Variable-diameter deployable carbon fiber reinforced polymer(CFRP)composites possess deformation and load-bearing functions and are composed of stiff-flexible coupled preforms and matrix.The stiff-flexible coupled pre...Variable-diameter deployable carbon fiber reinforced polymer(CFRP)composites possess deformation and load-bearing functions and are composed of stiff-flexible coupled preforms and matrix.The stiff-flexible coupled preform,serving as the reinforcing structure,directly determines the deployable properties,and its forming technology is currently a research challenge.This paper designs a braiding and needle-punching(BNP)composite preform forming technology suitable for stiff-flexible coupled preforms.Before forming,the preform is partitioned into flexible and rigid zones,with braiding and needle-punching performed layer by layer in the respective zones.A retractable rotating device is developed to form the stiff-flexible coupled preform,achieving a diameter variation rate of up to 26.6%for the BNP preform.A structural parameter model is also established to describe the geometric parameter changes in the deformation and load-bearing areas of the preform during deployment as a function of the braiding angle.Based on experiments,this paper explains the performance changes of BNP composites concerning the structural parameters of the preform.Experimental analysis shows that as the braiding angle increases,the tensile performance of BNP composites significantly decreases,with the change rate of tensile strength first decreasing and then increasing.Additionally,when the braiding angle is less than 21.89°,the impact toughness of BNP composites remains within the range of 83.66±2 kJ/m^(2).However,when the braiding angle exceeds 21.89°,the impact toughness of BNP composites gradually decreases with increasing braiding angle.Furthermore,a hybrid agent model based on Latin hypercube sampling and error back-propagation neural network is developed to predict the tensile and impact properties of BNP composites with different structural parameters,with maximum test relative errors of 1.89%for tensile strength and 2.37%for impact toughness.展开更多
BACKGROUND Bioabsorbable interference screws are a widely used option for graft fixation in anterior cruciate ligament(ACL)reconstruction.Their ability to degrade over time and avoid secondary hardware removal makes t...BACKGROUND Bioabsorbable interference screws are a widely used option for graft fixation in anterior cruciate ligament(ACL)reconstruction.Their ability to degrade over time and avoid secondary hardware removal makes them advantageous.However,complications such as breakage and intra-articular migration of screws can cause significant clinical issues,including joint pain,swelling,and cartilage damage.Early diagnosis and management are critical in such cases.CASE SUMMARY A 26-year-old male presented with knee pain and swelling one year after ACL reconstruction using a hamstring graft and bioabsorbable tibial interference screw.The patient had been engaged in rigorous physical activity as part of military training.Clinical examination revealed mild effusion without instability,and imaging showed screw breakage with intra-articular migration.Therapeutic arthroscopy confirmed intact graft tension,and broken screw fragments were removed successfully.The patient resumed normal activity two weeks after surgery.CONCLUSION This case highlights the potential complications associated with bioabsorbable screws,emphasizing the need for meticulous surgical technique,postoperative monitoring,and timely intervention.A comprehensive review of the literature illustrates the mechanisms,risk factors,and preventive strategies associated with screw-related complications.展开更多
BACKGROUND Pedicle screw instrumentation is a critical technique in spinal surgery,offering effective stabilization for various spinal conditions.However,the impact of intraoperative imaging quality—specifically the ...BACKGROUND Pedicle screw instrumentation is a critical technique in spinal surgery,offering effective stabilization for various spinal conditions.However,the impact of intraoperative imaging quality—specifically the use of both anteroposterior(AP)and lateral views—on surgical outcomes remains insufficiently studied.Evaluating whether the adequacy of these imaging modalities affects the risk of unplanned returns to theatre(URTT)within 90 days due to screw malplacement is essential for refining surgical practices and improving patient care.AIM To evaluate how intraoperative imaging adequacy influences unplanned returnto-theatre rates,focusing on AP and lateral fluoroscopic views.METHODS This retrospective cohort study analyzed 1335 patients who underwent thoracolumbar and sacral pedicle screw instrumentation between January 2013 and December 2022.Data on intraoperative imaging adequacy,screw placement,and URTT events were collected and statistically analyzed using IBM SPSS v23.Imaging adequacy was assessed based on the presence of both AP and lateral views,and outcomes were compared between imaging groups.RESULTS A total of 9016 pedicle screws were inserted,with 82 screws identified as malplaced in 52 patients.Of these,46 patients required URTT due to screw malplacement,with 37 returning within 90 days(URTT90).Patients with both AP and lateral imaging saved intraoperatively had significantly lower URTT90 rates compared to those with only lateral imaging saved,demonstrating the critical role of imaging adequacy in improving surgical outcomes.CONCLUSION This study underscores that comprehensive intraoperative imaging with both AP and lateral views reduces unplanned returns,improves outcomes,enhances precision,and offers a cost-effective approach for better spinal surgery results.展开更多
Objective The aim of this study was to explore the influence of working length(determined by the screw position)on the stiffness and interfragmentary strain(IFS)of femoral locking compression plate(LCP)external fixato...Objective The aim of this study was to explore the influence of working length(determined by the screw position)on the stiffness and interfragmentary strain(IFS)of femoral locking compression plate(LCP)external fixators for lower tibial fractures under full weight-bearing conditions,with the goal of providing a reference basis for clinical applications.Methods Finite element analysis software was used to construct a model of a lower tibial fracture with external femoral LCP fixation.The models were divided into four groups according to the different working lengths(external femoral locking plate fixation 1[EF1],EF2,EF3,and EF4).Stress distribution clouds,fracture end displacements,stiffness and IFS were tested for each model group at different loads.Results Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 28%,31%,and 37%,respectively,under axial compression loading.Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 19%,33%,and 35%,respectively,under axial torsion loading.Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 32%,33%,and 35%,respectively,under a three-point bending load.The IFS of the four finite element models increased with the working length of the plate,with EF1(76%)<EF2(107%)<EF3(110%)<EF4(122%).Finite element analysis revealed that under full weight-bearing conditions,the structural stiffness of the femoral LCP external fixator decreased with increasing working length,leading to an increase in the IFS,which resulted in an IFS that exceeded the ideal range required for secondary healing.Conclusion For unstable lower tibial fractures,screws in the femoral LCP external fixator should be placed as close to the fracture end as possible to increase stability and promote fracture healing.展开更多
BACKGROUND Retrograde pubic ramus screw placement is an effective technique but requires substantial surgical expertise and specialized equipment.The management of osteoporotic anterior pelvic ring injuries remains ch...BACKGROUND Retrograde pubic ramus screw placement is an effective technique but requires substantial surgical expertise and specialized equipment.The management of osteoporotic anterior pelvic ring injuries remains challenging due to technical difficulties and a high risk of complications.AIM To introduce a novel and simplified surgical approach that utilizes a custom-designed handheld pelvic alignment guide(HPAG)in combination with a 6.0 mm hollow screw,aiming to enhance the accuracy,efficiency,and safety of retrograde pubic ramus screw fixation in osteoporotic pelvic fragility fractures.METHODS The HPAG and 6.0 mm hollow screw were employed during surgical treatment.A 2.0-3.0 cm incision was made to expose the optimal screw entry point.Intraop-erative pelvic inlet and obturator oblique views were used to monitor fracture reduction and guide screw insertion.Clinical outcomes and fracture reduction quality were evaluated using Matta,visual analog scale,and Majeed scores during follow-ups.A representative case is presented to demonstrate the surgical procedure in detail.RESULTS No perioperative complications were observed.The mean operative time was 35.2±6.97 minutes,with a screw insertion time of 7.25±1.86 minutes,an average incision length of 2.8±0.67 cm,and mean blood loss of 43.25±15.64 mL.At one-year follow-up,seven patients achieved excellent Majeed scores and three achieved good scores.CONCLUSION No perioperative complications were observed.The mean operative time was 35.2±6.97 minutes,with a screw insertion time of 7.25±1.86 minutes,an average incision length of 2.8±0.67 cm,and mean blood loss of 43.25±15.64 mL.At one-year follow-up,seven patients achieved excellent Majeed scores and three achieved good scores.展开更多
In pedicle screw fixation,surgical robot and preoperative planning are enabling technologies to improve the accuracy and safety of pedicle screw placement.In this study,an automatic segmentation method for the pedicle...In pedicle screw fixation,surgical robot and preoperative planning are enabling technologies to improve the accuracy and safety of pedicle screw placement.In this study,an automatic segmentation method for the pedicle and vertebral body is proposed based on the 3D anatomical features of vertebrae.Further,an optimal insertion path is obtained to balance the safety of pedicle screw placement and the vertebral-screw interface strength.The pedicle screw radius is then determined based on the pedicle radius.A classification method is proposed to assess the accuracy of path planning.Finally,the surgical robot’s path can be updated based on the actual positions of the surgical robot and the patient.The CT data of 12 human vertebrae(T6−L5),10 porcine vertebrae(L1−L5)and 5 ovine vertebrae(L1−L5)are used to validate the effectiveness of the proposed method.All pedicle screw placement paths are successfully generated,achieving an excellence or good rate of 98%.Ex vivo pedicle screw placement experiments are conducted on human spine phantom,porcine and ovine spines,and in vivo experiment is conducted on a Bama miniature pig.In the proposed method,both safety and accuracy of pedicle screw placement are improved.According to the widely recognized Gertzbein-Robbins classification,93.18%of the outcomes achieve Grade A,showing promising potential in clinics.展开更多
Pedicle screw fixation remains the gold standard for stabilizing unstable thoracolumbar fractures.However,ensuring long-term instrumentation stability continues to challenge both surgeons and implant designers.The stu...Pedicle screw fixation remains the gold standard for stabilizing unstable thoracolumbar fractures.However,ensuring long-term instrumentation stability continues to challenge both surgeons and implant designers.The study by Bokov et al contributes significantly to this discussion,identifying predictors of pedicle screw loosening such as low bone radiodensity,longer fixation constructs,and extensive decompression.Adjunctive strategies-auxiliary posterior fusion,anterior column reconstruction,and intermediate screw usage-support an individualized,biomechanically sound surgical plan.In this article,we explore the clinical relevance of these findings within spinal trauma care.We emphasize the role of preoperative bone quality assessment,including computed tomography-based Hounsfield unit analysis and magnetic resonance imaging-derived vertebral bone quality score,as modifiable predictors of long-term outcomes.We also discuss innovations in screw design,surface coatings,and patient-specific planning to reduce failure risk.Furthermore,emerging technologies such as finite element modeling and 3D-printed instrumentation may refine patient-specific strategies.By integrating biomechanical principles with personalized surgical planning,future approaches may enhance fixation durability.Ultimately,aligning mechanical stability with biological sustainability is critical to reducing implant failure in complex thoracolumbar trauma cases.展开更多
BACKGROUND Comminuted calcaneal fractures present significant treatment challenges.Open reduction and internal fixation carries risks such as infection and skin necrosis,while minimally invasive techniques may comprom...BACKGROUND Comminuted calcaneal fractures present significant treatment challenges.Open reduction and internal fixation carries risks such as infection and skin necrosis,while minimally invasive techniques may compromise reduction stability.Conservative management is generally limited to minimally displaced fractures.Traditional Chinese manual bone-setting has a long history in fracture treatment and is renowned globally for achieving functional reduction.It offers distinct advantages including lower cost,minimal soft tissue trauma,and the avoidance of expensive reduction equipment or internal fixation materials.CASE SUMMARY A 60-year-old female presented with left foot pain and limited mobility following a fall.Computed tomography scan revealed a Sanders type IV calcaneal fracture with a Böhler angle of 0°.A standardized,stepwise Traditional Chinese manual bone-setting was initially performed,followed by percutaneous screw fixation through several mini-incisions after satisfactory alignment was confirmed under fluoroscopy.The Visual Analog Scale score decreased from 5 on postoperative day 1 to 3 by day 3.The American Orthopaedic Foot and Ankle Society score improved from 73 at 6 weeks to 90 at 3 months,indicating rapid functional recovery and high patient satisfaction.At 7 months postoperatively,the American Orthopaedic Foot and Ankle Society score reached 95,prompting removal of internal fixation.At the 6-year follow-up,reduction remained well maintained,with the Böhler angle preserved at 22°.CONCLUSION The combination of Traditional Chinese manual bone-setting and percutaneous screw fixation achieved satisfactory functional reduction for comminuted calcaneal fractures.展开更多
The aim of this study was to assess the potential of surgical guides as a complementary tool to augmented reality(AR)in enhancing the safety and precision of pedicle screw placement in spinal surgery.Four trainers wer...The aim of this study was to assess the potential of surgical guides as a complementary tool to augmented reality(AR)in enhancing the safety and precision of pedicle screw placement in spinal surgery.Four trainers were divided into the AR navigation group using surgical guides and the free-hand group.Each group consisted of a novice and an experienced spine surgeon.A total of 80 pedicle screws were implanted.First,the AR group reconstructed the 3D model and planned the screw insertion route according to the computed tomography data of L2 lumbar vertebrae.Then,the Microsoft HoloLens™2 was used to identify the vertebral model,and the planned virtual path was superimposed on the real cone model.Next,the screw was placed according to the projected trajectory.Finally,Micron Tracker was used to measure the deviation of screws from the preoperatively planned trajectory,and pedicle screws were evaluated using the Gertzbein-Robbins scale.In the AR group,the linear deviations of the experienced doctor and the novice were(1.59±0.39)mm and(1.73±0.52)mm respectively,and the angle deviations were 2.72°±0.61°and 2.87°±0.63°respectively.In the free-hand group,the linear deviations of the experienced doctor and the novice were(2.88±0.58)mm and(5.25±0.62)mm respectively,and the angle deviations were 4.41°±1.18°and 7.15°±1.45°respectively.Both kinds of deviations between the two groups were significantly different(P<0.05).The screw accuracy rate was 95%in the AR navigation group and 77.5%in the free-hand group.The results of this study indicate that the integration of surgical guides and AR is an innovative technique that can substantially enhance the safety and precision of spinal surgery and assist inexperienced doctors in completing the surgery.展开更多
Objective:To observe and study the actual effects of percutaneous pedicle screw minimally invasive surgery in the treatment of spinal fractures and its impact on spinal function.Methods:This study included 48 patients...Objective:To observe and study the actual effects of percutaneous pedicle screw minimally invasive surgery in the treatment of spinal fractures and its impact on spinal function.Methods:This study included 48 patients with spinal fractures admitted between May 2023 and May 2024.The patients were divided into a control group and an experimental group based on treatment differences,with 24 patients in each group.The control group underwent open internal fixation surgery,while the experimental group received percutaneous pedicle screw minimally invasive surgery.Clinical index improvements,cervical dysfunction index,Japanese Orthopaedic Association scores,and pain level improvements were compared between the two groups.Results:The intraoperative blood loss,incision length,operation time,and hospitalization duration in the experimental group were(88.63±18.85),(6.32±1.05),(73.42±4.05),and(12.58±2.56),respectively,compared to(279.95±17.32),(12.89±1.36),(89.93±4.79),and(22.41±2.87)in the control group.Significant differences were observed between the groups,with the experimental group showing superior improvements across all metrics(P<0.05).Conclusion:Percutaneous pedicle screw minimally invasive surgery shows more significant effects in treating spinal fractures,particularly in improving cervical and lumbar spine function,enhancing treatment efficacy and safety,reducing pain levels,and shortening recovery time.Clinical application and promotion are recommended.展开更多
Objective To compare the clinical outcomes of retrograde pubic ramus intramedullary nail(RPRIN)and percutaneous cannulated screw(PCS)in the treatment of anterior pelvic ring fractures(APRFs).Methods This retrospective...Objective To compare the clinical outcomes of retrograde pubic ramus intramedullary nail(RPRIN)and percutaneous cannulated screw(PCS)in the treatment of anterior pelvic ring fractures(APRFs).Methods This retrospective cohort study included 45 patients with APRFs treated between February 2019 and October 2022 in our trauma center.Patients were divided into two groups based on the surgical method:20 received RPRIN fixation,and 25 received PCS fixation.Key variables including operation time,fluoroscopic time,blood loss,and postoperative complications were analyzed.Fracture reduction quality was assessed using the Matta score system,and pelvic functional recovery was evaluated using the Majeed score system at the final follow-up.Quantitative variables were compared using the independent sample t test,while categorical variables were analyzed using Chisquare and Fisher’s exact tests.Results The RPRIN group had significantly shorter operation time(36.3±5.6 min vs.49.5±6.9 min,P<0.01),fluoroscopic time(32.0±2.8 s vs.48.4±3.6 s,P<0.01),and less blood loss(20.4±7.6 mL vs.34.0±5.7 mL,P<0.01)than the PCS group.Fracture reduction quality(Matta outcome)and pelvic functional recovery(Majeed outcome)were comparable between the two groups(P>0.05).No significant complications were reported in either group.Conclusions Both RPRIN and PCS are effective for treating APRFs.However,RPRIN offers distinct advantages by reducing operation time,fluoroscopic time,and blood loss,making it a more efficient and less invasive option.Further multicenter studies and biomechanical analyses are warranted to confirm these findings.展开更多
The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the fl...The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the flow domain are presented by using a fluid dynamics analysis package (Polyflow). The numerical results show that the temperatures are high in the intermeshing region and on the screw surface, the maximum pressure and the minimum pressure occur in the intermeshing region, and the flow rate is almost proportional to the screw speed.展开更多
背景:腰椎退行性疾病是一种中老年人常见疾病,临床表现主要为腰背部疼痛和下肢功能障碍。传统上使用腰椎融合联合双侧椎弓根螺钉固定进行外科干预,但存在创伤大、并发症多等问题。而腰椎融合联合单侧椎弓根螺钉固定是一种新兴的微创治...背景:腰椎退行性疾病是一种中老年人常见疾病,临床表现主要为腰背部疼痛和下肢功能障碍。传统上使用腰椎融合联合双侧椎弓根螺钉固定进行外科干预,但存在创伤大、并发症多等问题。而腰椎融合联合单侧椎弓根螺钉固定是一种新兴的微创治疗方式,具有较小的创伤和较低的并发症风险,已逐渐成为腰椎退行性疾病治疗的新选择。目的:探讨腰椎融合联合单侧椎弓根螺钉固定治疗腰椎退行性疾病的效果及优势。方法:通过检索中国知网和PubMed数据库2010年1月至2025年1月发表的相关文献,总结腰椎融合联合单侧椎弓根螺钉固定的临床研究及生物力学特点,以“腰椎融合术,单侧固定,双侧固定,生物力学,腰椎退行性疾病”为中文检索词,以“lumbar fusion,unilateral fixation,bilateral fixation,biomechanics,degenerative disease of the lumbar spine”为英文检索词,最终纳入70篇文献进行综述。结果与结论:①腰椎融合联合单侧椎弓根螺钉固定能有效减少手术创伤和术中失血量,提供与双侧椎弓根螺钉固定相似的生物力学稳定性,并降低邻近节段退变的风险;②单侧椎弓根螺钉固定在单节段及双节段腰椎退行性疾病治疗中已获得广泛认可,但在多节段腰椎退行性疾病中的应用效果仍需进一步研究;③腰椎融合联合单侧椎弓根螺钉固定为腰椎退行性疾病治疗提供了微创、安全的选择,未来需要更多高质量的研究验证其在复杂病例中的应用和长期疗效,进一步优化临床应用。展开更多
基金Supported by Jiangsu Provincial Frontier Leading Technology Basic Research Project(Grant No.BK20212007)Aero-Engine and Gas Turbine Basic Science Center(Grant No.P2022-B-IV-014-001)+1 种基金China Postdoctoral Program Fund(Grant No.1005/YBA23044)China Postdoctoral Assistance Fund(Grant No.1005/YBA23031)。
文摘Variable-diameter deployable carbon fiber reinforced polymer(CFRP)composites possess deformation and load-bearing functions and are composed of stiff-flexible coupled preforms and matrix.The stiff-flexible coupled preform,serving as the reinforcing structure,directly determines the deployable properties,and its forming technology is currently a research challenge.This paper designs a braiding and needle-punching(BNP)composite preform forming technology suitable for stiff-flexible coupled preforms.Before forming,the preform is partitioned into flexible and rigid zones,with braiding and needle-punching performed layer by layer in the respective zones.A retractable rotating device is developed to form the stiff-flexible coupled preform,achieving a diameter variation rate of up to 26.6%for the BNP preform.A structural parameter model is also established to describe the geometric parameter changes in the deformation and load-bearing areas of the preform during deployment as a function of the braiding angle.Based on experiments,this paper explains the performance changes of BNP composites concerning the structural parameters of the preform.Experimental analysis shows that as the braiding angle increases,the tensile performance of BNP composites significantly decreases,with the change rate of tensile strength first decreasing and then increasing.Additionally,when the braiding angle is less than 21.89°,the impact toughness of BNP composites remains within the range of 83.66±2 kJ/m^(2).However,when the braiding angle exceeds 21.89°,the impact toughness of BNP composites gradually decreases with increasing braiding angle.Furthermore,a hybrid agent model based on Latin hypercube sampling and error back-propagation neural network is developed to predict the tensile and impact properties of BNP composites with different structural parameters,with maximum test relative errors of 1.89%for tensile strength and 2.37%for impact toughness.
文摘BACKGROUND Bioabsorbable interference screws are a widely used option for graft fixation in anterior cruciate ligament(ACL)reconstruction.Their ability to degrade over time and avoid secondary hardware removal makes them advantageous.However,complications such as breakage and intra-articular migration of screws can cause significant clinical issues,including joint pain,swelling,and cartilage damage.Early diagnosis and management are critical in such cases.CASE SUMMARY A 26-year-old male presented with knee pain and swelling one year after ACL reconstruction using a hamstring graft and bioabsorbable tibial interference screw.The patient had been engaged in rigorous physical activity as part of military training.Clinical examination revealed mild effusion without instability,and imaging showed screw breakage with intra-articular migration.Therapeutic arthroscopy confirmed intact graft tension,and broken screw fragments were removed successfully.The patient resumed normal activity two weeks after surgery.CONCLUSION This case highlights the potential complications associated with bioabsorbable screws,emphasizing the need for meticulous surgical technique,postoperative monitoring,and timely intervention.A comprehensive review of the literature illustrates the mechanisms,risk factors,and preventive strategies associated with screw-related complications.
文摘BACKGROUND Pedicle screw instrumentation is a critical technique in spinal surgery,offering effective stabilization for various spinal conditions.However,the impact of intraoperative imaging quality—specifically the use of both anteroposterior(AP)and lateral views—on surgical outcomes remains insufficiently studied.Evaluating whether the adequacy of these imaging modalities affects the risk of unplanned returns to theatre(URTT)within 90 days due to screw malplacement is essential for refining surgical practices and improving patient care.AIM To evaluate how intraoperative imaging adequacy influences unplanned returnto-theatre rates,focusing on AP and lateral fluoroscopic views.METHODS This retrospective cohort study analyzed 1335 patients who underwent thoracolumbar and sacral pedicle screw instrumentation between January 2013 and December 2022.Data on intraoperative imaging adequacy,screw placement,and URTT events were collected and statistically analyzed using IBM SPSS v23.Imaging adequacy was assessed based on the presence of both AP and lateral views,and outcomes were compared between imaging groups.RESULTS A total of 9016 pedicle screws were inserted,with 82 screws identified as malplaced in 52 patients.Of these,46 patients required URTT due to screw malplacement,with 37 returning within 90 days(URTT90).Patients with both AP and lateral imaging saved intraoperatively had significantly lower URTT90 rates compared to those with only lateral imaging saved,demonstrating the critical role of imaging adequacy in improving surgical outcomes.CONCLUSION This study underscores that comprehensive intraoperative imaging with both AP and lateral views reduces unplanned returns,improves outcomes,enhances precision,and offers a cost-effective approach for better spinal surgery results.
基金supported by the Health Commission of Guizhou Province(No.gzwkj2024-400)the“Open Competition Project”of Bijie Science and Technology Bureau(BST Major Project No.1,2022).
文摘Objective The aim of this study was to explore the influence of working length(determined by the screw position)on the stiffness and interfragmentary strain(IFS)of femoral locking compression plate(LCP)external fixators for lower tibial fractures under full weight-bearing conditions,with the goal of providing a reference basis for clinical applications.Methods Finite element analysis software was used to construct a model of a lower tibial fracture with external femoral LCP fixation.The models were divided into four groups according to the different working lengths(external femoral locking plate fixation 1[EF1],EF2,EF3,and EF4).Stress distribution clouds,fracture end displacements,stiffness and IFS were tested for each model group at different loads.Results Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 28%,31%,and 37%,respectively,under axial compression loading.Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 19%,33%,and 35%,respectively,under axial torsion loading.Compared with those in the EF1 group,the stiffnesses in the EF2,EF3,and EF4 groups decreased by 32%,33%,and 35%,respectively,under a three-point bending load.The IFS of the four finite element models increased with the working length of the plate,with EF1(76%)<EF2(107%)<EF3(110%)<EF4(122%).Finite element analysis revealed that under full weight-bearing conditions,the structural stiffness of the femoral LCP external fixator decreased with increasing working length,leading to an increase in the IFS,which resulted in an IFS that exceeded the ideal range required for secondary healing.Conclusion For unstable lower tibial fractures,screws in the femoral LCP external fixator should be placed as close to the fracture end as possible to increase stability and promote fracture healing.
基金Supported by Shanghai Tongren Hospital,Shanghai Jiaotong University School of Medicine,No.TRYJ2024 LC16the National Natural Science Foundation of China,No.82102577the Laboratory Open Fund of Key Technology and Materials in Minimally Invasive Spine Surgery,No.2024JZWC-YBA05.
文摘BACKGROUND Retrograde pubic ramus screw placement is an effective technique but requires substantial surgical expertise and specialized equipment.The management of osteoporotic anterior pelvic ring injuries remains challenging due to technical difficulties and a high risk of complications.AIM To introduce a novel and simplified surgical approach that utilizes a custom-designed handheld pelvic alignment guide(HPAG)in combination with a 6.0 mm hollow screw,aiming to enhance the accuracy,efficiency,and safety of retrograde pubic ramus screw fixation in osteoporotic pelvic fragility fractures.METHODS The HPAG and 6.0 mm hollow screw were employed during surgical treatment.A 2.0-3.0 cm incision was made to expose the optimal screw entry point.Intraop-erative pelvic inlet and obturator oblique views were used to monitor fracture reduction and guide screw insertion.Clinical outcomes and fracture reduction quality were evaluated using Matta,visual analog scale,and Majeed scores during follow-ups.A representative case is presented to demonstrate the surgical procedure in detail.RESULTS No perioperative complications were observed.The mean operative time was 35.2±6.97 minutes,with a screw insertion time of 7.25±1.86 minutes,an average incision length of 2.8±0.67 cm,and mean blood loss of 43.25±15.64 mL.At one-year follow-up,seven patients achieved excellent Majeed scores and three achieved good scores.CONCLUSION No perioperative complications were observed.The mean operative time was 35.2±6.97 minutes,with a screw insertion time of 7.25±1.86 minutes,an average incision length of 2.8±0.67 cm,and mean blood loss of 43.25±15.64 mL.At one-year follow-up,seven patients achieved excellent Majeed scores and three achieved good scores.
基金Supported by Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011897)Shenzhen Science and Technology Program(Grant No.KQTD20210811090143060)+1 种基金Sustainable Development Science and Technology Special Project of Shenzhen(Grant No.KCXFZ20230731100900002)Tianjin Municipal Science and Technology Program(Grant No.22JCYBJC01240).
文摘In pedicle screw fixation,surgical robot and preoperative planning are enabling technologies to improve the accuracy and safety of pedicle screw placement.In this study,an automatic segmentation method for the pedicle and vertebral body is proposed based on the 3D anatomical features of vertebrae.Further,an optimal insertion path is obtained to balance the safety of pedicle screw placement and the vertebral-screw interface strength.The pedicle screw radius is then determined based on the pedicle radius.A classification method is proposed to assess the accuracy of path planning.Finally,the surgical robot’s path can be updated based on the actual positions of the surgical robot and the patient.The CT data of 12 human vertebrae(T6−L5),10 porcine vertebrae(L1−L5)and 5 ovine vertebrae(L1−L5)are used to validate the effectiveness of the proposed method.All pedicle screw placement paths are successfully generated,achieving an excellence or good rate of 98%.Ex vivo pedicle screw placement experiments are conducted on human spine phantom,porcine and ovine spines,and in vivo experiment is conducted on a Bama miniature pig.In the proposed method,both safety and accuracy of pedicle screw placement are improved.According to the widely recognized Gertzbein-Robbins classification,93.18%of the outcomes achieve Grade A,showing promising potential in clinics.
文摘Pedicle screw fixation remains the gold standard for stabilizing unstable thoracolumbar fractures.However,ensuring long-term instrumentation stability continues to challenge both surgeons and implant designers.The study by Bokov et al contributes significantly to this discussion,identifying predictors of pedicle screw loosening such as low bone radiodensity,longer fixation constructs,and extensive decompression.Adjunctive strategies-auxiliary posterior fusion,anterior column reconstruction,and intermediate screw usage-support an individualized,biomechanically sound surgical plan.In this article,we explore the clinical relevance of these findings within spinal trauma care.We emphasize the role of preoperative bone quality assessment,including computed tomography-based Hounsfield unit analysis and magnetic resonance imaging-derived vertebral bone quality score,as modifiable predictors of long-term outcomes.We also discuss innovations in screw design,surface coatings,and patient-specific planning to reduce failure risk.Furthermore,emerging technologies such as finite element modeling and 3D-printed instrumentation may refine patient-specific strategies.By integrating biomechanical principles with personalized surgical planning,future approaches may enhance fixation durability.Ultimately,aligning mechanical stability with biological sustainability is critical to reducing implant failure in complex thoracolumbar trauma cases.
基金Supported by Jin-Wen Liu Academic Experience Heritage Studio Special Fund of National Famous Traditional Chinese Medicine,No.75.
文摘BACKGROUND Comminuted calcaneal fractures present significant treatment challenges.Open reduction and internal fixation carries risks such as infection and skin necrosis,while minimally invasive techniques may compromise reduction stability.Conservative management is generally limited to minimally displaced fractures.Traditional Chinese manual bone-setting has a long history in fracture treatment and is renowned globally for achieving functional reduction.It offers distinct advantages including lower cost,minimal soft tissue trauma,and the avoidance of expensive reduction equipment or internal fixation materials.CASE SUMMARY A 60-year-old female presented with left foot pain and limited mobility following a fall.Computed tomography scan revealed a Sanders type IV calcaneal fracture with a Böhler angle of 0°.A standardized,stepwise Traditional Chinese manual bone-setting was initially performed,followed by percutaneous screw fixation through several mini-incisions after satisfactory alignment was confirmed under fluoroscopy.The Visual Analog Scale score decreased from 5 on postoperative day 1 to 3 by day 3.The American Orthopaedic Foot and Ankle Society score improved from 73 at 6 weeks to 90 at 3 months,indicating rapid functional recovery and high patient satisfaction.At 7 months postoperatively,the American Orthopaedic Foot and Ankle Society score reached 95,prompting removal of internal fixation.At the 6-year follow-up,reduction remained well maintained,with the Böhler angle preserved at 22°.CONCLUSION The combination of Traditional Chinese manual bone-setting and percutaneous screw fixation achieved satisfactory functional reduction for comminuted calcaneal fractures.
基金the National Natural Science Foundation of China(No.11502146)the 1 Batch of 2021 MOE of PRC Industry University Collaborative Education Program(No.202101042008)。
文摘The aim of this study was to assess the potential of surgical guides as a complementary tool to augmented reality(AR)in enhancing the safety and precision of pedicle screw placement in spinal surgery.Four trainers were divided into the AR navigation group using surgical guides and the free-hand group.Each group consisted of a novice and an experienced spine surgeon.A total of 80 pedicle screws were implanted.First,the AR group reconstructed the 3D model and planned the screw insertion route according to the computed tomography data of L2 lumbar vertebrae.Then,the Microsoft HoloLens™2 was used to identify the vertebral model,and the planned virtual path was superimposed on the real cone model.Next,the screw was placed according to the projected trajectory.Finally,Micron Tracker was used to measure the deviation of screws from the preoperatively planned trajectory,and pedicle screws were evaluated using the Gertzbein-Robbins scale.In the AR group,the linear deviations of the experienced doctor and the novice were(1.59±0.39)mm and(1.73±0.52)mm respectively,and the angle deviations were 2.72°±0.61°and 2.87°±0.63°respectively.In the free-hand group,the linear deviations of the experienced doctor and the novice were(2.88±0.58)mm and(5.25±0.62)mm respectively,and the angle deviations were 4.41°±1.18°and 7.15°±1.45°respectively.Both kinds of deviations between the two groups were significantly different(P<0.05).The screw accuracy rate was 95%in the AR navigation group and 77.5%in the free-hand group.The results of this study indicate that the integration of surgical guides and AR is an innovative technique that can substantially enhance the safety and precision of spinal surgery and assist inexperienced doctors in completing the surgery.
文摘Objective:To observe and study the actual effects of percutaneous pedicle screw minimally invasive surgery in the treatment of spinal fractures and its impact on spinal function.Methods:This study included 48 patients with spinal fractures admitted between May 2023 and May 2024.The patients were divided into a control group and an experimental group based on treatment differences,with 24 patients in each group.The control group underwent open internal fixation surgery,while the experimental group received percutaneous pedicle screw minimally invasive surgery.Clinical index improvements,cervical dysfunction index,Japanese Orthopaedic Association scores,and pain level improvements were compared between the two groups.Results:The intraoperative blood loss,incision length,operation time,and hospitalization duration in the experimental group were(88.63±18.85),(6.32±1.05),(73.42±4.05),and(12.58±2.56),respectively,compared to(279.95±17.32),(12.89±1.36),(89.93±4.79),and(22.41±2.87)in the control group.Significant differences were observed between the groups,with the experimental group showing superior improvements across all metrics(P<0.05).Conclusion:Percutaneous pedicle screw minimally invasive surgery shows more significant effects in treating spinal fractures,particularly in improving cervical and lumbar spine function,enhancing treatment efficacy and safety,reducing pain levels,and shortening recovery time.Clinical application and promotion are recommended.
基金supported by Clinical Application-oriented Medical Innovation Foundation from National Clinical Research Center for Orthopedics,Sports Medicine&Rehabilitation and Jiangsu China-Israel Industrial Technical Research Institute Foundation(No.2021-NCRC-CXJJ-ZH-24)National Key R&D Plan of the 14th Five-Year Plan(No.2022YFC2504303).
文摘Objective To compare the clinical outcomes of retrograde pubic ramus intramedullary nail(RPRIN)and percutaneous cannulated screw(PCS)in the treatment of anterior pelvic ring fractures(APRFs).Methods This retrospective cohort study included 45 patients with APRFs treated between February 2019 and October 2022 in our trauma center.Patients were divided into two groups based on the surgical method:20 received RPRIN fixation,and 25 received PCS fixation.Key variables including operation time,fluoroscopic time,blood loss,and postoperative complications were analyzed.Fracture reduction quality was assessed using the Matta score system,and pelvic functional recovery was evaluated using the Majeed score system at the final follow-up.Quantitative variables were compared using the independent sample t test,while categorical variables were analyzed using Chisquare and Fisher’s exact tests.Results The RPRIN group had significantly shorter operation time(36.3±5.6 min vs.49.5±6.9 min,P<0.01),fluoroscopic time(32.0±2.8 s vs.48.4±3.6 s,P<0.01),and less blood loss(20.4±7.6 mL vs.34.0±5.7 mL,P<0.01)than the PCS group.Fracture reduction quality(Matta outcome)and pelvic functional recovery(Majeed outcome)were comparable between the two groups(P>0.05).No significant complications were reported in either group.Conclusions Both RPRIN and PCS are effective for treating APRFs.However,RPRIN offers distinct advantages by reducing operation time,fluoroscopic time,and blood loss,making it a more efficient and less invasive option.Further multicenter studies and biomechanical analyses are warranted to confirm these findings.
文摘The 3 D non isothermal flow of non Newtonian viscous polymer melt in a co rotating twin screw extruder is modeled. The distributions of the velocity, temperature, pressure and the viscous dissipation in the flow domain are presented by using a fluid dynamics analysis package (Polyflow). The numerical results show that the temperatures are high in the intermeshing region and on the screw surface, the maximum pressure and the minimum pressure occur in the intermeshing region, and the flow rate is almost proportional to the screw speed.
文摘背景:腰椎退行性疾病是一种中老年人常见疾病,临床表现主要为腰背部疼痛和下肢功能障碍。传统上使用腰椎融合联合双侧椎弓根螺钉固定进行外科干预,但存在创伤大、并发症多等问题。而腰椎融合联合单侧椎弓根螺钉固定是一种新兴的微创治疗方式,具有较小的创伤和较低的并发症风险,已逐渐成为腰椎退行性疾病治疗的新选择。目的:探讨腰椎融合联合单侧椎弓根螺钉固定治疗腰椎退行性疾病的效果及优势。方法:通过检索中国知网和PubMed数据库2010年1月至2025年1月发表的相关文献,总结腰椎融合联合单侧椎弓根螺钉固定的临床研究及生物力学特点,以“腰椎融合术,单侧固定,双侧固定,生物力学,腰椎退行性疾病”为中文检索词,以“lumbar fusion,unilateral fixation,bilateral fixation,biomechanics,degenerative disease of the lumbar spine”为英文检索词,最终纳入70篇文献进行综述。结果与结论:①腰椎融合联合单侧椎弓根螺钉固定能有效减少手术创伤和术中失血量,提供与双侧椎弓根螺钉固定相似的生物力学稳定性,并降低邻近节段退变的风险;②单侧椎弓根螺钉固定在单节段及双节段腰椎退行性疾病治疗中已获得广泛认可,但在多节段腰椎退行性疾病中的应用效果仍需进一步研究;③腰椎融合联合单侧椎弓根螺钉固定为腰椎退行性疾病治疗提供了微创、安全的选择,未来需要更多高质量的研究验证其在复杂病例中的应用和长期疗效,进一步优化临床应用。
