BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

BACKGROUND:Lumbar degenerative disease is a disease of the musculoskeletal system that primarily affects the intervertebral structures,and the disease is treated with lumbar fusion and disc replacement.OBJECTIVE:To conduct comparative analysis of the differences between lumbar fusion,mechanical lumbar disc prosthesis replacement,and viscoelastic lumbar disc prosthesis replacement.METHODS:The computerized tomography images of a healthy adult were used to construct a finite element model of the L2-L5 normal lumbar spine with Mimic,Geomagic,and Ansys software.The equipment required for lumbar fusion and lumbar spine replacement was constructed using modeling software,and the L3-L4 segment of the lumbar spine was processed according to the surgical requirements for lumbar fusion and intervertebral disc replacement,creating the corresponding finite element model.Specific boundary conditions were applied to extract the mobility of each lumbar spine segment,the stresses on the neighboring intervertebral discs,and the stresses on the prosthesis lining.RESULTS AND CONCLUSION:(1)Compared with the preoperative period,the maximum stress in the upper neighboring discs increased by 64.09％and 39.79％in the forward flexion and lateral bending states if the original mobility was maintained after lumbar fusion surgery.The maximum stress in the lower neighboring discs increased by 24.39％and 20.98％in forward flexion and lateral bending.This suggested that the upper adjacent discs would suffer greater stress changes than the lower adjacent discs during heavy physical labor.(2)Disc replacement did not show significant changes in adjacent disc stress,with mechanical prosthesis replacement slightly reducing adjacent disc stress,while viscoelastic prosthesis replacement was more in line with the biological properties of the disc,with maximum adjacent disc stress similar to that of the preoperative period.(3)In terms of stability,the mechanical prosthesis replacement segment showed a 51.67％increase in range of motion in the lateral bending state and a 53.27％increase in range of motion in the posterior extension state,whereas the viscoelastic prosthesis was better able to maintain mobility in the replacement segment.(4)In addition,the stresses in the liner of the mechanical prosthesis were mainly concentrated in the edge region,and this stress distribution may lead to edge wear and thus affect the service life of the prosthesis.

BACKGROUND:In 2019,the modified cortical bone trajectory technique was proposed by our team,significantly improving traditional methods.Previous studies have highlighted its superior biomechanical properties for segment fixation.However,a comprehensive systematic analysis of its specific biomechanical effects on adjacent segment degeneration is lacking,particularly regarding its influence on range of motion and intervertebral disc stress in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques.OBJECTIVE:To investigate the biomechanical effects of modified cortical bone trajectory screw techniques on adjacent segment degeneration in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion.METHODS:CT scans were performed on three human cadaver specimens to establish and validate three-dimensional intact finite element models of the L1-S1 segment.For each of these,the posterior lumbar interbody fusion or transforaminal lumbar interbody fusion with three different fixation techniques was reconstructed at the L4-L5 segment.The L4-L5 segment was fixed using three different internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws).The range of motion and von Mises stress of the intervertebral disc of the L3-L4 and L5-S1 segments were recorded with a 400 N compressive load and 7.5 N moments in flexion,extension,left-right bending,and left-right rotation.The impacts of the three internal fixation techniques on adjacent segment degeneration in the two kinds of fusion were compared and analyzed.RESULTS AND CONCLUSION:(1)In the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw group showed a reduced range of motion on adjacent segments(L3-L4,L5-S1)under six loading conditions compared to both the cortical bone trajectory screw group and traditional bone trajectory screw group.Specifically,the modified cortical bone trajectory screw group significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared to the traditional bone trajectory screw group(P=0.005),while the stress on the intervertebral disc in the inferior adjacent segment(L5-S1)exhibited greater dispersion.Similarly,the cortical bone trajectory screw group also significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared with the traditional bone trajectory screw group(P=0.03).(2)Compared with transforaminal lumbar interbody fusion,the three internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws)showed a trend of reduced range of motion in the inferior adjacent segment(L5-S1)under six loading conditions.In contrast,the maximum stress on the intervertebral discs in both the superior and inferior adjacent segments(L3-L4,L5-S1)exhibited an increasing trend in the posterior lumbar interbody fusion model.(3)It is concluded that in the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw exhibited superior biomechanical properties in reducing the range of motion at adjacent segments,which may have a beneficial effect on reducing the risk of adjacent segment degeneration.

BACKGROUND:With the development of the aging trend of society,the incidence of femoral neck fractures is increasing.Currently,the preferred surgical treatment is cannulated screw internal fixation.However,post-surgical femoral neck shortening occurs in some cases,resulting in impaired hip functionality.OBJECTIVE:To investigate the incidence of femoral neck shortening following the use of half-threaded cannulated screws for internal fixation in patients with femoral neck fractures,to analyze the effect on hip function,and to identify factors contributing to neck shortening.METHODS:A retrospective analysis was conducted on the medical records of 102 patients treated with half-threaded cannulated screws in an inverted triangle setup for femoral neck fractures at Affiliated Hai'an Hospital of Nantong University from January 2016 to January 2021.This group included 36 males and 66 females at the mean age of(57.2±7.7)years,with 34 cases of Garden type Ⅰ and Ⅱ fractures and 68 of Garden type Ⅲ and Ⅳ fractures.The mean bone mineral density value T was-2.8 SD.The Harris score was used to evaluate the hip function.During the follow-up period,the occurrence of femoral neck shortening was determined using X-ray imagery,and the factors influencing this shortening were examined using both univariate and multivariate regression analyses.RESULTS AND CONCLUSION:(1)Among the 102 patients with femoral neck fractures,30 patients developed femoral neck shortening,accounting for 29.4％.72 patients had no femoral neck shortening(70.6％).(2)The Harris score for patients experiencing neck shortening was significantly lower than that for patients without shortening(P＜0.05).(3)The study identified several factors associated with femoral neck shortening following the internal fixation of femoral neck fractures included age,gender,bone mineral density value T,preoperative Garden classification,and quality of reduction.These factors not only affect the shortening of the femoral neck after surgery,but are also directly related to the functional performance of the patient's hip joint.(4)Femoral neck shortening after surgery for femoral neck fracture is associated with various clinical parameters,especially the patient's age,gender,bone mineral density,preoperative classification,and accuracy of reduction during surgery.

BACKGROUND:The correlation between sacroiliac joint degeneration and lumbar degenerative disease has been analyzed in the literature in the past,but the clinical efficacy and imaging changes after interbody fusion with sacroiliac joint ankylosis in patients with lumbar degenerative disease have not been reported in the literature.OBJECTIVE:To investigate the effect of sacroiliac joint ankylosis on the clinical efficacy and lumbar sagittal regression after L5/S1 single-segment transforminal lumbar interbody fusion in patients with lumbar degenerative disease.METHODS:Thirty-seven patients who underwent L5/S1 segmental transforminal lumbar interbody fusion for lumbar degenerative disease with sacroiliac joint ankylosis between June 2020 and September 2023 in Affiliated Hospital of Xuzhou Medical University were retrospectively analyzed as group A.Thirty-seven patients with lumbar degenerative disease without sacroiliac joint ankylosis who were matched for general information during the same period were selected as controls in group B.Clinical efficacy was assessed using the Oswestry disability index and visual analog scale for lumbar and lower limb pain.The lumbar sagittal parameters included lumbar anterior convexity angle,lumbar partial anterior convexity angle,and lower lumbar anterior convexity angle.Pfirrmann grading was used to assess the degree of preoperative disc degeneration,postoperative endplate damage and screw loosening,and to record the fusion of the operated segments at the final postoperative follow-up visit.RESULTS AND CONCLUSION:(1)There was no statistically significant difference in age,body mass index,bone mineral density,operation time,intraoperative bleeding,preoperative primary diagnosis and postoperative follow-up time between the two groups(P＞0.05).(2)The preoperative Pfirrmann grading of lumbar disc degeneration in group A patients(3.4±0.9)was significantly higher than that of group B(3.1±0.6),and the difference was statistically significant(t=2.059,P=0.044).(3)All patients showed significant improvement in postoperative lumbar sagittal parameters compared with preoperative ones(all P＜0.05).During the follow-up period,there was a loss of correction in patients in group A.There was no statistical difference in the lumbar anterior convexity angle,lower lumbar anterior convexity angle,and local anterior convexity angle at the last follow-up compared with the preoperative period(P＞0.05).The lumbar anterior convexity angle,lower lumbar anterior convexity angle,and local anterior convexity angle in group A were significantly lower than those of group B patients at both preoperative and final follow-up,and the differences were statistically significant(all P＜0.05).(4)There was no statistically significant difference in postoperative endplate injury between the two groups(x2=0.181,P=0.670),and screw loosening was significantly higher in group A than in group B,with a statistically significant difference(x2=4.163,P=0.041).(5)At the last follow-up,the incidence of grade 3 fusion and grade 4 fusion was significantly higher in group A than in group B.The difference in the distribution of fusion grades between the two groups was statistically significant(x2=7.848,P=0.031).(6)The Oswestry disability index and lower limb visual analog scale scores at the last follow-up of both groups were significantly improved compared with the preoperative period(P＜0.05).The visual analog scale scores for low back pain at 3 months after surgery and at the last follow-up of group A were significantly higher than those of group B(t=2.010,P=0.048;t=2.133,P=0.036).(7)It is concluded that regardless of whether it is accompanied by sacroiliac joint ankylosis or not,lumbar degenerative disease patients who undergo interbody fusion with foramen magnum can achieve good therapeutic effects,but lumbar degenerative disease patients with sacroiliac joint ankylosis who undergo interbody fusion with foramen magnum at the L5/S1 segments have a poorer improvement of low back pain than patients without sacroiliac joint ankylosis after the operation.Furthermore,patients with preoperative sacroiliac ankylosis who underwent L5/S1 segmental transforminal lumbar interbody fusion had a low fusion rate and were prone to loss of correction of the lumbar sagittal position.

BACKGROUND:Pediatric flexible flatfoot is a common foot deformity that often leads to foot pain and reduced quality of life.OBJECTIVE:To explore the relationship between radiographic parameters and clinical efficacy of subtalar arthroereisis in the treatment of pediatric flexible flatfoot.METHODS:A retrospective study was conducted on 56 pediatric patients(mean age of 11.8 years)who underwent subtalar arthroereisis at Guangzhou Orthopedic Hospital between January 2022 and May 2023.All patients underwent detailed radiographic examinations and clinical evaluations before and after surgery,including the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score and Visual Analog Scale score.Paired t-tests and independent t-tests were used to compare changes in radiographic parameters and clinical scores before and after surgery.Correlation analyses were conducted to evaluate the relationship between radiographic parameters and clinical outcomes.RESULTS AND CONCLUSION:(1)All radiographic parameters significantly improved during the 8 to 12-month follow-up after surgery(P＜0.001).(2)Clinical evaluation results indicated that the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot score significantly improved from 66.2±6.0 preoperatively to 91.3±5.8 postoperatively,and the Visual Analog Scale score significantly decreased from 3.1±0.8 preoperatively to 1.3±0.8 postoperatively(P＜0.001).(3)Independent t-tests showed a significant difference in postoperative the first metatarsal angle and Visual Analog Scale score grades(P=0.043),with a smaller the first metatarsal angle associated with less postoperative pain;preoperative lateral arch angle showed a significant difference between the"excellent"and"good"groups in postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot scores(P=0.033),suggesting that a smaller preoperative posterior arch angle might predict better postoperative foot function recovery.(4)Correlation analysis showed that preoperative posterior arch angle(r=-0.486,P＜0.01)and heel pitch angle(r=-0.344,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,while preoperative medial longitudinal arch angle(r=0.293,P＜0.05)was significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.Postoperative medial longitudinal arch angle(r=0.331,P＜0.05)and lateral arch angle(r=0.387,P＜0.01)were significantly positively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot,whereas postoperative Bohler's angle(r=-0.272,P＜0.05),posterior arch angle(r=-0.461,P＜0.01),and heel pitch angle(r=-0.318,P＜0.01)were significantly negatively correlated with postoperative American Orthopaedic Foot & Ankle Society Ankle-Hindfoot.(5)It is concluded that subtalar arthroereisis is significantly effective in correcting pediatric flexible flatfoot,and improvements in radiographic parameters are closely related to clinical efficacy.Preoperative and postoperative radiographic evaluations can serve as important reference indicators for predicting postoperative clinical outcomes,guiding clinicians to optimize treatment plansand rehabilitation programs.

BACKGROUND:H-type vessels(CD31hiEmcnhi)possess unique functionalities that offer new perspectives and entry points for comprehensively understanding the mechanisms of vascular-mediated bone metabolism regulation.This has triggered a significant paradigm shift in bone science research from a"bone-centric"approach to an"integrative bone-vascular"framework.OBJECTIVE:To perform a visual analysis based on literature data in the field of H-type vessels,aiming to identify research hotspots and emerging trends.METHODS:A systematic search was conducted in the CNKI and Web of Science databases for English and Chinese publications related to H-type vessels,covering the period from 2014 to 2024.The CiteSpace 6.2.R4 information visualization software was utilized to analyze and visualize data on publication countries,authors,institutions,keywords,and timeline views.RESULTS AND CONCLUSION:(1)A total of 59 Chinese and 185 English publications were included in the analysis.Since the introduction of the H-type vessel concept in 2014,the number of related research publications has been steadily increasing,accompanied by a significant growth in academic output.China leads the research in this domain,with major institutions including Southern Medical University,Sichuan University,and Shanghai Jiao Tong University.Keyword analysis indicated that current research hotspots primarily focus on the generation and regulatory mechanisms of H-type vessels,their roles in bone formation and remodeling,and their associations with bone metabolic diseases.Additionally,emerging keywords such as"induced membrane,""cartilage repair,"and"traditional Chinese medicine"suggest that research is progressively moving towards diversification and multidisciplinary integration.(2)H-type vessels play a crucial role in the development and progression of bone diseases,and relevant studies are pivotal for a deeper understanding of the physiological and pathological processes of bone tissue.Future research should further elucidate the specific mechanisms of H-type vessels in various disease contexts and promote the clinical translation of basic research findings.These efforts will provide innovative ideas and strategies for the prevention and treatment of bone-related diseases.

BACKGROUND:In China,the patient population with osteonecrosis is large,and there is an urgent need to find new preventive targets to develop more effective treatment strategies.Metabolomics studies have shown that there is an association between human metabolites and osteonecrosis,but the causal relationship between blood metabolites and osteonecrosis has not yet been clarified.OBJECTIVE:To investigate the causal relationship between blood metabolites and osteonecrosis through two-sample Mendelian randomization analysis.METHODS:The public data of 486 blood metabolites(exposure factors)and osteonecrosis(outcome factors)were collected.Data of 486 blood metabolites were derived from a genome-wide association estimate for blood metabolites published in Nature Genetics in 2014,which covered 7 824 European adults.The single nucleotide polymorphism data for osteonecrosis were obtained from the FinnGen public database R11 dataset,containing information on a total of 431 614 samples and 21 306 430 single nucleotide polymorphism loci,with 1 788 cases of osteonecrosis and 429 826 controls,with all participants being of European descent.Mendelian randomization analysis(inverse variance weighting method,MR-Egger method,and weighted median method)was performed by Rstudio software,and then the heterogeneity test,horizontal pleiotropy test and Steiger directionality test were performed to ensure the robustness and reliability of the results.RESULTS AND CONCLUSION:(1)Sixteen blood metabolites were identified as having a significant causal relationship with osteonecrosis(Pinverse variance weighting＜Pfalse discovery rate＜0.05).(2)Eight blood metabolites increased the risk of osteonecrosis(including four known metabolites and four unknown metabolites),specifically pantothenate,beta-hydroxyisovalerate,hippurate,salicyluric glucuronide,X-08766,X-11452,X-12776 and X-14662.(3)Eight blood metabolites could reduce the risk of osteonecrosis(six known metabolites and two unknown metabolites),including cortisol,1-palmitoylglycerol(1-monopalmitin),pyroglutamyl glycine,2-stearoylglycerophosphocholine,p-cresol sulfate,ergothioneine,X-06307,X-12092.(4)The above results suggest that there is a causal relationship between 16 blood metabolites and osteonecrosis,which is expected to be a potential target for intervention in the occurrence and treatment of osteonecrosis in the future.(5)Despite the lack of relevant data from large-scale Asian populations at present,this study provides important reference value for the field of osteonecrosis in China based on European population data.In the future,domestic medical workers may be able to achieve precise intervention for osteonecrosis by regulating metabolite levels.In addition,based on the results of this study,relevant researchers can further explore the mechanism of action of metabolites in the treatment of osteonecrosis with traditional Chinese medicine,which not only helps to deepen the understanding of traditional Chinese medical therapies but also promotes the progress of integrated traditional Chinese and Western medicine research,driving the development of personalized treatment plans that are more suitable for the characteristics of the Chinese population.

BACKGROUND:The number of patients receiving total knee arthroplasty has been increasing globally each year.Pain management is a crucial aspect following total knee arthroplasty,as effective pain control can facilitate early mobilization,reduce complications,enhance patient satisfaction,and accelerate the rehabilitation process.OBJECTIVE:To construct a visual map of post-total knee arthroplasty pain,understand the international research status and trends in this field,and provide a reference for future studies.METHODS:Relevant research articles on post-total knee arthroplasty pain were retrieved from the CNKI,WanFang Data,and Web of Science core databases,covering the period from January 2000 to December 2023.The CiteSpace software(version 6.2.3)was used to analyze the annual publication output,authors,institutions,countries,keywords,and references.Utilizing R programming language(version 4.4.1),a database was established to create line charts and bar graphs.RESULTS AND CONCLUSION:(1)Our analysis included 3 796 publications,predominantly in Chinese(3 509 articles)with the remainder in English(287 articles).(2)The United States was the most productive country in English literature,with Harvard University leading institutional output.Guangzhou University of Chinese Medicine was the top publishing institution in Chinese literature.(3)Keyword clustering identified"quality of life,""phobia,"and"acupuncture"as emerging focal points in Chinese literature,while"satisfaction"and"psychological factors"were prominent in English literature over the past five years.Co-occurrence and clustering analysis revealed dense internal connections among institutions,authors,and publications,but sparse external collaborations.(4)The study's bias on visualization analysis may have introduced bias by excluding less influential papers.(5)Regarding research hotspots,domestic research emphasized the efficacy and exploration of analgesic methods,in contrast to international research that focused on pain mechanism subtyping and analgesic drug innovation.Future research is expected to trend towards traditional Chinese medicine for postoperative pain,multimodal analgesia,and the investigation and prevention of pain typing mechanisms.

BACKGROUND:Forskolin,a diterpenoid natural compound extracted from Coleus forskohlii,has a crucial regulatory role in skeletal muscle repair.However,the regulatory role of forskolin on myogenic differentiation of C2C12 skeletal muscle cells has not been fully explored.OBJECTIVE:To explore the effects of forskolin on the differentiation of C2C12 myoblast cell line and probe into the underlying molecular mechanisms.METHODS:C2C12 cells were treated with 0,0.1,0.25,0.5,1,5,10 and 20 μmol/L forskolin during growth,and cell proliferation was detected by cell counting kit-8 and qRT-PCR.C2C12 cells were treated with 0,0.25,0.5 and 1 μmol/L forskolin during the induction of myogenic differentiation.Immunofluorescence staining and qRT-PCR were used to detect C2C12 cells differentiation.Western blot was used to detect the expression level of myogenic differentiation-related signaling pathway proteins.RESULTS AND CONCLUSION:(1)The viability of C2C12 cells was decreased and cell proliferation was inhibited after treatment with high concentrations(＞1 μmol/L)of forskolin.(2)The qRT-PCR results showed that forskolin up-regulated the expression of Myh2,Myh4,Myomaker,but down-regulated the expression of Myh7 compared with the 0 μmol/L group,when C2C12 cells were differentiated for 4 days.Immunofluorescence staining results showed that the fusion index and myotube diameter of C2C12 cells were increased after forskolin treatment,and the number of myotubes was also increased.(3)Western blot results showed that the phosphorylated extracellular signal-regulated kinase 1/2 expression was inhibited;however,the phosphorylated protein kinase B was promoted after treatment with forskolin.The protein expression level of the myogenic differentiation transcription factor Myogenin was significantly up-regulated after treatment with forskolin.The above results demonstrate that forskolin may promote myogenic differentiation of C2C12 skeletal muscle cells through the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathway.