Contact stress is the important cause of wear and failure of knee joint prostheses implanted in the human body during movement.The calculation of contact stress on joint prostheses is often inaccurate due to the devia...Contact stress is the important cause of wear and failure of knee joint prostheses implanted in the human body during movement.The calculation of contact stress on joint prostheses is often inaccurate due to the deviation of joint position during activity.This paper proposes a correction method for contact stress based on finite element results.Firstly,the contact stress and contact radius between femoral and tibial prostheses of knee joint were calculated and analyzed by Hertz contact theory.Then,individualized finite element models based on the individualized geometry of the joint prosthesis and individualized loading were constructed,and the finite element contact stress was analyzed.The finite element results were calibrated utilizing the Hertz contact theory.Additionally,this study investigated the impact of three gait patterns(normal gait,medial thrust gait,and bouncing gait)on the contact stress experienced by the tibial insert.The research methods and results can provide ideas for theoretical analysis and finite element simulation of prosthetic joint contact,as well as offer theoretical support and analysis methods for evaluating the lifespan of prosthetic joints.展开更多
Objective:To explore the diagnostic value of serum Interleukin-6(IL-6)combined with synovial IL-6 and C-reactive protein for prosthesis joint infection(PJI)in patients after joint arthroplasty.Methods:A total of 253 p...Objective:To explore the diagnostic value of serum Interleukin-6(IL-6)combined with synovial IL-6 and C-reactive protein for prosthesis joint infection(PJI)in patients after joint arthroplasty.Methods:A total of 253 patients undergoing revision surgery after the first total hip and total knee arthroplasty in the Second Affiliated Hospital of Hainan Medical College from January 2018 to April 2020 were recruited as the study object.The patients were divided into the PJI group(n=85)and non-PJI group(n=168)according to whether there was PJI,and the baseline characteristics and the laboratory indexe were collected and compared between the two groups.the factors associated with PJI in patients after joint arthroplasty were analyzed by multivariate logistic regression model.And the diagnostic value of each marker for PJI in patients after joint arthroplasty was evaluated by Receiver Operating Characteristic(ROC)curve.Results:The incidence of PJI in this study was 33.6%.Compared with the non-PJI group,the patients in the PJI group had more diabetes mellitus and shorter prosthesis duration(P<0.05).The levels of serum C-reactive protein(CRP),serum interleukin-6(IL-6),synovial IL-6,synovial CRP,synovial leukocyte,synovial neutrophil and ESR in the PJI group were higher than those in non-PJI group,and the level of synovial lymphocyte was lower,with statistically significant differences(P<0.05).Multivariate logistic regression analysis showed that diabetes mellitus(OR=1.706,95%CI:1.02~2.376,P=0.037),prosthesis duration(OR=0.781,95%CI:0.690~0.884,P<0.001),serum IL-6(OR=1.008,95%CI:1.004~1.012,P=0.046),synovial IL-6(OR=1.004,95%CI:1.002~1.006,P=0.011)and synovial CRP(OR=1.481,95%CI:1.010~2.170,P=0.044)were independently related to PJI in patients after joint arthroplasty.ROC curve analysis showed that the area under ROC curve(AUC)of serum IL-6 combined with synovial IL-6 and CRP for diagnose PJI in patients after joint arthroplasty was significantly greater than each marker(0.941 vs 0.760,Z=6.333,P<0.001;0.941 vs 0.743,Z=7.189,P<0.001;0.941 vs 0.785,Z=4.999,P=0.006).Conclusion:Serum IL-6,synovial IL-6 and CRP were independently related to PJI in patients after joint arthroplasty.They all had some diagnostic value,and serum IL-6 combined with synovial IL-6 and CRP had higher capability to diagnose PJI in patients after joint arthroplasty than each marker alone.展开更多
UHMWPE composites reinforced with Bovine Bone Hydroxyapatite(BHA)in different contents were prepared by heat pressing formation method.A hip joint wear simulator was used to investigate the biotribological behavior of...UHMWPE composites reinforced with Bovine Bone Hydroxyapatite(BHA)in different contents were prepared by heat pressing formation method.A hip joint wear simulator was used to investigate the biotribological behavior of UHMWPE/BHA composite acetabular cups against CoCrMo alloy femoral heads in bovine synovia lubrication at 37±1 ℃.It was found that the addition of BHA powder to UHMWPE can improve the hardness and creep modulus of UHMWPE/BHA composites,and decrease their wear rates under bovine synovia lubrication.When the content of BHA filler particles was up to 30 wt%, UHMWPE/BHA composites demonstrated the well design performances of the surface and biotribological properties.Fatigue, ploughing and slight adhesive wear were the main wear mechanisms for UHMWPE and its composites.In addition,the sizes of wear particles became larger with an increase in BHA powder addition.These results suggest that BHA filler is a desirable component to increase the wear resistance of UHMWPE/BHA composites for biomedical applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant numbers 12102287,12302477,11972243)the Fundamental Research Program of Shanxi Province(Grant number 202203021222081).
文摘Contact stress is the important cause of wear and failure of knee joint prostheses implanted in the human body during movement.The calculation of contact stress on joint prostheses is often inaccurate due to the deviation of joint position during activity.This paper proposes a correction method for contact stress based on finite element results.Firstly,the contact stress and contact radius between femoral and tibial prostheses of knee joint were calculated and analyzed by Hertz contact theory.Then,individualized finite element models based on the individualized geometry of the joint prosthesis and individualized loading were constructed,and the finite element contact stress was analyzed.The finite element results were calibrated utilizing the Hertz contact theory.Additionally,this study investigated the impact of three gait patterns(normal gait,medial thrust gait,and bouncing gait)on the contact stress experienced by the tibial insert.The research methods and results can provide ideas for theoretical analysis and finite element simulation of prosthetic joint contact,as well as offer theoretical support and analysis methods for evaluating the lifespan of prosthetic joints.
基金Natural science fund project of Hainan Province(No.819MS128)。
文摘Objective:To explore the diagnostic value of serum Interleukin-6(IL-6)combined with synovial IL-6 and C-reactive protein for prosthesis joint infection(PJI)in patients after joint arthroplasty.Methods:A total of 253 patients undergoing revision surgery after the first total hip and total knee arthroplasty in the Second Affiliated Hospital of Hainan Medical College from January 2018 to April 2020 were recruited as the study object.The patients were divided into the PJI group(n=85)and non-PJI group(n=168)according to whether there was PJI,and the baseline characteristics and the laboratory indexe were collected and compared between the two groups.the factors associated with PJI in patients after joint arthroplasty were analyzed by multivariate logistic regression model.And the diagnostic value of each marker for PJI in patients after joint arthroplasty was evaluated by Receiver Operating Characteristic(ROC)curve.Results:The incidence of PJI in this study was 33.6%.Compared with the non-PJI group,the patients in the PJI group had more diabetes mellitus and shorter prosthesis duration(P<0.05).The levels of serum C-reactive protein(CRP),serum interleukin-6(IL-6),synovial IL-6,synovial CRP,synovial leukocyte,synovial neutrophil and ESR in the PJI group were higher than those in non-PJI group,and the level of synovial lymphocyte was lower,with statistically significant differences(P<0.05).Multivariate logistic regression analysis showed that diabetes mellitus(OR=1.706,95%CI:1.02~2.376,P=0.037),prosthesis duration(OR=0.781,95%CI:0.690~0.884,P<0.001),serum IL-6(OR=1.008,95%CI:1.004~1.012,P=0.046),synovial IL-6(OR=1.004,95%CI:1.002~1.006,P=0.011)and synovial CRP(OR=1.481,95%CI:1.010~2.170,P=0.044)were independently related to PJI in patients after joint arthroplasty.ROC curve analysis showed that the area under ROC curve(AUC)of serum IL-6 combined with synovial IL-6 and CRP for diagnose PJI in patients after joint arthroplasty was significantly greater than each marker(0.941 vs 0.760,Z=6.333,P<0.001;0.941 vs 0.743,Z=7.189,P<0.001;0.941 vs 0.785,Z=4.999,P=0.006).Conclusion:Serum IL-6,synovial IL-6 and CRP were independently related to PJI in patients after joint arthroplasty.They all had some diagnostic value,and serum IL-6 combined with synovial IL-6 and CRP had higher capability to diagnose PJI in patients after joint arthroplasty than each marker alone.
基金supports by the Tribology Science Fund from the State Key Laboratory of Tribology(SKLT)at Tsinghua University (No.SKLTKF08A01)the National Nature Science Foundation of China(Grant No.50535050)
文摘UHMWPE composites reinforced with Bovine Bone Hydroxyapatite(BHA)in different contents were prepared by heat pressing formation method.A hip joint wear simulator was used to investigate the biotribological behavior of UHMWPE/BHA composite acetabular cups against CoCrMo alloy femoral heads in bovine synovia lubrication at 37±1 ℃.It was found that the addition of BHA powder to UHMWPE can improve the hardness and creep modulus of UHMWPE/BHA composites,and decrease their wear rates under bovine synovia lubrication.When the content of BHA filler particles was up to 30 wt%, UHMWPE/BHA composites demonstrated the well design performances of the surface and biotribological properties.Fatigue, ploughing and slight adhesive wear were the main wear mechanisms for UHMWPE and its composites.In addition,the sizes of wear particles became larger with an increase in BHA powder addition.These results suggest that BHA filler is a desirable component to increase the wear resistance of UHMWPE/BHA composites for biomedical applications.