BACKGROUND:Pelvic tilt,which is often seen in hip diseases,is also a common functional problem after total hip arthroplasty. OBJECTIVE:To investigate the mechanism of occurrence and recovery of pelvic tilt after unilateral total hip arthroplasty in patients with femoral head necrosis. METHODS:The clinical data of 100 patients with femoral head necrosis who underwent unilateral total hip arthroplasty in the Department of Femoral Head Necrosis,Bone Injury Center of First Affiliated Hospital of Guangzhou University of Chinese Medicine were collected retrospectively from June 2021 to February 2023.The patients were divided into three groups,namely,groups A(<2°,n=48),B(2°-3°,n=34),and C(>3°,n=18),according to the severity of pelvic tilt on postoperative 3 day.Statistical data were collected and compared between the pre-and postoperative periods of patients of these three groups in terms of the angle of the coronal plane of the pelvis tilt,the length of the gluteus medius muscles of the bilateral sides,the heights of the rotational centers of the femoral heads,the difference in the lengths of the gluteus medius muscles of the bilateral sides and the heights of the rotational centers of the femoral heads,and the ratio of changes in the angle of the pelvic tilt.Pearson correlation coefficient was used to examine the correlation between pelvic tilt angle and other indexes. RESULTS AND CONCLUSION:(1)Pelvic tilt aggravation occurred in the short term after surgery.(2)The ratio of change in pelvic tilt angle from postoperative 3 days to postoperative 1 month time period differed between the groups,with group C>group B>group A.There was a difference between group C and the other groups in the time period from postoperative 1 to postoperative 3 months,with the ratio of change being the smallest in group C.There was no difference in the ratio of change between the groups in the time period from postoperative 3 days to postoperative 3 months.(3)The difference in bilateral gluteus medius muscles decreased gradually after surgery,and there was no difference in the comparison of bilateral gluteus medius muscles in the time period from postoperative 3 months.(4)The difference between bilateral centers of rotation increased after surgery,and the difference between bilateral heights at 3 months after surgery was smaller than that before surgery.(5)The pelvic tilt angle at 3 days after surgery,the duration of the disease and the pelvic tilt angle at 3 months after surgery were significantly correlated(all P=0.000),and the difference between bilateral gluteus medius muscles before surgery and the pelvic tilt angle at 3 days after surgery was significantly correlated(P=0.006)(6)The functional pelvic tilt occurred in the patients with femoral head necrosis after total hip arthroplasty.Correction of the pelvic tilt after surgery was based on the adaptive restoration of the functional pelvic tilt angle after surgery.Functional pelvic tilt arises as a compensatory adaptation of the organism based on the short-term postoperative reconstruction of bony structures and the survival of cumulative soft tissue damage.

Objective:To investigate the correlation between triglyceride-glucose (TyG) index on admission and unfavorable outcomes of patients with moderate-to-severe traumatic brain injury (msTBI) at 6 months postinjury.Methods:A retrospective cohort study was conducted to analyze the clinical data of 277 patients with msTBI admitted to Affiliated Jiangyin Hospital of Nantong University from January 2019 to December 2022, including 208 males and 69 females, aged 18-88 years [(57.0±15.1)years]. Glasgow Coma Scale (GCS) scores on admission were 3-8 points in 168 patients and 9-12 points in 109. According to the Glasgow Outcome Scale-Extended (GOSE) assessment at 6 months after injury, there were 121 patients with unfavorable outcomes (GOSE≤4 points) and 156 with favorable outcomes (GOSE≥5 points). The following indicators of the patients were recorded, including gender, age, history of diabetes, cause of injury, admission GCS, GCS motor score (GCSM), pupillary light reflex, worst Marshall CT classification within the first 24 hours after admission, admission TyG index, Mean Amplitude of Glycemic Excursions (MAGE) within 24 hours after admission, GCSM decline≥2 points within 72 hours after admission, craniotomy or not after admission, and prognosis, etc. TyG index served as the exposure variable focused in this study, which was calculated with fasting triglycerides and fasting blood glucose within 24 hours after admission. The 6-month prognosis of the patients was designated as the outcome variable of the study. After the patients were divided into different groups according to the three quantiles of the TyG index and unfavorable or favorable outcomes, the univariate analysis was conducted on watch variables, and variables with statistically significant differences were included in directed acyclic graphs (DAGs) for further identification of confounding variables. Factors which were found with no statistical significance in the univariate analysis but might affect insulin resistance after injury according to the authors′ previous researches were also included in the DAGs analysis. Three Logistic regression models were designed (Model 1 without correction, Model 2 with core variables of International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) corrected, and Model 3 with confounding variables screened by DAGs corrected) to analyze whether the TyG index was an independent risk factor for the prognosis of msTBI patients. The optimal Logistic regression model was selected and then restricted cubic spline (RCS) was employed to investigate the relationship between the TyG index and the unfavorable outcomes.Results:The univariate analysis suggested that there were significant differences in gender, history of diabetes, MAGE, GCSM decline, and prognosis among the three quantiles of the TyG index ( P<0.05 or 0.01). Significant differences in age, history of diabetes, GCSM, pupillary light reflex, Marshall CT classification, TyG index, MAGE and GCSM decline were observed between unfavorable and favorable outcome groups ( P<0.05 or 0.01). The results of Logistic regression analysis that identified the confounding variables that influenced the correlation between the TyG index and unfavorable prognosis with DAGs suggested that a high TyG index level was significantly correlated with unfavorable outcomes in msTBI patients. Moreover, Model 3 that was corrected with confounding variables screened by DAGs had an optimal goodness-of-fit and adaptability. Model 3-based further RCS analysis indicated that the risk of unfavorable outcomes following msTBI may increase approximately linearly with the increase in TyG index within a certain range (TyG index<9.79). Conclusions:A high TyG index level on admission is the identified as an independent risk factor for unfavorable outcomes of patients with msTBI at 6 months postinjury. As the TyG index level increases, the risk of unfavorable outcomes also rises and may show a linear increasing trend within a certain range (TyG index<9.79).

Objective:To determine the relationship between tibial plateau stresses and malunion by exploring the changes in mechanical conduction in the knee joint after malunion of Hoffa fracture of the tibial plateau.Methods:This study selected 28 knee joint specimens treated with formalin for preservation, half of which were from male and half from female individuals with an age of (51.4±9.5) years. Their structures were intact, and flexion-extension activities normal. X-ray examinations excluded osteoporosis, tuberculosis, and diseases that could have potentially affected bone quality. The knee specimens were divided into a control group (intact tibia) ( n=4) and 6 groups of tibial plateau Hoffa fracture malunion model: 3 vertical malunion groups (groups V1, V2, and V3, with a vertical displacement of 1, 2, and 3 mm, respectively, n=4) and 3 separation malunion groups (groups S3, S5, and S7, with a separation displacement of 3, 5, and 7 mm, respectively), with half males and half females in each group. After a 600N vertical load was applied at passive knee flexions at 0°, 30°, 60°, 90°, and 120°, the stress levels in the medial and lateral compartments of the knee joint were measured using pressure-sensitive films. Results:Under a vertical load of 600 N, when the knee joint was in a neutral position (flexion of 0°), the differences in the medial and lateral tibial plateau stress values were not statistically significant between the malunion models groups and the control group ( P>0.05). When the knee flexion increased to 30°, the medial tibial plateau stress in the V3 and S7 groups was significantly greater than that in the control group ( P<0.05). At a knee flexion of 60°, the medial plateau stress was significantly greater in the V3, S5 and S7 groups than that in the control group, and the differences were significantly greater than the comparisons at a knee flexion of 30° (all P<0.05). When the knee flexion was 90°, the medial plateau stress in the V2, V3, S5 and S7 groups was significantly greater than that in the control group ( P<0.05), but the lateral tibial plateau stress in the V3 group was significantly smaller than that in the control group ( P<0.05). When the knee flexion was further increased to 120°, the differences in the medial and lateral plateau stress values were statistically significant between all the malunion groups and the control group ( P<0.05), and the differences significantly greater than the comparisons at a knee flexion of 90° (all P<0.05). Under a vertical load of 600 N, the differences in the stresses on the medial and lateral plateaus were not statistically significant between the control group and all the malunion groups at a knee flexion of 0° ( P>0.05). When the knee flexion increased to 30°, the difference between the medial and lateral stresses was not statistically significant in the control group ( P>0.05), but was statistically significant in the V3 and S7 groups ( P<0.05). When the knee flexion reached 60°, 90°, and 120°, the differences between the medial and lateral tibial plateau stresses in all the groups were statistically significant ( P<0.05). Conclusions:The peak knee stresses after malunion of Hoffa fracture of the tibial plateau correlate with the severity of malunion and knee flexion angles. The mechanical properties are not significantly different between a mild malunion knee and a normal knee, but a significant displacement (vertical displacement >2 mm and separation displacement ≥5 mm) may increase the peak knee stresses to increase the risk of knee osteoarthritis. When the severity of malunion is certain, an increase in knee flexion angle increases the difference in the peak stress between the medial and lateral tibial plateaus, thus increasing the risk of knee osteoarthritis.

Objectives:To investigate the association between normal-weight central obesity with new-onset cardiovascular disease and all-cause mortality risk. Methods:A prospective cohort study was conducted,selecting a total of 93885 participants from the Kailuan Study who had their first physical examination in 2006-2007.According to waist circumference (central obesity:male waist circumference ≥90 cm,female waist circumference ≥85 cm;no central obesity:male waist circumference<90 cm,female waist circumference<85 cm) and body mass index (BMI,normal weight:18.5 kg/m2≤BMI<24.0 kg/m2;overweight/obesity:BMI ≥24.0 kg/m2),the participants were divided into 4 groups:normal weight no central obesity group (G1 group),normal weight central obesity group (G2 group),overweight/obesity no central obesity group (G3 group) and overweight/central obesity group (G4 group);Using the Kaplan-Meier method,the cumulative incidence of new-onset cardiovascular diseases (including hemorrhagic stroke,ischemic stroke and myocardial infarction) and all-cause mortality in different groups was calculated,and the Log-rank test was used for intergroup comparisons.Furthermore,the associations between the different groups and the risk of new-onset cardiovascular diseases and all-cause mortality were analyzed using the multivariate Cox proportional hazard regression model. Results:After a median follow-up of 14.97 (14.55,15.17) years,the cumulative incidence of new-onset cardiovascular diseases in G1 group,G2 group,G3 group and G4 group was 7.62％,10.84％,8.67％,12.91％ respectively (log-rank P<0.05) and the cumulative incidence of all-cause mortality was 12.83％,19.72％,10.65％,16.33％ respectively (log-rank P<0.01).After adjusting for confounding factors,Cox regression analysis showed that the HR (95％CI) of new-onset cardiovascular diseases in G2 group,G3 group and G4 group were 1.14 (1.04-1.25),1.07 (1.01-1.14),1.27 (1.21-1.34),respectively compared with G1 group (all P<0.05).The HR (95％CI) of all-cause mortality were 1.06 (1.00-1.14),0.90 (0.85-0.95),0.97 (0.93-1.01) compared with G1 group,and P values were 0.07,<0.01,0.15,respectively.The results of sensitivity analysis were consistent with the above major studies after excluding overweight/obesity and cancer participants during follow-up. Conclusions:Normal-weight central obesity increases the risk of new-onset cardiovascular diseases and all-cause mortality.

Objective:To investigate the correlations between the bone mineral densities and biomechanical properties on different layers of the cancellous bone in the proximal tibia.Methods:Quantitative CT was conducted of the 15 specimens of adult male tibia. Based on the artificial destruction levels at the trabecular bone on the tibial plateau, the 15 specimens were randomly divided into 3 groups ( n=5): group A (cancellous bone on the 1.5 cm layer below the articular cartilage), group B (cancellous bone on the 3.0 cm layer under the articular cartilage) and group C (cancellous bone on the 0 to 3 cm range of the subchondral bone). After standing positions were simulated in the 3 sets of specimens, they were connected to a biomechanical testing machine. Twenty-four sites were selected and subjected to a vertical load of 600 N. Strain values and overall displacement values of the specimens were recorded before and after trabecular bone destruction. The correlations were analyzed between bone density and displacement values in groups A and B. The strain values before and after trabecular bone destruction, as well as the overall deformation values of the specimens were compared between the 3 groups. Results:The bone densities of specimens in groups A and B were negatively correlated with the displacement values before and after destruction ( P<0.05). Comparisons of strain values at the 24 sites before and after trabecular bone destruction within 3 groups: There were statistically significant differences in the strain values at 8 sites between before and after trabecular bone destruction in group A ( P<0.05). Of the 8 sites, 6 showed increased strains which were mainly concentrated around the insertion point of the anterior cruciate ligament and the medial tibial plateau. There were statistically significant differences in the strain values between before and after trabecular bone destruction at 3 sites in group B ( P<0.05). The strains at all the 3 sites increased, mainly concentrated behind the surface below the level of destruction. There were statistically significant differences in the strain values at 10 sites in group C between before and after trabecular bone destruction ( P<0.05). Of the 10 sites, 5 showed a decrease in the strain which was concentrated above the destruction plane, and 5 showed an increase in the strain which was concentrated below the destruction plane. The overall deformation values of the specimens in groups A, B, and C were (0.033±0.003) mm, (0.015±0.003) mm, and (0.066±0.007) mm, respectively, showing statistically significant differences between the 3 groups ( P<0.05) as well as between any 2 groups ( P<0.05). Conclusions:Bone mineral density in the cancellous bone of the proximal tibia has some value in assessment of the bone strength. Destruction of the proximal tibial cancellous bone can significantly change the strain distribution on the proximal tibia. The proximal cancellous bone of the tibia plays a key role in stress support and load conduction.

Objective:To develop a deep transfer learning method for the differential diagnosis of osteonecrosis of the femoral head (ONFH) with other common hip diseases using anteroposterior hip radiographs.Methods:Patients suffering from ONFH, DDH, and other hip diseases including primary hip osteoarthritis, non-infectious inflammatory hip disease, and femoral neck fracture treated in the First Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2018 to December 2020 were enrolled in the study. A clinical data set containing anteroposterior hip radiographs of the eligible patients was created. Data augmentation by rotating and flipping images was performed to enlarge the data set, then the data set was divided equally into a training data set and a testing data set. The ResNet-152, a deep neural network model, was used in the study, but the original Batch Normalization was replaced with Transferable Normalization to construct a novel deep transfer learning model. The model was trained to distinguish ONFH and DDH from other common hip diseases using anteroposterior hip radiographs on the training data set and its classification performance was evaluated on the testing data set.Results:The clinical data set was comprised of anteroposterior hip radiographs of 1024 hips, including 542 with ONFH, 296 with DDH, and 186 with other common hip diseases (56 hips with primary osteoarthritis, 85 hips with non-infectious inflammatory osteoarthritis, 45 hips with femoral neck fracture). After data augmentation, the size of the data set multiplied to 6144. The model was trained 100 050 times in each task. Accuracy was used as the representative parameter to evaluate the performance of the model. In the binary classification task to identify ONFH, the best accuracy was 95.80%. As for the multi-classification task for classification of ONFH and DDH from other hip diseases, the best accuracy was 91.40%. The plateau of the model was observed in each task after 50 000 times of training. The mean accuracy in plateaus was 95.35% (95% CI: 95.33%, 95.37%), and 90.85% (95% CI: 90.82%, 90.87%), respectively. Conclusion:The present study proves the encouraging performance of a deep transfer learning method for the first-visit classification of ONFH, DDH, and other hip diseases using the convenient and economical anteroposterior hip radiographs.

The neutrophil-to-lymphocyte ratio (NLR), the ratio of inflammatory cell counts in the blood, reflects the changes of neutrophils and lymphocytes in the inflammatory system in the peripheral blood. More and more scholars have found that NLR increases in patients with bone and joint injury, which can be used to predict postoperative mortality, infection, deep vein thrombosis, pain and other complications. This article is intended to review the application of NLR in bone and joint injury and related complications, providing reference for clinical application of NLR.

Objective:To compare the biomechanical properties of triangular supporting fixation and Gamma nail fixation for intertrochanteric fractures of the femur.Methods:The femoral CT imaging data provided by a healthy adult male volunteer aged 40 years, height 172 cm, and weight 75 kg were used to reconstruct the femur model using Mimics 21.0 software and Geomagics 2013 software. Evans type I intertrochanteric fracture models were established using UG12.0 software, and Gamma nail and triangular supporting intramedullary nail models were reconstructed to simulate intertrochanteric fracture internal fixation, respectively. In Abaqus software, two internal fixation models of Gamma nail and triangular supporting intramedullary nail in standing state are simulated, and the stress peaks of the main nail, fixation screw and bone substance were collected, also the stress peak of supporting screw of the triangular supporting intramedullary nail is obtained. Additionally, the maximum displacement of the fracture model fixed by Gamma nail and triangular supporting intramedullary nail is measured.Results:Under the load of 1 200 N, the peak stress of the two fracture internal fixation models was located in the main nail, in which the peak stress of the triangular supporting intramedullary nail was 233.73 MPa, which was 11.9% lower than that of the Gamma nail (265.21 MPa); the peak stress of the fixation screw was located in the contact area between the pressure screw and the main nail, which was 23.2% lower in triangular supporting intramedullary nail than that of the Gamma nail (138.86 MPa vs. 180.75 MPa); the peak stress of the bone model was located in the medial cortex of the femur, which was 61.67 MPa and 32.38 MPa, respectively, 47.5% lower in the triangular supporting intramedullary nail than that of the Gamma nail; the peak stress of the supporting screw in the triangular supporting intramedullary nail was 92.04 MPa. The maximum displacement of the fracture model fixed with triangular supporting intramedullary nail was 17.34 mm, which was 10.5% less than the maximum displacement of the fracture model fixed with Gamma nail (19.37 mm). Conclusion:Compared with Gamma nail, triangular supporting intramedullary nail fixation can significantly improve the stability of intertrochanteric fractures and stress distribution as well as reduce stress peak and stress concentration area, which is helpful to improve the efficacy of intertrochanteric fractures.

Objective:To summarize the experience of surgical treatment of pelvic retroperitoneal neoplasms.Methods:A total of 107 patients with pelvic retroperitoneal neoplasms underwent surgical treatment from Apr 2015 to Sep 2020. According to the neoplasm location, size, and the relationship with the surrounding tissues, individualize the surgical plan, analyze the patient's basic condition, bleeding volume, tumor size, whether it is the first operation,or combined organ resection, etc.to find out the relevant factors affecting the surgical complications.Results:The surgical route included anterior approach in 67 cases , sacrococcygeal approach in 21 cases, combined abdominal-sacral approach in 13 cases, and laparoscopy in 5 cases. Twenty-nine patients underwent combined organ resection, postoperative complications occurred in 27 patients including colorectal anastomotic leakage in 6 cases, urinary fistula in 6 cases, delayed pelvic floor healing in 6 cases, rectovaginal fistula in 3 cases, and postoperative bleeding in 2 cases. The statistical analysis show whether or not first operation is related to the occurrence of complications ( χ2=4.79, P<0.05) Conclusion:Pelvic retroperitoneal neoplasms need to be fully prepared before surgery and individualized design. Intraoperative combined bleeding control measures and combined organ resection can effectively increase the resection rate and ensure the safety of surgery.

Objective:To compare the biomechanical properties between triangular supporting fixation and conventional dynamic hip screw (DHS) fixation in the treatment of femoral intertrochanteric fractures.Methods:Eight pairs of 16 femoral specimens with an average death age of 51.9 years were used in this study. After thawing, they were randomly divided into an experimental group ( n=8) and a control group ( n=8) according to the left or right laterality. They were made models of femoral intertrochanteric fracture of AO 31-A1 type with strain gauges pasted. The experimental group was subjected to fixation with double triangu-lar supporting and the control group conventional DHS fixation to achieve anatomical reduction. The specimens were then mounted onto a biomechanical testing machine and subjected to loading till 400 N at a rate of 10 N/s. The values of overall deformation of the specimens and strain at 16 selected sites were recorded and compared between the 2 model groups. Results:Under the load of 400 N, the overall deformation was (0.31±0.13) mm for the experimental group and (0.49±0.21) mm for the control group, showing a significant difference ( t=-2.456, P=0.023). The strain values in front of femoral neck, upon front fracture line, at inferior-lateral, inferior-median and inferior-interior sites of front fracture line, at the root of anterior fixation screw, below medial femoral neck fracture line, behind femoral neck, at superior-lateral, superior-median and superior-interior sites of posterior fracture line, below posterior fracture line, at superior and inferior roots of posterior fixation screw, at points parallel to the fixation screw in front of and behind femoral shaft were, respectively, -244.90, 13.16, -71.77, -124.38, -366.89,121.62, -10.94, -166.00, -54.93, -367.38, -608.93, -69.09, 326.50, 133.14, 52.97, and -185.82 in the experimental group and -24.62, -40.39, -36.99, -120.97, -486.38, 99.20, 35.36, -205.67, -74.30, -566.01, -1, 085.40, -77.41, 334.34, 114.08, 38.50, and -235.74 in the control group. Internal fixation failure occurred in one specimen in the control group after 1,759 cycles of loading but in none in the experimental group. Conclusion:For femoral intertrochanteric fractures, double triangular supporting fixation may result in less overall deformation and is more consistent with the normal biomechanical conduction of the femur than conventional DHS fixation.