. With the application of engineering software in medicine, a new type of plate placed posterolateral can be designed to solve the above-described problems. OBJECTIVE: To design a new type of posterior lateral low-profile steel plate with the aid of medical bioengineering software, based on the 3D CT data of the distance between the top of the lateral ankle fracture line to the anterior starting point (ACD), the distance between the top of the fracture line to the tip of the lateral ankle (CTD), the distance between the top of the fracture line to the posterior edge of the fracture line (PCD) and the angle between the anterior and posterior lateral sides of the distal fibula (CA).  METHODS: Thirty cases of unstable lateral malleolar fracture and normal ankle were taken for CT scanning and three-dimensional reconstruction. The ACD, CTD, and PCD values in patients with lateral malleolar fracture were measured by 3-matic software, and the characteristics of lateral malleolar fracture line were plotted and described. The mimics software was used to measure the value of CA in the normal ankle joint. Based on the data measured above, 3-matic software and solidworks software were used to design the low-profile steel plate and the thickness of the steel plate and the direction of the nail path were constructed. In Geomagic Studio software, fine surface, automatic surface, and fitting surface were used to generate the prototype of the low-profile steel plate, and then 3D printing was performed. After making a posterolateral incision of the lateral malleolus, the peroneus longus and brevis tendons were removed, and the prototype of the 3D-printed steel plate was placed behind the fibula to test its size and fit to the bone surface. RESULTS AND CONCLUSION: (1) The mean of ACD was (2.97±0.03) cm, and the variation was 5.23. The mean of PCD was (3.17±0.11) cm, and the variation was 17.60. The mean of CTD was (4.52±0.07) cm, and the variation was 8.60. (2) The fracture line of the lateral malleolus was drawn with an inverted “V” shape. The mean of CA between anterior and posterior lateral surfaces of the distal fibula was (103.20±1.94)°. At the midpoint section of the upper and lower vertices of the anterior edge of the distal fibula, the angle of the anterior and posterior lateral sides (CA) of the distal fibula was (78.50±1.78)°. (3) By using 3-matic, Solidworks, and Geomagic Studio software, a new type of posterior lateral low-profile steel could be successfully designed. Three to four holes were reserved for the screw holes at the proximal end of the plate with screw directions from back to front, and three screw holes were reserved on the inner and outer sides at the far end. The direction of the inner three holes could be from back to front, and the outer three screw holes needed to be biased towards the inner side, with an angle of 9.72°-13.28°. (4) It is indicated that the variability of the ACD position on the anterior lateral fracture line of the lateral malleolus is relatively small, while the variability of the posterior lateral PCD position is relatively large. The angle between the anterolateral and posterolateral sides of the lateral ankle fracture block shows a decreasing trend, with a smaller variation in the proximal angle and a larger variation in the distal angle. Based on three-dimensional CT reconstruction data of the external ankle, with the help of computer bioengineering software and the use of reverse design concept, a new type of low-profile lateral malleolus steel plate with a good fit can be quickly and conveniently designed to provide a valuable reference for the design of internal fixation devices. Figures and Tables | References | Related Articles | Metrics

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Multi-criteria decision model in treatment of adolescent scoliosis with three-dimensional printed scoliosis orthosis Zhang Hongsheng, Huang Hanwei, Wang Jinwu, Zheng Junwei, Liu Rixin, Liao Zijie, Wang Peng, Xu Yuanjing, Wang Zanbo, Wan Keming 2024, 28 (30):  4806-4811.  doi: 10.12307/2024.634 Abstract ( 70 )   PDF (962KB) ( 28 )   Save BACKGROUND: Traditional scoliosis orthosis has some disadvantages, such as complex manufacturing process, long processing cycle, poor fit and so on. Three-dimensional printed scoliosis orthosis has the advantages of high manufacturing precision and personalization. OBJECTIVE: To evaluate the efficacy of three-dimensional printed scoliosis orthosis for scoliosis based on multi-criteria decision model.  METHODS: Clinical data of 72 patients with scoliosis admitted to Chen Xinghai Hospital of Integrated Traditional Chinese and Western Medicine from January 2019 to October 2022 were retrospectively collected and divided into two groups according to the treatment of orthosis. Study group (n=23) received three-dimensional printed scoliosis orthosis. Traditional group (n=49) received the traditional polypropylene spine brace treatment. The clinical efficacy and complications were compared between the two groups. A multi-criteria decision model for the treatment of scoliosis with three-dimensional printed scoliosis orthosis was established, and the stability of the benefit value, risk value and decision model of the two groups were evaluated.  RESULTS AND CONCLUSION: (1) Compared with the traditional group, there were significant differences in the top vertebral offset distance, Cobb angle, top vertebral rotation, Functional Movement Screen score, visual analog scale score and total effective rate in the study group at 6 months after surgery (P < 0.05). (2) Among the benefit indexes, Cobb angle had the greatest impact on the condition of patients, while the risk indexes had the greatest impact on dyspnea. (3) The benefit values of the study group and the traditional group for scoliosis were 79 and 64, and the risk values were 74 and 57, respectively. The combined benefit and risk values found that the benefit-risk value of the study group was 16 higher than that of the traditional group. (4) In the range of 0-100% relative risk weight, the benefit-risk value of the study group was always higher than that of the traditional group, which proved that the multi-criteria decision-making model had good stability. (5) It is indicated that three-dimensional printed scoliosis orthosis can better restore the physiological curvature of scoliosis and improve the efficiency of treatment. Figures and Tables | References | Related Articles | Metrics

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Application of mixed reality technology in vertebroplasty Jiang Yong, Guan Tianmin, Ci Yuan, Zhu Ye, Zhao Peng, Zheng Jiafa, Yang Tao, Zhang Guangyu 2024, 28 (30):  4812-4816.  doi: 10.12307/2024.633 Abstract ( 98 )   PDF (1419KB) ( 57 )   Save BACKGROUND: How to improve the accuracy of puncture, reduce surgical damage, and improve surgical efficiency during vertebroplasty is currently one of the focuses of exploration and improvement in vertebroplasty techniques.  OBJECTIVE: To explore the clinical significance of application of mixed reality technology in percutaneous vertebroplasty for spinal fractures. METHODS: Two patients with osteoporotic vertebral compression fracture in Dalian Second People’s Hospital in June 2023 were selected. Before operation, 128-row CT scanning of the lumbar spine was performed and the original data of digital imaging and communications in medicine (DICOM) were obtained. Visual Volume software was used to build the three-dimensional network model of vertebral compression fracture. Holographic imaging glasses were used to accurately map 3D network model images to the real world, assist the surgeon in completing preoperative simulation, explaining preoperative conditions and treatment plans, and guiding puncture and bone cement injection during surgery. RESULTS AND CONCLUSION: (1) Precise puncture was achieved with the assistance of a mixed reality technology. Postoperative imaging examination showed good bone cement filling and no obvious leakage. The postoperative symptoms of the patient were alleviated well, and they were able to move to the ground on the same day after surgery. (2) It is concluded that a mixed reality technology is helpful for preoperative surgical design and communication efficiency with patients and their families. Assisting with precise puncture during surgery, shortening surgical time, and reducing side injuries is a new and effective clinical diagnosis and treatment model, which has development potential in minimally invasive, precise, and personalized treatment of spinal surgery. Figures and Tables | References | Related Articles | Metrics

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Biomechanical optimization scheme of artificial ankle inserts based on porous structure design Xu Zhi, Liu Ziming, Li Yuwan, , Chen Yufei, Jin Ying, Rao Jingcheng, Tian Shoujin 2024, 28 (30):  4817-4824.  doi: 10.12307/2024.644 Abstract ( 79 )   PDF (1650KB) ( 34 )   Save BACKGROUND: Prosthesis loosening and wear are still the main problems in the failure of total ankle replacement, which are closely related to the micro-motion of the implant-bone interface, the contact stress of the articular surface and joint motion. The design of artificial joint components, including insert and tibial/talar stem prosthesis, is a key factor affecting the force, motion, and micromotion of the contact interface of the ankle joint. The development of new inserts is of great significance to improve the survival rate of artificial ankle joints. OBJECTIVE: The finite element model of the total ankle replacement model was constructed to detect the biomechanical properties of the porous structure-optimized inserts, and the effect of the porous structure-optimized inserts on reducing prosthesis micromotion and improving the contact behavior of the articular surface was analyzed. METHODS: Based on the CT scan data of the right ankle joint of a healthy adult and the INBONE II system product manual, a three-dimensional model including bone and artificial joint system was established, and the total ankle replacement model (model A) was obtained after osteotomy and prosthesis installation, and then through four new types of inserts, G50, G60, D50, and D60, were obtained by transforming the porous structure of the original insert, and the original one was replaced with different inserts to establish an optimized total ankle replacement model (models B-E) corresponding to the inserts. The gait loads were applied on the five models to simulate the gait conditions. The differences in micromotion and articular surface contact behaviors at the implant-bone interface of all five models were compared.  RESULTS AND CONCLUSION: (1) In the gait cycle, the micromotion of the prosthesis of the four optimized total ankle replacement models was lower than that of the original model. Compared with model A, the micromotion of the prosthesis in models B-E decreased by 5.4%, 10.1%, 8.1%, and 20.9%, respectively. The high micromotion area of the tibial groove dome in the optimized model was significantly smaller than that of the original model. (2) The four optimized models obtained a larger articular surface contact area. Compared with model A, the average contact area of the inserts in models B-E increased by 11.8%, 14.7%, 8.1%, and 32.6%, respectively. (3) Similar to the effect of increasing the contact area, compared with the original model, the contact stress of the optimized model decreased in varying degrees, and the value of model E decreased the most significantly (P < 0.05), it is due to good mechanical properties and large porosity of the Diamond lattice that constitutes the D60-type insert. (4) The research results show that the use of porous structure to improve the inserts can improve the elasticity of the inserts and increase its ability to absorb joint impact, for favorable conditions are created for reducing micromotion at the implant-bone interface and improving joint contact behavior. Figures and Tables | References | Related Articles | Metrics

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Moderate and severe valgus knee by total knee arthroplasty through medial and lateral parapatellar approach Wang Tihui, Wang Xu, Wu Jinqing, Chen Jiliang, Wang Qijin, Xu Hongwei, Lin Jianguo 2024, 28 (30):  4825-4830.  Abstract ( 56 )   PDF (2189KB) ( 38 )   Save BACKGROUND: Prosthesis restricted selection, soft tissue release, patellar trajectory recovery, and bone defect reconstruction were need to be optimized in total knee arthroplasty for moderate and severe valgus knee. The medial parapatellar approach has disadvantages in the treatment of valgus knee, such as aggravating the medial soft tissue relaxation. In recent years, it has been found that the lateral parapatellar approach has advantages in the treatment of valgus knee, such as exposure and release.  OBJECTIVE: To observe the efficacy of the lateral and medial parapatellar approach in total knee arthroplasty for moderate and severe valgus knee, and to explore a more suitable surgical approach for moderate and severe valgus knee.  METHODS: Totally 56 patients with moderate and severe valgus knee underwent total knee arthroplasty and would take turns performing surgery through the medial and lateral parapatellar approach according to the order of admission. The lateral group (n=28) underwent total knee arthroplasty through lateral parapatellar approach, and the medial group (n=28) through medial parapatellar approach. Posterior stablized knee prosthesis was used in all patients. The restricted types of prosthesis, thickness of polyethylene, operation time, amount of blood loss, femoro-tibia angle, patellar tilt angle, range of motion, Hospital for Special Surgery score, Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and complications were collected as observation indexes for statistical analysis.   RESULTS AND CONCLUSION: (1) The utilization rate of condyle-restricted prosthesis in the lateral group was significantly lower than that in the medial group. The average thickness of polyethylene liner was lower, and the operation time was shorter in the lateral group compared with the medial group. There were significant differences between the two groups (P < 0.05), and there was no significant difference in the amount of surgical bleeding. (2) 56 patients were followed up for an average of 2-5 years. There were no signs of prosthesis loosening or bone resorption in all patients. The average patellar tilt angle and femoral tibial angle of the lateral group were lower than those of the medial group, and the average Hospital for Special Surgery score and WOMAC score of the lateral group were higher than those of the medial group, with significant differences (P < 0.05). There was no significant difference in the range of motion of the knees between the two groups. (3) Incision fat liquefaction and calf intermuscular venous thrombosis occurred in one case in each group. No infection, poor incision healing, incisional hematoma, prosthesis dislocation, iatrogenic nerve injury, ectopic ossification, or periprosthesis fracture occurred during follow-up. (4) In conclusion, the treatment of moderate and severe valgus knee by lateral parapatellar approach can better protect the tension of the medial soft tissue of the knee, use less condylar restrictive prostheses, and have a more friendly patellar trajectory and higher postoperative function score. Figures and Tables | References | Related Articles | Metrics

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Analgesic effect of cocktail therapy combined with femoral nerve block in unicompartmental knee arthroplasty Wang Guoliang, Pei Fang, Peng Dalin, Jin Wangyi, Yan Ziwen, Zhou Shen, Wang Yuan, Guo Kaijin 2024, 28 (30):  4831-4836.  doi: 10.12307/2024.623 Abstract ( 80 )   PDF (1177KB) ( 17 )   Save BACKGROUND: With the further development of minimally invasive concepts, unicompartmental knee arthroplasty has become an important treatment for osteoarthritis of the knee; however, early postoperative pain adversely affects the recovery process, so effective analgesic measures are necessary. Femoral nerve block and cocktail therapy are common analgesic methods for unicompartmental knee arthroplasty, but there is a lack of studies confirming the analgesic effect and safety of their combined application.   OBJECTIVE: To investigate the analgesic effect of cocktail therapy combined with femoral nerve block in unicompartmental knee arthroplasty.  METHODS: One hundred patients who received unicompartmental knee arthroplasty from October 2021 to January 2023 were selected as the study subjects. They were divided into a control group (n=50) and a study group (n=50) using a random number table method. The femoral nerve block was used in the control group, while cocktail therapy combined with femoral nerve block was used in the study group during unicompartmental knee arthroplasty. Postoperative analgesia effect, analgesic frequency of dezocine injection within 2 days after surgery, motion range of affected knee joint, KSS function scores, and the occurrence of postoperative adverse reactions were compared between the two groups. RESULTS AND CONCLUSION: (1) Visual analog scale scores in the study group were lower than those in the control group at 12, 24, and 48 hours after surgery (P < 0.05). (2) The analgesic frequency of dezocine in the study group was less than that in the control group within 2 days after surgery (P < 0.05). (3) The motion range in the study group was higher than that in the control group 1 and 3 days after surgery (P < 0.05). On day 14 after surgery, there was no significant difference in motion range between the two groups (P > 0.05). (4) The knee KSS score in the study group was higher than that in the control group at 2 weeks after surgery (P < 0.05). There was no statistically significant difference in knee KSS scores between the two groups from 6 weeks to 6 months after surgery (P > 0.05). (5) The difference in the occurrence of adverse reactions within 14 days after surgery was not significant between the two groups (P > 0.05). (6) These results show that the use of cocktail therapy combined with femoral nerve block in unicompartmental knee arthroplasty can effectively reduce postoperative pain, improve the analgesic effect, reduce the frequency of analgesic drugs, and improve motion range of the early affected knee joint of patients. Figures and Tables | References | Related Articles | Metrics

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Risk factors and establishment of a nomogram prediction model for hypoproteinemia after hip revision Chen Junfeng, Xie Rongzhen, Hong Weishi, Sun Yu 2024, 28 (30):  4837-4841.  doi: 10.12307/2024.646 Abstract ( 72 )   PDF (925KB) ( 15 )   Save BACKGROUND: The high rate of postoperative hypoproteinemia in patients undergoing hip revision is associated with severe trauma, which affects the rapid recovery of patients. OBJECTIVE: To investigate the risk factors of perioperative hypoproteinemia in patients with hip revision, and to provide guidance for early screening of high-risk patients with postoperative hypoproteinemia.  METHODS: According to the inclusion and exclusion criteria, 161 patients who underwent hip revision were divided into hypoproteinemia group (76 cases) and normal group (85 cases). The rate of hypoproteinemia was 47.2%. Data such as age, gender, body mass index, osteoporosis, operation time, preoperative erythrocytes, preoperative hemoglobin, preoperative leukocytes, preoperative platelets, preoperative fibrinogen, preoperative C-reaction protein, preoperative sedimentation rate, preoperative blood calcium, preoperative albumin, postoperative drainage tube placement, American Society of Anesthesiologists score, and postoperative hypoproteinemia were collected. SPSS software was used to analyze the independent risk factors of hypoproteinemia after hip revision using multivariate binary logistic regression analysis. R software was used to construct the nomogram prediction model. Receiver operating characteristic curve and calibration curve and decision curve were drawn to evaluate the model.  RESULTS AND CONCLUSION: (1) Univariate analysis results showed that body mass index, preoperative erythrocytes, preoperative hemoglobin, preoperative platelets, preoperative fibrinogen, preoperative C-reaction protein, and operation time were significantly different between the two groups (P < 0.05). (2) Multivariate binary Logistic regression analysis results showed that body mass index (OR=0.859, P=0.021), operation time (OR=1.010, P=0.002), preoperative erythrocytes (OR=0.424, P=0.036), and preoperative C-reaction protein (OR=1.043, P=0.032) levels were independent risk factors for postoperative hypoproteinemia in patients with hip revision. (3) Based on four independent risk factors: body mass index, operation time, preoperative erythrocytes and preoperative C-reaction protein, the nomogram can effectively predict the risk of hypoproteinemia after hip revision. This nomogram prediction model has good differentiation and accuracy, and may lead to better clinical net benefits for patients. Figures and Tables | References | Related Articles | Metrics

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Comparison of percutaneous transverse fixation of a Kirschner wire with miniplate placement for treatment of a fifth metacarpal shaft fracture Zhang Zheng, Zhang Daijie, Li Peng 2024, 28 (30):  4842-4847.  doi: 10.12307/2024.626 Abstract ( 95 )   PDF (1189KB) ( 32 )   Save BACKGROUND: Fractures of the fifth metacarpal shaft are common in the clinic, and surgical treatment is mostly performed with open reduction plate fixation, but postoperatively, most patients require removal of the internal fixation and require secondary hospitalization. Transcutaneous fixation with a Kirschner wire has many advantages, such as less trauma, small incision, and no need for reoperation. OBJECTIVE: To comparatively analyze the clinical efficacy of percutaneous fixation of a Kirschner wire with miniplate placement in the transverse plane for treatment of the fifth metacarpal shaft fracture.  METHODS: A total of 60 patients who underwent surgery for the fifth metacarpal shaft fracture at Binzhou Medical University Hospital between May 2018 and May 2020 were retrospectively analyzed and divided into two groups according to the operation method. 30 patients in the plate group were treated with open reduction miniplate internal fixation; 30 patients in the Kirschner wire group were treated with closed reduction and percutaneous fixation with a Kirschner wire (of which 5 patients were treated with mini-incision incision assisted fixation). The length of hospital stay, operation time, incision healing grade, incision length, intraoperative blood loss, intraoperative fluoroscopy number, and postoperative complications were compared between the two groups. The fracture healing time, grip strength, and the motion range of the fifth metacarpophalangeal joint were recorded in the two groups, and the functional outcomes of the fingers were evaluated by the total active movement method.  RESULTS AND CONCLUSION: (1) Patients in both groups were followed up for 13-18 months. The differences in hospital stay, operation time, and incision healing grade between the two groups were not statistically significant (P > 0.05). (2) The amount of intraoperative blood loss and incision length in the Kirschner wire group were less than those in the plate group (P < 0.05). The number of intraoperative fluoroscopies in the plate group was less than that in the Kirschner wire group (P < 0.05). There was no significant difference in the fracture healing time between the two groups (P > 0.05). (3) At the last follow-up, the efficacy was evaluated according to the total active movement method. The excellent and good rate was 87% in the Kirschner wire group and 90% in the plate group, with no significant difference. There were no significant differences between the two groups in the motion range and grip strength of the fifth metacarpophalangeal joint at the last follow-up (P > 0.05). (4) Pin tract infection occurred in one case after Kirschner wire placement, which improved after giving iodophor to enhance the dressing change. There was 1 case of pin tail irritating skin symptoms, which resolved after the removal of the Kirschner wires. There were 12 patients in the plate group who were hospitalized after 12 months for personal reasons for plate removal, and all in the Kirschner wire group were removed on an outpatient basis. In the plate group, three patients developed sensory numbness of the skin on the dorsal side of the distal fifth metacarpal and the dorsal side of the little finger, which resolved gradually with oral administration of mecobalamin after surgery. There were no instances of nonunion and refracture with internal fixation in either group. (5) Our results showed that both of these surgical procedures achieved good results in the treatment of fifth metacarpal shaft fracture with excellent functional recovery of the fingers, but the transverse fixation with percutaneous Kirschner wire has many advantages, such as less trauma, small incision, low cost, and convenient removal of internal fixation.  Figures and Tables | References | Related Articles | Metrics

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Treatment of high ankle sprains with Suture-button elastic fixation assisted by arthroscopy Xie Wei, Zhao Jingjing, Hao Cheng, Li Zi, Fang Zhenhua 2024, 28 (30):  4848-4853.  doi: 10.12307/2024.628 Abstract ( 81 )   PDF (1319KB) ( 57 )   Save BACKGROUND: High ankle sprain is easily missed and leads to ankle dysfunction. Arthroscopy can detect hidden high ankle sprain. Suture-button elastic fixation can restore the biomechanical stability of the distal tibiofibular syndesmosis. OBJECTIVE: To explore the clinical efficacy of Suture-button elastic fixation for high ankle sprain under ankle arthroscopy. METHODS: A retrospective analysis was performed on 40 cases of high ankle sprain patients treated with Suture-button elastic fixation under ankle arthroscopy from August 2019 to August 2021 in the Department of Foot and Ankle Surgery, Wuhan Fourth Hospital. All patients underwent Suture-button elastic fixation. The American Orthopedic Foot and Ankle Society function score, Visual Analog Scale pain score, ankle range of motion, preoperative imaging data, and arthroscopic tibiofibular syndesmosis separation degree were recorded. Meislin criteria were used to evaluate the curative effect and postoperative complications were recorded. RESULTS AND CONCLUSION: (1) 40 patients were followed up for 16-48 months after operation. (2) At the last follow-up, American Orthopedic Foot and Ankle Society score was (88.95±6.64 points). Visual Analog Scale score was (1.78±1.23 points). Ankle dorsiflexion range of motion was (33.50±5.79 degrees). Ankle plantarflexion range of motion was (34.50±5.97 degrees). There were statistically significant differences before and after surgery (P < 0.05). (3) There was a low positive correlation between the radiographic separation index and the degree of arthroscopic separation (r=0.612, P < 0.01). (4) The curative effect was evaluated by Meislin standard, with an excellent and good rate of 95% (38/40). Postoperative ankle joint pain was relieved, and ankle joint activities were significantly improved. (5) During the follow-up period, all patients had no nerve injury or incision infection. In 1 patient, the internal fixation was removed due to skin irritation and squatting sensation after operation. (6) It is concluded that Suture-button elastic fixation for high ankle sprain is effective under ankle arthroscopy in restoring ankle function and maintaining joint stability without the need for secondary removal, and it is worth clinical application.  Figures and Tables | References | Related Articles | Metrics

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Changes in cervical sagittal balance parameters after anterior cervical decompression and fusion Zhang Shilin, Lei Fei, Yuan Hao, Zheng Lipeng, Chen Zan, Liu Yuxi, Wang Minglang, Feng Daxiong 2024, 28 (30):  4854-4859.  doi: 10.12307/2024.638 Abstract ( 62 )   PDF (1352KB) ( 53 )   Save BACKGROUND: Some patients with cervical spondylosis have not been fully corrected sagittal position balance after cervical surgery, and this continuous sagittal position imbalance may be an important reason for the poor long-term clinical outcome of patients. OBJECTIVE: To analyze the correlation between the cervical sagittal position balance parameters and their changes and the clinical efficacy of patients in the unbalanced state after anterior cervical decompression and fusion and to explore the necessity of surgical correction of sagittal balance in order to improve the clinical effect in the later stage.  METHODS: A retrospective analysis was performed on 125 patients with cervical spondylosis who underwent anterior cervical decompression and fusion in the Department of Spinal Surgery of Affiliated Hospital of Southwest Medical University from July 2019 to July 2022. Follow-up patients had good postoperative recovery (neck disability index score less than 10% one week after surgery) and had complete follow-up data. According to the axial vertical distance (C2-7 SVA) in sagittal position one week after surgery, patients were divided into type I imbalance group (C2-7 SVA loss ≤ 5 mm, n=27), type II imbalance group (C2-7 SVA loss > 5 mm, and ≤ 10 mm, n=19), and type III imbalance group (C2-7 SVA loss> 10 mm, n=12), and non-unbalanced group (C2-7 SVA in the normal range, n=67). The changes of visual analog scale score and neck disability index were compared among groups postoperatively and the last follow-up, as well as the changes of imaging sagittal balance parameters C2-7 cobb angle, C2-7 SVA value, neck inclination angle, T1 inclination angle, and thoracic entrance angle. The correlation between the late clinical effect and postoperative cervical sagittal disequilibrium was explored.  RESULTS AND CONCLUSION: (1) There was no statistical difference in general data among the four groups (P > 0.05). All patients underwent successful surgery without serious complications and postoperative wound infection. The follow-up time was more than 1 year. (2) There was no significant difference in preoperative symptom score and clinical efficacy one week after surgery (P > 0.05). At the last follow-up, pain visual analog scale score, neck disability index and C2-7 SVA were lower than those before surgery but higher than those one week after surgery (P < 0.05). C2-7 cobb angle was increased compared with those before operation (P < 0.05). T1 inclination angle was decreased compared with those before operation (P < 0.05). (3) Pearson correlation test showed that the change of neck disability index was positively correlated with the change of C2-7 SVA (P < 0.05). (4) It is indicated that anterior cervical decompression and fusion is effective in the treatment of cervical spondylosis, and can effectively relieve the symptoms of patients. Patients with more severe cervical sagittal disequilibrium after surgery had worse curative effect in the later period. Continuous sagittal disequilibrium in patients with cervical spondylosis after surgery is an important cause of poor curative effect in the later stage. Clinicians should pay more attention to the correction of cervical sagittal balance before and during surgery, formulate surgical strategies and plans according to sagittal balance parameters before surgery, and correct C2-7 SVA intraoperatively to the normal range. Figures and Tables | References | Related Articles | Metrics

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Effect of neutral position magnetic resonance imaging on cervical discs herniation volume and cervical curvature Jin Yikai, Ma Zhanhua, Fu Su, Yan Xu, Zhang Chunlin 2024, 28 (30):  4860-4865.  doi: 10.12307/2024.643 Abstract ( 65 )   PDF (1322KB) ( 147 )   Save BACKGROUND: Cervical neutral position magnetic resonance imaging is widely used for the diagnosis and treatment of cervical spondylotic myelopathy. However, it is not possible for patients to maintain the exact same position of the head and neck during repeated cervical magnetic resonance imaging examinations. The cervical spine undergoes minor flexion and extension movements in the sagittal plane, and the head may have a certain degree of variation in flexion and extension. Whether these changes in the neutral position of the cervical spine affect the volume of cervical discs herniation and cervical curvature is unclear.  OBJECTIVE: Using artificial intelligence-assisted measurement, this study aimed to analyze the accuracy and reliability of magnetic resonance imaging examinations for measuring the volume of cervical discs herniation and cervical curvature in patients with cervical spondylotic myelopathy undergoing two consecutive cervical neutral positions in the short term.  METHODS: A retrospective study was conducted on patients with cervical spondylotic myelopathy who underwent conservative treatment and underwent two consecutive cervical magnetic resonance imaging examinations within three months between June 2012 and June 2023. We proposed the use of occipital-thoracic distance and occipital-thoracic angle to evaluate the variation in flexion and extension of the head in the neutral position of the cervical spine. Based on the changes in occipital-thoracic angle, patients were divided into occipital-thoracic angle increase group and occipital-thoracic angle decrease group. Cervical discs herniation volume, C2-6 Cobb angle, and cervical (C3-C7) curvature were measured using artificial intelligence-assisted measurement software. Normal distribution data were represented by mean±SD, while non-normal distribution data were represented by the median (interquartile range). Spearman’s rank correlation coefficient was used to analyze the correlation between changes in Cobb angle, cervical (C3-C7) curvature, and cervical discs herniation volume.  RESULTS AND CONCLUSION: (1) A total of 104 patients and 326 cervical discs herniation were included in the study. There were 47 patients in the occipital-thoracic angle increase group and 57 patients in the occipital-thoracic angle decrease group. (2) Extension and flexion index of the head: There were no significant differences in occipital-thoracic distance and occipital-thoracic angle during the initial diagnosis and follow-up examination. The variation of occipital-thoracic distance was 0.035 (3.23) mm, and the variation of occipital-thoracic angle was -0.31 (3.28)°. The deviation range of occipital-thoracic distance and occipital-thoracic angle was small, and there was no significant correlation. (3) Cervical curvature index: There were no significant differences in C2-6 Cobb angle and C3-C7 curvature during the initial diagnosis and follow-up examination. There were no significant differences in C2-6 Cobb angle and C3-C7 curvature between the occipital-thoracic angle increase group and occipital-thoracic angle decrease group. (4) There was no significant difference in volume of cervical discs herniation during the initial diagnosis and follow-up examination. There was no significant difference in volume of cervical discs herniation between the occipital-thoracic angle increase group and occipital-thoracic angle decrease group. There was no significant correlation between the change of cervical discs herniation volume and the change of C2-6 Cobb angle and the cervical (C3-C7) curvature. (5) These results indicate that in the neutral position of the cervical spine, there were negligible minor flexion and extension movements in the sagittal plane, and the head was limited to a specific position. Although the head has a certain range of flexion and extension variation, it does not affect the accuracy and reliability of parameters including cervical discs herniation volume, C2-6 Cobb angle, and cervical (C3-C7) curvature.  Figures and Tables | References | Related Articles | Metrics

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Quantitative evaluation of lumbar facet arthritis-induced cartilage injury by MR T2* mapping Chen Ji, Zhang Chen, Zhang Bin, Huang Leitao 2024, 28 (30):  4866-4870.  doi: 10.12307/2024.631 Abstract ( 62 )   PDF (941KB) ( 37 )   Save BACKGROUND: Lumbar facet arthritis is one of the main causes of low back pain. At present, MRI is mainly used for preliminary diagnosis, and there is still a certain probability of missed diagnosis and misdiagnosis. Therefore, MR T2* mapping imaging technology is expected to become an important means of quantitative detection of cartilage damage in lumbar facet arthritis.   OBJECTIVE: To investigate the application value of MR T2* mapping imaging technique in quantitative analysis of cartilage damage and degeneration of lumbar facet joint.  METHODS: A total of 110 outpatient or inpatient patients with low back pain in Fourth Affiliated Hospital of Nanjing Medical University from April 2020 to March 2022 were collected and set as case group. At the same time, 80 asymptomatic volunteers were recruited as the control group. T2* mapping transectal images and T2WI images were obtained by 3.0T MR Scanning for the facet joints of all included subjects L1-S1. Weishaupt grading and T2* value measurement were performed for all facet joint cartilage, and the data were collected for parallel statistical analysis. The comparison of T2* values of facet joint cartilage between different articular Weishaupt grades was performed by one-way analysis of variance. RESULTS AND CONCLUSION: (1) Statistical analysis found that the T2* value of lumbar facet joint cartilage in the case group (17.6±1.5) ms was significantly lower than that in the control group (21.4±1.3) ms (P < 0.05). (2) In the case group, with the hierarchical increase of lumbar facet joint Weishaupt, the T2* value of facet joint cartilage also showed a gradual decreasing trend, and the difference was statistically significant (P < 0.05). (3) It is concluded that T2* mapping can better display the early pathological changes of lumbar facet joint cartilage injury, and T2* value of lumbar facet joint cartilage can quantitatively evaluate the degree of lumbar facet joint cartilage injury. T2* mapping imaging technique can provide a good theoretical basis for the imaging diagnosis of the early cartilage injury induced by lumbar facet arthritis and has important clinical application value.  Figures and Tables | References | Related Articles | Metrics

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Natural collapse course of ARCO II stage osteonecrosis of the femoral head based on China-Japan Friendship Hospital classification Zhao Rushun, Hao Yangquan, Xu Hanbo, Yang Zhi, Xu Peng, Zheng Xin, Zhang Kun, Lu Chao 2024, 28 (30):  4871-4875.  doi: 10.12307/2024.629 Abstract ( 123 )   PDF (927KB) ( 30 )   Save BACKGROUND: Osteonecrosis of the femoral head is one of the refractory diseases in orthopedic diseases. The natural collapse course of osteonecrosis of the femoral head under different stages and types affects the progression and prognosis of the disease.   OBJECTIVE: To explore the progression of natural collapse within 5 years in patients under the different classifications of China-Japan Friendship Hospital (CJFH) with stage II osteonecrosis of the International Association for Research Circulation Osseous (ARCO), and to analyze the collapse rate and collapse risk of the femoral head under the different classifications of CJFH.  METHODS: A retrospective study was performed to select patients diagnosed with ARCO II stage osteonecrosis of the femoral head without collapse in the Honghui Hospital Affiliated to Xi’an Jiaotong University from October 2016 to October 2017. According to whether it collapsed, the number of hips was divided into the collapse group (n=82) and the non-collapsed group (n=70). The collapse risk of patients with osteonecrosis of the femoral head under different CJFH classifications, as well as the collapse time, number of collapses, and collapse rate within 5 years were counted, and then the Kaplan-Meier survival curve of the femoral head under different classification of CJFH was plotted.    RESULTS AND CONCLUSION: (1) A total of 97 patients with 152 hips were enrolled, and 82 hips collapsed during the follow-up period, with a total collapse rate of 53.9%, of which the collapse rates of M type, C type, L1 type, L2 type, and L3 type were 0.0%, 36.7%, 51.4%, 72.2%, and 77.8%, respectively, and the comparison between the groups was statistically significant (P < 0.05). (2) In terms of collapse risk, the collapse risk of L1 type was 1.704 times that of C-type (P > 0.05), while the collapse risks of L2 type and L3 type were 3.866 times and 6.423 times that of C type (P < 0.05), respectively. (3) In terms of the Kaplan-Meier survival curve, the median survival time of the femoral head of ARCO II stage patients was 3 years, with a 95% confidence interval of 2.885-3.471 years, and the survival rates of the femoral head at the first, third and fifth years were 65.1% (99/152), 50.7% (77/152), and 46.1% (70/152), respectively. (4) These findings conclude that different CJFH classifications affect the collapse rate of ARCO II stage osteonecrosis of the femoral head patients, among which L3 type patients have the highest collapse rate, followed by L2 type and L1 type patients; C type patients have a lower collapse rate, and M type patients do not collapse, which indicates that the preservation of the lateral column of the femoral head is of great significance for the natural collapse course of osteonecrosis of the femoral head. Figures and Tables | References | Related Articles | Metrics

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Effect of photon cervical vertebra massage instrument on improving neck pain and related functions in patients with chronic neck pain Yao Yuan, Zhang Shizhen, Jin Lei, Yang Yunxiao, Yu Wenqiang, Xu Yuanjing, Wang Jinwu 2024, 28 (30):  4876-4880.  doi: 10.12307/2024.099 Abstract ( 63 )   PDF (804KB) ( 44 )   Save BACKGROUND: Red light therapy has the non-invasive and cost-effective characteristics, and is widely used in various acute and chronic pains in clinic. However, currently, the phototherapy equipment used in clinic is expensive and has certain site limitations, so it is necessary to explore more convenient and economical phototherapy applications.  OBJECTIVE: To observe the clinical efficacy of a self-developed photon cervical vertebra massage instrument for chronic neck pain.  METHODS: From November 2022 to February 2023, 24 patients with chronic neck pain were recruited from the Department of Rehabilitation Medicine, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, including 18 females and 6 males, with a mean age of (29.67±6.40) years. The body mass index was (21.39±3.52) kg/m2. Photon cervical vertebra massage instrument was used twice a day for 20 minutes each time for four weeks. The changes in visual analog scale score, pressure pain threshold, neck active activity, neck disability index, and Pittsburgh sleep quality index were observed before, after 2 and 4 weeks of treatment. RESULTS AND CONCLUSION: (1) Compared with before treatment, after four weeks of treatment, visual analog scale score, pressure pain threshold, neck disability index, and Pittsburgh sleep quality index were all improved (P < 0.05), while some cervical motion (extension, left and right rotation) improved (P < 0.05) after 4 weeks of treatment. (2) Bilateral visual analog scale scores, left trapezius muscle pressure pain threshold, C5C6 pressure pain threshold, and neck disability index improved after 2 weeks of treatment (P < 0.05). (3) It is indicated that the application of photon cervical vertebra massage instrument can improve the pain score, muscle tenderness, sleep quality, functional level, and partial active activity of patients with chronic neck pain in a short period, and is a convenient, effective, and safe treatment method. Figures and Tables | References | Related Articles | Metrics

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Molecular biological mechanism of acquired heterotopic ossification Xiong Yang, Zhou Shibo, Yu Xing, Bi Lianyong, Yang Jizhou, Wang Fengxian, Qu Yi, Yang Yongdong, Zhao Dingyan, Zhao He, Qiu Ziye, Jiang Guozheng 2024, 28 (30):  4881-4888.  doi: 10.12307/2024.647 Abstract ( 104 )   PDF (1249KB) ( 54 )   Save BACKGROUND: Heterotopic ossification is a dynamic growth process. Diverse heterotopic ossification subtypes have diverse etiologies or induction factors, but they exhibit a similar clinical process in the intermediate and later phases of the disease. Acquired heterotopic ossification produced by trauma and other circumstances has a high incidence.  OBJECTIVE: To summarize the molecular biological mechanisms linked to the occurrence and progression of acquired heterotopic ossification in recent years.  METHODS: The keywords “molecular biology, heterotopic ossification, mechanisms” were searched in CNKI, Wanfang, PubMed, Embase, Web of Science, and Google Scholar databases for articles published from January 2016 to August 2022. Supplementary searches were conducted based on the obtained articles. After the collected literature was screened, 131 articles were finally included and summarized.  RESULTS AND CONCLUSION: (1) The occurrence and development of acquired heterotopic ossification is a dynamic process with certain concealment, making diagnosis and treatment of the disease difficult. (2) By reviewing relevant literature, it was found that acquired heterotopic ossification involves signaling pathways such as bone morphogenetic protein, transforming growth factor-β, Hedgehog, Wnt, and mTOR, as well as core factors such as Runx-2, vascular endothelial growth factor, hypoxia-inducing factor, fibroblast growth factor, and Sox9. The core mechanism may be the interaction between different signaling pathways, affecting the body’s osteoblast precursor cells, osteoblast microenvironment, and related cytokines, thereby affecting the body’s bone metabolism and leading to the occurrence of acquired heterotopic ossification. (3) In the future, it is possible to take the heterotopic ossification-related single-cell osteogenic homeostasis as the research direction, take the osteoblast precursor cells-osteogenic microenvironment-signaling pathways and cytokines as the research elements, explore the characteristics of each element under different temporal and spatial conditions, compare the similarities and differences of the osteogenic homeostasis of different types and individuals, observe the regulatory mechanism of the molecular signaling network of heterotopic ossification from a holistic perspective. It is beneficial to the exploration of new methods for the future clinical prevention and treatment of heterotopic ossification. (4) Meanwhile, the treatment methods represented by traditional Chinese medicine and targeted therapy have become research hotspots in recent years. How to link traditional Chinese medicine with the osteogenic homeostasis in the body and combine it with targeted therapy is also one of the future research directions. (5) At present, the research on acquired heterotopic ossification is still limited to basic experimental research and the clinical prevention and treatment methods still have defects such as uncertain efficacy and obvious side effects. The safety and effectiveness of relevant targeted prevention and treatment drugs in clinical application still need to be verified. Future research should focus on clinical prevention and treatment based on basic experimental research combined with the mechanism of occurrence and development. Figures and Tables | References | Related Articles | Metrics

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Application and prospect of robotic-assisted total knee arthroplasty Wang Ruoyu, Zhang Zhifeng, Huang Jian 2024, 28 (30):  4889-4895.  doi: 10.12307/2024.639 Abstract ( 114 )   PDF (909KB) ( 196 )   Save BACKGROUND: The basic principle of the design of the robot system used for total knee arthroplasty is to combine three-dimensional surgical planning, early warning of danger areas during surgery, real-time data feedback, robot arm assisted osteotomy and other technologies to achieve precision and personalization of total knee arthroplasty, which is exactly its biggest advantage. Therefore, it has become a hot topic in the field of joint surgery in recent years and attracted much attention.     OBJECTIVE: To summarize the development status of robotic-assisted total knee arthroplasty in the field of joint surgery and the comparison of advantages and disadvantages with conventional total knee arthroplasty and to prospect the future development of robotic-assisted total knee arthroplasty.  METHODS: Relevant articles were searched from PubMed, CNKI, Wanfang and VIP databases by computer. English key words were “robot OR robotic OR robotics OR robotically OR computer, total knee arthroplasty OR total knee replacement, TKA OR TKR”. Chinese key words were “robotic-assisted, computer navigation, total knee arthroplasty”. Finally, 64 articles were included for review and analysis. RESULTS AND CONCLUSION: (1) The robot system used to assist total knee arthroplasty is divided into active, semi-active and passive according to its degree of freedom. The semi-active system, currently widely used in robotic systems, effectively enhances the accuracy and personalization of total knee arthroplasty. However, its high implementation cost and relatively steep learning curve remain key factors to be balanced when promoting its adoption in joint surgery field. (2) Robotic-assisted total knee arthroplasty can achieve precise osteotomy and correct placement of prosthesis in local three-dimensional space of the knee joint. It has been widely proven that it can provide better accuracy of prosthesis implantation, reduce imaging abnormalities, obtain good soft tissue balance during the operation, and ultimately improve the motion and functional status of the knee joint after the operation. (3) However, the current robotic-assisted system still has objective shortcomings, including the problem of learning curve between different robot devices and operators, additional installation and maintenance costs, and potential complications related to robot surgery. Therefore, whether it can truly benefit the medical system and patients still needs to be proven by long-term research, and the robotic-assisted system also needs to be further improved substantially. (4) Robotic-assisted total knee arthroplasty technique is still in the preliminary research stage in clinical practice and has not been widely applied. To better define the usage of robotic-assisted total knee arthroplasty and enhance its clinical procedural standards and safety, refining these aspects will become a focal point of future research on robotic-assisted total knee arthroplasty.  Figures and Tables | References | Related Articles | Metrics

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Application of finite element analysis in lumbar biomechanics Fan Guangya, Su Wenshuo, Zhong Musen, Dong Liqiang 2024, 28 (30):  4896-4901.  doi: 10.12307/2024.625 Abstract ( 79 )   PDF (1068KB) ( 46 )   Save BACKGROUND: Finite element analysis is a commonly used mathematical modeling method to analyze the biomechanics of the lumbar spine. By constructing finite element models of the complex tissues such as muscles, blood vessels, and nerves in the lumbar region, mechanical analysis is performed to elucidate the pathogenesis of lumbar spine disorders and the mechanical mechanisms of treatment approaches.  OBJECTIVE: To review the progress of finite element analysis in understanding the pathogenesis and treatment modalities of lumbar spine disorders, and to propose a new clinical workflow for the implementation of finite element analysis, aiming to provide a reference for future studies and promote the widespread utilization of finite element analysis in clinical diagnosis and treatment. METHODS: The PubMed database was searched using English keywords “finite element analysis, lumbar vertebra”, while the WanFang and China National Knowledge Infrastructure (CNKI) databases were searched using Chinese keywords “finite element analysis, lumbar vertebra”. A total of 73 articles were included for review.  RESULTS AND CONCLUSION: (1) Lumbar spine degeneration in non-slipped patients typically originates from the posterior annulus fibrosus, while in patients with lumbar spine spondylolisthesis, degeneration starts from the lumbar facet joints due to abnormal mechanical mechanisms. (2) Restoring vertebral body height can prevent adjacent-level degeneration, and finite element analysis-measured vertebral compression strength can serve as an effective predictor of fracture risk, replacing bone density measurements. (3) In lumbar spine fusion surgery, selecting fusion devices of appropriate height and placing them transversely can prevent device subsidence. Increased intervertebral strain, circumferential stress, and intervertebral pressure in adjacent segments after fusion surgery may contribute to the occurrence of degenerative changes in neighboring segments. (4) Finite element analysis results suggest that preoperative planning for transforaminal endoscopic surgery should include considerations for osteotomy size to avoid excessive destruction of the articular process, and intraoperatively, preferential selection of a technique that traverses the superior articular process for foraminal dilatation. (5) In percutaneous kyphoplasty, bilateral pedicle screw augmentation should be performed, distributing bone cement on both sides of the pedicle. More advanced non-aluminum glass polyalkenoate cement materials should be selected. (6) Traction therapy should be personalized based on individual patient characteristics, including customized traction angles and forces, to achieve optimal therapeutic effects. (7) Manual therapy can induce relative displacement between the herniated intervertebral disc and the nerve root, thereby reducing compression. (8) The workflow involving CT/MR-AI Plus FEA-AI Plus Surgical robots can enable more precise diagnosis and treatment. Figures and Tables | References | Related Articles | Metrics

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Mechanical stress affects occurrence and development of osteoarthritis by regulating Hippo pathway Yang Pan, Dong Wantao, Liu Jingyi, Qiu Shiming, Yuan Peng 2024, 28 (30):  4902-4908.  doi: 10.12307/2024.632 Abstract ( 110 )   PDF (1067KB) ( 51 )   Save BACKGROUND: Osteoarthritis is a common chronic inflammation of joints caused by degenerative changes of articular cartilage. More and more studies have shown that mechanical stress is closely related to the development of osteoarthritis. The Hippo pathway is not only involved in the development of tissue cells, but also an effecting factor of mechanical stress, which is involved in the regulation of bone metabolism and cartilage metabolism.  OBJECTIVE: Regulation of the Hippo pathway may become one of the new targets for intervention in osteoarthritis. Therefore, this paper reviewed the research on the effect of mechanical stress regulation of the Hippo pathway on osteoarthritis to provide ideas for the pathogenesis of osteoarthritis and provide a new theoretical basis for the treatment of osteoarthritis. METHODS: PubMed, Web of Science, Embase, CNKI, VIP, and WanFang databases were used for a literature search for articles published from inception to 2023 concerning the influence of mechanical stress on osteoarthritis and mechanical stress, Hippo pathway, and osteoarthritis. A total of 75 articles were finally reviewed. RESULTS AND CONCLUSION: (1) Different mechanical stresses may play different roles in cell proliferation, apoptosis and differentiation, osteoarthritis inflammation, and vascular homeostasis in osteoarthritis. (2) Hard extracellular matrix, low cell density, medium shear force, medium tensile force, and compression force can achieve cell proliferation, osteogenic differentiation, and vascular homeostasis, and inhibit inflammatory response by activating YAP/TAZ. (3) Soft extracellular matrix, high cell density, excessive shear force, excessive tensile force, and compressive force inhibit cell proliferation, enhance cartilage differentiation, disrupt vascular homeostasis, and promote inflammation through inactivation of YAP/TAZ, thus promoting the process of osteoarthritis. Figures and Tables | References | Related Articles | Metrics

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Identification of ferroptosis signature genes in osteoarthritis based on WGCNA and machine learning and experimental validation Xu Wenfei, Ming Chunyu, Duan Kan, Yuan Changshen, Guo Jinrong, Hu Qi, Zeng Chao, Mei Qijie 2024, 28 (30):  4909-4914.  doi: 10.12307/2024.619 Abstract ( 80 )   PDF (2637KB) ( 104 )   Save BACKGROUND: Ferroptosis is strongly associated with the occurrence and progression of osteoarthritis, but the specific characteristic genes and regulatory mechanisms are not known. OBJECTIVE: To identify osteoarthritis ferroptosis signature genes and immune infiltration analysis using the WGCNA and various machine learning methods. METHODS: The osteoarthritis dataset was downloaded from the GEO database and ferroptosis-related genes were obtained from the FerrDb website. R language was used to batch correct the osteoarthritis dataset, extract osteoarthritis ferroptosis genes and perform differential analysis, analyze differentially expressed genes for GO function and KEGG signaling pathway. WGCNA analysis and machine learning (random forest, LASSO regression, and SVM-RFE analysis) were also used to screen osteoarthritis ferroptosis signature genes. The in vitro cell experiments were performed to divide chondrocytes into normal and osteoarthritis model groups. The dataset and qPCR were used to verify expression and correlate immune infiltration analysis. RESULTS AND CONCLUSION: (1) 12 548 osteoarthritis genes were obtained by batch correction and PCA analysis, while 484 ferroptosis genes were obtained, resulting in 24 differentially expressed genes of osteoarthritis ferroptosis. (2) GO analysis mainly involved biological processes such as response to oxidative stress and response to organophosphorus, cellular components such as apical and apical plasma membranes, and molecular functions such as heme binding and tetrapyrrole binding. (3) KEGG analysis exhibited that differentially expressed genes of osteoarthritis ferroptosis were related to signaling pathways such as the interleukin 17 signaling pathway and tumor necrosis factor signaling pathway. (4) After using WGCNA analysis and machine learning screening, we obtained the characteristic gene KLF2. After validation by gene microarray, we found that the gene expression of KLF2 was higher in the test group than in the control group in the meniscus (P=0.000 14). (5) In vitro chondrocyte assay showed that type II collagen and KLF2 expression was lower in the osteoarthritis group than in the control group in chondrocytes (P < 0.05), while in osteoarthritis ferroptosis, mast cells activated was closely correlated with dendritic cells (r=0.99); KLF2 was closely correlated with natural killer cells (r=-1, P=0.017) and T cells follicular helper (r=-1, P=0.017). (6) The findings indicate that using WGCNA analysis and machine learning methods confirmed that KLF2 can be a characteristic gene for osteoarthritis ferroptosis and may improve osteoarthritis ferroptosis by interfering with KLF2.  Figures and Tables | References | Related Articles | Metrics

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Research hotspots of artificial intelligence in the field of spinal deformity: visual analysis Tao Guangyi, Wang Linzi, Yang Bin, Huang Junqing 2024, 28 (30):  4915-4920.  doi: 10.12307/2024.640 Abstract ( 90 )   PDF (1882KB) ( 184 )   Save BACKGROUND: With the continuous improvement and progress of artificial intelligence technology in the treatment of spinal deformity, a large number of studies have been invested in this field, but the main research status, hot spots and development trends are still unclear. OBJECTIVE: To visually analyze the literature related to artificial intelligence in the field of spinal deformities by using bibliometrics, identify the research hotspots and shortcomings in this field, and provide references for future research. METHODS: The core database of Web of Science was used to search the articles related to artificial intelligence in the field of spinal deformities published from inception to 2023. The data were visually analyzed by Citespace 5.6.R5 and VOSviewer 1.6.19. RESULTS AND CONCLUSION: (1) A total of 165 papers were included, and the number of papers published in this field showed a fluctuating upward trend. The author with the largest number of articles is Lafage V, and the country with the largest number of articles is China. (2) Keyword analysis results show that adolescent scoliosis, deep learning, classification, precision and robot are the main keywords. (3) The in-depth analysis results of co-cited and highly cited articles show that artificial intelligence has three hotspots in the field of spinal deformities, including the use of U-shaped architecture (a mature mode of deep learning convolutional neural networks) to automatically measure imaging parameters (Cobb angle and accurate segmentation of paraspinal muscles), multi-view correlation network architecture (i.e., spine curvature assessment framework), and robot-guided spinal surgery. (4) In the field of artificial intelligence treatment of spinal malformations, the mechanism research such as genomics is very weak. In the future, unsupervised hierarchical clustering and other machine learning techniques can be used to study the basic mechanism of susceptibility genes in the field of spinal deformities by genome-wide association analysis and other genomics research methods.  Figures and Tables | References | Related Articles | Metrics