Total knee arthroplasty(TKA)is mainly used for the treatment of advanced knee osteoarthritis.Accurate preoperative planning and rapid prosthesis recognition are essential for smooth operation and postoperative rehabilitation.However,manual prosthesis recognition rely on doctors'experience,easily leading to misdiagnosis or missed diagnosis.Recent years,artificial intelligence(AI)had been integrated with medical imaging,represented by machine learning(ML)and its branch deep learning(DL),and displayed relatively powerful auxiliary functions in TKA.The research status and application progresses of AI combined with imaging in TKA were reviewed in this article.

BACKGROUND:Finite element analysis is an advanced computer-based engineering technique that uses mathematical approximations to simulate the human body.This method accurately reflects the biomechanical characteristics within the knee,providing a powerful tool for understanding knee disease pathogenesis,optimizing surgical protocols,and developing new implant materials.OBJECTIVE:To review the establishment of finite element modelling of the knee joint and its application in the study of knee joint diseases,and look forward to the future development trend.METHODS:The first author searched the PubMed and EI databases in April 2024 by applying a computer with English search terms"finite element analysis,FEA,knee joint,finite element model,knee biomechanics,knee osteoarthritis,knee prosthesis,knee ligaments,meniscus"and searched CNKI and WanFang databases with Chinese search terms"finite element analysis,finite element model,knee joint,biomechanics,osteoarthritis,computational model,knee prosthesis,knee ligament,meniscus."Finally,75 papers were included in the analysis.RESULTS AND CONCLUSION:(1)Finite element analysis method uses medical imaging data to obtain a three-dimensional human model,simplifies the complex human joint structure into finite and interconnected units,and visually displays the internal stress distribution of the knee joint by applying external loads to the model.(2)The researchers deeply study the internal stress and strain distribution of the knee joint under different working conditions by means of finite element analysis,revealing the overloading of the articular cartilage and the decrease of load in some areas when the balance of the internal load distribution of the knee joint is changed,and that such long-term abnormal stresses cause deformation,wear and tear,and eventual loss of cartilage,which is crucial for understanding how biomechanical factors cause degenerative changes of the knee joint.(3)The effect of physical therapy methods such as Tai Chi and gait adjustment in patients with osteoarthritis of the knee joint was evaluated by finite element analysis,and the results showed that these treatments reduced the overloading of the cartilage,which provided a scientific theoretical basis for clinical treatment.(4)Clinicians are able to optimize surgical treatment strategies by performing three-dimensional reconstruction,data measurement,and simulation of surgery before surgery through finite element analysis.Furthermore,the mechanical characteristics of different prostheses can be simulated to improve the shape,material,and fixation of the prostheses,reduce patient complications,and improve patient outcomes.(5)The combination of artificial intelligence and finite element analysis makes the construction of finite element models more accurate and easy to operate,greatly contributing to the efficiency of clinicians'medical practice and patient outcomes.(6)Finite element analysis is only a digital simulation,which is still somewhat different from the real physical state.

BACKGROUND:Finite element analysis is an advanced computer-based engineering technique that uses mathematical approximations to simulate the human body.This method accurately reflects the biomechanical characteristics within the knee,providing a powerful tool for understanding knee disease pathogenesis,optimizing surgical protocols,and developing new implant materials.OBJECTIVE:To review the establishment of finite element modelling of the knee joint and its application in the study of knee joint diseases,and look forward to the future development trend.METHODS:The first author searched the PubMed and EI databases in April 2024 by applying a computer with English search terms"finite element analysis,FEA,knee joint,finite element model,knee biomechanics,knee osteoarthritis,knee prosthesis,knee ligaments,meniscus"and searched CNKI and WanFang databases with Chinese search terms"finite element analysis,finite element model,knee joint,biomechanics,osteoarthritis,computational model,knee prosthesis,knee ligament,meniscus."Finally,75 papers were included in the analysis.RESULTS AND CONCLUSION:(1)Finite element analysis method uses medical imaging data to obtain a three-dimensional human model,simplifies the complex human joint structure into finite and interconnected units,and visually displays the internal stress distribution of the knee joint by applying external loads to the model.(2)The researchers deeply study the internal stress and strain distribution of the knee joint under different working conditions by means of finite element analysis,revealing the overloading of the articular cartilage and the decrease of load in some areas when the balance of the internal load distribution of the knee joint is changed,and that such long-term abnormal stresses cause deformation,wear and tear,and eventual loss of cartilage,which is crucial for understanding how biomechanical factors cause degenerative changes of the knee joint.(3)The effect of physical therapy methods such as Tai Chi and gait adjustment in patients with osteoarthritis of the knee joint was evaluated by finite element analysis,and the results showed that these treatments reduced the overloading of the cartilage,which provided a scientific theoretical basis for clinical treatment.(4)Clinicians are able to optimize surgical treatment strategies by performing three-dimensional reconstruction,data measurement,and simulation of surgery before surgery through finite element analysis.Furthermore,the mechanical characteristics of different prostheses can be simulated to improve the shape,material,and fixation of the prostheses,reduce patient complications,and improve patient outcomes.(5)The combination of artificial intelligence and finite element analysis makes the construction of finite element models more accurate and easy to operate,greatly contributing to the efficiency of clinicians'medical practice and patient outcomes.(6)Finite element analysis is only a digital simulation,which is still somewhat different from the real physical state.

Total knee arthroplasty(TKA)is mainly used for the treatment of advanced knee osteoarthritis.Accurate preoperative planning and rapid prosthesis recognition are essential for smooth operation and postoperative rehabilitation.However,manual prosthesis recognition rely on doctors'experience,easily leading to misdiagnosis or missed diagnosis.Recent years,artificial intelligence(AI)had been integrated with medical imaging,represented by machine learning(ML)and its branch deep learning(DL),and displayed relatively powerful auxiliary functions in TKA.The research status and application progresses of AI combined with imaging in TKA were reviewed in this article.

Knee osteoarthritis(KOA)is a chronic degenerative joint disease which could result disabling in late stage.The objectivity in imaging diagnosis of KOA is often various due to human factors and other influences.Artificial intelligence(AI)has been proved highly valuable for KOA.The progresses of AI in imaging diagnosis and grading of KOA,detecting cartilages lesions,predicting pain and long-term care of KOA were reviewed in this article.