OBJECTIVE: To evaluate precise assessment methods for predicting the optimal acetabular cup size in total hip arthroplasty (THA). METHODS: A clinical data of 73 patients (80 hips) who underwent primary THA between December 2022 and July 2024 and met the inclusion criteria was analyzed. There were 39 males and 34 females with an average age of 66.3 years (range, 56-78 years). Among them, 66 cases were unilateral THA and 7 were bilateral THAs. There were 29 patients (34 hips) of osteoarthritis, 35 patients (35 hips) of femoral neck fractures, and 9 patients (11 hips) of osteonecrosis of the femoral head. Based on anteroposterior pelvic X-ray films, three methods were employed to predict acetabular cup size, including preoperative template planning, radiographic femoral head diameter (FHD) measurement, and intraoperative FHD measurement. The predicted acetabular cup sizes from these methods were compared with the actual implanted sizes. RESULTS: The predicted acetabular cup sizes using the preoperative template planning, radiographic FHD measurement, and intraoperative FHD measurement were (51.25±2.81), (49.72±3.11), and (49.90±2.74) mm, respectively, compared to the actual implanted cup size of (50.57±2.74) mm, with no significant difference ( P>0.05). Regarding agreement with the actual implanted cup size, the preoperative template planning achieved exact matches in 35 hips (43.75%), one-size deviation in 41 hips (51.25%), and two-size deviations in 4 hips (5%); the radiographic FHD measurement achieved exact matches in 12 hips (15%), one-size deviation in 57 hips (71.25%), and two-size deviations in 11 hips (13.75%); and the intraoperative FHD measurement achieved exact matches in 26 hips (32.5%), one-size deviation in 52 hips (65%), and two-size deviations in 2 hips (2.5%). There were significant differences in agreement distributions between the three methods and the actual implanted cup sizes ( H=18.579, P<0.001). CONCLUSION The intraoperative FHD measurement, as a simple, cost-effective, and accurate method, effectively guides acetabular cup selection, reduces the risk of prosthesis wear, enhances postoperative joint stability.
Humans ; Arthroplasty, Replacement, Hip/instrumentation* ; Male ; Female ; Middle Aged ; Acetabulum/diagnostic imaging* ; Aged ; Hip Prosthesis ; Prosthesis Design ; Femur Head/surgery* ; Osteoarthritis, Hip/surgery* ; Radiography ; Femoral Neck Fractures/surgery* ; Femur Head Necrosis/surgery*

OBJECTIVE: To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. METHODS: Based on CT data of a healthy adult male volunteer's femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. RESULTS: The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. CONCLUSION For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.
Finite Element Analysis ; Humans ; Femoral Neck Fractures/diagnostic imaging* ; Bone Screws ; Fracture Fixation, Internal/instrumentation* ; Male ; Bone Plates ; Stress, Mechanical ; Biomechanical Phenomena ; Tomography, X-Ray Computed ; Adult ; Femur Neck/surgery*

OBJECTIVES: To analyze bone mass distribution and the factors affecting bone mass in a general Chinese Han cohort undergoing physical examinations at our center. METHODS: We retrospectively collected the data of bone mineral density (BMD) measurements from 30 599 healthy Han Chinese adults (age≥20 years) who underwent dual-energy X-ray absorptiometry scans at our hospital from July, 2013 to July, 2023. Basic parameters including height, body weight, and gender were recorded, and descriptive statistics and correlation analyses were performed using R software. RESULTS: In this cohort, the male individuals had a mean peak BMD of 1.00±0.12 g/cm² in the lumbar vertebrae, 0.94±0.14 g/cm² in the femoral neck, and 0.99±0.13 g/cm² in the total hip, significantly higher than the values in the female individuals [0.99±0.12 g/cm² in the lumbar vertebrae (P=0.022), 0.79±0.11 g/cm² in the femoral neck (P<0.001), and 0.88±0.11 g/cm² in the total hip (P<0.001)]. In the overall cohort, the BMD values of the lumbar spine and femur decreased with age after reaching their peak levels. There was a positive correlation between BMD value and body mass index (BMI) in both male and female individuals. The 2013-2014 period recorded the lowest BMD values in the lumbar, hip, and femoral neck, which tended to increase steadily in the following years (2015-2023). CONCLUSIONS Our data suggest that the BMD values vary among different populations, and future multi-center studies using more accurate BMD detection technology are warranted to capture the variation patterns of BMD with demographic characteristics of specific populations.
Humans ; Bone Density ; Absorptiometry, Photon ; Male ; Female ; Retrospective Studies ; Osteoporosis/diagnostic imaging* ; Adult ; Middle Aged ; Lumbar Vertebrae/diagnostic imaging* ; China/epidemiology* ; Femur Neck/diagnostic imaging* ; Aged ; Beijing/epidemiology* ; Young Adult

OBJECTIVE: To explore the effect of femoral neck cortical fragments and surfacial area on avascular necrosis(AVN) after internal fixation of femoral neck fractures based on CT imaging in young adult. METHODS: From January 2011 to January 2021, 218 young and middle-aged patients with femoral neck fractures were reverse triangle fixed with three cannulated lag screws, including 104 males and 114 females;aged 19 to 60 years old with a mean of (48.22±10.58) years old. The preoperative waiting time≤48 h was 155 cases, and the preoperative waiting time> 48 h was 63 cases; 68 cases were comminuted cortex of the femoral neck, 32 of them with superficial area of the comminuted cortex>25 mm². All patients were followed up for at least 2 years, the age, gender, injury side, body mass index, injury mechanism, preoperative waiting time, operation time, Garden classification, whether femoral neck cortex fracture and size by CT analysis and complications were analyzed the correlation to the definite occurrence of AVN. The AVN group and the non-AVN group were divided according to the final efficacy results.Univariate analysis yielded significant independent variables, Multiple Logistic regression analysis was further performed to identify the independent risk factors for AVN. RESULTS: By univariate analysis, the AVN and non-AVN groups were significant in injury mechanism(χ²=18.552, P=0.000), preoperative waiting time( χ²=2.065, P=0.033), Garden classification (χ²=12.598, P=0.006), comminuted cortex (χ²=16.357, P=0.000), and the superficial area of the comminuted cortex(χ²=23.371, 0.000, P=0.000). Multiple Logistic regression indicated injury mechanism high energy injury[Exp(B)=3.487, 95%CI(1.583, 10.464), P=0.002], comminuted cortex of the femoral neck[Exp(B)=2.494, 95%CI(1.315, 10.861), P=0.002];the superficial area of the comminuted cortex>25 mm²[Exp(B)=22.161, 95%CI(3.922, 1242.828), P=0.001] were independent risk factors for AVN after internal fixation of femoral neck fractures. CONCLUSION High energy injury mechanism, with comminuted cortex of the femoral neck and the superficial area of the comminuted cortex> 25 mm² were independent risk factors for AVN.The larger the superficial area of the cortex fragment may suggest more complicated injury mechanism and worse outcome.
Humans ; Male ; Female ; Adult ; Femoral Neck Fractures/diagnostic imaging* ; Tomography, X-Ray Computed ; Middle Aged ; Femur Head Necrosis/etiology* ; Young Adult ; Fracture Fixation, Internal/methods*

OBJECTIVE: To explore the related factors of femoral stem anteversion (FSA) after total hip arthroplasty (THA), so as to provide reference for clinical design of FSA before operation and reduce the risk of hip dislocation after arthroplasty. METHODS: Ninty-three patients (103 hips) who underwent THA between October 2021 and September 2022 and met the selection criteria were selected as the study subjects. Among them, there were 48 males and 45 females with an average age of 58.5 years (range, 25-88 years). Body mass index was 18.00-37.84 kg/m ², with an average of 24.92 kg/m ². There were 51 cases (57 hips) of osteonecrosis of femoral head, 35 cases (39 hips) of hip osteoarthritis, and 7 cases (7 hips) of congenital hip dysplasia. Based on CT images, the following indicators were measured: preoperative femoral neck anteversion (FNA), preoperative femoral rotation angle (FRA), preoperative acetabular anteversion (AA), and preoperative combined anteversion (CA; the sum of preoperative FNA and AA); postoperative FSA and the change in femoral anteversion angle (the difference between postoperative FSA and preoperative FNA). Based on preoperative X-ray films, the following indicators were measured: femoral cortical thickness index (CTI) and canal flare index (CFI), the proximal femoral medullary cavity was classified according to Noble classification (champagne cup type, normal type, chimney type), neck-shaft angle (NSA), and femoral offset (FO). Pearson correlation analysis, one-way ANOVA, and Point-biserial correlation analysis were used to investigate the correlation between postoperative FSA, postoperative change in femoral anteversion angle, and patient diagnosis, proximal femoral medullary cavity anatomy type, gender, age, as well as preoperative FNA, FRA, AA, CA, NSA, FO, CTI, and CFI. FSA was used as the dependent variable and the independent variables that may be related to it were included for multiple linear regression analysis. RESULTS: Based on CT image measurement, preoperative FNA was (15.96±10.01)°, FRA (3.36±10.87)°, AA (12.94±8.83)°, CA (28.9±12.6)°, postoperative FSA (16.18±11.01)°, and postoperative change in femoral anteversion angle was (0.22±9.98)°. Based on preoperative X-ray films measurements, the CTI was 0.586±0.081; the CFI was 4.135±1.125, with 23 hips classified as champagne cup type, 68 hips as normal type, and 12 hips as chimney type in the proximal femoral medullary cavity anatomy; NSA was (132.87±7.83)°; FO was (40.53±10.11) mm. There was no significant difference between preoperative FNA and postoperative FSA ( t=-0.227, P=0.821). Pearson correlation analysis showed that postoperative FSA was positively correlated with preoperative FNA, preoperative CA, postoperative change in femoral anteversion angle, and age ( P<0.05), while negatively correlated with preoperative FRA ( P<0.05). The postoperative change in femoral anteversion angle were positively correlated with preoperative FRA and postoperative FSA ( P<0.05), and negatively correlated with preoperative CA and FNA ( P<0.05). One-way ANOVA analysis showed that the above two indicators were not correlated with diagnosis and the proximal femoral medullary cavity anatomy type ( P>0.05). Multiple linear regression analysis showed a linear correlation between FSA and FNA, CA, age, and FRA ( F=10.998, P<0.001), and the best fit model was FSA=0.48×FNA-2.551. CONCLUSION The factors related to FSA after THA include patient's age, preoperative FNA, CA, FRA and postoperative femoral anteversion, of which preoperative FNA is the most closely related. When designing a surgical plan before surgery, attention should be paid to the patient's preoperative FNA, and if necessary, CT around the hip joint should be scanned to gain a detailed understanding of the proximal femoral anatomical structure.
Female ; Male ; Humans ; Middle Aged ; Arthroplasty, Replacement, Hip ; Femur/diagnostic imaging* ; Femur Neck ; Femur Head ; Hip Joint

BACKGROUND: Areal bone mineral density (aBMD) applied for osteoporosis diagnosis unavoidably results in the missingdiagnosis in patients with large bones and misdiagnosis in those with small bones. Therefore, we try to find a new adjusted index of bone mineral content (BMC) to make up shortcomings of aBMD in osteoporosis diagnosis. METHODS: In this multi-center epidemiological study, BMC and aBMD of lumbar spines (n = 5510) and proximal femurs (n = 4710) were measured with dual energy X-ray absorptiometry (DXA). We analyzed the correlation between the bone mass and body weight in all subjects including four age groups (<19 years, 20-39 years, 40-49 years, >50 years). And then the body weight was used for standardizing BMC (named wBMC) and applied for the epidemiological analysis of osteoporosis. RESULTS: The correlation of body weight and BMC is 0.839 to 0.931 of lumbar vertebra 1-4 (L1-4), and 0.71 to 0.95 of femoral neck in different age groups. When aBMD was applied for diagnosing osteoporosis, the prevalence was 7.55%, 16.39%, and 25.83% in patients with a high, intermediate, and low body weight respectively. However, the prevalence was 21.8%, 18.03%, and 11.64% by wBMC applied for diagnosing osteoporosis. Moreover, the prevalence of osteoporosis increased by 3.76% by wBMC with the body weight increased by 5 kg. The prevalence decreased by 1.94% when the body weight decreased by 5 kg. CONCLUSIONS wBMC can reduce the missed diagnosis in patients with large body weight and reduce misdiagnosis in those with small body weight. Including children, wBMC may be feasible for osteoporosis diagnosis individuals at any age.
Absorptiometry, Photon ; Adult ; Age Factors ; Body Weight ; physiology ; Bone Density ; physiology ; Female ; Femur Neck ; diagnostic imaging ; metabolism ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; metabolism ; Middle Aged ; Osteoporosis ; diagnostic imaging ; metabolism ; Prevalence ; Young Adult

Diagnostic Errors ; Female ; Femoral Neck Fractures ; diagnosis ; diagnostic imaging ; Femur Neck ; diagnostic imaging ; injuries ; Humans ; Radiography ; Young Adult

OBJECTIVETo discern the differences between femoral neck anteversion (FNA) and torsion angle through 3D CT reconstruction.

METHODSFrom March 2010 to October 2010,30 healthy adult volunteers' femur were reconstructed by 3D CT, included 15 males and 15 females with an average age of (43.66 +/- 7.57) years old ranging from 25 to 65 years. Display the FNA and the torsion angle by image post-processing, measuring torsion angle by "Center way" and direct measurement of FNA.

RESULTSFNA was the angle between the axle wire of femoral neck and the shape face of femoral,the angle were (13.326 +/- 6.085) degrees. Torsion angle was the angle between the macropinacoid of cross section of femoral neck and the shape face of femoral, the angle were(31.335 +/- 2.079) degrees. There was no significant difference in left and right femur.

CONCLUSIONFNA is different from torsion angle. FNA is the angle between the line and the surface with the sharp angle towards the lower outside. The torsion angle is the angle between the two surfaces with the sharp angle towards the lower back.

Adult ; Aged ; Female ; Femur Neck ; anatomy & histology ; diagnostic imaging ; Humans ; Imaging, Three-Dimensional ; methods ; Male ; Middle Aged ; Tomography, X-Ray Computed ; methods

INTRODUCTIONThe morphology of the proximal femur has often been investigated in the literature, but the normal population ranges and standard deviations have still not been determined for this area. This study aimed to determine the age-, gender- and body mass index (BMI)-related changes in the femoral neck, especially on the neck-shaft angle, by using dual-energy X-ray absorptiometry (DXA) measurements.

METHODSRetrospective analyses of DXA images of the proximal femur from 18,943 individuals aged 20-108 years were performed. The age, gender, weight and height of each individual were obtained at the time of bone measurement. Data on theta angle were obtained from DXA measurements. Simple linear regression analysis and Pearson's correlation coefficients were used to investigate the relationships between theta and age, gender and BMI.

RESULTSThere was a significant correlation between theta and age (p < 0.001). We also found a significant difference between the various age groups using analysis of variance (p < 0.001), but there was no meaningful correlation between theta and BMI (p = 0.377) and the BMI groups (p = 0.180). There were small but statistically significant differences in the neck-shaft angle between males and females (p < 0.05).

CONCLUSIONIn this study, DXA-based measurements were used and many parameters of proximal femur geometry were calculated with limited radiation exposure. We have demonstrated that the mean neck-shaft angle is greater in males than in females, and that theta increases with age. We also found a significant difference between different age groups, but no meaningful correlation between theta and BMI.

Absorptiometry, Photon ; Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Biomechanical Phenomena ; Body Mass Index ; Female ; Femur Neck ; anatomy & histology ; diagnostic imaging ; Humans ; Linear Models ; Male ; Middle Aged ; Reference Standards ; Reference Values ; Retrospective Studies ; Sex Distribution

OBJECTIVETo measure the displacement parameters of femoral head in space through three-dimensional reconstruction so as to reunderstand undisplaced femoral neck fractures.

METHODSThe clinical data of 80 undisplaced femoral neck fractures from January 2010 to June 2011 were selected, included Garden I 40 cases (group Garden I) and Garden II 40 cases (group Garden II), bilateral proximal femurs of everyone were scanned by CT and reconstructed by professional software. Registered the normal femur and fracture with mirror model, marked key points in the model and measured the displacement parameters of femoral head. The measurement accuracy of distance and angle were 0.01 mm and 0.01°, respectively. The parameters of femoral head displacement between group Garden I and Garden II were analyzed by independent-sample t-test.

RESULTSEighty cases on X-ray films were not found rotated displacement. But 24 cases of them (30.0%) showed rotated displacement and rotation direction of the femoral head through three-dimensional reconstruction. Ten cases showed incomplete fractures on X-ray films, but only 3 cases were incomplete fractures with three-dimensional reconstruction. In group Garden I, the femoral head displacement angle was 18° ± 11°, the average displacement distance of femoral head center and deepest point of fovea capitis were (6 ± 3) mm and (10 ± 6) mm respectively. In group Garden II, the femoral head displacement angle was 17° ± 10°, the average displacement distance of femoral head center and deepest point of fovea capitis were (7 ± 5) mm and (13 ± 8) mm respectively. There were not statistical significance of the parameters of femoral head displacement between group Garden I and Garden II (P > 0.05).

CONCLUSIONSThree-dimensional reconstruction and digital measurement is a precise, efficient method for the measurement of femoral head displacement parameters in femoral neck fractures, has important clinical significance in the diagnosis and treatment of the femoral neck fractures. There are certain defects and limitations of the classical Garden classification for undisplaced femoral neck fractures.

Adolescent ; Adult ; Aged ; Female ; Femoral Neck Fractures ; diagnostic imaging ; Femur Head ; diagnostic imaging ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Tomography, X-Ray Computed ; Young Adult