Objective:This study aims to explore clinical subtypes of Garden typeⅠfemoral neck fractures and develop corresponding reduction strategies based on the characteristics of the fractures.Methods:A retrospective analysis was conducted on the data of 256 patients with Garden type I femoral neck fractures admitted to Tianjin Hospital from January 2015 to January 2018. There were 89 males and 167 females included, with a mean age of 56.5±12.8 years (range, 17-86 years), and with 159 on the left side and 97 on the right side. According to the anteroposterior and lateral X-ray images, the fractures were further classified into two subtypes: 111 cases of Garden type I a (simple abduction without hypsokinesis of the femoral head), characterized by abduction and impaction of the femoral head on anteroposterior images, and no obvious hypsokinesis of the femoral head or only central impaction of the femoral head on lateral images; 145 cases of Garden I b type (femoral head abduction with hypsokinesis), characterized by abduction and impaction of the femoral head on anteroposterior images, and remarkable hypsokinesis on lateral images. The injury mechanism of type I a involved abduction and impaction caused by the violent extension, abduction, and external rotation of the hip joint. Mild flexion and adduction of the hip joint can be used to reduce the abduction and impaction. The injury mechanism of type I b is similar to type Ia in the first stage, but the violence continues to increase and leading to significant hypsokinesis of the femoral head. Reduction was achieved by excessive flexion, adduction, and mild internal rotation, tilting the femoral head backward to facilitate reduction. The surgical strategy were close reduction and cannulated screw fixation (three cannulated screws in an "inverted triangle" arrangement). Postoperatively, anteroposterior and lateral X-rays were taken immediately to assess the quality of reduction, including the Garden index, Lowell "S" curve, and screw placement. During follow-up, fracture healing and complications were recorded, and Harris score was used to evaluate hip joint function at the final follow-up.Results:All patients successfully received operative therapy and were followed up with a mean of 7.1±1.9 years (range, 5-10 years). Garden index showed 91.4%(234/256) achieved anatomical reduction, with an excellent reduction rate of 97.3%(249/256). The excellent rate of the Lowell "S" curve was 97.7%(250/256), and the excellent and good rate for screw insertion was 98.8%(253/256). All patients achieved primary fracture healing without infection, nonunion of fractures, failure of internal fixation, or other complications. Two patitents with Garden I b fractures (0.8%) developed femoral head necrosis due to premature weight-bearing at 9 and 12 months postoperatively, respectively, after fracture healing. However, with strict hip preservation treatment, their symptoms resolved without further progression of necrosis or need for reoperation. At the final follow-up, the mean Harris score was 93.9±4.5 points (range, 81-100 points), with an excellent and good rate of 98.8%(253/256).Conclusions:Garden I femoral neck fractures can be categorized into two subtypes based on their characteristics and injury mechanisms. Adopting corresponding reduction methods according to subtypes can achieve anatomical reduction and favorable early to mid-stage therapeutic outcomes (primary fracture healing and low incidence of femoral head necrosis).

Objective:To compare the infection status of severe fever with thrombocytopenia syndrome (SFTS) between the non-endemic area (Yixian county, Huangshan city) and the endemic area (Qianshan city, Anqing city) in Anhui province, and to explore the possibility of Yixian county being a natural focus of SFTS, thereby providing a scientific basis for the formulation of prevention and control strategies.Methods:In Xidi town, Yixian county, and Shuihou town, Qianshan city, one administrative village with the highest number of reported cases in the past three years was selected as the study village in each area, along with one control village with no reported cases. The study investigated the total antibody positivity rates of SFTS virus (SFTSV) in natural populations and host animals, as well as the density and virus-carrying rate of the vector ticks. Differences in total antibody positivity rates between the two regions were compared.Results:The total SFTSV antibody positivity rates in the natural population and host animals in the surveyed villages (control villages) of Qianshan city and Yi county were 8.7% and 8.0% (3.3%, 4.1%) and 0.0%, 9.1% (50.0%, 66.7%), respectively. There was no statistically significant difference in the infection rates of the natural population and host animals between the surveyed villages (control villages) in different endemic regions (all P>0.05). In the surveyed villages of Qianshan city and Yi county, the free-living tick densities were 1.4 ticks/hour per flag and 1.7 ticks/hour per flag, respectively; the parasitic tick densities were 0.4 ticks/host and 2.5 ticks/host, respectively; the tick infestation rates were 33.3% and 35.3%, respectively; and the tick density indices were 1.3 ticks/host and 7.2 ticks/host, respectively. Conclusions:The natural populations and host animals in some areas of Yixian county exhibit high SFTSV infection rates, and the tick density is also high, suggesting that the region may have become a natural focus of SFTS. Therefore, it is necessary to further strengthen capabilities in surveillance, diagnosis, and clinical treatment to address the potential risk of SFTS outbreaks.

Objective:This study aims to explore clinical subtypes of Garden typeⅠfemoral neck fractures and develop corresponding reduction strategies based on the characteristics of the fractures.Methods:A retrospective analysis was conducted on the data of 256 patients with Garden type I femoral neck fractures admitted to Tianjin Hospital from January 2015 to January 2018. There were 89 males and 167 females included, with a mean age of 56.5±12.8 years (range, 17-86 years), and with 159 on the left side and 97 on the right side. According to the anteroposterior and lateral X-ray images, the fractures were further classified into two subtypes: 111 cases of Garden type I a (simple abduction without hypsokinesis of the femoral head), characterized by abduction and impaction of the femoral head on anteroposterior images, and no obvious hypsokinesis of the femoral head or only central impaction of the femoral head on lateral images; 145 cases of Garden I b type (femoral head abduction with hypsokinesis), characterized by abduction and impaction of the femoral head on anteroposterior images, and remarkable hypsokinesis on lateral images. The injury mechanism of type I a involved abduction and impaction caused by the violent extension, abduction, and external rotation of the hip joint. Mild flexion and adduction of the hip joint can be used to reduce the abduction and impaction. The injury mechanism of type I b is similar to type Ia in the first stage, but the violence continues to increase and leading to significant hypsokinesis of the femoral head. Reduction was achieved by excessive flexion, adduction, and mild internal rotation, tilting the femoral head backward to facilitate reduction. The surgical strategy were close reduction and cannulated screw fixation (three cannulated screws in an "inverted triangle" arrangement). Postoperatively, anteroposterior and lateral X-rays were taken immediately to assess the quality of reduction, including the Garden index, Lowell "S" curve, and screw placement. During follow-up, fracture healing and complications were recorded, and Harris score was used to evaluate hip joint function at the final follow-up.Results:All patients successfully received operative therapy and were followed up with a mean of 7.1±1.9 years (range, 5-10 years). Garden index showed 91.4%(234/256) achieved anatomical reduction, with an excellent reduction rate of 97.3%(249/256). The excellent rate of the Lowell "S" curve was 97.7%(250/256), and the excellent and good rate for screw insertion was 98.8%(253/256). All patients achieved primary fracture healing without infection, nonunion of fractures, failure of internal fixation, or other complications. Two patitents with Garden I b fractures (0.8%) developed femoral head necrosis due to premature weight-bearing at 9 and 12 months postoperatively, respectively, after fracture healing. However, with strict hip preservation treatment, their symptoms resolved without further progression of necrosis or need for reoperation. At the final follow-up, the mean Harris score was 93.9±4.5 points (range, 81-100 points), with an excellent and good rate of 98.8%(253/256).Conclusions:Garden I femoral neck fractures can be categorized into two subtypes based on their characteristics and injury mechanisms. Adopting corresponding reduction methods according to subtypes can achieve anatomical reduction and favorable early to mid-stage therapeutic outcomes (primary fracture healing and low incidence of femoral head necrosis).

Objective:To compare the infection status of severe fever with thrombocytopenia syndrome (SFTS) between the non-endemic area (Yixian county, Huangshan city) and the endemic area (Qianshan city, Anqing city) in Anhui province, and to explore the possibility of Yixian county being a natural focus of SFTS, thereby providing a scientific basis for the formulation of prevention and control strategies.Methods:In Xidi town, Yixian county, and Shuihou town, Qianshan city, one administrative village with the highest number of reported cases in the past three years was selected as the study village in each area, along with one control village with no reported cases. The study investigated the total antibody positivity rates of SFTS virus (SFTSV) in natural populations and host animals, as well as the density and virus-carrying rate of the vector ticks. Differences in total antibody positivity rates between the two regions were compared.Results:The total SFTSV antibody positivity rates in the natural population and host animals in the surveyed villages (control villages) of Qianshan city and Yi county were 8.7% and 8.0% (3.3%, 4.1%) and 0.0%, 9.1% (50.0%, 66.7%), respectively. There was no statistically significant difference in the infection rates of the natural population and host animals between the surveyed villages (control villages) in different endemic regions (all P>0.05). In the surveyed villages of Qianshan city and Yi county, the free-living tick densities were 1.4 ticks/hour per flag and 1.7 ticks/hour per flag, respectively; the parasitic tick densities were 0.4 ticks/host and 2.5 ticks/host, respectively; the tick infestation rates were 33.3% and 35.3%, respectively; and the tick density indices were 1.3 ticks/host and 7.2 ticks/host, respectively. Conclusions:The natural populations and host animals in some areas of Yixian county exhibit high SFTSV infection rates, and the tick density is also high, suggesting that the region may have become a natural focus of SFTS. Therefore, it is necessary to further strengthen capabilities in surveillance, diagnosis, and clinical treatment to address the potential risk of SFTS outbreaks.

Intertrochanteric fractures of the femur are common hip fractures in the elderly. Their treatment goals include reducing incidence of complications, improving quality of life and increasing survival rate for the patients. Compared with traditional internal fixation, hip arthroplasty shows certain advantages in the primary treatment of intertrochanteric fractures of the femur and the revision following failure of internal fixation. It enables patients to do early weight-bearing activities to effectively improve their joint function, and reduces the risk of complications associated with long-term bed rest. However, at present, there has been no unified consensus in the academic community regarding the treatment plan of hip arthroplasty for intertrochanteric fractures of the femur. This paper mainly reviews the research progress in such aspects as indications of hip arthroplasty for primary intertrochanteric fractures of the femur and for revision after failure of internal fixation, anatomical and biomechanical characteristics of the femoral trochanter, principles for selection of types and models of joint prosthesis, key operative techniques like intraoperative fixation of bone fragments and prosthesis implantation, and methods of peri-operative comprehensive assessment.

Objective:To compare the efficacy of closed reduction and internal fixation combined with percutaneous kyphoplasty (PKP) and non-operative treatment for intertrochanteric fracture combined with osteoporotic vertebral compression fracture (OVCF) in the elderly.Methods:A retrospective cohort study was conducted to analyze the clinical data of 59 patients with intertrochanteric fracture combined with OVCF admitted to Tianjin Hospital from June 2020 to June 2023, including 16 males and 43 females, aged 66-91 years [(80.2±6.8)years]. The injured vertebral segments included T 10 in 3 patients, T 11 in 9, T 12 in 18, L 1 in 17, L 2 in 8, and L 3 in 4. According to the Genant semi-quantitative classification of vertebral fracture, 42 patients were scaled into grade 1 and 17 into grade 2. Based on the AO classification of intertrochanteric fracture, 33 patients were classified as type A1, 21 type A2, and 5 type A3. All the patients underwent closed reduction and internal fixation for intertrochanteric fractures, among whom 26 patients received PKP after the internal fixation of OVCF (PKP group) and 33 patients received non-surgical treatment after the internal fixation of OVCF (non-surgical group). The healing of the hip incision at 2 weeks after internal fixation and the healing of intertrochanteric fractures at 6 months after surgery were observed in both groups. The visual analogue scale (VAS) for low back pain was compared between the two groups before PKP, immediately after PKP, at 3 months after PKP, and at the last follow-up. The Oswestry disability index (ODI), anterior vertebral height ratio, and Cobb angle of the injured vertebrae were compared between the two groups before PKP, at 3 months after PKP, and at the last follow-up. The Harris hip function score was compared between the two groups at 3 months after internal fixation and at the last follow-up. Cement leakage was observed. The incidence of deep vein thrombosis (DVT) in the lower extremities after internal fixation were compared between the two groups. Results:All the patients were followed up for 10-46 months [(25.5±9.9)months]. The hip incisions of both groups all healed by first intention at 2 weeks after internal fixation, and the intertrochanteric fracture in both groups had bony union at 6 months after surgery. There were no significant differences between the two groups in VAS or ODI before PKP ( P>0.05). Immediately after PKP, at 3 months after PKP, and at the last follow-up, the VAS scores for low back pain were (2.6±0.6)points, (2.4±0.9)points, and (1.5±0.5)points in the PKP group, which were lower than those in the non-surgical group [(8.2±0.8)points, (3.7±1.2)points, and (3.3±0.6)points] ( P<0.01). At 3 months after PKP and at the last follow-up, the ODI values were (21.4±6.9)% and (16.2±6.3)% in the PKP group, which were lower than (38.6±11.6)% and (32.7±12.0)% in the non-surgical group ( P<0.01). The VAS for low back pain and ODI in both groups were gradually improved at each time point after PKP compared with those before PKP ( P<0.05 or 0.01). There were no significant differences in the anterior vertebral height ratio or Cobb angle of the injured vertebrae in the two groups before PKP ( P>0.05). At 3 months after PKP and at the last follow-up, the anterior vertebral height ratio was (79.8±9.6)% and (79.3±9.4)% in the PKP group, which were higher than (73.4±9.3)% and (62.0±10.4)% in the non-surgical group ( P<0.05 or 0.01); the values of the Cobb angle of the injured vertebrae were (12.6±3.6)° and (12.0±3.3)°in the PKP group, which were lower than (15.5±2.6)° and (20.4±4.9)° in the non-surgical group ( P<0.01). There were no significant differences in the anterior vertebral height ratio and Cobb angle of the injured vertebrae in the PKP group before PKP and at each time point after PKP ( P>0.05) while in the non-surgical group, the anterior vertebral height ratio at each time point after PKP was lower than that before PKP and the Cobb angle of the injured vertebrae was increased compared with that before PKP ( P<0.01). At 3 months after internal fixation and at the last follow-up, the Harris hip function scores in the PKP group were (76.4±3.4)points and (87.7±4.5)points, which were higher than (57.0±6.8)points and (76.3±8.9)points in the non-surgical group ( P<0.01). The Harris hip function scores in both groups were improved at the last follow-up, compared with those at 3 months after internal fixation. Five patients had cement leakage in the PKP group, all of which were lateral leakage.There was no occurrence of radiating pain in the lower extremities. The incidence of DVT at 1 month after internal fixation was 19.2% (5/26) in the PKP group, which was lower than 57.6% (19/33) in the non-surgical group ( P<0.01). Conclusion:Compared with non-operative treatment after the closed reduction and internal fixation, PKP after internal fixation can significantly relieve low back pain in the early stage, improve the functional restoration of the vertebral column, maintain vertebral height, prevent kyphosis, promote the recovery of the hip joint function, and reduce the occurrence of DVT in the lower extremities in the treatment of intertrochanteric fracture combined with OVCF.

Objective:To compare the efficacy of closed reduction and internal fixation combined with percutaneous kyphoplasty (PKP) and non-operative treatment for intertrochanteric fracture combined with osteoporotic vertebral compression fracture (OVCF) in the elderly.Methods:A retrospective cohort study was conducted to analyze the clinical data of 59 patients with intertrochanteric fracture combined with OVCF admitted to Tianjin Hospital from June 2020 to June 2023, including 16 males and 43 females, aged 66-91 years [(80.2±6.8)years]. The injured vertebral segments included T 10 in 3 patients, T 11 in 9, T 12 in 18, L 1 in 17, L 2 in 8, and L 3 in 4. According to the Genant semi-quantitative classification of vertebral fracture, 42 patients were scaled into grade 1 and 17 into grade 2. Based on the AO classification of intertrochanteric fracture, 33 patients were classified as type A1, 21 type A2, and 5 type A3. All the patients underwent closed reduction and internal fixation for intertrochanteric fractures, among whom 26 patients received PKP after the internal fixation of OVCF (PKP group) and 33 patients received non-surgical treatment after the internal fixation of OVCF (non-surgical group). The healing of the hip incision at 2 weeks after internal fixation and the healing of intertrochanteric fractures at 6 months after surgery were observed in both groups. The visual analogue scale (VAS) for low back pain was compared between the two groups before PKP, immediately after PKP, at 3 months after PKP, and at the last follow-up. The Oswestry disability index (ODI), anterior vertebral height ratio, and Cobb angle of the injured vertebrae were compared between the two groups before PKP, at 3 months after PKP, and at the last follow-up. The Harris hip function score was compared between the two groups at 3 months after internal fixation and at the last follow-up. Cement leakage was observed. The incidence of deep vein thrombosis (DVT) in the lower extremities after internal fixation were compared between the two groups. Results:All the patients were followed up for 10-46 months [(25.5±9.9)months]. The hip incisions of both groups all healed by first intention at 2 weeks after internal fixation, and the intertrochanteric fracture in both groups had bony union at 6 months after surgery. There were no significant differences between the two groups in VAS or ODI before PKP ( P>0.05). Immediately after PKP, at 3 months after PKP, and at the last follow-up, the VAS scores for low back pain were (2.6±0.6)points, (2.4±0.9)points, and (1.5±0.5)points in the PKP group, which were lower than those in the non-surgical group [(8.2±0.8)points, (3.7±1.2)points, and (3.3±0.6)points] ( P<0.01). At 3 months after PKP and at the last follow-up, the ODI values were (21.4±6.9)% and (16.2±6.3)% in the PKP group, which were lower than (38.6±11.6)% and (32.7±12.0)% in the non-surgical group ( P<0.01). The VAS for low back pain and ODI in both groups were gradually improved at each time point after PKP compared with those before PKP ( P<0.05 or 0.01). There were no significant differences in the anterior vertebral height ratio or Cobb angle of the injured vertebrae in the two groups before PKP ( P>0.05). At 3 months after PKP and at the last follow-up, the anterior vertebral height ratio was (79.8±9.6)% and (79.3±9.4)% in the PKP group, which were higher than (73.4±9.3)% and (62.0±10.4)% in the non-surgical group ( P<0.05 or 0.01); the values of the Cobb angle of the injured vertebrae were (12.6±3.6)° and (12.0±3.3)°in the PKP group, which were lower than (15.5±2.6)° and (20.4±4.9)° in the non-surgical group ( P<0.01). There were no significant differences in the anterior vertebral height ratio and Cobb angle of the injured vertebrae in the PKP group before PKP and at each time point after PKP ( P>0.05) while in the non-surgical group, the anterior vertebral height ratio at each time point after PKP was lower than that before PKP and the Cobb angle of the injured vertebrae was increased compared with that before PKP ( P<0.01). At 3 months after internal fixation and at the last follow-up, the Harris hip function scores in the PKP group were (76.4±3.4)points and (87.7±4.5)points, which were higher than (57.0±6.8)points and (76.3±8.9)points in the non-surgical group ( P<0.01). The Harris hip function scores in both groups were improved at the last follow-up, compared with those at 3 months after internal fixation. Five patients had cement leakage in the PKP group, all of which were lateral leakage.There was no occurrence of radiating pain in the lower extremities. The incidence of DVT at 1 month after internal fixation was 19.2% (5/26) in the PKP group, which was lower than 57.6% (19/33) in the non-surgical group ( P<0.01). Conclusion:Compared with non-operative treatment after the closed reduction and internal fixation, PKP after internal fixation can significantly relieve low back pain in the early stage, improve the functional restoration of the vertebral column, maintain vertebral height, prevent kyphosis, promote the recovery of the hip joint function, and reduce the occurrence of DVT in the lower extremities in the treatment of intertrochanteric fracture combined with OVCF.

Intertrochanteric fractures of the femur are common hip fractures in the elderly. Their treatment goals include reducing incidence of complications, improving quality of life and increasing survival rate for the patients. Compared with traditional internal fixation, hip arthroplasty shows certain advantages in the primary treatment of intertrochanteric fractures of the femur and the revision following failure of internal fixation. It enables patients to do early weight-bearing activities to effectively improve their joint function, and reduces the risk of complications associated with long-term bed rest. However, at present, there has been no unified consensus in the academic community regarding the treatment plan of hip arthroplasty for intertrochanteric fractures of the femur. This paper mainly reviews the research progress in such aspects as indications of hip arthroplasty for primary intertrochanteric fractures of the femur and for revision after failure of internal fixation, anatomical and biomechanical characteristics of the femoral trochanter, principles for selection of types and models of joint prosthesis, key operative techniques like intraoperative fixation of bone fragments and prosthesis implantation, and methods of peri-operative comprehensive assessment.

Objective:To explore the relationships among the activity level of coagulation factor XII (FXII), coagulation function indexes, polymorphisms of F12 gene loci rs17876030 and rs1801020, as well as their correlations with deep venous thrombosis (DVT) in fracture patients. Methods:A case-cohort control study was conducted. 200 fracture patients diagnosed and treated in the Department of Traumatic Orthopedics of Tianjin Hospital from September 2015 to September 2023 were included. They received routine anticoagulant prophylaxis for DVT treatment but still developed DVT during hospitalization (thrombus group). 100 fracture patients hospitalized during the same period without DVT under the same anticoagulant strategy were matched (non-thrombus group). 100 healthy people who underwent physical examinations in the outpatient department of Tianjin Hospital during the same period were also matched (normal group). Plasma samples of all subjects were collected. Laboratory tests were performed to measure activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (Fg), D-Dimer. The activity level of FXII was detected by the one-stage fixation method, the antigen of FXII was detected by enzyme-linked immunosorbent assay, and the polymorphisms of F12 gene loci rs17876030 and rs1801020 were detected by direct sequencing method. The relationships among various detection indexes and their correlations with DVT were analyzed. Results:There were no statistically significant differences in APTT, PT, and TT among the thrombus group, non-thrombus group, and normal group ( F=0.748, P=0.483; F=0.092, P=0.840; F=0.031, P=0.660). The Fg in the thrombus group was 4.5±2.4 g/L and D-Dimer was 786.2±234.9 mg/L, which were statistically different from 2.9±1.8 g/L and 261.3±165.5 mg/L in the non-thrombus group and 2.2±1.1 g/L and 198.1±96.4 mg/L in the normal group respectively ( F=3.473, P=0.046; F=34.960, P<0.001; P<0.05). The activity of FⅫ in the thrombus group was 78.3%±21.9%, which was statistically different from 97.8%±31.4% in the non-thrombus group and 94.5%±35.7% in the normal group ( F=3.581, P=0.032; P<0.05). The activity of FXII was negatively correlated with APTT ( r=-0.149, P=0.035). In the thrombus group, there were 122 cases (61.0%) with the TT genotype of rs17876030, which was statistically different from 34 cases (34.0%) in the non-thrombus group and 30 cases (30.0%) in the normal group (χ 2=12.630, P=0.002). In the thrombus group, there were 115 cases (57.5%) with the CC genotype of rs1801020, which was statistically different from 25 cases (25.0%) in the non-thrombus group and 16 cases (16.0%) in the normal group (χ 2=26.820, P<0.001). The activity levels of FXII of the TT genotype of rs17876030 in the thrombus group, non-thrombus group, and normal group were lower than those of the CC and CT genotypes, and the differences were statistically significant ( F=27.130, P<0.001; F=18.384, P<0.001; F=12.830, P=0.001; P<0.05). The activity levels of FXII of the CC genotype of rs1801020 in the three groups were lower than those of the TT and CT genotypes, and the differences were statistically significant ( F=38.631, P<0.001; F=23.562, P<0.001; F=25.829, P<0.001; P<0.05). The proportion of the TT genotype of rs17876030 was the highest in the thrombus group, and the activity level of FⅫ in patients with this genotype was lower. The TT genotype of rs17876030 was related to DVT ( r=-0.831, P=0.043). The proportion of the CC genotype of rs1801020 was the highest in the thrombus group, and the activity level of FⅫ in patients with this genotype was lower. The CC genotype of rs1801020 was related to DVT ( r=-0.784, P=0.040). Conclusion:Fg and D-Dimer are related to DVT. The activity level of FXII is negatively correlated with APTT. Prolonged APTT suggests the possibility of FⅫ deficiency, and the decreased activity level of FXII may be related to DVT.

Objective The biomechanical model for the musculoskeletal system of a human knee joint was established using a numerical simulation method.The kinematic and dynamic information captured during jumping motion simulated by the human dynamic model was used as driven data of the knee biomechanical model,followed by further analysis of the stress field distribution characteristics of the meniscus under different thermal-force coupling knee brace conditions.Methods Based on computed tomography and magnetic resonance imaging of the subject,a realistic human knee model,including bone,articular cartilage,meniscus,ligaments and peripheral soft tissues of the knee joint,was constructed.Furthermore,two gaits,namely taking-off and landing-on,of jumping motion with an increased risk of meniscus injuries were selected according to mechanical features in full-cycle jumping motion.Subsequently,the stress field characteristics of the knee meniscus under four different thermal-force coupling knee braces were analyzed,the changes of the peak stress of the meniscus and its stress concentration area were discussed,and the protective efficacy and mechanical basis of meniscal injuries and wearing knee braces were explored.Results The anterior part of the medial knee meniscus was a vulnerable area under concentrated stress.Under the knee brace thermal-force coupling condition,the stress concentration area of the medial meniscus was transferred from its narrow and weak anterior part to its wide and thick middle part,and the peak stress was also significantly reduced.The peak stress on the medial meniscus and that on the lateral meniscus were similar,indicating that the two parts of the meniscus bore the external load evenly,and the meniscus stress concentration area decreased.Conclusions Thermal-force coupling knee braces have good protective effects against knee meniscus injury.The numerical simulation provides theoretical support and technical guidance for the design of multifunctional thermal knee braces.