Purpose: The good of this survey was to analyze the epidemiological aspects and evaluate anatomical and functional results of the treatment by screwing of femoral neck fracture in adulthood at the Teaching Hospital of...Purpose: The good of this survey was to analyze the epidemiological aspects and evaluate anatomical and functional results of the treatment by screwing of femoral neck fracture in adulthood at the Teaching Hospital of an underequipped country. Material and Methods: This is a retrospective study from January 1, 2011 to December 31, 2015, concerning patients hospitalized for fractures of femoral neck and having been operated by screwing. The variables studied were epidemiological and therapeutic aspects. Anatomical results were examined on standard x rays of the pelvis in front and the hip in profil, based on the consolidation of the bony axis. Functional results were analyzed according to the quotation of Postel Merle D’Aubigné. Results: Eleven screwings of femoral neck have been done to 11 patients (9 men and 2 women), average age was 47 years (29 and 60 years) from January 2011 to December 2015, at the mean recoil of 19 months (12 and 24 months). Amongst consolidated patients (n = 7), one patient presented a necrosis of femoral head at two years hindsight. Four patients presented an aseptic pseudarthrosis of femoral neck, or a bad anatomical result. Amidst this group of patients, one underwent a joint replacement type Moore and suggestion of intermediary prothesis was recommended to three patients. According to the quotation of Postel Merle D’Aubigné, results were very satisfactory to 5 patients, good to 2 patients and bad to 4 patients. According to the score of Parker, 7 patients presented a score of 9 and 4 patients a score of 7. Conclusion: The treatment of femoral neck fractures in adulthood requires a surgical approach by osteosynthesis and must be precocious before 24 hours in order to reduce risks of pseudarthrosis of femoral neck and necrosis of femoral head.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
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
A cable-driven redundant manipulator(CDRM)characterized by redundant degrees of freedom and a lightweight,slender design can perform tasks in confined and restricted spaces efficiently.However,the complex multistage c...A cable-driven redundant manipulator(CDRM)characterized by redundant degrees of freedom and a lightweight,slender design can perform tasks in confined and restricted spaces efficiently.However,the complex multistage coupling between drive cables and passive joints in CDRM leads to a challenging dynamic model with difficult parameter identification,complicating the efforts to achieve accurate modeling and control.To address these challenges,this paper proposes a dynamic modeling and adaptive control approach tailored for CDRM systems.A multilevel kinematic model of the cable-driven redundant manipulator is presented,and a screw theory is employed to represent the cable tension and cable contact forces as spatial wrenches,which are equivalently mapped to joint torque using the principle of virtual work.This approach simplifies the mapping process while maintaining the integrity of the dynamic model.A recursive method is used to compute cable tension section-by-section for enhancing the efficiency of inverse dynamics calculations and meeting the high-frequency demands of the controller,thereby avoiding large matrix operations.An adaptive control method is proposed building on this foundation,which involves the design of a dynamic parameter adaptive controller in the joint space to simplify the linearization process of the dynamic equations along with a closed-loop controller that incorporates motor parameters in the driving space.This approach improves the control accuracy and dynamic performance of the CDRM under dynamic uncertainties.The accuracy and computational efficiency of the dynamic model are validated through simulations,and the effectiveness of the proposed control method is demonstrated through control tests.This paper presents a dynamic modeling and adaptive control approach for CDRM to enhance accuracy and performance under dynamic uncertainties.展开更多
Rational tuning of chiral nanostructures of supramolecular assemblies as catalysts and investigating their chiral morphology-enantioselectivity dependence is rarely reported. Herein, we report a series of supramolecul...Rational tuning of chiral nanostructures of supramolecular assemblies as catalysts and investigating their chiral morphology-enantioselectivity dependence is rarely reported. Herein, we report a series of supramolecular M/P-helical nanoribbons(HNs) assembled from the chiral L/D-glutamate-based amphiphiles(L/D-Glu C16) and Cu(Ⅱ) ions, with their helical screw pitches adjusted from 217 nm to 104 nm through the facile regulation of their water/organic solvent assembly environment. They were then used as ideal models to reveal the chiral morphology-enantioselectivity relationship by catalyzing the asymmetric Diels-Alder reaction. Better enantioselectivity was achieved with more twist morphology. Experimental evidences of stronger chiral transfer effect from the supramolecular HNs with more twist to the aza-chalcone as reactant were obtained to understand such dependence. Our study demonstrates a new perspective for designing supramolecular catalysts with higher enantioselectivity.展开更多
The intricate relationship between origami and mechanism underscores the fertile ground for innovation,which is particularly evident in the construction theory of thick-panel origami.Despite its potential,thick panel ...The intricate relationship between origami and mechanism underscores the fertile ground for innovation,which is particularly evident in the construction theory of thick-panel origami.Despite its potential,thick panel origami remains relatively unexplored in the context of single-loop metamorphic mechanisms.Drawing inspiration from thickpanel origami,particularly Miura origami,this study proposes a pioneering single-loop 6R multiple metamorphic mechanism.Through rigorous mathematical modeling(including the construction and resolution of the D-H closed-loop equation)and leveraging advanced analytical tools such as the screw theory and Lie theory,this study meticulously elucidates the planar,spherical,and Bennett motion branches of the mechanism.Furthermore,it delineates all the three bifurcation points between the motion branches,thereby providing a comprehensive understanding of the kinematic behavior of the mechanism.A metamorphic network can be constructed by applying several single-loop mechanisms to a symmetrical layout.Owing to its metamorphic properties,this network can act as a structural backbone for deployable antennas,aerospace shelters,and morphing wing units,thereby enabling a single mechanism to achieve multiple folding configurations.This paper not only introduces innovative metamorphic mechanisms but also suggests a promising method for uncovering and designing metamorphic mechanisms by developing new mechanisms from thick-panel origami.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
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
BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation...BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation failure is poor bone quality.On the other hand,some evidence suggests that surgical tactics can influence long-term instrumentation stability.AIM To assess factors that influence the stability of spinal instrumentation in patients with thoracolumbar injuries.METHODS This study is a non-randomized single center ambispective evaluation of 204 consecutive patients(117 men;87 women)with unstable thoracolumbar injuries.All patients underwent either stand-alone or combined with anterior column reconstruction instrumentation.In cases with spinal cord and nerve root injuries,either posterior or anterior decompression were performed.Patients with pedicle screw loosening were identified via computed tomography imaging.Out of those,cases with clinically significant instrumentation failure were registered.RESULTS The rate of pedicle screw loosening detected by computed tomography was inversely correlated with bone radiodensity figures and an increased association with the number of instrumented levels,residual kyphotic deformity,laminectomy,and lumbosacral fixation.Intermediate screws and anterior reconstruction were associated with a clinically relevant decreased risk of pedicle screw loosening development.Either complete or partial posterior fusion within instrumented levels was capable of decreasing instrumentation failure risk,while extensive decompression with laminectomy and at least one-level total facetectomy were associated with an increased risk of instrumentation failure.Anterior decompression does not have a negative impact on instrumentation stability.CONCLUSION Intermediate screws,anterior reconstruction and posterior tension band preservation are associated with decreased rates of instrumentation instability development.Posterior fusion is beneficial in terms of instrumentation failure prevention.展开更多
Current research on reconfigurable parallel mechanisms(RPMs)primarily focuses on achieving limited configuration changes,while mechanisms capable of extensive mode switching with distinct motion branches remain challe...Current research on reconfigurable parallel mechanisms(RPMs)primarily focuses on achieving limited configuration changes,while mechanisms capable of extensive mode switching with distinct motion branches remain challenging to design.Conventional kinematotropic chains offer limited reconfigurability,underscoring the need for novel designs that enable broader operational adaptability.In this research,a novel diamond-like chain(DLC)with metamorphic units is proposed developed from generalized diamond kinematotropic chains.By altering the axes of the metamorphic units,the DLC realizes three distinct configurations,each corresponding to one of five motion branches characterized by bifurcation and metamorphic transitions.This DLC serves as the fundamental building block for constructing a reconfigurable hybrid limb.Using screw theory,the constraint properties of the limb in its five phases are analyzed and classified into three types:unconstrained limbs,limbs applying constraint forces,and limbs applying constraint couples.Based on this analysis,a RPM consisting of three reconfigurable limbs is developed.Its reconfigurability stems from the inherent bifurcation and metamorphic capabilities of the DLC-based limbs.This research introduces a RPM capable of controlled switching among ten distinct motion modes,with mobility ranging from three to six degrees of freedom.The proposed mechanism demonstrates high versatility and practical feasibility,offering a promising solution for applications requiring variable motion characteristics and adaptive performance.展开更多
BACKGROUND Spinal tuberculosis,a destructive extrapulmonary form,often causes severe deformity and neurological deficits.Surgical intervention aims to debride lesions,reconstruct stability,and correct deformities.This...BACKGROUND Spinal tuberculosis,a destructive extrapulmonary form,often causes severe deformity and neurological deficits.Surgical intervention aims to debride lesions,reconstruct stability,and correct deformities.This study evaluates a combined posterior fixation and minimally invasive anterior approach for lumbar tuberculosis.AIM To evaluate the clinical outcomes and radiological parameters of posterior internal fixation combined with minimally invasive anterior lesion clearance and bone graft fusion for the treatment of lumbar tuberculosis.METHODS Clinical data from 24 patients with lumbar tuberculosis who underwent posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance were analyzed.The Cobb angle,visual analog scale(VAS)score,and Frankel classification were statistically assessed preoperatively and postoperatively.Complications and bone graft fusion were also recorded.RESULTS Wounds healed in the first stage in 22 patients;one patient developed a posterior incisional sinus tract,and one experienced postoperative tuberculosis recurrence.At the final follow-up,according to the Frankel classification,there were 1,2,and 21 cases classified as grade C,grade D,and grade E,respectively.By the last follow-up,the Cobb angle,VAS score,and erythrocyte sedimentation rate had all decreased.Both X-ray and computed tomography images confirmed bone healing.The fusion time ranged from 3 to 9 months,with an average of 5.2 months.CONCLUSION Posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance is an effective and safe treatment for lumbar tuberculosis.展开更多
Background:The risk of internal fixation failure remains relatively high in stable femoral neck fracture(FNF)(Garden I or II).Preoperative sagittal displacement of the femoral head has been proposed as a potential inf...Background:The risk of internal fixation failure remains relatively high in stable femoral neck fracture(FNF)(Garden I or II).Preoperative sagittal displacement of the femoral head has been proposed as a potential influencing factor.This study aimed to evaluate the impact of sagittal displacement on the outcomes of cannulated screw internal fixation(CSIF)in patients with stable FNF(Garden I or II)by reconstructing the axial sagittal oblique plane of the fracture using preoperative computed tomography(CT)imaging.Methods:This study included 167 patients with FNF who underwent CSIF.The sagittal tilt angle of the femoral head(STAFH)was evaluated using three-dimensional CT(3D-CT).The distribution of preoperative STAFH was analyzed,and its independent association with treatment failure was assessed.Treatment failure was defined as the need for revision surgery within 2 years postoperatively due to avascular necrosis,nonunion,or internal fixation failure.Results:Among the 167 patients,9(5.4%)exhibited anterior tilt(AT)of the femoral head,158(94.60%)presented with posterior tilt(PT).A total of 50 patients(29.9%)demonstrated excessive sagittal displacement(AT≥10°or PT≥20°).In the failure group,80.0%of patients had excessive sagittal displacement compared to 28.1%in the healed group.Excessive sagittal displacement was significantly associated with an increased risk of surgical failure(odds ratio:11.953,95%CI:3.656-39.083,p<0.05).Conclusions:In patients with Garden I or II FNF,greater preoperative sagittal displacement of the femoral head was correlated with a higher likelihood of CSIF failure.AT≥10°or PT≥20°were identified as independent predictors of CSIF failure in FNF patients.Nevertheless,these findings still require confirmation through prospective,multi-center clinical trials with large sample sizes.展开更多
BACKGROUND Surgical intervention is a critical treatment approach for symptomatic atlantoaxial dislocation.However,vertebral artery injury remains a significant challenge during such procedures.We present a case of su...BACKGROUND Surgical intervention is a critical treatment approach for symptomatic atlantoaxial dislocation.However,vertebral artery injury remains a significant challenge during such procedures.We present a case of successful treatment of atlantoaxial dislocation with concurrent vertebral artery injury using interlaminar screw technology,and review the relevant literature.CASE SUMMARY A 69-year-old female patient,with no history of trauma,was diagnosed with atlantoaxial dislocation based on X-ray,computed tomography(CT),and magnetic resonance imaging.Preoperative CT angiography(CTA)revealed vertebral artery developmental anomalies,and she underwent posterior cervical surgery.Postoperative follow-up showed improvement in the patient’s clinical symptoms such as unstable walking and dizziness,as well as functional scores compared to pre-surgery.Intraoperative vertebral artery injury was successfully managed,and postoperative CTA review revealed no complications related to vascular damage.CONCLUSION Thorough preoperative evaluation,such as CTA imaging,and the surgeon’s expertise in various spinal screw placement techniques are crucial for improving the success rate of atlantoaxial dislocation surgeries.展开更多
The demand for high-precision large-aperture antennas has continued to increase owing to the expanding application of spaceborne deployable active phased array antennas in remote sensing observation,satellite communic...The demand for high-precision large-aperture antennas has continued to increase owing to the expanding application of spaceborne deployable active phased array antennas in remote sensing observation,satellite communication,navigation positioning,and deep space exploration.However,deployment errors in deployable mechanisms,particularly hinge-induced deflection errors during array surface deployment,degrade on-orbit surface accuracy.This study proposes an active adjustment strategy that installs compliant parallel mechanisms on the backplane of antenna subarrays to regulate surface splicing precision.For one-dimensional(1D)deployable antennas,a two-translation one-rotation(2T1R)parallel mechanism configuration is employed for precision adjustment,whereas two-dimensional(2D)deployable antennas adopt a one-translation two-rotation(1T2R)configuration.A reconfigurable parallel mechanism architecture satisfying space deployment constraints-the 3PSS-2RPU-UPR/RPU parallel mechanism-is designed via configuration synthesis.The degrees of freedom(DOF)are verified via the screw theory,with complete inverse kinematics solutions derived.Search algorithms further quantify the adjustment workspace while clarifying the coupling relationships between DOFs.Equivalent compliant parallel mechanism models are obtained using the rigid-body replacement method,followed by a compliance analysis and motion simulation of compliant joints(notched flexure hinges and leaf-spring flexure prismatic joints).A systematic investigation of the deformation characteristics under different actuation modes confirmed the validity of the equivalent models.Ground experiments demonstrated close agreement between the measured and simulated adjustments,with open-loop adjustment errors constituting less than 10%of the adjustment range,thereby validating the feasibility of the method.The precision adjustment mechanism achieved configuration switching(2T1R/1T2R)through an inverted central limb design,integrating dual-mode compensation into a reconfigurable system.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 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
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
To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Un...To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Undersea Tunnel.To evaluate the discharging performance of short screw conveyor in different cases,the full-scale transient slurry-rock two-phase model for a short screw conveyor actively discharging rocks was established using computational fluid dynamics-discrete element method(CFD-DEM)coupling approach.In the fluid domain of coupling model,the sliding mesh technology was utilized to describe the rotations of the atmospheric composite cutterhead and the short screw conveyor.In the particle domain of coupling model,the dynamic particle factories were established to produce rock particles with the rotation of the cutterhead.And the accuracy and reliability of the CFD-DEM simulation results were validated via the field test and model test.Furthermore,a comprehensive parameter analysis was conducted to examine the effects of TBM operating parameters,the geometric design of screw conveyor and the size of rocks on the discharging performance of short screw conveyor.Accordingly,a reasonable rotational speed of screw conveyor was suggested and applied to Jiaozhou Bay Second Undersea Tunnel project.The findings in this paper could provide valuable references for addressing the excavation chamber clogging during ultra-large-diameter slurry TBM tunneling in hard rock for similar future.展开更多
Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for ...Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.展开更多
文摘Purpose: The good of this survey was to analyze the epidemiological aspects and evaluate anatomical and functional results of the treatment by screwing of femoral neck fracture in adulthood at the Teaching Hospital of an underequipped country. Material and Methods: This is a retrospective study from January 1, 2011 to December 31, 2015, concerning patients hospitalized for fractures of femoral neck and having been operated by screwing. The variables studied were epidemiological and therapeutic aspects. Anatomical results were examined on standard x rays of the pelvis in front and the hip in profil, based on the consolidation of the bony axis. Functional results were analyzed according to the quotation of Postel Merle D’Aubigné. Results: Eleven screwings of femoral neck have been done to 11 patients (9 men and 2 women), average age was 47 years (29 and 60 years) from January 2011 to December 2015, at the mean recoil of 19 months (12 and 24 months). Amongst consolidated patients (n = 7), one patient presented a necrosis of femoral head at two years hindsight. Four patients presented an aseptic pseudarthrosis of femoral neck, or a bad anatomical result. Amidst this group of patients, one underwent a joint replacement type Moore and suggestion of intermediary prothesis was recommended to three patients. According to the quotation of Postel Merle D’Aubigné, results were very satisfactory to 5 patients, good to 2 patients and bad to 4 patients. According to the score of Parker, 7 patients presented a score of 9 and 4 patients a score of 7. Conclusion: The treatment of femoral neck fractures in adulthood requires a surgical approach by osteosynthesis and must be precocious before 24 hours in order to reduce risks of pseudarthrosis of femoral neck and necrosis of femoral head.
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 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 National Natural Science Foundation of China(Grant No.52405040)Research Project of State Key Laboratory of Mechanical System and Vibration(Grant No.MSV202514)。
文摘A cable-driven redundant manipulator(CDRM)characterized by redundant degrees of freedom and a lightweight,slender design can perform tasks in confined and restricted spaces efficiently.However,the complex multistage coupling between drive cables and passive joints in CDRM leads to a challenging dynamic model with difficult parameter identification,complicating the efforts to achieve accurate modeling and control.To address these challenges,this paper proposes a dynamic modeling and adaptive control approach tailored for CDRM systems.A multilevel kinematic model of the cable-driven redundant manipulator is presented,and a screw theory is employed to represent the cable tension and cable contact forces as spatial wrenches,which are equivalently mapped to joint torque using the principle of virtual work.This approach simplifies the mapping process while maintaining the integrity of the dynamic model.A recursive method is used to compute cable tension section-by-section for enhancing the efficiency of inverse dynamics calculations and meeting the high-frequency demands of the controller,thereby avoiding large matrix operations.An adaptive control method is proposed building on this foundation,which involves the design of a dynamic parameter adaptive controller in the joint space to simplify the linearization process of the dynamic equations along with a closed-loop controller that incorporates motor parameters in the driving space.This approach improves the control accuracy and dynamic performance of the CDRM under dynamic uncertainties.The accuracy and computational efficiency of the dynamic model are validated through simulations,and the effectiveness of the proposed control method is demonstrated through control tests.This paper presents a dynamic modeling and adaptive control approach for CDRM to enhance accuracy and performance under dynamic uncertainties.
基金support of this research by the National Natural Science Foundation of China(Nos.22202171,21922202,and 22272146)the Natural Science Foundation of Jiangsu Basic Research Program(No.BK20220559)+1 种基金the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(No.22KJD150009)the Jiangsu Specially-Appointed Professor Plan(Z.Xi)from the Jiangsu Education Department。
文摘Rational tuning of chiral nanostructures of supramolecular assemblies as catalysts and investigating their chiral morphology-enantioselectivity dependence is rarely reported. Herein, we report a series of supramolecular M/P-helical nanoribbons(HNs) assembled from the chiral L/D-glutamate-based amphiphiles(L/D-Glu C16) and Cu(Ⅱ) ions, with their helical screw pitches adjusted from 217 nm to 104 nm through the facile regulation of their water/organic solvent assembly environment. They were then used as ideal models to reveal the chiral morphology-enantioselectivity relationship by catalyzing the asymmetric Diels-Alder reaction. Better enantioselectivity was achieved with more twist morphology. Experimental evidences of stronger chiral transfer effect from the supramolecular HNs with more twist to the aza-chalcone as reactant were obtained to understand such dependence. Our study demonstrates a new perspective for designing supramolecular catalysts with higher enantioselectivity.
基金Supported by National Natural Science Foundation of China(Grant Nos.52192634,52305015,52335003)Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515011268)Science and Technology Innovation Committee of Shenzhen(Grant Nos.GXWD20231129102029003,KQTD20210811090146075).
文摘The intricate relationship between origami and mechanism underscores the fertile ground for innovation,which is particularly evident in the construction theory of thick-panel origami.Despite its potential,thick panel origami remains relatively unexplored in the context of single-loop metamorphic mechanisms.Drawing inspiration from thickpanel origami,particularly Miura origami,this study proposes a pioneering single-loop 6R multiple metamorphic mechanism.Through rigorous mathematical modeling(including the construction and resolution of the D-H closed-loop equation)and leveraging advanced analytical tools such as the screw theory and Lie theory,this study meticulously elucidates the planar,spherical,and Bennett motion branches of the mechanism.Furthermore,it delineates all the three bifurcation points between the motion branches,thereby providing a comprehensive understanding of the kinematic behavior of the mechanism.A metamorphic network can be constructed by applying several single-loop mechanisms to a symmetrical layout.Owing to its metamorphic properties,this network can act as a structural backbone for deployable antennas,aerospace shelters,and morphing wing units,thereby enabling a single mechanism to achieve multiple folding configurations.This paper not only introduces innovative metamorphic mechanisms but also suggests a promising method for uncovering and designing metamorphic mechanisms by developing new mechanisms from thick-panel origami.
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.
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Supported by AI For Spinal Surgery Planning and Results Assessment Project under the“Priority 2030”Academic Leadership Initiative,No.6.18-01/240724-15.
文摘BACKGROUND Pedicle screw fixation is frequently used to treat unstable thoracolumbar injuries;however,the rate of instrumentation failure remains considerable.The primary contributing factor leading to instrumentation failure is poor bone quality.On the other hand,some evidence suggests that surgical tactics can influence long-term instrumentation stability.AIM To assess factors that influence the stability of spinal instrumentation in patients with thoracolumbar injuries.METHODS This study is a non-randomized single center ambispective evaluation of 204 consecutive patients(117 men;87 women)with unstable thoracolumbar injuries.All patients underwent either stand-alone or combined with anterior column reconstruction instrumentation.In cases with spinal cord and nerve root injuries,either posterior or anterior decompression were performed.Patients with pedicle screw loosening were identified via computed tomography imaging.Out of those,cases with clinically significant instrumentation failure were registered.RESULTS The rate of pedicle screw loosening detected by computed tomography was inversely correlated with bone radiodensity figures and an increased association with the number of instrumented levels,residual kyphotic deformity,laminectomy,and lumbosacral fixation.Intermediate screws and anterior reconstruction were associated with a clinically relevant decreased risk of pedicle screw loosening development.Either complete or partial posterior fusion within instrumented levels was capable of decreasing instrumentation failure risk,while extensive decompression with laminectomy and at least one-level total facetectomy were associated with an increased risk of instrumentation failure.Anterior decompression does not have a negative impact on instrumentation stability.CONCLUSION Intermediate screws,anterior reconstruction and posterior tension band preservation are associated with decreased rates of instrumentation instability development.Posterior fusion is beneficial in terms of instrumentation failure prevention.
基金Supported by National Natural Science Foundation of China(Grant No.52175019)Beijing Municipal Natural Science Foundation(Grant Nos.L222038,20240484699)+1 种基金Joint Funds of Industry-university-research of Shanghai Academy of Spaceflight Technology(Grant No.SAST2022-017)Beijing Municipal Key Laboratory of Space-ground Interconnection and Convergence of China and Key Laboratory of IoT Monitoring and Early Warning,Ministry of Emergency Management,Project‘Vice President of Science and Technology’of Changping District,Beijing.
文摘Current research on reconfigurable parallel mechanisms(RPMs)primarily focuses on achieving limited configuration changes,while mechanisms capable of extensive mode switching with distinct motion branches remain challenging to design.Conventional kinematotropic chains offer limited reconfigurability,underscoring the need for novel designs that enable broader operational adaptability.In this research,a novel diamond-like chain(DLC)with metamorphic units is proposed developed from generalized diamond kinematotropic chains.By altering the axes of the metamorphic units,the DLC realizes three distinct configurations,each corresponding to one of five motion branches characterized by bifurcation and metamorphic transitions.This DLC serves as the fundamental building block for constructing a reconfigurable hybrid limb.Using screw theory,the constraint properties of the limb in its five phases are analyzed and classified into three types:unconstrained limbs,limbs applying constraint forces,and limbs applying constraint couples.Based on this analysis,a RPM consisting of three reconfigurable limbs is developed.Its reconfigurability stems from the inherent bifurcation and metamorphic capabilities of the DLC-based limbs.This research introduces a RPM capable of controlled switching among ten distinct motion modes,with mobility ranging from three to six degrees of freedom.The proposed mechanism demonstrates high versatility and practical feasibility,offering a promising solution for applications requiring variable motion characteristics and adaptive performance.
基金Supported by Medical Research Project of Wuhan Municipal Health Commission,No.WX21M02.
文摘BACKGROUND Spinal tuberculosis,a destructive extrapulmonary form,often causes severe deformity and neurological deficits.Surgical intervention aims to debride lesions,reconstruct stability,and correct deformities.This study evaluates a combined posterior fixation and minimally invasive anterior approach for lumbar tuberculosis.AIM To evaluate the clinical outcomes and radiological parameters of posterior internal fixation combined with minimally invasive anterior lesion clearance and bone graft fusion for the treatment of lumbar tuberculosis.METHODS Clinical data from 24 patients with lumbar tuberculosis who underwent posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance were analyzed.The Cobb angle,visual analog scale(VAS)score,and Frankel classification were statistically assessed preoperatively and postoperatively.Complications and bone graft fusion were also recorded.RESULTS Wounds healed in the first stage in 22 patients;one patient developed a posterior incisional sinus tract,and one experienced postoperative tuberculosis recurrence.At the final follow-up,according to the Frankel classification,there were 1,2,and 21 cases classified as grade C,grade D,and grade E,respectively.By the last follow-up,the Cobb angle,VAS score,and erythrocyte sedimentation rate had all decreased.Both X-ray and computed tomography images confirmed bone healing.The fusion time ranged from 3 to 9 months,with an average of 5.2 months.CONCLUSION Posterior pedicle screw fixation combined with minimally invasive anterior lesion clearance is an effective and safe treatment for lumbar tuberculosis.
基金supported by the National Natural Science Foundation of China(82422045).
文摘Background:The risk of internal fixation failure remains relatively high in stable femoral neck fracture(FNF)(Garden I or II).Preoperative sagittal displacement of the femoral head has been proposed as a potential influencing factor.This study aimed to evaluate the impact of sagittal displacement on the outcomes of cannulated screw internal fixation(CSIF)in patients with stable FNF(Garden I or II)by reconstructing the axial sagittal oblique plane of the fracture using preoperative computed tomography(CT)imaging.Methods:This study included 167 patients with FNF who underwent CSIF.The sagittal tilt angle of the femoral head(STAFH)was evaluated using three-dimensional CT(3D-CT).The distribution of preoperative STAFH was analyzed,and its independent association with treatment failure was assessed.Treatment failure was defined as the need for revision surgery within 2 years postoperatively due to avascular necrosis,nonunion,or internal fixation failure.Results:Among the 167 patients,9(5.4%)exhibited anterior tilt(AT)of the femoral head,158(94.60%)presented with posterior tilt(PT).A total of 50 patients(29.9%)demonstrated excessive sagittal displacement(AT≥10°or PT≥20°).In the failure group,80.0%of patients had excessive sagittal displacement compared to 28.1%in the healed group.Excessive sagittal displacement was significantly associated with an increased risk of surgical failure(odds ratio:11.953,95%CI:3.656-39.083,p<0.05).Conclusions:In patients with Garden I or II FNF,greater preoperative sagittal displacement of the femoral head was correlated with a higher likelihood of CSIF failure.AT≥10°or PT≥20°were identified as independent predictors of CSIF failure in FNF patients.Nevertheless,these findings still require confirmation through prospective,multi-center clinical trials with large sample sizes.
基金Supported by Applied Basic Research Programs of Science and Technology Commission Foundation of Yunnan Province of China,No.202401AY070001-158.
文摘BACKGROUND Surgical intervention is a critical treatment approach for symptomatic atlantoaxial dislocation.However,vertebral artery injury remains a significant challenge during such procedures.We present a case of successful treatment of atlantoaxial dislocation with concurrent vertebral artery injury using interlaminar screw technology,and review the relevant literature.CASE SUMMARY A 69-year-old female patient,with no history of trauma,was diagnosed with atlantoaxial dislocation based on X-ray,computed tomography(CT),and magnetic resonance imaging.Preoperative CT angiography(CTA)revealed vertebral artery developmental anomalies,and she underwent posterior cervical surgery.Postoperative follow-up showed improvement in the patient’s clinical symptoms such as unstable walking and dizziness,as well as functional scores compared to pre-surgery.Intraoperative vertebral artery injury was successfully managed,and postoperative CTA review revealed no complications related to vascular damage.CONCLUSION Thorough preoperative evaluation,such as CTA imaging,and the surgeon’s expertise in various spinal screw placement techniques are crucial for improving the success rate of atlantoaxial dislocation surgeries.
基金Supported by National Natural Science Foundation of China(Grant No.52475023)Shanghai Municipal Natural Science Foundation(Grant Nos.24ZR1424300,23DZ2229032).
文摘The demand for high-precision large-aperture antennas has continued to increase owing to the expanding application of spaceborne deployable active phased array antennas in remote sensing observation,satellite communication,navigation positioning,and deep space exploration.However,deployment errors in deployable mechanisms,particularly hinge-induced deflection errors during array surface deployment,degrade on-orbit surface accuracy.This study proposes an active adjustment strategy that installs compliant parallel mechanisms on the backplane of antenna subarrays to regulate surface splicing precision.For one-dimensional(1D)deployable antennas,a two-translation one-rotation(2T1R)parallel mechanism configuration is employed for precision adjustment,whereas two-dimensional(2D)deployable antennas adopt a one-translation two-rotation(1T2R)configuration.A reconfigurable parallel mechanism architecture satisfying space deployment constraints-the 3PSS-2RPU-UPR/RPU parallel mechanism-is designed via configuration synthesis.The degrees of freedom(DOF)are verified via the screw theory,with complete inverse kinematics solutions derived.Search algorithms further quantify the adjustment workspace while clarifying the coupling relationships between DOFs.Equivalent compliant parallel mechanism models are obtained using the rigid-body replacement method,followed by a compliance analysis and motion simulation of compliant joints(notched flexure hinges and leaf-spring flexure prismatic joints).A systematic investigation of the deformation characteristics under different actuation modes confirmed the validity of the equivalent models.Ground experiments demonstrated close agreement between the measured and simulated adjustments,with open-loop adjustment errors constituting less than 10%of the adjustment range,thereby validating the feasibility of the method.The precision adjustment mechanism achieved configuration switching(2T1R/1T2R)through an inverted central limb design,integrating dual-mode compensation into a reconfigurable system.
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.
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 the Fundamental Research Funds for the Central Universities(Grant No.2023YJS053)the National Natural Science Foundation of China(Grant No.52278386).
文摘To fundamentally alleviate the excavation chamber clogging during slurry tunnel boring machine(TBM)advancing in hard rock,large-diameter short screw conveyor was adopted to slurry TBM of Qingdao Jiaozhou Bay Second Undersea Tunnel.To evaluate the discharging performance of short screw conveyor in different cases,the full-scale transient slurry-rock two-phase model for a short screw conveyor actively discharging rocks was established using computational fluid dynamics-discrete element method(CFD-DEM)coupling approach.In the fluid domain of coupling model,the sliding mesh technology was utilized to describe the rotations of the atmospheric composite cutterhead and the short screw conveyor.In the particle domain of coupling model,the dynamic particle factories were established to produce rock particles with the rotation of the cutterhead.And the accuracy and reliability of the CFD-DEM simulation results were validated via the field test and model test.Furthermore,a comprehensive parameter analysis was conducted to examine the effects of TBM operating parameters,the geometric design of screw conveyor and the size of rocks on the discharging performance of short screw conveyor.Accordingly,a reasonable rotational speed of screw conveyor was suggested and applied to Jiaozhou Bay Second Undersea Tunnel project.The findings in this paper could provide valuable references for addressing the excavation chamber clogging during ultra-large-diameter slurry TBM tunneling in hard rock for similar future.
文摘Objectives: Atlantoaxial dislocation remains a rare and serious condition with a high preoperative and postoperative morbidity and mortality. Its successful surgical management is still challenging and gratifying for neurosurgeons. Several technics have been described such as wiring, trans articular screwing, C1C2 screwing with plate and screw introduced by Goel et al., and modified by insertion of polyaxially screw and rod many years later by Harms. Unavailability and expensiveness of upper cervical spine instrumentation device led us to C1C2 Wiring resulting in a good outcome. Finally, a quadriplegic patient with a more comfortable financial condition had ordered devices from abroad and benefit for Goel and Harms screwing technique and improved dramatically from ASIA A to ASIA E. Material and methods: This is a retrospective study of patients managed in our department by a same neurosurgeon from January 2019 to April 2024. Results: We defined 6 men and 1 woman with an average age of 33 years. Unrestrained driver in a rollover motor vehicle accident was most common. Only one patient was neurologically intact on admission. Neurovegetative disorders were noticed in one patient. Dislocation was associated to a fracture of the dens in two patients. Three patients have been successfully operated with remarkable outcome, mostly from ASIA A to E. Conclusion: C1C2 dislocation is a serious condition and C1C2 Wiring represents an effective and cheaper technic. Therefore, this technic should deserve consideration above all in low incomes countries when screwing devices are not available. Seatbelt should be demanded for motor vehicle drivers and passengers.
