Loading...

Table of Content

    28 October 2021, Volume 25 Issue 30 Previous Issue    Next Issue
    For Selected: Toggle Thumbnails
    Application of three-dimensional printing in accurate puncture vertebroplasty in fresh vertebral compression fractures
    Yuan Lingli, Xu Wendi, Bai Jianzhong, Zhang Zhongchuan, Zhu Xunbing, Geng Chunhui
    2021, 25 (30):  4757-4761.  doi: 10.12307/2021.257
    Abstract ( 225 )   PDF (1520KB) ( 19 )   Save
    BACKGROUND: At present, when clinicians use percutaneous vertebroplasty to repair vertebral compression fractures, how do they accurately operate and evenly distribute the bone cement between the injured vertebral fractures, thereby reducing the symptoms of lower back pain, for patients with vertebral compression fractures, is essential for postoperative recovery. The technology of three-dimensional (3D) printed injured vertebral body developed in recent years can provide clinical surgeons with reference for the anatomy of injured vertebra.
    OBJECTIVE: To explore the clinical effect of 3D printed model of injured vertebral fracture and vertebroplasty by accurately puncturing in fresh vertebral compression fracture. 
    METHODS: Sixty patients with vertebroplasty in the Second Affiliated Hospital of Bengbu Medical College from February 2019 to August 2020 were randomly divided into 3D printing group and control group. The accurately punctured vertebroplasty instructed by 3D printing model of the injured vertebra and the traditional vertebroplasty was performed respectively. The operation time, the times of fluoroscopy, the times of changing the puncture point, the amount of bone cement, and Visual Analogue Scale scores at 1 day, 1, 4 weeks and 3 months after operation were compared between the two groups. 
    RESULTS AND CONCLUSION: (1) Visual Analogue Scale scores were lower in the 3D printing group than in the control group at 1 day and 1 week (P < 0.05). (2) The operation time, the times of fluoroscopy, and the times of changing the puncture point were reduced (P < 0.05); the amount of bone cement was increased (P < 0.05) in the 3D printing group compared with the control group. (3) There were two cases of local vertebral cement leakage in both groups, and there were no clinical symptoms after operation. There was no case of adjacent vertebral fractures in both groups during the follow-up. (4) The results show that the combination of 3D printing model of the injured vertebra and vertebroplasty can guide the accurate puncture of pedicle, make it easier for the puncture needle to enter the fracture area, and increase the amount of bone cement injected into the fracture area, and effectively avoid bone cement leakage, and relieve patients’ low back pain in a short time after operation.

    Figures and Tables | References | Related Articles | Metrics
    Biomechanical analysis of sagittal balance restoration of ankylosing kyphosis based on pelvic sagittal parameters
    Xie Jiang, Dai Jie, Li Hui, Zhu Xu
    2021, 25 (30):  4762-4766.  doi: 10.12307/2021.258
    Abstract ( 185 )   PDF (1211KB) ( 18 )   Save
    BACKGROUND: As kyphosis is mainly manifested as sagittal deformity. The angle of osteotomy is one of the key problems to be solved before operation. Insufficient and excessive correction of angle may cause secondary imbalance of sagittal spine.  
    OBJECTIVE: To establish a three-dimensional finite element model of kyphotomy for ankylosing spondylitis by using computer-aided software, design a personalized surgical scheme based on pelvic sagittal parameters, restore sagittal balance, and analyze biomechanical characteristics.
    METHODS:  CT data from C1 to sacrococcyx of a hospitalized patient from the Sixth Affiliated Hospital of Xinjiang Medical University were collected. According to 301 classification, kyphosis was determined as IIIA type. CT data were imported into computer modeling software to establish a three-dimensional finite element model of ankylosing spondylitis kyphosis. The values of pelvic incidence and pelvic tilt were measured, and the angle of theoretical pelvic tilt was calculated by pelvic incidence. Two different osteotomy models were designed. In model 2, the pre-osteotomy angle of L3 measured by hilar hip axis measurement was 32.2°. In model 1, and the osteotomy angle was set at 40° under the sagittal plane balance without reconstruction. The cancellous osteotomy was simulated on the two models; and the finite element calculation was carried out on the nail rod system and osteotomy surface of the model after osteotomy.  
    RESULTS AND CONCLUSION: (1) Finite element analysis results showed that in the condition of spinal flexion, except S1 segment, the screw stress of model 1 of the other five fixed segments was higher than that of model 2, and the stress of titanium rod and bone connecting surface was also the same. (2) In the condition of spinal extension, due to too large osteotomy angle, the patient’s center of gravity moved backward, resulting in more obvious stress difference between the two. The largest distance was L4 segment screw, and the difference was 149.69 MPa between model 1 and model 2. (3) The stress diagram of osteotomy surface showed that the stress mainly concentrated in the rear of the osteotomy surface, while the stress in the front was generally less than 
    12 MPa. (4) It is a reasonable and scientific surgical plan to restore sagittal balance of ankylosing kyphosis based on pelvic sagittal parameters, which can ensure the orthopedic effect and reduce the stress distribution.
    Figures and Tables | References | Related Articles | Metrics
    Effects of internal fixation types and osteoporosis on oblique lateral interbody fusion: three-dimensional finite element analysis
    Qin Yichuan, Zhao Bin, Yuan Jie, Xu Chaojian, Lü Jie Hao Jiaqi Wang Yongfeng
    2021, 25 (30):  4767-4773.  doi: 10.12307/2021.259
    Abstract ( 208 )   PDF (1560KB) ( 22 )   Save
    BACKGROUND: At present, whether the oblique lateral interbody fusion requires internal fixation is still controversial, and whether the osteoporosis will affect the choice of the type of internal fixation during the application of oblique lateral interbody fusion is also lack of biomechanical research support.  
    OBJECTIVE: To study the biomechanical effects of osteoporosis and different types of posterior pedicle screw fixation on the lumbar spine during oblique lateral interbody fusion by three-dimensional finite element method.
    METHODS:  CT scan data of L3-L5 segments of healthy people were obtained. The normal intact three-dimensional finite element model (M0) and osteoporosis model (N0) of L3-L5 were established by using Mimics, Geomagic, Solidworks and ANSYS software. M0 and N0 were used as the basis at L4-L5 to establish the normal oblique lateral interbody fusion stand-alone model (M1), the normal oblique lateral interbody fusion with unilateral pedicle screw fixation model (M2), the normal oblique lateral interbody fusion with bilateral pedicle screw fixation model (M3), the osteoporotic oblique lateral interbody fusion stand-alone model (N1), the osteoporotic oblique lateral interbody fusion with unilateral pedicle screw fixation model (N2) and the osteoporotic oblique lateral interbody fusion with bilateral pedicle screw fixation model (N3). A vertical load of 500 N and a moment of 7.5 N•m were applied to the L3 upper surface to simulate the physiological activities of lumbar spine in flexion, extension, right/left lateral bending and right/left axial rotation. The L4-L5 segment range of motion, stress distribution of L5 superior endplate, cage, and internal fixation under different working conditions was observed. The maximum Von Mises stresses were recorded.  
    RESULTS AND CONCLUSION: (1) Whether in the normal models or the osteoporotic models, with the increase of posterior internal fixation, the L4-L5 range of motion, the L5 superior endplate stress, and the cage stress generally showed a downward trend. (2) The internal fixation stress of M2 increased by 115.26% mostly compared with that of M3. Compared with that of N3, the internal fixation stress of N2 increased by 78.87% mostly. (3) At the same type of internal fixation, the L4-L5 range of motion, L5 superior endplate stress, and cage stress of the osteoporotic models were all higher than those of the normal models. (4) Compared with that of M2, the internal fixation stress of N2 increased by 39.59% mostly. The internal fixation stress of N3 increased by 43.30% compared with that of M3. (5) It is indicated that the lumbar spine with normal bone mineral density and without significant alignment imbalance should be given priority for oblique lateral interbody fusion stand-alone or unilateral pedicle screw fixation. If there is significant alignment imbalance in the lumbar spine, bilateral pedicle screw fixation should be combined. The lumbar spine with osteoporosis should be combined with bilateral pedicle screw fixation to help reduce the incidence of cage settlement, endplate collapse and improve surgical safety.
    Figures and Tables | References | Related Articles | Metrics
    Cervical microendoscopic laminoplasty and intervertebral disc resorption after conservative treatment assessed with three-dimensional volume method
    Zhang Chunlin, Zhao Xiao, Yan Xu, Ning Yongming, Cao Zhengming
    2021, 25 (30):  4774-4780.  doi: 10.12307/2021.260
    Abstract ( 194 )   PDF (1540KB) ( 18 )   Save
    BACKGROUND: In the follow-up of patients after cervical microendoscopic laminoplasty, we observed that most of the herniated cervical discs decreased spontaneously. The resorption of herniated nucleus pulposus phenomenon has attracted our attention.  
    OBJECTIVE:  To measure and compare the volume changes of patients with herniated cervical discs after cervical microendoscopic laminoplasty and conservative treatment using picture archiving and communication systems software three-dimensional volume method, and to discuss the characteristics and clinical significance of the resorption of herniated nucleus pulposus phenomenon.
    METHODS:  A retrospective analysis of 68 patients with degenerative cervical spondylosis from January 2014 to June 2018 in the Department of Orthopedics, the First Affiliated Hospital of Zheng University (all had surgical indications) was conducted. Thirty-five people received cervical microendoscopic laminoplasty surgery, and 33 people insisted on conservative treatment for fear of surgery. The volume changes of herniated cervical discs patients in the two groups were measured and analyzed by picture archiving and communication systems software and three-dimensional volume method. The measurement results were evaluated with indexes such as the absorption ratio and absorption rate of the herniated cervical intervertebral disc, the re-protrusion ratio and the re-protrusion rate. The maximum error rate of 5% measured by picture archiving and communication systems software was taken as the reference standard of measurement error of cervical disc herniation. The Odom score was used to evaluate the clinical efficacy of conservative treatment and surgical treatment.  
    RESULTS AND CONCLUSION: (1) The follow-up time in the cervical microendoscopic laminoplasty group was 7-76 months. There were 122 herniated cervical discs in 35 patients, 91 of them were absorbed by herniated intervertebral disc, and the absorption ratio was 74.6%(91/122) and the absorption rate was 5%-100%. Statistical analysis showed that there was no significant difference in the absorptive ratio between disc herniation, central type and lateral type, inclusive type and ruptured type (P > 0.05). There were 17 cases of disc re-protrusion, and the re-protrusion ratio was 13.9% and the re-protrusion rate was 5.0%-48.0%. In the cervical microendoscopic laminoplasty group, resorption of herniated nucleus pulposus could be seen as early as 7 days after operation and 76 months at the latest. (2) In the conservative treatment group, the follow-up time was 2-60 months. There were 105 herniated cervical discs in 33 patients. No resorption of herniated intervertebral disc was observed. Another 57 intervertebral discs were re-herniated, and the ratio of re-protrusion was 54.3% and the rate of re-protrusion was 5.0%-80.3%. (3) In the final follow-up, the excellent and good rate of clinical efficacy was 83% in the cervical microendoscopic laminoplasty group and 36% in the conservative treatment group (P < 0.01). (4) There were statistically significant differences in the absorption ratio and re-protrusion ratio between the cervical microendoscopic laminoplasty group and the conservative treatment group (P < 0.01). (5) It is indicated that there are extensive resorption of herniated nucleus pulposus phenomena after cervical microendoscopic laminoplasty, and the occurrence time is early and the duration is long. There is no significant difference in the absorption ratio of different segments. The confirmation of this phenomenon provides a new basis for the selection of anterior and posterior cervical spine surgery strategies and combined anterior and posterior surgery.
    Figures and Tables | References | Related Articles | Metrics
    Parameters of finite element model of the knee joint
    Zhang Jichao, Dong Wanpeng, Dong Yuefu, Zhang Zhen, Li Jiayi, Ren Meng
    2021, 25 (30):  4781-4786.  doi: 10.12307/2021.261
    Abstract ( 238 )   PDF (1093KB) ( 20 )   Save
    BACKGROUND: With the deepening of knee joint related research, there are still some controversies about the accuracy and applicability of parameter selection when establishing the knee joint finite element model, and it is urgent to study.  
    OBJECTIVE: To synthesize the literature of knee joint finite element model, provide more reasonable parameter settings for model construction and analysis, and improve its applicability.
    METHODS:  The four aspects of model assumptions, material assignment, meshing and load application of osseous and non-osseous tissues in nine sets of domestic knee finite element model documents in the past five years were compared, and foreign literature and foreign research were combined to verify its rationality.  
    RESULTS AND CONCLUSION: (1) Model assumptions: Bones are set to rigid body; ligaments are set to be superelasticity; meniscus is set to be laterally isotropic; cartilage is set to be single-phase isotropic linear elasticity. (2) Material assignment: Bones do not need to be assigned; ligaments are assigned shear modulus; meniscus are assigned values in axial, radial and circumferential directions; cartilage is assigned elastic modulus. (3) Meshing: Shell elements for bones; 8-node hexahedral or second-order tetrahedral elements for non-bone tissues. (4) Load application: Axial load of twice the body weight is applied at the femoral reference point. (5) The parameter settings obtained by comparison can make the finite element model of the knee joint more applicable and provide more accurate simulation results for further research.
    Figures and Tables | References | Related Articles | Metrics
    Biomechanical analysis of different internal fixation methods of locking plate or cortical bone plate for Vancouver type B2 fracture
    Dong Wei, Zhang Tianyi, Lu Bo, Wang Yifeng, Gong Shusen, Fan Guofeng
    2021, 25 (30):  4787-4792.  doi: 10.12307/2021.262
    Abstract ( 227 )   PDF (2011KB) ( 17 )   Save
    BACKGROUND: Periprosthetic fractures are severe complications after hip arthroplasty. The treatments could be varied. However, there is still a lack of validated comparison of these treatments.  
    OBJECTIVE: To compare different treatments of Vancouver type B2 fracture based on finite element analysis.
    METHODS:  The data of femurs of 30 healthy volunteers, primary and revision prosthesis and locking compress plate were collected. The data were input into finite element analysis software. Different surgeries for Vancouver type B2 fracture and different types of loads were simulated. The fracture end offset of the cortical bone plate group, locking plate group, cortical bone plate + cortical bone plate group, and cortical bone plate + locking plate group under different loads were recorded, and statistical analysis was performed.  
    RESULTS AND CONCLUSION: (1) Under 2 300 N force load, the offset of cortical bone plate group was significantly greater than that of the other three groups (P < 0.05). The offset of locking plate group was significantly greater than that of cortical bone plate + cortical bone plate group and cortical bone plate + locking plate group (P < 0.05). However, the offset of cortical bone plate + cortical bone plate group was not significantly different from that of cortical bone plate + locking plate group (P > 0.05). (2) Under 40 N•m torque load, there was no significant difference in offset between cortical bone plate group and cortical bone plate + cortical bone plate group (P > 0.05). There was no significant difference in the offset between the locking plate group and the cortical bone plate + locking plate group (P > 0.05). The offset of cortical bone plate group and cortical bone plate + cortical bone plate group was significantly greater than that of locking plate group and cortical bone plate + locking plate group (P < 0.05). (3) For Vancouver type B2 fracture, after stem revision, if it is not stable enough, locking plate should be used as first choice, and adding a allograft strut could be sensible if necessary.
    Figures and Tables | References | Related Articles | Metrics
    Unicompartmental knee arthroplasty superior to open-wedge high tibial osteotomy: differences of mechanical parameters and knee function
    Lin Xiaodong, Liu Wengang, Xu Xuemeng, Liu Xin, Lu Chao, Song Min, Li Congcong
    2021, 25 (30):  4793-4798.  doi: 10.12307/2021.263
    Abstract ( 211 )   PDF (1163KB) ( 18 )   Save
    BACKGROUND: Although high tibial osteotomy and unicompartmental knee arthroplasty are often used to treat unicompartmental knee osteoarthritis with varus deformity, whether there are differences in knee function at different postoperative periods and whether there are changes in knee parameters on preoperative and postoperative imaging still need further clinical study.  
    OBJECTIVE: To compare the early clinical efficacy and the differences in knee imaging-related parameters of unicompartmental knee arthroplasty and open-wedge high tibial osteotomy in the treatment of unicompartmental knee osteoarthritis with varus deformity.
    METHODS:  The medical record data of 126 patients with unicompartmental knee osteoarthritis with varus deformity were retrospectively analyzed, including 60 patients undergoing open-wedge high tibial osteotomy and 66 patients undergoing unicompartmental knee osteoarthritis with varus deformity. The Hospital for Special Surgery knee score was used to assess knee function preoperatively, 1 month postoperatively and the late follow-up between the two groups. Long-leg full-weight-bearing radiograph and anteroposterior and lateral radiograph of knee were taken before and after operation. The postoperative hip-knee-ankle angle, tibial posterior slope and patellar height were measured. The differences in the relevant imaging parameters of knee joint were compared between the two groups before and after operation.  
    RESULTS AND CONCLUSION: (1) A total of 53 knees with high tibial osteotomy and 61 knees with unicompartmental knee arthroplasty were included in this study. The overall follow-up time was (26.29±3.84) months. (2) The Hospital for Special Surgery scores were higher in the unicompartmental knee arthroplasty group than those in the high tibial osteotomy group (P < 0.05). At the last follow-up, there was no significant difference in Hospital for Special Surgery scores between the two groups (P > 0.05). (3) Compared with preoperative data in the same group, the hip-knee-ankle angle and tibial posterior slope increased (P < 0.05), but patellar height decreased (P < 0.05) in the high tibial osteotomy group. Compared with preoperative data in the same group, hip-knee-ankle angle increased (P < 0.05), but tibial posterior slope decreased (P < 0.05), patellar height increased in the unicompartmental knee arthroplasty group, but the difference was not significantly different (P > 0.05). (4) Total hip-knee-ankle angle increased from (-5.68±3.48)° preoperatively to (0.69±0.69)° postoperatively. No significant difference was detected in hip-knee-ankle angle, tibial posterior slope and patellar height between the two groups before operation (P > 0.05). Significant differences were found in hip-knee-ankle angle, tibial posterior slope, patellar height, Δ hip-knee-ankle angle (postoperation-preoperation), Δ tibial posterior slope (postoperation-preoperation) and Δ patellar height (postoperation-preoperation) between the two groups after operation (P < 0.05). (5) It is concluded that the two groups of patients obtained satisfactory results in the late follow-up. However, the patients in the unicompartmental knee arthroplasty group had better knee function scores 1 month after surgery compared with the high tibial osteotomy group. In contrast, the high tibial osteotomy group was prone to postoperative patellar baja and increased posterior tibial slope. In the unicompartmental knee arthroplasty group, the patellar height did not change significantly after surgery, but the posterior tibial slope showed a significant decrease.
    Figures and Tables | References | Related Articles | Metrics
    Three-dimensional finite element modeling of the foot and its multi-posture biomechanical analysis
    Zhang Leilei, Wang Mengsheng, Xu Dawei, Huang Hong, Yang Yongtai
    2021, 25 (30):  4799-4804.  doi: 10.12307/2021.264
    Abstract ( 290 )   PDF (1813KB) ( 41 )   Save
    BACKGROUND: The biomechanical properties and injury mechanisms of the foot have always been a major concern for doctors and sports science researchers. Three-dimensional finite element analysis has become an effective technique for numerical simulation of biomechanical behavior.  
    OBJECTIVE: To establish an effective finite element analysis model of the foot to analyze the biomechanical properties of the foot in different landing postures.
    METHODS:  CT images of one foot of a healthy adult male were acquired. The images were segmented using Mimics to obtain the point cloud. To obtain a smooth 3D geometric model of the foot, Geomagic was used for the processing and optimization of the point cloud. After that, the geometric model was imported into Hypermesh to complete the finite element pre-processing. Finally, Abaqus was used to solving and calculating. The effectiveness of the finite element model was verified through the contrast of the simulation result and the measured plantar pressure. According to the internal stress distribution obtained from the simulation, the biomechanical characteristics of the foot in multiple landing postures were analyzed.  
    RESULTS AND CONCLUSION: (1) The proposed mesh quality control method improved the quality of the mesh divided by the pre-processing of finite element analysis; it solved the problem of non-convergence of the finite element analysis model without significantly increasing the computational cost. (2) Simulation analysis of different postures of the foot found that: when the landing mode was forefoot strike, the foot load was concentrated on the forehand, leading to increased stress on the metatarsal bone and plantar fascia, which was easy to cause damage to the metatarsal bone and plantar fascia; when the landing mode was heel strike, the foot load was concentrated on the heel, and the stress on the heel bone was increased, which increased the risk of heel pain and knee injury. (3) Therefore, prolonged and repetitive stimulation with high loads should be avoided during exercise, especially for those who already have related diseases and should avoid exercise that aggravates their condition.
    Figures and Tables | References | Related Articles | Metrics
    Establishment of a total cervical spine model and characteristics of traction force and traction angles under different traction orientations
    Zhang Xinming, Liu Zhihua, Zhang Xinmin, Shen Yankui, Wang Chunli
    2021, 25 (30):  4805-4811.  doi: 10.12307/2021.265
    Abstract ( 313 )   PDF (1733KB) ( 17 )   Save
    BACKGROUND: This paper designs a new type of cervical spine traction robot. During the development of the equipment, there are problems of uncertain traction and traction angle. These problems are important factors that affect the treatment effect of patients.  
    OBJECTIVE: To establish a three-dimensional finite element model of the cervical vertebrae C1-C7 , verify the validity of the model, and discuss the influence of different traction forces and traction angle changes on cervical intervertebral discs.
    METHODS:  The cervical spine CT data of a 30-year-old healthy adult volunteer with no history of cervical spondylosis were collected. The intervertebral disc and cervical bone body CAD models were generated by Mimics 21.0 and 3-matic software, and the grids were divided. The data were imported into Abaqus 2016 finite element analysis software to add cervical ligaments and verify their effectiveness. Constraints and loads were applied on the generated cervical spine model to simulate the traction treatment with the change of traction force and angle when the person was sitting, and the influence of traction force and angle on traction effect was analyzed.  
    RESULTS AND CONCLUSION: (1) For the new type of traction equipment, in the range of 50 N to 150 N traction, the greater the traction, the better the traction, but too much traction would cause the patient’s pain to increase significantly. 130 N with better therapeutic effect could be chosen as the traction. (2) As the traction angle increased from 0° to 20°, the deformation of the intervertebral disc in the anterior flexion position gradually decreased. The traction angle less than 10° was more suitable for the anteflexion treatment of the new traction equipment. (3) The deformation of the intervertebral disc in the posterior flexion and left-right flexion position gradually increased with the increase of the traction angle, and reached a relatively stable amount of deformation at about 16° to 17°. Therefore, the traction angle of 16° to 20° should be selected for the posterior and left-right flexion of the new equipment. (4) The model of C1-C7 cervical spine was successfully established and the traction force and traction angle were analyzed by finite element method.
    Figures and Tables | References | Related Articles | Metrics
    Anatomical features of anterior cruciate ligament on MRI in children, adolescents and adults
    Zhong Ruixin, Gao Haiyan, Huang Haoran, Teng Xueren, Dai Shiyou
    2021, 25 (30):  4812-4817.  doi: 10.12307/2021.266
    Abstract ( 210 )   PDF (1153KB) ( 18 )   Save
    BACKGROUND: Children and adolescents are in the growth and development stage, so the use of the same reconstruction methods as adults is easy to induce complications including limb length differences, high graft failure rate and re-surgical intervention. Simultaneously, the occurrence of osteoarthritis will also be advanced.  
    OBJECTIVE: To explore the anatomical characteristics of the anterior cruciate ligament between children, adolescents and adults on MRI, and to provide an anatomical basis for the reconstruction of the anterior cruciate ligament in children and adolescents.
    METHODS:  A retrospective analysis of patients undergoing knee MRI examination in Qingdao Municipal Hospital from October 2016 to October 2018 was conducted. These patients were divided into child and adolescent group and adult group (n=48 per group). The angle between the anterior cruciate ligament and the tibia and femur on the sagittal plane and the position of the anterior cruciate ligament tibial insertion, the angle between the anterior cruciate ligament and the tibia on the coronal plane, the tibial insertion of the anterior cruciate ligament and femur, and the position of the femur stop point on the axial position were measured in both groups. The data obtained from the measurement of the anterior cruciate ligament of children and adolescents were processed. The growth curves of the shape and position of the anterior cruciate ligament of children and adolescents were drawn, and the law of its growth changes was analyzed.  
    RESULTS AND CONCLUSION: (1) The angle between the sagittal plane of the anterior cruciate ligament and the femur (t=-2.906, P < 0.05), the angle between the sagittal plane of the anterior cruciate ligament and the tibia (t=-10.280, P < 0.05), the anterior cruciate ligament angle between the coronal plane and the tibia (t=-5.714, P < 0.05) were smaller in the child and adolescent group than those of the adult group, and the difference was significant. (2) The ratio of the tibia coronal plane of the anterior cruciate ligament (t=-7.263, P < 0.05) and the ratio of the anterior cruciate ligament and femur axial plane (t=-7.378, P < 0.05) were lower in the child and adolescent group than those of the adult group, and the difference was significant. (3) There was no significant difference in the anterior cruciate ligament and tibia sagittal plane ratio (t=-1.588, P > 0.05) and anterior cruciate ligament and femoral coronal surface ratio (t=-1.647, P > 0.05) between the child and adolescent group and the adult group. (4) The growth curve results showed that during the growth and development, the angle between the anterior cruciate ligament and the femur and tibia on the sagittal plane and the angle with the tibia on the coronal plane changed from small to large (P < 0.05). The relative position of the tibial insertion in the coronal position changed from small to large, which indicates that during the growth and development, the tibial insertion moved from inside to outside relative to the inside of the tibial plateau on the coronal plane (P < 0.05). (5) The relative position of femoral insertion in the axial position changed from small to large, suggesting that during the growth and development, the femoral insertion moved from the outside to the inside relative to the lateral femoral condyle (P < 0.05). (6) There was no significant difference in the tibial insertion and the femoral insertion between the child and adolescent group and adult group (P > 0.05).
    Figures and Tables | References | Related Articles | Metrics
    Capsule protection reduces the incidence risk of adjacent segment diseases after percutaneous endoscopic discectomy: a biomechanical analysis
    Huang Chenyi, Li Jingchi, Xu Wenqiang, Zhang Xiaoyu, Fang Zhongxin, Liu Zongchao
    2021, 25 (30):  4818-4822.  doi: 10.12307/2021.267
    Abstract ( 146 )   PDF (1185KB) ( 29 )   Save
    BACKGROUND: Biomechanical deterioration was the most significant trigger of lumbar degenerative diseases. Capsule of the zygapophyseal joint has been proven to be of great significance to maintain the overall biomechanical environment of lumbar spine.  
    OBJECTIVE: To investigate the biomechanical effect of various degrees of capsule injury in the percutaneous endoscopic discectomy on the deterioration of biomechanical indicators related to adjacent segment diseases.
    METHODS:  Lumbo-sacral finite element models from L3 to S1 constructed and validated in our previously published studies, and finite element models after percutaneous endoscopic discectomy were used. Different ranges of capsule injury in percutaneous endoscopic discectomy were simulated by adjusting the cross-sectional area of the joint capsule. To evaluate the risk of adjacent vertebral disease after operation, the changes of biomechanical indexes such as intradiscal pressure, maximum shear force of annulus fibrosus and von Mises stress of cartilage endplate were observed in different models before and after operation.  
    RESULTS AND CONCLUSION: (1) The decrease of the capsule cross-sectional areas in percutaneous endoscopic discectomy models leads to the obvious increase of the von-Mises stress of the cartilage endplate and the maximum shear force of annulus fibrosus, becoming an important risk factor for the increased risk of postoperative adjacent segment disease. (2) Therefore, joint capsule protection in percutaneous endoscopic discectomy plays an important positive role in reducing the risk of adjacent segment disease.
    Figures and Tables | References | Related Articles | Metrics
    Calcium sulfate antibiotic carrier in the treatment of periprosthetic infection after arthroplasty and its effect on serum calcium
    Gao Tianhao, Qian Huifang, Yang Shangliang, Xin Chaofei, Lu Shitao, Xu Jianzhong
    2021, 25 (30):  4823-4827.  doi: 10.12307/2021.268
    Abstract ( 202 )   PDF (1512KB) ( 25 )   Save
    BACKGROUND: Calcium sulfate, as an antibiotic carrier, has been widely used in the treatment of osteomyelitis, but its role in periprosthetic infection still needs to be further explored. 
    OBJECTIVE: To observe the effects of calcium sulfate sustained-release system on the treatment of periprosthetic joint infection following arthroplasty and the postoperative serum calcium concentration.
    METHODS: Retrospective analysis was performed on 24 patients who were admitted to the Department of Orthopedics of the First Affiliated Hospital of Zhengzhou University and developed periprosthetic joint infection following arthroplasty from January 2019 to April 2020. Depending on the stage of the patient’s periprosthetic joint infection and whether there was etiological evidence, the patients were treated with arthroscopic debridement, incision debridement, one-stage revision arthroplasty or two-stage revision arthroplasty. All patients were implanted with a calcium sulfate sustained-release system intraoperatively. The trial was approved by the Ethics Committee of First Affiliated Hospital of Zhengzhou University (Approval No. 2020-KY-0229). 
    RESULTS AND CONCLUSIONS: (1) All patients completed the three-month follow-up. (2) The incidence of asymptomatic hypocalcemia was high. Specifically, two patients experienced hypocalcemia requiring emergency treatment, and one patient experienced hypercalcemia not requiring treatment at 1 day postoperatively. The preoperative and postoperative serum calcium levels were comparable in these patients. (3) Totally 23 patients had satisfactory wound healing, and the prosthesis was well positioned without recurrence of infection; one patient developed infection that recurred following reoperation. (4) In all the patients, erythrocyte sedimentation rate and C-reactive protein decreased significantly postoperatively (P < 0.01); Harris hip and knee scores improved postoperatively (P < 0.01). (5) These suggest that calcium sulfate sustained-release system can effectively improve periprosthetic joint infection following arthroplasty, and the patients are at a high risk of postoperative asymptomatic hypocalcemia.
    Figures and Tables | References | Related Articles | Metrics
    Gap balance technology can reduce the amount of osteotomy and maintain the balance of lower limb alignment and flexion and extension gap in total knee arthroplasty
    Chen Hongqiang, Zhou Hua, Chen Debin, Wu Xizhi, Wu Dewei, Zhao Bin
    2021, 25 (30):  4828-4832.  doi: 10.12307/2021.269
    Abstract ( 198 )   PDF (1131KB) ( 15 )   Save
    BACKGROUND: Total knee arthroplasty is an effective method for the treatment of end-stage knee osteoarthritis. The key to total knee arthroplasty is to restore the accurate lower limb alignment and good flexion and extension space balance. Gap balance technique and measurement osteotomy technique are two classical osteotomy methods, which methods to choose is still controversial.  
    OBJECTIVE: To compare radiographical manifestations of gap balance technique and measurement osteotomy technique in total knee arthroplasty patients, and analyze application effect of gap balance technique in total knee arthroplasty patients.
    METHODS:  Clinical data of 118 patients with total knee arthroplasty were retrospectively analyzed, including 42 males and 76 females, aged 53-72 years old. According to intraoperative osteotomy methods, they were divided into gap balance group (61 cases) and measurement osteotomy group (57 cases). In 12-month follow-up, X-ray films were taken to measure the coronal hip-knee-ankle angle, lower line force angle and femoral flexion angle. Visual analogue scale score and American knee society knee score were used to evaluate the pain degree and knee function. This study was approved by the Ethics Committee of Guiyang Fourth People’s Hospital.  
    RESULTS AND CONCLUSION: (1) The gap balance group had local infection in three cases. The measurement osteotomy group had local infection in four cases, rejection in one case, and immune reaction in one case. There was no significant difference in complications between the two groups (4.92%, 10.53%, P > 0.05). (2) In 12-month follow-up, knee flexion 90° stress angle of medial and lateral tibiofemoral joint was lower in the gap balance group than that in the measurement osteotomy group (P < 0.001). Coronal hip-knee-ankle angle and lower limb alignment were smaller in the gap balance group than those in the measurement osteotomy group (P < 0.001). Maximum femoral flexion angle was larger in the gap balance group than that in the measurement osteotomy group (P < 0.001). (3) In 12-month follow-up, visual analogue scale scores were lower in the gap balance group than those in the measurement osteotomy group (P < 0.001). American knee society knee score was higher in the gap balance group than that in the measurement osteotomy group (P < 0.01). (4) Results showed that gap balance technology help to maintain a good lower limb alignment and flexion extension gap space, relieve the pain and improve the knee function during total knee arthroplasty.
    Figures and Tables | References | Related Articles | Metrics
    Conventional instrument SuperPATH approach versus the anterolateral approach for femoral head replacement: a randomized controlled comparison of efficacy
    Ji Dong, Xia Liangzheng, Jiang Yunyun, Wang Kang, Deng Yinghu, Zhu Dongqi, Yuan Zhongshan, Li Shenghua
    2021, 25 (30):  4833-4838.  doi: 10.12307/2021.270
    Abstract ( 182 )   PDF (1240KB) ( 23 )   Save
    BACKGROUND: The incision of anterolateral approach for femoral head replacement is larger; the cut muscle needs time to heal; and the recovery time is longer. The incision of the SuperPATH approach is very small, and it does not cut off the muscle, so it can recover quickly. However, it needs special artificial prosthesis and special instruments, and the cost is high.  
    OBJECTIVE: To compare the efficacy of conventional instrument SuperPATH approach and anterolateral approach for femoral head replacement.
    METHODS:  From December 2016 to August 2018, 43 elderly patients with femoral neck fracture were randomly divided into experimental group (21 cases, SuperPATH group) and control group (22 cases, anterolateral group). All patients were operated with conventional instruments and femoral head, The incision length, intraoperative blood loss, the time from skin incision to incision closure, the changes of hemoglobin and red blood cells before and after operation, the time of getting off the ground after operation, pain score and hip joint function score were recorded.  
    RESULTS AND CONCLUSION: All patients were followed up for 24 to 36 months. Among them, the length of incision, the time from skin incision to incision closure, the time to get off the ground after operation, Visual Analogue Scale score at 1 week, Harris score at 1 week and 3 months after operation were significantly different between the two groups (P < 0.05), and the experimental group was better than the control group. There was no significant difference in blood loss during operation, changes of erythrocytes and hemoglobin before and after operation, Visual Analogue Scale score at 3 months after operation and Harris score at 6 months after operation between the two groups (P > 0.05). These findings confirm that compared with anterolateral approach, SuperPATH approach has the advantages of shorter incision, less trauma and faster recovery.
    Figures and Tables | References | Related Articles | Metrics
    Nail breakage of proximal femoral nail anti-rotation for treating intertrochanteric fracture: construction and validation of finite element simulation model
    Xu Long, Zeng Zhanpeng, Chen Zijie, Zhang Yan, Lin Ziling,
    2021, 25 (30):  4839-4844.  doi: 10.12307/2021.271
    Abstract ( 206 )   PDF (1497KB) ( 29 )   Save
    BACKGROUND: Nail breakage of proximal femoral nail anti-rotation is one of the severe implant failure that must be revised. At present, the biomechanical causes for the nail breakage are mostly inferred from metal fatigue; however, there is still no direct research or method to prove the mechanical mechanism of nail breakage. Therefore, to construct a finite element model of proximal femoral nail anti-rotation in treating intertrochanteric fracture and to realize the visualization of nail breakage are of great significance in studying the failure mechanism.
    OBJECTIVE: To simulate biomechanical process of the nail breakage of proximal femoral nail anti-rotation in treating intertrochanteric fracture.
    METHODS: Femoral CT data of a hip fracture patient, who was hospitalized in Department of Traumatic Orthopedics, First Affiliated Hospital of Guangzhou University of Chinese Medicine, were imported into Mimics 19.0 and polished in Geomagic Studio software to reconstruct a three-dimensional finite element model of proximal femur. The proximal femoral nail anti-rotation model was created in SolidWorks based on the specification and matched with the polished femoral model according to the surgical protocol. The proximal femoral nail anti-rotation intramedullary nail was fixed to the proximal femur, and the assembly model of the femur and proximal femoral nail anti-rotation intramedullary nail was established. The component including proximal femoral nail anti-rotation and proximal femur was meshed as tetrahedron and constructed as AO-31A1.3 type fracture (2018 version) in Hypermesh software. After material contents (including critical fatigue parameter of implants and biomechanical material parameter of femur), loading, boundary condition and friction coefficient were completed, the K file was finally solved in LS-DYNA.
    RESULTS AND CONCLUSION: (1) Crack first appeared on the weakness on the blade hole of nail. (2) The maximal Von Mises stress of nail reached 412 MPa before breakage. During the crack propagation, stress concentrated at the intersection between nail and helical blade, locking bolt and nail. Stress distributed around the head-neck part and the insertion point of the great trochanter on femur. The maximal Von Mises stress of femur during the nail breakage was  248.3 MPa. (3) The tip of helical blade and the femoral head varus in the coronal plane, and being the most displaced parts. (4) The validation results suggest that this model can effectively simulate the nail breakage of proximal femoral nail anti-rotation in treating intertrochanteric fracture. The weak part of nail was the critical area of stress concentration and destruction. 
    Figures and Tables | References | Related Articles | Metrics
    TightRope versus metallic screw fixation for treatment of tibiofibular syndesmosis injury
    Su Boyuan, Yao binfu, Zeng Guanglong, ye Zhongsen, Xie Qingxiang
    2021, 25 (30):  4845-4850.  doi: 10.12307/2021.272
    Abstract ( 263 )   PDF (1237KB) ( 30 )   Save
    BACKGROUND: Syndesmosis injury is usually a common complication after ankle sprain, especially with rotation type of malleolar fracture, and is a damaged part that needs special attention. The classical therapy of syndesmosis injury is syndesmosis fixation with one or two screws. As the minimal invasive technique developed, syndesmosis flexible fixation is more widely used.  
    OBJECTIVE: To investigate the arthroscopic reduction of the lower tibiofibular syndesmosis of the ankle, and compare the clinical efficacy of tibiofibular syndesmosis screw and TightRope fixation.
    METHODS:  From January 2016 to August 2019, 51 patients with ankle joint fracture and distal tibiofibular syndesmosis injury were randomly divided into two groups. Arthroscopic ankle reduction was performed in both groups, including 23 cases in metal screw fixation group and 28 cases in TightRope fixation group. The weight-bearing time and postoperative complications were compared between the two groups. Ankle function was evaluated by gait analysis and American Orthopaedic Foot and Ankle Society score at the last follow-up.  
    RESULTS AND CONCLUSION:  (1) 51 patients were followed up for 6 to 18 months. (2) The partial and full weight-bearing time of TightRope fixation group was significantly shorter than that of metal screw fixation group (P < 0.05). (3) There was no significant difference in gait analysis between the two groups at the last follow-up (P > 0.05). (4) There was no significant difference in American Orthopaedic Foot and Ankle Society score between the two groups at the last follow-up (P > 0.05), and the excellent rates both were 100%. (5) Arthroscopic ankle reduction can more accurately restore the structure of the lower tibiofibular syndesmosis. Compared with metal screw, TightRope in the treatment of distal tibiofibular syndesmosis injury can provide enough fixation strength, which can make patients load weight underground earlier, but the long-term effect is uncertain under the premise of stable tibiofibular syndesmosis.
    Figures and Tables | References | Related Articles | Metrics
    Locking plate fixation combined with different bone grafts for Neer 3- and 4-part fractures of proximal humerus in the elderly
    Liu Wenjie, Yu Lijuan, Xu Bin
    2021, 25 (30):  4851-4856.  doi: 10.12307/2021.273
    Abstract ( 215 )   PDF (1296KB) ( 14 )   Save
    BACKGROUND: Elderly patients with Neer 3- and 4-part fractures of the proximal humerus have poor proximal bone, so the bone defect after fracture reduction is very serious, which will lead to poor effect of simple locking plate fixation.  
    OBJECTIVE: To evaluate the efficacy and mechanism of allogeneic ilium and fibula in the treatment of Neer 3- and 4-part fractures of the proximal humerus in the elderly.
    METHODS:  Data of 64 elderly patients with Neer 3- and 4-part fractures of the proximal humerus and undergoing different surgery techniques in Department of Orthopedics, The First Affiliated Hospital of Shanxi Medical University from November 2014 to March 2019 were retrospectively analyzed. They were divided into three groups: single locking plate (group A, 24 cases), locking plate combined with allogeneic ilium (group B, 19 cases) and locking plate combined with allogeneic fibula (group C, 21 cases). The following observation indexes were compared in three groups: (1) General indicators: operation time, intraoperative blood loss, hospital stay; (2) imaging indicators: the neck-shaft angle, humerus head height, and healing time; (3) efficacy indicators: Constant-Murley score, visual analog scale, the incidence of complications.  
    RESULTS AND CONCLUSION: (1) All patients were healed and followed up from 12 to 24 months. (2) The operation time and hospital stay in group A were significantly better than those in groups B and C (P < 0.05). However, there was no significant difference in intraoperative blood loss compared with groups B and C (P > 0.05). There was no significant difference in three indicators between groups B and C (P > 0.05). (3) Group A had higher neck-shaft angle and humerus head height than groups B and C (P < 0.05), and there was no significant difference between group B and group C (P > 0.05). There were significant differences in the healing time between groups A, B and C (P < 0.05), in which group A > group C > group B. (4) The total Constant-Murley score and the score of active items in group A were lower than those in groups B and C (P < 0.05), and there was no significant difference between group B and group C (P > 0.05). There was no statistically significant difference in visual analog scale score among groups A, B and C (P > 0.05). (5) Complications in group A included screw resection in 1 case, humeral head necrosis in 1 case, and joint stiffness in 2 cases. There was 1 case of acromial impingement syndrome in group B. In group C, screw resection occurred in 1 case and head necrosis of humerus in 1 case. There was no significant difference in the incidence of complications in the three groups (P > 0.05). (6) It is indicated that locking plate is the first choice for the treatment of Neer 3- and 4-part fractures of the proximal humerus in the elderly. For those with significant bone defects, mechanical stability can be achieved by combining fibula allografts. For partial bone defects, ilium allograft can be used to accelerate osteogenic healing.
    Figures and Tables | References | Related Articles | Metrics
    Correlation of endplate fractures with height loss of injured vertebral body, kyphosis and chronic pain after vertebral augmentation
    Ma Riji, Song Wenhui, Liu Changwen, Liang Kaiheng, Wang Ziao, Shi Fan
    2021, 25 (30):  4857-4862.  doi: 10.12307/2021.274
    Abstract ( 160 )   PDF (1339KB) ( 19 )   Save
    BACKGROUND: Although vertebral augmentation can quickly stabilize fractures, relieve pain symptoms, and correct kyphosis, as the number of cases continues to increase, it has been clinically found that some patients have long-term kyphosis and chronic pain problems after surgery.  
    OBJECTIVE: To explore the effects of endplate fractures on the loss of injured vertebral height, kyphosis and chronic pain after percutaneous vertebroplasty/percutaneous kyphoplasty.
    METHODS:  A retrospective study investigated the medical records of 82 patients with osteoporotic vertebral compression fracture, who treated with percutaneous vertebroplasty/percutaneous kyphoplasty. The patients were divided into three groups according to the presence or absence of endplate fractures: unfractured group, superior vertebral endplate fracture group, and inferior endplate fracture group. The vertebral compression rate, vertebral height recovery rate, Cobb angle, and bone mineral density of each patient were measured and visual analogue scale, bone cement dispersion type, bone cement distribution area, and cement leakage were recorded. Univariate analysis and chi-square test were used to analyze whether endplate fractures were related to postoperative injury vertebral height loss, kyphosis and chronic pain, and the influence of endplate fractures on the distribution of bone cement.  
    RESULTS AND CONCLUSION: (1) The height of the injured vertebrae and kyphosis in the three groups were significantly improved. In the last follow-up, all patients observed a significant decrease in the height of the anterior vertebrae and an increase in Cobb angle. The loss rate of injured vertebral height and Cobb angle in the superior vertebral and inferior endplate fracture groups were greater than those in the unfractured group (P < 0.05). (2) There was no significant difference in the preoperative visual analogue scale scores between the groups (P > 0.05). The postoperative visual analogue scale scores of the three groups were significantly lower than the preoperative scores (P < 0.05), but the last follow-up visual analogue scale scores of the endplate fracture group were higher than those of the postoperative group, while the unfractured group had no significant difference in visual analogue scale scores during the last follow-up and after operation (P > 0.05). (3) The proportion of bone cement masses and the bone cement not contacting the two endplates at the same time was significantly higher in the superior vertebral and inferior endplate fracture groups than that of the unfractured endplate group (P < 0.05). There was no significant difference between the groups with insufficient bone cement distribution at the fracture site (P > 0.05). (4) It is suggested that percutaneous vertebroplasty/percutaneous kyphoplasty can significantly improve the height of injured vertebrae, kyphosis and pain. However, long-term endplate fractures after surgery are not only related to the increased incidence of postoperative vertebral height loss and kyphosis, but also an important cause of chronic pain in patients. Other factors that affect the long-term loss of vertebral body height and the occurrence of kyphosis include the degree of bone cement dispersion, bone density, surgical methods, and bone cement materials. The degree of bone cement dispersion is affected by endplate fractures, and the lower the bone density, the more likely to fracture the endplate. Therefore, surgery should not only restore the compression height of the injured vertebrae and correct the kyphosis, but also correct the deformity of the endplate to effectively treat patients with endplate fractures.
    Figures and Tables | References | Related Articles | Metrics
    Long-term survival rate and reoperation of Wallis interspinous dynamic stabilization system for treatment of lumbar degenerative disc disease
    Gu Honglin, Zheng Xiaoqing, Liang Changxiang, Zeng Shixing, Zhan Shiqiang, Chang Yunbing
    2021, 25 (30):  4863-4869.  doi: 10.12307/2021.275
    Abstract ( 261 )   PDF (1173KB) ( 27 )   Save
    BACKGROUND: Wallis interspinous dynamic stabilization system has been used in China for more than 10 years, but its long-term survivorship and reoperation rate are rarely reported.
    OBJECTIVE: To observe the long-term efficacy, complication rate, reoperation rate and survival rate of Wallis interspinous process dynamic stabilization system in the treatment of lumbar degenerative disc disease.
    METHODS:  126 patients with lumbar disc degenerative disease who underwent posterior decompression or discectomy + Wallis fixation in Guangdong Provincial People’s Hospital from May 2008 to March 2013 followed up for more than 7 years were retrospectively selected. Indications, preoperative and postoperative Japanese Orthopedic Association, Oswestry disability index, visual analogue scale score, complications, reoperation, and device survival rate were evaluated.  
    RESULTS AND CONCLUSION: (1) A total of 103 cases completed follow-up, with a mean value of (124.43±11.44) months. Of 103 patients, 9 cases were diagnosed as lumbar stenosis, 46 cases as lumbar disc herniation, 41 cases as lumbar stenosis combined with lumbar disc herniation, and 7 cases as spondylolisthesis. (2) Japanese Orthopedic Association, Oswestry disability index, visual analogue scale scores at last follow-up were better than those before surgery (P < 0.05). (3) Overall complication rate was 14.5% (15/103), including prosthesis burst, spinous process fracture, recurrence of surgical or adjacent disc herniation, wound infection and recurrent low back pain. The reoperation rate was 7.8% (8/103). (4) The 5-year and 10-year survival rates were 98.1% (101/103) and 97.1% (100/103). (5) Compared with patients with other diseases, patients with lumbar disc herniation had the highest rate of complication (21.7%, 10/46) and reoperation rate (13%, 6/46), and the lowest 5-year 95.7% (44/46) and 10-year 93.5% (43/46) survival rates. (6) Wallis implantation can achieve satisfactory long-term survival rate and clinical outcomes in the treatment of lumbar disc degenerative diseases. However, complication rate and reoperation rate in patients with lumbar disc herniation are higher, and the survival rate is lower. Thus, Wallis implant should be used cautiously in patients with this diagnosis.
    Figures and Tables | References | Related Articles | Metrics
    Relationship between prosthetic dislocation and lumbar pelvic sagittal parameters in patients undergoing total hip replacement after lumbar fusion
    Wang Yachao, Huang Jian
    2021, 25 (30):  4870-4876.  doi: 10.12307/2021.276
    Abstract ( 180 )   PDF (1016KB) ( 21 )   Save
    BACKGROUND: Dislocation of the prosthesis after total hip replacement is one of the most important factors that limit the life of the prosthesis, which brings huge physical pain and economic burden to the patient. Studies have found that lumbar fusion is the most important independent risk factor for prosthesis dislocation after total hip arthroplasty. Exploring the reasons for the dislocation and proposing treatment options have always been an important topic for joint surgeons.
    OBJECTIVE: To analyze and review the reasons for the increased dislocation rate of the prosthesis after total hip replacement in patients with a history of lumbar fusion surgery and the treatment plan by studying the sagittal plane of the lumbar spine and pelvis.
    METHODS: The Chinese key words were “lumbar fusion; total hip replacement; pelvic sagittal plane; impingement; dislocation” and the English key words were “lumbar fusion; total hip replacement; pelvic sagittal plane; impingement; dislocation”. After searching the articles published from 2016 to 2020 in Wanfang, CNKI, and PubMed databases, 39 articles were finally included according to the inclusion and exclusion criteria. 
    RESULTS AND CONCLUSION: (1) The reason for the increased prosthesis dislocation rate of patients with a history of lumbar fusion surgery and undergoing total hip replacement is impingement, and the most economical and effective way to study impact is the sagittal X-ray of the lumbar pelvis. (2) After lumbar fusion, the lumbar spine affects the sagittal plane of pelvis through balance and mobility, increasing impact risk: the lumbar spine is severely unbalanced, causing the pelvis to tilt backward and the acetabulum to be vertical, increasing the risk of impact; stiffness of the lumbar spine leads to decreased pelvic mobility and increased hip joint mobility, which increases the risk of impact. (3) The relationship between the sagittal plane of lumbar spine, pelvis and hip joint has a wide range of applications.
    Figures and Tables | References | Related Articles | Metrics
    Treatment of distal clavicle fractures and selection of implants
    Wei Yongan, Zhou Jihui, Chen Wenyao, Li Bo, Huang Jing, Wang Jie, Zhu Xiaokang, Li Xinzhi
    2021, 25 (30):  4877-4882.  doi: 10.12307/2021.277
    Abstract ( 203 )   PDF (1006KB) ( 20 )   Save
    BACKGROUND: Unstable distal clavicle fractures need surgical treatment, and there is no gold standard for the intraoperative implants. The improvement of the implants and the progress of technology are the focus of research in recent years.
    OBJECTIVE: To summarize the new progress of the treatment of distal clavicle fracture with internal fixation, to explore the principles and advantages and disadvantages of various surgical treatment methods, and to guide the direction of further research.
    METHODS: Chinese database of Wanfang, VIP, and China National Knowledge Infrastructure was searched by the first and the second authors. The search terms were “distal clavicular fracture; classification; biomechanics; internal fixation; tendon reconstruction; complications; prognosis”. At the same time, the English database of PubMed and Web of Science was retrieved with the search terms of “patella fracture, classification, biomechanics, implants, tendon reconstruction, complications, prognosis”. The retrieval period was from July 2015 to August 2020. A total of 466 articles were retrieved. According to the inclusion and exclusion criteria, 48 articles were finally selected and summarized. 
    RESULTS AND CONCLUSION: (1) Unstable fracture of distal clavicle needs to be treated by operation, which should not only consider fracture treatment, but also consider the instability caused by coracoclavicular ligament injury. (2) There are many kinds of implants for distal clavicle fracture, but there is no unified gold standard. (3) Surgical treatment methods include Kirschner wire tension band internal fixation, hook plate internal fixation, locking plate internal fixation, ligament strengthening, and reconstruction technology. Ligament reconstruction technology is more and more popular; the improvement of the internal object and technology is the focus of research.
    Figures and Tables | References | Related Articles | Metrics
    Indications and timing of surgical treatment of tophi in limbs
    Zhu Kunzhi, Lu Tao, Luo Zhangfeng, Wu Zhanyu, Zhou Yuhu, Ye Chuan
    2021, 25 (30):  4883-4890.  doi: 10.12307/2021.278
    Abstract ( 256 )   PDF (1269KB) ( 24 )   Save
    BACKGROUND: The treatment of tophi can be divided into medical treatment and surgical intervention. The indications and timing of surgical intervention continue to be debated, and it is lack of understanding of the operation and skills of the operation. As a result, a large number of patients have not received effective and timely treatment.
    OBJECTIVE: To review the current research progress and future development prospects of tophi in limbs, to explore the indications, contraindications, timing and key points of surgical treatment, hoping to play a certain guiding role for surgical treatment of tophi in limbs.
    METHODS: The databases of Wanfang Medical Network, China National Knowledge Infrastructure and PubMed were searched by computer, using the Chinese key words of “tophus, surgery, surgical treatment, arthroplasty, arthroscopy, medical engineering, biomaterials” and English key words of “tophi, tophaceous, gout, gouty arthritis, tophus, surgery, arthroplasty, arthroscopy, medical engineering, biomaterials”. According to the inclusion and exclusion criteria, 74 related articles were finally included and summarized. 
    RESULTS AND CONCLUSION:  (1) At present, medication is the basis of the treatment of gout, but there are still a large number of patients who require surgical intervention. (2) Patients with early gout can be treated by surgery after balancing the potential advantages and related risks of surgical treatment. For advanced patients, surgery is a more efficient way, but surgical treatment cannot avoid iatrogenic injury. (3) In the future, we also need to find an effective and non-injury method to treat tophi; medical engineering and tissue engineering technology are expected to solve this problem.
    Figures and Tables | References | Related Articles | Metrics
    Effects and safety of fenestrated and conventional pedicle screw combined with cement-augmentation in osteoporotic vertebral fixation: a meta-analysis
    Guo Haiwei, Xie Jiahao, Lin Yanping, Wang Yufeng, Yang Qingqi
    2021, 25 (30):  4891-4899.  doi: 10.12307/2021.279
    Abstract ( 168 )   PDF (1383KB) ( 19 )   Save
    OBJECTIVE: Cement-augmentation fenestrated pedicle screws have been widely used in spinal internal fixation surgery combined with osteoporosis in recent years, which can significantly improve the fixation strength and stability, but compared with conventional methods, whether it has more advantages is still inconclusive. To compare the difference in repair effect between the fenestrated and conventional pedicle screw combined with cement-augmentation in osteoporotic vertebrae fixation.
    METHODS: Studies compared the fenestrated pedicle screw and the conventional pedicle screw combined with cement-augmentation in osteoporotic vertebrae fixation were retrieved from the electronic database of PubMed, EMbase, Cochrane Library, CNKI, Wanfang and SinoMed. Two reviewers independently extracted the data and assessed the quality of the relevant articles which were screened strictly according to the inclusion and exclusion criteria. The quality evaluation of studies included was carried out according to the Cochrane collaboration’s tool for randomized controlled trials or Newcastle-Ottawa Scale for retrospective cohort studies. Meta-analysis was conducted by using RevMan 5.3 software to compare the clinical efficacy, radiological results and complications of the two methods. 
    RESULTS: (1) Totally 12 articles were eventually included into this meta-analysis, involving 6 randomized controlled studies and 6 retrospective cohort studies, totaling 823 patients with 408 cases in the fenestrated pedicle screw group and 415 cases in the conventional pedicle screw group. (2) Meta-analysis results showed there was no statistical significance in operation time, inpatient time, postoperative visual analogue scale score, JOA score, ODI score, Cobb angle, deformation index of vertebrae, and fusion rate between the two groups (P > 0.05). Compared with the conventional pedicle screw group, the fenestrated pedicle screw group had less intraoperative blood loss (MD=-10.66, 95%CI:-18.63 to -2.68, P=0.009), less loss of anterior vertebral height (MD=-0.62, 95%CI:
    -0.89 to -0.35), P < 0.000 01) and lower incidence of complications (RR=0.44, 95%CI:0.32-0.60, P < 0.000 01), including bone cement leakage (RR=0.59, 95%CI:0.40-0.88, P=0.009) and screw loosening (RR=0.29, 95%CI:0.13-0.61, P=0.001). 
    CONCLUSION: The existing clinical evidence shows that compared with conventional pedicle screw combined with cement-augmentation, the fenestrated pedicle screw combined with cement-augmentation can reduce intraoperative blood loss, maintain vertebral height and significantly reduce the incidence of complications such as bone cement leakage and screw loosening in osteoporotic vertebral fixation.
    Figures and Tables | References | Related Articles | Metrics
    Efficacy and safety of three-dimensional model assisted screw placement technique and traditional screw placement technique in the treatment of spinal deformity: a meta-analysis
    Zhong Yuanming, Wan tong, Zhong Xifeng, Wu Zhuotan, He Bingkun, Wu Sixian
    2021, 25 (30):  4900-4906.  doi: 10.12307/2021.280
    Abstract ( 191 )   PDF (1396KB) ( 18 )   Save
    OBJECTIVE: It remains disputed whether three-dimensional (3D) model assisted screw placement technique and traditional screw placement technique in the treatment of spinal deformity. Thus, this study systematically assessed the difference between 3D model assisted screw placement technique and traditional screw placement technique in the treatment of spinal deformity. 
    METHODS: A computer-based online search of CNKI, Wanfang, VIP, The Cochrane library, PubMed, CBM, and EMBASE was performed to retrieve clinical studies of comparison between 3D model assisted screw placement technique and traditional screw placement technique in the treatment of spinal deformity published before April 2020. Moreover, related papers were manually retrieved. After two evaluators independently selected literature, extracted data and evaluated the quality of methodology included in the study, meta-analysis was carried out by using Stata/SE 12.0 software.
    RESULTS:  (1) Eight clinical controlled trials were included, and the quality of a randomized controlled trial was grade B. NOS scores of all cohort studies were greater than 5. A total of 479 patients were included in the final analysis, and divided into model group (n=219) and traditional group (n=260). (2) The meta-analysis results showed that there were significant differences in Cobb angle (MD=-4.69, 95%CI:-8.05 to -1.32, P < 0.05), accuracy of pedicle screw placement (RR=1.11, 95%CI:1.08-1.14, P < 0.05), average screw placement time (MD=-1.52, 95%CI:-1.75 to -1.29, P < 0.05), operation time (MD=-28.59, 95%CI:-30.67 to -26.52, P < 0.05), intraoperative fluoroscopy times (MD=-3.11, 95%CI:-4.70 to -1.53, P < 0.05), and intraoperative blood loss (MD=-177.79, 95%CI:-250.08 to -105.50, P < 0.05) between the two methods. There was no significant difference in rate of complications (RR=0.94, 95%CI:0.75-1.17, P=0.576] between the two methods.  
    CONCLUSION: Compared with the traditional screw placement technology, 3D model assisted screw placement technique has the advantages of good deformity correction, accurate and rapid screw placement, and less intraoperative blood loss. Given the limited quality of included studies, a large number of high-quality multicenter randomized controlled trials are needed to provide more evidence.
    Figures and Tables | References | Related Articles | Metrics
    Meta-analysis of adverse events between anterior and posterior fusion surgery for multiple-level cervical spondylosis
    Wang Shuguang, Cai Tongchuan, Feng Xinmin, Nan Liping, Wang Feng, Zhu Lei, Chen Dong, Zhang Liang
    2021, 25 (30):  4907-4914.  doi: 10.12307/2021.281
    Abstract ( 199 )   PDF (1887KB) ( 25 )   Save
    OBJECTIVE: The best surgical method for the treatment of multi-segment cervical spondylotic myelopathy is still controversial. In recent years, the application of posterior laminectomy/laminaplasty and fusion in the treatment of cervical spondylotic myelopathy has gradually increased. However, few comprehensive studies have compared the incidence of postoperative adverse events between anterior decompression and fusion and posterior laminectomy/laminaplasty and fusion. Therefore, we conducted a meta-analysis to observe the difference in postoperative adverse events of anterior and posterior cervical fusion for multiple-level cervical spondylosis.
    METHODS:  PubMed, EMbase, Medline, The Cochrane Library, CBM, CNKI, and Wanfang Database were searched by computer for randomized controlled trials published before March 1, 2020 regarding anterior decompression and fusion and posterior laminectomy/laminaplasty and fusion for the treatment of multiple-level cervical spondylosis. The methodological quality of the included literature was evaluated using NOS scale, and then meta-analysis was performed using RevMan 5.3. Various adverse events were compared to evaluate the difference between anterior and posterior depression fusion surgery in various adverse events.  
    RESULTS: (1) Two prospective cohort studies and nine retrospective cohort studies were included, with a total of 36 862 patients. The NOS quality assessment was above 5 points. (2) There was no significant difference between the two surgical methods in adverse events such as fixation failure and mortality (P > 0.05). (3) The incidence of new nerve dysfunction (OR=2.68, 95%CI:1.98-3.63, P < 0.000 01), incidence of cerebral fluid leakage (OR=1.73, 95%CI:1.18-2.54, P=0.005), infection rate at surgical site (OR=4.01, 95%CI:1.66-9.72, P=0.002), incidence of axial cervical pain (OR=7.27, 95%CI:3.04-17.40, P < 0.000 01), incidence of revision surgery (RR=3.14, 95%CI:2.80-3.15, P < 0.000 01), and incidence of chronic neck pain (OR=3.60, 95%CI:2.48-5.24, P < 0.000 01) were higher in the posterior laminectomy/laminaplasty and fusion group than those in the anterior decompression and fusion group. (4) The incidence of dysphagia and hoarseness was higher in the anterior decompression and fusion group than that in the posterior laminectomy/laminaplasty and fusion group (OR=0.23, 95%CI:0.12-0.42, P < 0.000 01). 
    CONCLUSION: (1) Evidence from 11 cohort studies showed that regarding the incidence of postoperative adverse events, the incidences of new neurological dysfunction, cerebrospinal fluid leakage, surgical site infection, cervical axial pain, and revision surgery were less after anterior decompression and fusion. Dysphagia and hoarsenes were less after posterior laminectomy/laminaplasty and fusion. (2) However, limited by the quality of the included literature, above conclusions need to be validated by high-quality, multicenter and blinded randomized controlled trials.
    Figures and Tables | References | Related Articles | Metrics
    Efficacy of anterograde and retrograde intramedullary nails in the treatment of distal femoral extraarticular fracture: a meta-analysis
    Yuan Jiaqin, Luan Fujun, Chen Yangfan, Li Bo
    2021, 25 (30):  4915-4920.  doi: 10.12307/2021.282
    Abstract ( 205 )   PDF (2287KB) ( 30 )   Save
    OBJECTIVE: Currently, there is some controversy regarding the use of anterograde or retrograde intramedullary nails for extrararticular fractures of the distal femor. Therefore, this article systematically evaluated the difference in the efficacy and safety of anterograde and retrograde intramedullary nailing in the treatment of distal femoral extrararticular fractures. 
    METHODS: The databases, including PubMed, Web of Science, The Cochrane Library, EMbase, Sciencedirect, Scopus, China National Knowledge Infrastructure, Chinese BioMedical Literature System, Wanfang Data, VIP database for Chinese Technical Periodicals, and Google Scholar were searched through Internet to collect clinical randomized controlled trials of antegrade and retrograde intramedullary nails for distal femoral fractures in adults at home and abroad. The basic data included in the study including the Harris score at the time of discharge, bone nonunion, fracture healing time, knee pain, operation time, intraoperative blood loss, and heterotopic ossification of the hip joints were extracted. The quality evaluation and analysis were conducted using Cochrane Handbook. The results of the included study were meta-analyzed by RevMan 5.3 software.
    RESULTS: Ten randomized controlled clinical trials were included, with a total of 757 fractures, including 370 cases in the retrograde intramedullary nail group and 387 cases in the antegrade intramedullary nail group. There were no statistically significant differences in operation time, intraoperative blood loss, fracture healing time, knee pain and heterotopic ossification of the hip joints between retrograde intramedullary nails and antegrade intramedullary nails (P > 0.05). At the time of discharge, the hip joints Harris score showed that the retrograde intramedullary nail group was superior to the antegrade intramedullary nail group (RR=1.22, 95% CI:1.04-1.45, P=0.02). The incidence of bone nonunion in retrograde intramedullary nail group was lower than that in antegrade intramedullary nail group (RR=0.37, 95% CI: 0.14-0.96, P=0.04).  
    CONCLUSION: Evidence from 10 existing randomized controlled trials shows that retrograde intramedullary nails to repair the distal femoral shaft extraarticular fractures are superior to antegrade intramedullary nails in terms of hip function recovery and fracture healing. Therefore, retrograde intramedullary nails have certain advantages in the treatment of the distal femoral fractures.
    Figures and Tables | References | Related Articles | Metrics