National Medical Journal of China
Volume 102 · Issue 09 · 2022
Natl Med J China
Marathon-related musculoskeletal injuries are very common. The imaging research of musculoskeletal injuries may provide scientific support for the health protection of marathon athletes. Unfortunately, imaging studies on musculoskeletal system injury are relatively lacking, large sample studies are almost blank, and neither imaging methods nor study populations are comprehensive enough. The imaging study of marathon-related musculoskeletal injuries remains to be further studied. As a country with a large number of marathon participants, China should strengthen relevant imaging studies to provide more health protection for marathon enthusiasts and professional athletes.
As a relatively new and rapidly developing technology, pulmonary electrical impedance tomography (EIT) realizes bedside visual lung ventilation and lung perfusion monitoring, which is increasingly accepted and applied in clinic, and has important practical value in severe respiratory management. However, there is still a lack of consensus standards for clinical application related to EIT in China. The Standards Committee of Critical Care Medicine Branch of China Health Information and Health Medical Big Data Society, the Critical Care Medicine Professional Committee of Beijing Cancer Society, and the China Critical Lung Electrical Impedance Working Group systematically reviewed the animal and clinical research related to EIT, extensively solicited the opinions of domestic multidisciplinary experts, and organized expert discussions through the improved Delphi method, forming a total of 23 recommendations on EIT method and image analysis, application of critical respiratory therapy, existing problems and technical progress, so as to promote the application of EIT in critical respiratory management.
To explore the value of ultra-short echo time (UTE)-T2* component analysis techniques in dynamic monitoring the morphological and biochemical changes in amateur marathon athletes′ achilles tendon before and after the marathon.
Twenty-nine amateur marathon runners were recruited between October 2020 and March 2021 in Zhuhai City, Guangdong Province, including 25 males and 4 females, aged from 24 to 50 (40±6) years old. All volunteers underwent bilateral achilles tendon MRI examination 1 week before the marathon, 48 hours after the race, and 1 month after the race. The shape and signal of the achilles tendon were evaluated by routine T1-weighted, proton density weighted with fat saturation sequence and different echo time (TE) UTE sequence, and the changes of achilles tendon after running was quantitatively analyzed by UTE-T2* sequence. The values of single-component analysis (T2*M), short T2* components (T2*S), and long T2* components (T2*L) and Fraction values were obtained using UTE-T2* sequence. The value of the whole achilles tendon was measured on the sagittal images of achilles tendon, and the Achilles tendon was equally divided into three subregions [muscle-tendon junction (MTJ), middle (MID), and insertion (INS)]. The region of interest was delineated by two radiologists independently. The intra-group correlation coefficient (ICC) was used to evaluate the consistency of the data measured by two radiologists. Nonparametric Friedman M test was used to compare the differences of T2*M, T2*S, T2*L and Fraction values in different time points and different subregions. Wilcoxon rank-sum test was used to compare the difference between 48 h post-race and pre-race T2*S values (ΔT2*S) of different distance, different running posture, different pace and different amount of training, in which ΔT2*S equals the T2*S value of 48 h post-race minus the T2*S value of pre-race.
On the sequence of short TE (TE≤0.6 ms), achilles tendinopathy can manifest as scattered punctate hypointensity in areas of high signal intensity. The two radiologists showed a good consistency in measuring the T2*M, T2*S, T2*L and Fraction values of the achilles tendon, and the ICC values were 0.96, 0.94, 0.83 and 0.94, respectively. The T2*s values was significantly higher in the whole Achilles tendon, MTJ and MID segment at 48 h post-exercise compared to pre-exercise, and decreased after 1 month of exercise, [0.49 (0.45, 0.59) vs 0.54 (0.49, 0.59) vs 0.53 (0.49, 0.57), 0.48 (0.44, 0.54) vs 0.53 (0.47, 0.58) vs 0.50 (0.46, 0.57), 0.48 (0.43, 0.58) vs 0.54 (0.47, 0.59) vs 0.52 (0.46, 0.57); respectively, all P<0.05]. The changes in T2*M, T2*L and Fraction values are not statistically significant (all P>0.05). In different running gestures, the ΔT2*S of achilles tendon who using the postures of front-middle feet is higher than that using the postures of back feet (0.03(-0.05, 0.07) vs -0.03(-0.17, 0.11), P=0.001).
The Bi-component analysis of UTE-T2* technology is superior to single component analysis in monitoring the dynamic changes of achilles tendon before and after exercise, and T2*S is a more sensitive sequence to evaluate the subtle changes in the chemical composition of achilles tendon.
To explore the dynamic changes of morphological characteristics of patellar tendon (PT) in amateur athletes after a half-marathon using magnetic resonance imaging.
A total of 19 male amateur marathon runners with 38 knee joints,aged from 26 to 53(41.5±7.9) years, running for 3 to 18 years, with a weekly running volume of 30-90 km and a monthly running volume of 100-300 km were enrolled and underwent 1.5T MRI scan before the half-marathon, within 3 hours after running and 3 days after running. Ten healthy male volunteers with 20 knee joints, who had never participated in marathon and exercised (including but not limited to running) per week for less than 150 minutes were recruited as the control group, aged from 26 to 54 (39.4±9.1) years. Firstly, the PT signal was qualitatively assessed on fat-suppressed proton density-weighted imaging (fs-PDWI) sequence to observe the presence of patellar tendinitis. Then, the length, proximal, middle and distal cross-sectional area (CSA), and volume of PT were measured using the post-processing tool ITK-SNAP, and the data were standardized. The independent sample t-test was used for comparing. One-way repeated measures analysis of variance was used to analyze the morphological changes of PT before and after half-marathon running.
The incidence of asymptomatic patellar tendinitis in amateur marathon runners was 26.3% (5/19). No significant MR signal changes of PT were observed in all runners after running. The proximal CSA in runners group was larger than that in controls [(4.20±0.62) mm2/kg3/4 vs (3.63±0.57) mm2/kg3/4, P<0.05], and there was no significant difference in length, medium and distal CSA and volume(all P>0.05). The length, proximal and distal CSA and volume of PT in runners group increased at 3 h after running [(47.35±3.22) mm vs (46.83±3.35) mm; (102.52±13.03) mm2 vs (98.98±13.14) mm2; (108.67±15.72) mm2 vs (100.27±14.37) mm2; (4 020.36±514.38) mm3 vs (3 826.57±499.23) mm3, all P<0.05]. There was no significant difference between before running and 3 days after running(all P>0.05). The middle CSA were not significantly different among different periods(all P>0.05).
Marathon has effect on the normal PT morphology in male amateur marathon runners, showing an increase in proximal CSA. A half-marathon will cause reversible changes in PT length, regional CSA and volume.
To investigate the effect of half marathon on thigh muscle in male amateur marathon runners by diffusion tensor imaging (DTI).
A total of 17 male amateur marathon runners aged from 27 to 57 (43.7±2.8) years were recruited from May to August 2020 in Hangzhou, Zhejiang Province. MRI examination of bilateral thigh muscles were performed before and 3 h, 3 d and 7 d after a half marathon. The fractional anisotropy (FA) values was obtained by DTI sequence. The FA values of rectus femoris, intermedius femoris, medial femoris, lateral femoris, biceps femoris longus, semitendinosus, semimembranosus, adductor magnus and adductor longus were measured on the horizontal axis of bilateral thigh muscles. Friedman M test was used to compare the changes of FA values of each muscle at each time point before and after running, and pairwise comparison of FA values of statistically significant muscles at 3 h, 3 d and 7 d after running was performed.
The overall FA value of thigh muscle group [M (Q1, Q3)] at 3 h after running was decreased compared to before running [0.24 (0.20, 0.28) to 0.25 (0.21, 0.29), P<0.001], and there was no significant difference between baseline values at 3 d and 7 d after running (all P>0.05). FA values of vastus intermedius, vastus medialis, semimembranosus and adductor magnus at 3 h after running were lower than those before running [(0.19 (0.18, 0.22) vs 0.21 (0.19, 0.24), 0.19 (0.17, 0.20) vs 0.21 (0.18, 0.23), 0.26 (0.24), 0.29) vs 0.27 (0.15, 0.30) and 0.20 (0.19, 0.22) vs 0.21 (0.20, 0.23), both P<0.05], and there was no statistical significance between 3 d and 7 d after running and those before running (all P>0.05). FA value of vastus lateralis muscle at 3 h after running decreased compared with that before running, but the difference was not statistically significant (P>0.05). FA value began to increase at 7 d after running, and the difference was statistically significant [0.24 (0.21, 0.27) vs 0.23 (0.19, 0.25), P = 0.002]. FA value of rectus femoris muscle at 3 h after running decreased compared with that before running, but the difference was not statistically significant (P>0.05), and began to increase at 3 d after running and the difference was statistically significant [0.29 (0.26, 0.34) vs 0.26 (0.23, 0.29), P=0.006]. FA value of adductor longus muscle increased at 3 h after running, but the difference was not statistically significant (P>0.05). FA value continued to increase at 3 d and 7 d after running, and the difference was statistically significant [0.23 (0.21, 0.25) vs 0.22 (0.19, 0.24), 0.23 (0.21, 0.26) vs 0.22 (0.19, 0.24), all P<0.05].
The change of FA value of thigh muscle after half marathon is reversible. At 3 h after half marathon, FA values of femoris intermedius, femoris medialis, semimembranosus muscle and adductor magnus muscle of amateur marathon runners decreased most obviously, which may be the dominant muscle group during running.
To evaluate the characteristics of MRI T2 value changes of muscles around the knee joint in amateur marathon athletes based on T2 mapping.
A total of 12 amateur marathon runners (5 males and 7 females) were recruited as the marathon group, aged from 21 to 37(27.5±5.4) years. MRI examination of bilateral knee joint was performed one week before the race, within 12 hours after the race and two months after the race, respectively. Fifteen healthy volunteers (5 males and 10 females) were recruited as the control group, aged from 24 to 27(24.9±1.0) years, and underwent MRI examination of both knee joints. The T2 mapping imaging sequence was used to measure the T2 values of the sartorius, vastus medialis, biceps femoris, semimembranosus, medial head of gastrocnemius and lateral gastrocnemius head on the post-processing platform, and analyzed the marathon group before and after the race. The differences in the T2 value of each muscle of the marathon group before and after the race within 12 hours, before and 2 months after the race, and between the control group and the marathon group before the marathon were analyzed.
All subjects had not knee joint pain during the examination. Routine MRI examination showed that there was no obvious abnormality in the shape and signal of the muscles around the knee joint. The T2 value of the semimembranosus [(34.3±2.8) ms vs (35.5±2.5) ms, P=0.008], medial head of gastrocnemius [(34.1±3.4) ms vs (37.7±3.1) ms,P<0.001] and lateral head of gastrocnemius [(35.2±2.9) ms vs (37.2±3.9) ms,P=0.011] increased after the competition compared with that of pre-competition in the marathon group, while the T2 value of the remaining muscles showed no significant difference compared with that of pre-competition(P>0.05). At the follow-up of 2 months, the T2 value of semimembranosus remains higher than before the marathon [(34.3±2.8) ms vs (35.4±2.5) ms,P=0.043], and the T2 value of the medial head of the gastrocnemius and lateral head of gastrocnemius showed no statistically difference compared with pre-competition (P>0.05). Compared with the control group, the T2 value of the lateral head of the gastrocnemius in the marathon group was decreased [(35.3±3.0) ms vs (38.5±4.1) ms,P=0.007]. There was no significant difference in the T2 value of the remaining muscles in the marathon group (P>0.05).
After the marathon, the changes in the T2 value of the muscles around the knee joint is reversible. T2 mapping imaging sequence can indirectly reflect the changes of skeletal muscle microstructure to a certain extent.
To analyze the changes of patellar tendon elasticity quantitatively of amateur marathon runners by shear wave elastography (SWE) in a half marathon.
A total of 47 amateur marathon runners (31 males and 16 females, aged from 20 to 44 years) were enrolled as the marathon group, and divided into dominant side (47 patellar tendons) and non-dominant side (47 patellar tendons). Grey-scale ultrasound and SWE were performed on the bilateral patellar tendons before and after the half marathon within 2 h and after a period of 1 week. Thirty healthy volunteers (18 males and 12 females, aged from 22 to 39 years) were enrolled as the control group, the SWE-values derived from the patellar tendon were collected and analyzed. Multivariate logistic regression was performed to analyze the relationship between the changes of SWE-values and running age as well as weekly amount of running.
None of any runners showed knee pain and sports injury during the test. The dominant side had a higher SWE-values than non-dominant side in marathon group before running [(55.1±15.7) kPa vs (43.8±15.9) kPa, P<0.05]. The marathon group had higher SWE-values than the control group both in dominant side [(55.1±15.7) kPa vs (18.5±3.7) kPa] and non-dominant side [(43.8±15.9) kPa vs (17.4±3.2) kPa], respectively, before running (P<0.05). The SWE-values increased significantly both in dominant side [(80.2±23.2) kPa vs (55.1±15.7) kPa] and non-dominant side [(76.5±26.6) kPa vs (43.8±15.9) kPa] 2 h after running in marathon group. After a week, the SWE-values were not statistically different from those before running (P>0.05). Multivariate logistic regression showed that running age and weekly amount of running were related factors leading to the increase of SWE-values after running.
The patellar tendon of amateur marathon runners has higher SWE-values. SWE can dynamically evaluate the changes of patellar tendon during exercise and is helpful for runners in scientific training and avoiding sports injury.
To assess the effects of long-distance march and training on acute knee injury and knee cartilage sub-regions of college students using quantitatively magnetic resonance imaging analysis.
Twenty-seven young male students from freshman classes in the Army Military Medical University were enrolled in September 2019, aged from 17 to 20 (19.48±0.14) years, participated in the whole 8-day, 240 km long-distance march and training. Three-dimensional quantitative MRI was performed on the right knee using high-field MRI before (baseline) and 1 day after (follow-up) march. The assessment indexes included: meniscus and cartilage injury(5-point scale), bone marrow and ligament injury, and joint effusion(3-point scale). Using semi-automatic cartilage segmentation and 3D data post-processing techniques, a total of 21 sub-regions of cartilage volume and thickness were measured in the medial and lateral femur, medial and lateral tibia. Paired-samples t-test was used to compare the changes in quantitative cartilage indices of the knee joint before and after march.
In terms of acute knee injuries, medial and lateral meniscus injuries (grade 1-3) occurred in 8 and 9 college students, respectively compared with those before march. Anterior cruciate ligaments injury occurred in 4 college students and developed from grade 0 to grade 1. Bone marrow edema occurred in 10 students and developed from grade 0 to grade 2, and in 5 students from grade 0 to grade 1. Joint effusion occurred in 5 college students and developed from grade 1 to grade 2 (all P<0.05). In terms of quantitative analysis of cartilage subregion of knee joint, the volume of central region of femoral pulley increased [(1.84±0.32) mm3 vs (1.67±0.29) mm3] and the volume of central region of medial femoral condyle decreased [(1.18±0.21) mm3 vs (1.26±0.17) mm3] compared with that before march (all P<0.05); The cartilage thickness of 11 cartilage subregion [(1.37±0.27) mm vs (1.53±0.18) mm], [(1.42±0.25) mm vs (1.54±0.17) mm], [(1.53±0.20) mm vs (1.62±0.20) mm], [(1.72±0.28) mm vs (1.83±0.28) mm], [(1.84±0.45) mm vs (2.04±0.42) mm], [(2.20±0.58) mm vs (2.46±0.50) mm], [(1.74±0.19) mm vs (1.85±0.21) mm] [(1.45±0.21) mm vs (1.58±0.16) mm], [(1.81±0.22) mm vs (1.91±0.15) mm], [(1.44±0.13) mm vs (1.53±0.15) mm] was thinner than that before march (all P<0.05). The T2 values of 7 cartilage subregion [(40.57±26.23) ms vs (67.10±47.46) ms], [(80.10±20.56) ms vs (98.42±23.58) ms], [(87.92±24.95) ms vs (108.84±29.24) ms], [(50.49±19.18) ms vs (76.97±37.16) ms], [(38.89±15.82) ms vs (69.70±40.16) ms] [(55.84±24.53) ms vs (106.35±50.01) ms] and [(72.38±36.64) ms vs (105.31±39.34) ms] were lower than those before march, while the T2 values of the two subregions of patellar cartilage [(102.13±44.47) ms vs (72.20±28.37) ms], [(97.42±44.86) ms vs (76.67±51.64) ms] were higher than those before march (P<0.05). There was no significant difference in other cartilage subareas (P>0.05).
Long distance hiking will lead to acute injury of knee joint of young college students. The thickness of cartilage subregion of knee joint showed a thinning trend as a whole, while the volume and T2 values showed different trends.
To observe the incidence of Tapia syndrome after posterior cervical spine surgery under oral tracheal intubation general anesthesia and to explore the risk factors for its occurrence.
The data of patients suffered from Tapia syndrome after posterior cervical spine surgery under oral tracheal intubation general anesthesia from June 2018 to May 2021 were retrospectively reviewed. The type of procedure, surgeon, age and gender were selected as matching factors, 4 patients without Tapia syndrome were selected as control group for each case. The radiological parameters including mandibular-vertebral distance, thyroid-vertebral distance, thyroid cartilage-vertebral distance, and C2-C7 lordotic Cobb angle were measured on lateral radiographs of the cervical spine. The above parameters were measured on neutral, over-flexion and over-extension radiographs. The difference between the Tapia group and the control group were analyzed.
There were 9 patients (0.37%) suffered from Tapia syndrome after posterior cervical spine surgery under oral tracheal intubation general anesthesia in 2 431 patients, and it happened in 0.67 days (0-2 days) after the operation. There were 3 males and 6 females with a mean age of (61±5) years. The clinical manifestations was tongue extension deviation in 8 cases (88.9%), dysarthria in 6 cases (66.7%), dysphagia in 3 cases (33.3%), tongue stiffness in 3 cases (33.3%), hoarseness in voice and pharyngeal discomfort in 1 case (11.1%). All of the symptoms were relieved in all patients at 3 months postoperative follow-up. In neutral position, the mandibular-vertebral distance was (7.19±3.96) mm in the control group and it was (3.98±3.01) mm in Tapia group (P<0.05). From neutral position to hyperflexion position, the distance between mandible and vertebral body was reduced from 3.98 mm to 1.95 mm in the Tapia group and decreased for 51.0%, and it decreased from 7.19 mm for 31.8% to 4.90 mm in the control group.
The incidence of Tapia syndrome after posterior cervical spine surgery under oral tracheal intubation general anesthesia is low. A smaller mandibular-vertebral distance on pre-operative cervical spine lateral view radiograph maybe a risk factor for Tapia syndrome after posterior cervical surgery under oral tracheal intubation general anesthesia.
To investigate the effect of left atrial enlargement on the prognosis of patients with acute ischemic stroke.
Patients with acute ischemic stroke who were admitted to Beijing Tsinghua Changgung Hospital from January 2019 to April 2020 were included in the study. The left atrial size of the patients was measured by echocardiography. Patients were divided into left atrial enlargement group and normal left atrial group. Telephone/outpatient follow-up was conducted for enrolled patients. The functional independence, good prognosis within 3 months and recurrent ischemic stroke within one year was taken as the prognostic indicators. Univariate analysis and Cox proportional hazard model were performed to evaluate the prognosis risk of left atrial enlargement for acute ischemic stroke.
Totally, 187 patients were included in the study, including 135 males and 52 females, with an average age of (66.6±13.4) years. There were 43.3% (81/187) of patients who showed left atrial enlargement, 11.2% (21/187) of patients suffered recurrence within 1 year, 87.7% (164/187) of patients achieved functional independence at 3 months, and 78.6% (147/187) of patients had a favorable prognosis at 3 months. The recurrence rate in the left atrial enlargement group was significantly higher than that in the non-enlargement group (18.5% vs 6.6%, P=0.020). In terms of functional independence and good prognosis at 3 months, the left atrial enlargement group was similar to normal left atrial group. After adjustment for age and sex, acute ischemic stroke patients with left atrial enlargement had a higher 1-year risk of recurrence (HR=2.739, 95%CI: 1.100-6.816). However, there was no significant effect on good prognosis and functional independence at 3 months. After adjustment for all potential variables, acute ischemic stroke patients with left atrial enlargement still had a higher 1-year risk of recurrence (HR=2.449, 95%CI: 0.948-6.326).
Left atrial enlargement occurs in 43.3% of patients with acute ischemic stroke. Acute ischemic stroke with left atrial enlargement has a higher risk of recurrence.
Eighty-four amateur half marathon athletes (168 side feet) in Beijing from October 2018 to May 2021 were recruited, and their age, gender and whether they have foot pain were collected, including 44 males and 40 females, aged from 21 to 60 (40.7±9.3) years. All participants underwent bipedal magnetic resonance imaging (MRI) examinations, and the degree of foot pain was graded by foot ankle injury scale (FASS scale). The relationship between MRI features and the foot pain of amateur half marathon athletes were analyzed. The study found that the proportion of foot pain symptoms among amateur half marathon athletes in Beijing was high(122/168), and the MRI manifestations were mainly heel tendinitis and plantar fasciitis, which accounted for about 59.5% of all cases.
In this study, a finite element model of the hip joint of a marathon runner was established based on the method of assigning material properties by CT gray value, and the biomechanics of the hip joint were analyzed when standing on one foot. The results of the study demonstrated that the stress was concentrated in the arcuate line, the greater sciatic notch, the pubic comb, and the acetabular region in the pelvis model; in the femoral model, the stress was concentrated in the femoral head, medial side of femoral neck and femoral shaft. The stress is transmitted from the sacroiliac joint to the acetabular dome through the arcuate line, on one side of the femoral head, from the medial side of the femoral neck to the lower side of the lesser trochanter to the medial side of the femoral shaft, and on the other side from the upper side of the femoral neck to the lateral side of the femoral shaft. The maximum principal stress was distributed in the posterior superior of the acetabular roof (7.22 MPa) and the posterior superior of the femoral head (6.68 MPa). The displacement of the model was about 1 to 3 mm at the upper edge of the ilium, and gradually decreased along the femoral axis, and the displacement at the hip joint was about 0.1 to 0.3 mm.
The lesions of tendons, ligaments and their attachment points are closely related to many inflammatory and degenerative diseases of the musculoskeletal system. MRI has great advantages in the diagnosis of osteomuscular and soft tissue lesions because of its good tissue resolution, but the transverse relaxation time of normal tendons and attachment points (T2At present, conventional MRI sequences have almost no signal, which brings great difficulties to the study of MRI characteristics of tendons and attachment points. The study used a novel 3.0 T magnetic resonance three-dimensional ultrashort echo time (3D UTE) sequence and a 11.7 T conventional MRI sequence to display normal tendon and attachment point structures. In this study, five ankle specimens [2 males and 3 females, mean age (35.4 ± 5.0) years] were scanned using a 3D UTE sequence of 3.0 T magnetic resonance to investigate the T of the Achilles tendon and attachment points2*, T1And magnetization transfer rate (MTR), and macromolecular proton component MT modeling was performed. At the same time, it was morphologically observed using 11.7 T conventional MRI sequence, and the mechanical properties of Achilles tendon and attachment points were studied by indentation test, and histological analysis was performed by pathological sections. T of the Achilles tendon and attachment point2*Values were (0.93 ± 0.48) ms and (2.77 ± 0.79) ms, respectively, T1The values were (644 ± 22) ms and (780 ± 55) ms, the MTR was 0.373 ± 0.030 and 0.244 ± 0.009, the average power was 1 000°, the frequency offset was 2 kHz, and the macromolecular proton fraction was (18.0 ± 2.2) % and (13.9 ± 1.9) %, respectively. Compared to the Achilles tendon, the attachment point usually has a longer T2* and T1Values, lower MTR and macromolecular proton fraction, and higher Young's modulus and stiffness. This study provides baseline values for the Achilles tendon and attachment sites in normal subjects, which can be used for the diagnosis of seronegative arthritis and other terminal diseases.
Finite element technology plays an important role in digitized orthopedic research. Among them, as the largest weight-bearing joint in human body, the finite element analysis related to hip joint has been the focus of research. The researchers conducted mechanical studies on the standing hip joint model and realized that in the standing posture, the contact area of the femoral head and the weight-bearing area are the direct acting surfaces of forces, and their position distribution and magnitude directly affect the stress distribution of the femoral head. However, in most studies related to FEM of the femur, the division of this region is vague, imprecise, and non-individualized. To investigate the effect of the load-bearing area of the femoral head in the standing position and the positional distribution and magnitude of the direct moving surface of the force on the results of finite element analysis, five adult volunteers were recruited for X-ray and CT examination with a patented device in the same simulated bipedal standing position. The two-dimensional weight-bearing area on the X-ray image is calculated, and the three-dimensional model of proximal femur is reconstructed according to the CT data, and it is registered to realize the conversion from the two-dimensional weight-bearing area to the three-dimensional quantized area. One of the three-dimensional models of the proximal femur was randomly selected for finite element analysis, three different loading surfaces were defined, and their finite element results were compared. The results showed that five volunteers constructed a total of 10 weight-bearing surfaces, mainly distributed in crescent shape in the dome and anterolateral side of the femoral head, ranging from 1 218.63~1 871.06 mm2。 The stress magnitude and distribution of the proximal femur finite element model are significantly different under three different loading conditions, and the loading conditions of quantifying the load-bearing area are more in line with the physical phenomena of the hip. In this study, a set of simple methods was used to quantify the position distribution and size of the weight-bearing area of the femoral head while standing, and the individualized reconstruction of the proximal femoral finite element model was realized. This method can define more reasonable load surface settings without increasing the difficulty of actual modeling.
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