BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND:Macrophage polarization plays a key role in chronic inflammatory joint diseases such as rheumatoid arthritis.Cerium dioxide(CeO2)nanoparticles have a wide range of biomedical applications such as modulating the local inflammatory microenvironment of tissues.OBJECTIVE:To investigate the role of CeO2 nanoparticles on macrophage polarization and inflammatory factor expression,as well as inflammatory modulation in a co-culture system of macrophages and fibroblasts.METHODS:(1)CeO2 nanoparticles were dispersed and observed morphologically by transmission electron microscopy.(2)Human leukemia monocytes(THP-1)were induced to differentiate and establish the M1 macrophage pro-inflammatory cell model of rheumatoid arthritis.The cells were divided into M0 group(undifferentiated macrophages),M1 group(successful macrophage modeling),CeO2 nanoparticle treatment group(M1 group with CeO2 nanoparticle treatment),and dexamethasone control group(M1 group with dexamethasone treatment)and incubated for 48 hours.The effects of CeO2 nanoparticles on the expression of inflammatory factors(endogenous nitric oxide synthase,CD86,CD80)in M1 macrophages and M1 macrophage phenotype(CD80,CD206)were detected by RT-qPCR,western blot assay,and flow cytometry.(3)A co-culture system of macrophages and fibroblasts was established,and CeO2 nanoparticles acted on the upper macrophages.The regulation of CeO2 nanoparticles on the expression of inflammatory factors(interleukin-6,tumor necrosis factor-α,cyclooxygenase-2,and endogenous nitric oxide synthase)of fibroblasts in the co-culture system was observed at the mRNA and protein levels.RESULTS AND CONCLUSION:(1)Transmission electron microscopy showed that the diameter of CeO2 nanoparticles was(19.5±2.0)nm.(2)Compared with the M0 group,the mRNA of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the M1 group were upregulated.Compared with the M1 group,the mRNA expression of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the CeO2 nanoparticle treatment group were downregulated.Flow cytometry showed that 20 nm CeO2 nanoparticles downregulated the number of M1 macrophages.(3)Compared with the M1 group,20 nm CeO2 nanoparticles downregulated the mRNA and protein expression of inflammatory factors(tumor necrosis factor α,interleukin 6,cyclooxygenase 2,and endogenous nitric oxide synthase)in the co-culture system HFL1 cells.(4)The results showed that 20 nm CeO2 nanoparticles can alleviate inflammation in the co-culture system by inhibiting the expression of pro-inflammatory factors in M1 macrophages,providing a new idea for the treatment of inflammatory diseases such as rheumatoid arthritis.

BACKGROUND:Fracture healing is a very complex physiological process,which is influenced by many factors.In recent years,the use of biomechanical factors in fracture healing has been a major focus in the field of orthopedics,and the mechanical stress environment around the fracture end has an important role in regulating fracture healing.Among them,the study of the mechanism of compressive mechanics on the cytokines of fracture ends is a hot spot for bone-related researchers.OBJECTIVE:To summarize the current status and recent advances in the study of the mechanism of action of compressive stress on cytokines in fracture healing in recent years.METHODS:A search with the keywords of"compressive stress,fracture healing,cytokine,bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,tumor necrosis factor-α"in Chinese and English was conducted in the CNKI,WanFang,PubMed,and Web of Science.Initially 506 articles were retrieved,and 94 eligible articles that met the criteria were screened and finally summarized.RESULTS AND CONCLUSION:Current studies have found that compressive stress has different effects on different cytokines during fracture healing,which can be achieved mainly by influencing cell signaling,gene expression regulation,and modulation of cell behavior.Among them,compressive stress can be linked to cytokines such as bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,and tumor necrosis factor-α.This process involves cell proliferation,differentiation and migration,inflammatory response,and changes in the environmental and nutritional conditions of the fracture end,which are key factors affecting fracture healing.The whole paper summarizes the complexity of cytokine action mechanism,the mechanism of compressive stress on its regulation needs to be further carried out in-depth research,and the problems and limitations in the research are considered and future prospects.

BACKGROUND:With changing lifestyles and aging,sagittal spinal imbalance has become a common orthopedic issue significantly affecting knee and pelvic function.Understanding the impact of sagittal spinal imbalance and its compensatory mechanisms is crucial for improving the clinical management of chronic pain.OBJECTIVE:To evaluate the alignment of the spine-pelvis-lower extremities using whole-body EOS imaging,analyze the correlation between spinal sagittal imbalance and knee joint parameters,and explore their compensatory mechanisms.METHODS:A total of 71 patients with chronic low back pain or patellofemoral pain who visited Department of Orthopedics,First Affiliated Hospital of Soochow University between January 1,2021 and December 31,2023 were included.Radiographic measurements were performed using whole-body EOS to determine pelvic tilt,pelvic incidence,lumbar lordosis,sagittal vertical axis,global tilt,hip-knee-angle,knee flexion angle,lateral distal femoral angle,and medial proximal tibial angle.Patients were classified into normal group(pelvic incidence-lumbar lordosis＜10°),compensated group(10°＜pelvic incidence-lumbar lordosis＜20°),and decompensated group(pelvic incidence-lumbar lordosis＞20°)based on the SRS-Schwab spinal deformity classification according to pelvic incidence-lumbar lordosis difference.The differences in radiographic parameters among the groups were analyzed.The differences in American Knee Society Knee Score and Oswestry Disability Index scores were compared among each group.Patients were divided into chronic low back pain group and non-chronic low back pain group,patellofemoral pain group and non-patellofemoral pain group based on clinical symptoms,and the relationship between radiographic parameter differences and clinical symptoms was analyzed.RESULTS AND CONCLUSION:(1)When pelvic incidence-lumbar lordosis was less than 20°,lateral distal femoral angle and medial proximal tibial angle tended to stabilize.When pelvic incidence-lumbar lordosis was greater than 20°,it showed a linear correlation with lateral distal femoral angle and medial proximal tibial angle,with lateral distal femoral angle increasing and medial proximal tibial angle decreasing with increasing pelvic incidence-lumbar lordosis values.(2)Compared with the normal group,the compensated group had significantly increased pelvic tilt(P＜0.01),while knee joint parameters hip-knee-angle and knee flexion angle showed no significant differences;the decompensated group showed significant increases in pelvic tilt(P＜0.01),and decreases in hip-knee-angle,and knee flexion angle(P＜0.01).Compared with the compensated group,the decompensated group showed a significant decrease in hip-knee-angle(P＜0.05),but had no significant differences in pelvic tilt and knee flexion angle.(3)Compared with the non-patellofemoral pain group,patients with patellofemoral pain had significant decreases in spinal lumbar lordosis,lateral distal femoral angle,and medial proximal tibial angle(P＜0.05)and a significant increase in pelvic incidence-lumbar lordosis(P＜0.05).(4)Patients with low back pain had significant differences in radiographic parameters compared with the non-chronic low back pain group(P＜0.05).(5)Compared with the normal group,both the compensated and decompensated groups showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).Compared with the compensated group,the decompensated group showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).(6)Pelvic incidence-lumbar lordosis values increased with age and were higher in females compared with males.(7)This study systematically reveals the spine and lower limbs play an important role in disease progression and clinical symptoms.Associated symptoms low back pain and patellofemoral pain are related to the stability of the spine-pelvis-lower extremity alignment.Furthermore,spinal sagittal imbalance is more severe in elderly and female patients.

BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P＜0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P＜0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P＜0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P＜0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P＞0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.

OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11％to 87％,with a median compliance of 54％.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4％to 35％.(2)Of all included studies,61％had a high risk of bias and 39％had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07％to 89.65％.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND:Macrophage polarization plays a key role in chronic inflammatory joint diseases such as rheumatoid arthritis.Cerium dioxide(CeO2)nanoparticles have a wide range of biomedical applications such as modulating the local inflammatory microenvironment of tissues.OBJECTIVE:To investigate the role of CeO2 nanoparticles on macrophage polarization and inflammatory factor expression,as well as inflammatory modulation in a co-culture system of macrophages and fibroblasts.METHODS:(1)CeO2 nanoparticles were dispersed and observed morphologically by transmission electron microscopy.(2)Human leukemia monocytes(THP-1)were induced to differentiate and establish the M1 macrophage pro-inflammatory cell model of rheumatoid arthritis.The cells were divided into M0 group(undifferentiated macrophages),M1 group(successful macrophage modeling),CeO2 nanoparticle treatment group(M1 group with CeO2 nanoparticle treatment),and dexamethasone control group(M1 group with dexamethasone treatment)and incubated for 48 hours.The effects of CeO2 nanoparticles on the expression of inflammatory factors(endogenous nitric oxide synthase,CD86,CD80)in M1 macrophages and M1 macrophage phenotype(CD80,CD206)were detected by RT-qPCR,western blot assay,and flow cytometry.(3)A co-culture system of macrophages and fibroblasts was established,and CeO2 nanoparticles acted on the upper macrophages.The regulation of CeO2 nanoparticles on the expression of inflammatory factors(interleukin-6,tumor necrosis factor-α,cyclooxygenase-2,and endogenous nitric oxide synthase)of fibroblasts in the co-culture system was observed at the mRNA and protein levels.RESULTS AND CONCLUSION:(1)Transmission electron microscopy showed that the diameter of CeO2 nanoparticles was(19.5±2.0)nm.(2)Compared with the M0 group,the mRNA of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the M1 group were upregulated.Compared with the M1 group,the mRNA expression of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the CeO2 nanoparticle treatment group were downregulated.Flow cytometry showed that 20 nm CeO2 nanoparticles downregulated the number of M1 macrophages.(3)Compared with the M1 group,20 nm CeO2 nanoparticles downregulated the mRNA and protein expression of inflammatory factors(tumor necrosis factor α,interleukin 6,cyclooxygenase 2,and endogenous nitric oxide synthase)in the co-culture system HFL1 cells.(4)The results showed that 20 nm CeO2 nanoparticles can alleviate inflammation in the co-culture system by inhibiting the expression of pro-inflammatory factors in M1 macrophages,providing a new idea for the treatment of inflammatory diseases such as rheumatoid arthritis.

BACKGROUND:Fracture healing is a very complex physiological process,which is influenced by many factors.In recent years,the use of biomechanical factors in fracture healing has been a major focus in the field of orthopedics,and the mechanical stress environment around the fracture end has an important role in regulating fracture healing.Among them,the study of the mechanism of compressive mechanics on the cytokines of fracture ends is a hot spot for bone-related researchers.OBJECTIVE:To summarize the current status and recent advances in the study of the mechanism of action of compressive stress on cytokines in fracture healing in recent years.METHODS:A search with the keywords of"compressive stress,fracture healing,cytokine,bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,tumor necrosis factor-α"in Chinese and English was conducted in the CNKI,WanFang,PubMed,and Web of Science.Initially 506 articles were retrieved,and 94 eligible articles that met the criteria were screened and finally summarized.RESULTS AND CONCLUSION:Current studies have found that compressive stress has different effects on different cytokines during fracture healing,which can be achieved mainly by influencing cell signaling,gene expression regulation,and modulation of cell behavior.Among them,compressive stress can be linked to cytokines such as bone morphogenetic protein,fibroblast growth factor,platelet-derived growth factor,vascular endothelial growth factor,interleukin,and tumor necrosis factor-α.This process involves cell proliferation,differentiation and migration,inflammatory response,and changes in the environmental and nutritional conditions of the fracture end,which are key factors affecting fracture healing.The whole paper summarizes the complexity of cytokine action mechanism,the mechanism of compressive stress on its regulation needs to be further carried out in-depth research,and the problems and limitations in the research are considered and future prospects.

BACKGROUND:With changing lifestyles and aging,sagittal spinal imbalance has become a common orthopedic issue significantly affecting knee and pelvic function.Understanding the impact of sagittal spinal imbalance and its compensatory mechanisms is crucial for improving the clinical management of chronic pain.OBJECTIVE:To evaluate the alignment of the spine-pelvis-lower extremities using whole-body EOS imaging,analyze the correlation between spinal sagittal imbalance and knee joint parameters,and explore their compensatory mechanisms.METHODS:A total of 71 patients with chronic low back pain or patellofemoral pain who visited Department of Orthopedics,First Affiliated Hospital of Soochow University between January 1,2021 and December 31,2023 were included.Radiographic measurements were performed using whole-body EOS to determine pelvic tilt,pelvic incidence,lumbar lordosis,sagittal vertical axis,global tilt,hip-knee-angle,knee flexion angle,lateral distal femoral angle,and medial proximal tibial angle.Patients were classified into normal group(pelvic incidence-lumbar lordosis＜10°),compensated group(10°＜pelvic incidence-lumbar lordosis＜20°),and decompensated group(pelvic incidence-lumbar lordosis＞20°)based on the SRS-Schwab spinal deformity classification according to pelvic incidence-lumbar lordosis difference.The differences in radiographic parameters among the groups were analyzed.The differences in American Knee Society Knee Score and Oswestry Disability Index scores were compared among each group.Patients were divided into chronic low back pain group and non-chronic low back pain group,patellofemoral pain group and non-patellofemoral pain group based on clinical symptoms,and the relationship between radiographic parameter differences and clinical symptoms was analyzed.RESULTS AND CONCLUSION:(1)When pelvic incidence-lumbar lordosis was less than 20°,lateral distal femoral angle and medial proximal tibial angle tended to stabilize.When pelvic incidence-lumbar lordosis was greater than 20°,it showed a linear correlation with lateral distal femoral angle and medial proximal tibial angle,with lateral distal femoral angle increasing and medial proximal tibial angle decreasing with increasing pelvic incidence-lumbar lordosis values.(2)Compared with the normal group,the compensated group had significantly increased pelvic tilt(P＜0.01),while knee joint parameters hip-knee-angle and knee flexion angle showed no significant differences;the decompensated group showed significant increases in pelvic tilt(P＜0.01),and decreases in hip-knee-angle,and knee flexion angle(P＜0.01).Compared with the compensated group,the decompensated group showed a significant decrease in hip-knee-angle(P＜0.05),but had no significant differences in pelvic tilt and knee flexion angle.(3)Compared with the non-patellofemoral pain group,patients with patellofemoral pain had significant decreases in spinal lumbar lordosis,lateral distal femoral angle,and medial proximal tibial angle(P＜0.05)and a significant increase in pelvic incidence-lumbar lordosis(P＜0.05).(4)Patients with low back pain had significant differences in radiographic parameters compared with the non-chronic low back pain group(P＜0.05).(5)Compared with the normal group,both the compensated and decompensated groups showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).Compared with the compensated group,the decompensated group showed a significant decrease in American Knee Society Knee Score scores and a significant increase in Oswestry Disability Index scores(P＜0.05).(6)Pelvic incidence-lumbar lordosis values increased with age and were higher in females compared with males.(7)This study systematically reveals the spine and lower limbs play an important role in disease progression and clinical symptoms.Associated symptoms low back pain and patellofemoral pain are related to the stability of the spine-pelvis-lower extremity alignment.Furthermore,spinal sagittal imbalance is more severe in elderly and female patients.