Proximal Femoral Geometry Research Articles

Osteoarthritis Changes Hip Geometry and Biomechanics Regardless of Bone Mineral Density-A Quantitative Computed Tomography Study.

We aimed to compare proximal femur geometry and biomechanics in postmenopausal women with osteoarthritis (OA) and/or osteoporosis (OP), using quantitative computed tomography (QCT). A retrospective analysis of QCT scans of the proximal femur of 175 postmenopausal women was performed. Morphometric and densitometric data of the proximal femur were used to evaluate its biomechanics. We found, 21 had a normal bone mineral density (BMD), 72 had osteopenia, and 81 were diagnosed with OP. Radiographic findings of hip OA were seen in 43.8%, 52.8%, and 39.5% of the normal BMD, osteopenic, and OP groups, respectively (p < 0.05). OA was significantly correlated with total hip volume (r = 0.21), intertrochanteric cortical volume (r = 0.25), and trochanteric trabecular volume (r = 0.20). In each densitometric group, significant differences in hip geometry and BMD were found between the OA and non-OA subgroups. Hip OA and OP often coexist. In postmenopausal women, these diseases coexist in 40% of cases. Both OA and OP affect hip geometry and biomechanics. OA does so regardless of densitometric status. Changes are mostly reflected in the cortical bone. OA leads to significant changes in buckling ratio (BR) in both OP and non-OP women.

Meta-Analysis of Genomewide Association Studies Reveals Genetic Variants for Hip Bone Geometry.

Hip geometry is an important predictor of fracture. We performed a meta-analysis of GWAS studies in adults to identify genetic variants that are associated with proximal femur geometry phenotypes. We analyzed four phenotypes: (i) femoral neck length; (ii) neck-shaft angle; (iii) femoral neck width, and (iv) femoral neck section modulus, estimated from DXA scans using algorithms of hip structure analysis. In the Discovery stage, 10 cohort studies were included in the fixed-effect meta-analysis, with up to 18,719 men and women ages 16 to 93 years. Association analyses were performed with ∼2.5 million polymorphisms under an additive model adjusted for age, body mass index, and height. Replication analyses of meta-GWAS significant loci (at adjusted genomewide significance [GWS], threshold p ≤ 2.6 × 10-8 ) were performed in seven additional cohorts in silico. We looked up SNPs associated in our analysis, for association with height, bone mineral density (BMD), and fracture. In meta-analysis (combined Discovery and Replication stages), GWS associations were found at 5p15 (IRX1 and ADAMTS16); 5q35 near FGFR4; at 12p11 (in CCDC91); 11q13 (near LRP5 and PPP6R3 (rs7102273)). Several hip geometry signals overlapped with BMD, including LRP5 (chr. 11). Chr. 11 SNP rs7102273 was associated with any-type fracture (p = 7.5 × 10-5 ). We used bone transcriptome data and discovered several significant eQTLs, including rs7102273 and PPP6R3 expression (p = 0.0007), and rs6556301 (intergenic, chr.5 near FGFR4) and PDLIM7 expression (p = 0.005). In conclusion, we found associations between several genes and hip geometry measures that explained 12% to 22% of heritability at different sites. The results provide a defined set of genes related to biological pathways relevant to BMD and etiology of bone fragility. © 2019 American Society for Bone and Mineral Research.

Does Proximally Coated Single-Wedge Cementless Stem Work Well in Dorr Type C Femurs? Minimum 10-year Followup.

Background:Total hip arthroplasty (THA) with a proximally coated single-wedge (PSW) cementless stem had been generally considered not to be suitable for Dorr Type C femurs. This study compares the long term outcomes of PSW stem according to the type of proximal femoral geometry.Materials and Methods:307 primary THAs in 247 patients were performed with PSW cementless stem and followed up for over 10 years in this retrospective study. According to Dorr's criteria, 89 femurs were classified as Type A, 156 as Type B, and 62 as Type C. They were followed up for an average of 13.2 years (range 10.0–17.3 years). All the hips were evaluated clinically and radiologically.Results:There was no significant difference in stem survivorship and clinical outcomes including the incidence of thigh pain and the mean postoperative Harris hip score (HHS) in all three groups. No significant differences were observed in osteolysis, pedestal formation, or cortical hypertrophy among the groups. Radiolucent lines <2 mm in thickness in Gruen zone 4 and 7 (P = 0.003 and P = 0.044, respectively), spot-weld (P < 0.001), and stress shielding (P = 0.010) of proximal femur were more pronounced in Dorr C type femora than in Type A or B. Fifty-six intraoperative fractures were identified among 307 hips with PSW stems. The incidence of intraoperative or postoperative femoral fractures was not significantly different among the groups.Conclusions:From over a 10-year followup, the PSW stem provided a recommendable option with satisfactory outcomes and excellent stem survivorship regardless of the Dorr type.

Geometrical Analysis of the Proximal Femur and the Clinical Application in Total Hip Replacement: A Study of the Igbo Population of South East Nigeria.

Adult hip reconstruction following trauma and hip pathologies depends on a sound knowledge of the proximal femoral geometry (PFG), which varies from one ethnic population to another. The aim of the study, therefore, was to evaluate parameters of the proximal femoral geometry in Igbos of South Eastern Nigeria. A 5-year review of normal X-rays of the pelvis showing both hips of patients' age 18-64 between 1 January 2012 to 31 December 2016 at Radiology Department of University of Nigeria Teaching Hospital Enugu was done. There were 554 patients, 273 (49.3%) males and 281 (50.7%) females. The values of the head width established in this study showed there was a mean difference between the right and left proximal femurs, which was statistically significant (P < 0.05). There was statistical significant difference (P < 0.05) between the means of the parameters of the proximal femoral geometry when compared between gender, the only exception being the left medial cortical thicknes, which did not show any difference (P > 0.05). A comparison of means of PFG parameters of the Igbos and that of the Turkish population showed that there was statistically significant difference on both sides. Our study demonstrated that there was no difference in the means of both sides of femoral neck width and the intertrochanteric width of the left side. The correlations between PFG parameters showed that there was strong positive correlation that was significant apart from the right acetabular angle that did not correlate with other parameters.

Clinical and Radiological Outcomes of Rectangular Tapered Cementless Stem According to Proximal Femoral Geometry in Elderly Asian Patients.

PurposeA retrospective analysis of mid- to long-term clinical and radiological outcomes of Korean patients over 60 years of age who underwent hip arthroplasty using a cementless rectangular tapered stem according to Dorr proximal femur geography.Materials and MethodsFrom January 2007 to December 2013, 107 patients (112 hips) underwent hip arthroplasty using the C2 stem. The mean age of patients was 77.4 years (range, 60–91 years) and the mean follow-up duration was 91.1 months (range, 60–116 months). All patients were evaluated clinically and radiologically with special attention to Dorr femoral bone classification, implant fixation, radiolucent line (RLL), and thigh pain.ResultsAll implants demonstrated radiographic evidence of stable fixation by bone ingrowth without any change in position. The mean Harris hip score improved from 65.5±16.0 (preoperative) to 90.5±15.9 (final follow-up) (P<0.001). Incidence of RLLs, stress shielding, and thigh pain was highest in patients with Dorr type A (RLL, P=0.021; stress shielding, P=0.030; thigh pain, P<0.001). One stem revision was performed due to deep infection. The Kaplan–Meier survival rate of the femoral stem was 97.6%.ConclusionThe overall survival rate of the C2 stems was greater than 97%; there were no significant differences in survival of the C2 stem according to the Dorr classification. The incidences of RLL of thigh pain and RLL were significantly different among Dorr classifications and (highest in patients with Dorr type A).

Comparison of Proximal Femoral Geometry and Risk Factors between Femoral Neck Fractures and Femoral Intertrochanteric Fractures in an Elderly Chinese Population.

Background:Few studies have investigated the differences in proximal femoral geometry and risk factors between patients with different types of hip fracture, especially in elderly Chinese. This study aimed to assess the differences in proximal femoral geometry parameters between patients with femoral neck fractures and patients with intertrochanteric fractures to provide guidance for individualized customized prosthesis and accurate reconstruction of proximal femurs in elderly Chinese patients.Methods:We retrospectively studied the electronic medical records of 198 elderly patients over 65 years of age who were admitted to the orthopedic department with hip fractures between January 2017 and December 2017 in The Third Hospital, Hebei Medical University. Age, fracture site, gender, and proximal femoral geometry parameters (neck shaft angle [NSA], center edge angle [CEA], femoral head diameter [FHD], femoral neck diameter [FND], femoral neck axial length [FNAL], hip axial length [HAL], and femoral shaft diameter [FSD]) were recorded. Student's t-test was used to compare the continuous variables, Chi-square test was used to analyze categorical variables, and multiple logistic stepwise regression analysis was used to evaluate the influencing factors of hip fracture type.Results:Statistically significant differences in NSA (137.63 ± 4.56° vs. 132.07 ± 4.17°, t = 1.598, P < 0.001), CEA (37.62 ± 6.77° vs. 43.11 ± 7.09°, t = 5.597, P < 0.001), FND (35.21 ± 3.25 mm vs. 34.09 ± 3.82 mm, t = 2.233, P = 0.027), and FNAL (99.30 ± 7.91 mm vs. 103.58 ± 8.39 mm, t = 3.715, P < 0.001) were found between the femoral neck fracture group and femoral intertrochanteric fracture group. FHD, FND, FSD, HAL, and FNAL were different between sexes (all P < 0.001). The greater NSA was the risk factor for femoral neck fractures (odds ratio [OR]: 0.70, P < 0.001), greater CEA and longer FNAL were risk factors for femoral intertrochanteric fractures (OR: 1.15, 1.17, all P < 0.001), and greater FND was a protective factor for femoral intertrochanteric fractures (OR: 0.74, P < 0.001).Conclusions:We demonstrate differences in geometric morphological parameters of the proximal femur in different hip fracture types, as well as an effect of sex. These differences should be considered in the selection of prostheses for fracture internal fixation and hip replacements. These data could help guide the design of individualized customized prostheses and improve the accurate reconstruction of the proximal femur for elderly Chinese hip fracture patients.

Prophylactic Fixation Can Be Cost-effective in Preventing a Contralateral Bisphosphonate-associated Femur Fracture.

Bisphosphonates reduce the risk of fractures associated with osteoporosis but increase the risk of atypical subtrochanteric femur fractures. After unilateral atypical femur fracture, there is risk of contralateral fracture, but the indications for prophylactic fixation are controversial. The purpose of this study is to use Markov modeling to determine whether contralateral prophylactic femur fracture fixation is cost-effective after a bisphosphonate-associated atypical femur fracture and, if so, what patient-related factors may influence that determination. Markov modeling was used to determine the cost-effectiveness of contralateral prophylactic fixation after an initial atypical femur fracture. Simulated patients aged 60 to 90 years were included and separated into standard and high fracture risk cohorts. Patients with standard fracture risk were defined as those presenting with one atypical femur fracture but without symptoms or findings in the contralateral femur, whereas patients with high fracture risk were typified as those with more than one risk factor, including Asian ethnicity, prodromal pain, femoral geometry changes, or radiographic findings in the contralateral femur. Outcome probabilities and utilities were derived from studies matching to patient characteristics, and fragility fracture literature was used when atypical femur fracture data were not available. Associated costs were largely derived from Medicare 2015 reimbursement rates. Sensitivity analysis was performed on all model parameters within defined ranges. Prophylactic fixation for a 70-year-old patient with standard risk for fracture costs USD 131,300/quality-adjusted life-year (QALY) and for high-risk patients costs USD 22,400/QALY. Sensitivity analysis revealed that prophylaxis for high-risk patients is cost-effective at USD 100,000/QALY when the cost of prophylaxis was less than USD 29,400, the probability of prophylaxis complications was less than 21%, or if the patient was younger than 89 years old. The parameters to which the model was most sensitive were the cost of prophylaxis, patient age, and probability of prophylaxis-related complications. Prophylactic fixation of the contralateral side after unilateral atypical femur fracture is not cost-effective for standard-risk patients but is cost-effective among high-risk patients between 60 and 89 years of age with a high risk for an atypical femur fracture defined by patients with more than one risk factor such as Asian ethnicity, prodromal pain, varus proximal femur geometry, femoral bowing, or radiographic changes such as periosteal beaking and a transverse radiolucent line. However, our findings are based on several key assumptions for modeling such as the probability of fractures and complications, the costs associated for each health state, and the risks of surgical treatment. Future research should prospectively evaluate the degree of risk contributed by known radiographic and demographic parameters to guide management of the contralateral femur after a patient presents with an atypical femur fracture. Level III, economic and decision analyses.

Ex Vivo Evaluation of Hip Fracture Risk by Proximal Femur Geometry and Bone Mineral Density in Elderly Chinese Women

BackgroundThe incidence of hip fracture is steadily increasing. We aimed to establish a creative approach to precisely estimate the risk of hip fracture by exploring the relationship between hip fracture and bone mineral density (BMD)/femur geometry.Material/MethodsSixteen samples of cadaveric female proximal femora were randomly selected. Experiments were performed experimental measurement of the femoral neck BMD and geometric parameters (including neck length, neck diameter, head diameter, and neck-shaft angle). In addition, the experimental measurements contain the failure load, which represents the mechanical strength of the femoral neck, and we calculated the correlation coefficient among BMD, geometric parameters, and failure load.ResultsSignificant correlations were discovered between femoral mechanical properties and femoral neck BMD (r=0.792, r2=0.628, P<0.001), trochanteric BMD (r=0.749, r2=0.560, P=0.001), and head diameter (r=0.706, r2=0.499, P=0.002). Multiple linear regression analyses indicated that the best predictor of hip fracture was the combination of femoral neck BMD, head diameter, and neck diameter (r2=0.844, P<0.001).ConclusionsThe results confirmed that, compared with BMD alone, the combination of BMD and geometric parameters of proximal femur is a better estimation of hip fracture. The geometry of the proximal femur played an important role in assessing the biomechanical strength of femur. This method greatly assists in predicting the risk of hip fracture in clinical trials and will assist studies on why the incidence of hip fracture varies among races.

Anthropometric Study of Proximal Femur Geometry and Its Clinical Application

The implants for fixation of proximal femur fractures and joint replacements have been designed taking into consideration of the anthropometry of the western population which vary from other ethnic groups. The present study aimed to study the morphology of the upper end of femur in relation to its various diameters and angles and compare the external and internal geometry of proximal femur as obtained from radiographs, with actual measurements on cadaveric specimens in Indian population. Seventy five pairs (150 bones) of cadaveric femora were studied morphologically and radiologically using standardized techniques to obtain various anthropometrics measurements. These values were compared with those reported in the literature for Hong Kong Chinese, Caucasian, Chinese and Western populations. Data were found to be quite different from them. It is proposed that implants designed for Western populations should be used judiciously and future implants be designed to match the morphology of the Indian bones.

Does fully-threaded Headless Compression Screw provide a length-stable fixation in undisplaced femoral neck fractures?

Femoral neck shortening is a common complication after surgical treatment for intracapsular femoral neck fractures. This study investigated whether fully-threaded Headless Compression Screw (FTHCS) can be a more length-stable implant than partially-threaded cannulated screw (PTCS) in reducing femoral neck shortening. A total of 50 patients with undisplaced femoral neck fractures (17 treated by internal fixation with three FTHCS, and 33 treated by three PTCS) from 2011 to 2014 were enrolled in this study. The radiography of the hips and medical records were reviewed for proximal femur geometry and complications. Significant shortening of the femoral neck length until union were noted in both group (FTHCS group: -2.5mm, p=0.045; PTCS group: -2.4mm, p=0.011). There was no significant difference in the length of femoral neck shortening between groups (p=0.855). Age was the only significant risk factor for >5mm of femoral neck shortening (p=0.041). The femoral neck-shaft angle tended to reduce and become more varus in both groups (FTHCS: -2.7°, SD=4.5, p=0.028; PTCS: -5.0°, SD=8.3, p=0.002), but the differences between groups were nonsignificant (p=0.577). The complication rates were similar between FTHCS and PTCS (17.6% and 21.2%, p>0.999). The FTHCSs may be a substitute for PTCSs, but it cannot prevent femoral neck shortening and varus collapse after fracture fixation. Future studies should focus on how to preserve femoral neck length and hip function after femoral neck fractures.

The influence of proximal femur geometry in identifying femoral neck fractures and intertrochanteric fractures in senile patients

The influence of proximal femur geometry in identifying femoral neck fractures and intertrochanteric fractures in senile patients

Evaluation of femoral neck-shaft angle in subHimalayan population of North West India using digital radiography and dry bone measurements

Background: Femoral neck-shaft angle is an important parameter of proximal femoral geometry. Not only it has an anthropological value but also it gives an insight into possible underlying hip pathology. The present study was conducted with an aim to find femoral neck-shaft angle values in subHimalayan population of Northwest India, and to measure the neck-shaft angle of proximal femur in both gender types using two different methods. Materials and Methods: This study was carried out to determine the average femoral neck-shaft angle in subHimalayan population of Northwest India. Neck-shaft angle in 89 femora was measured by digital radiography using PACS software while 93 dry bones were analyzed by direct measurements. The results obtained were statistically analyzed. Results: The results were analyzed using SPSS software. The mean femoral neck-shaft angle using digital radiography method was 127.45 ± 2.50 when compared to dry bone group 126.90 ± 2.50. Gender-wise males had higher neck-shaft angle values when compared to females in both groups and were statistically nonsignificant. Conclusion: Any increase or decrease in the angle of femoral neck-shaft angle is associated with various clinical conditions. Data from this study would help to establish values for subHimalayan population of Northwest India, provide insight into various associated disease conditions, and also serve as guidelines for manufacturing of orthopedic implants.

A Morphometric Study of Proximal Femoral Geometry in Maharashtrian Population and its Clinical Perspective

A Morphometric Study of Proximal Femoral Geometry in Maharashtrian Population and its Clinical Perspective

Bone Geometric Properties of the Femoral Neck in Underweight Eumenorrheic Women

The aim of this study was to describe femoral neck (FN) geometry among eumenorrheic underweight women around the age of peak bone mass. Proximal femur geometry and body composition were assessed in 12 underweight women and in 24 healthy controls using dual-energy X-ray absorptiometry. The Hip Structural Analysis program was used to determine bone geometry at the FN. The cross-sectional area (CSA) and the cross-sectional moment of inertia (CSMI) were significantly lower in underweight women than in controls (p < 0.05). There was a trend toward lower sectional modulus (Z) and strength index in underweight women (p < 0.15). Body weight, body mass index, and lean mass (LM) were positively correlated with CSA, CSMI, Z, and neck-shaft angle (r = 0.428–0.611, p < 0.05). After controlling for body weight, body mass index, and LM, the differences in CSA, CSMI, Z, and neck-shaft angle were no more statistically significant between the 2 groups. The multivariate analysis retained LM as the main predictor of CSA, CSMI, and Z in the whole population. The present study suggests that thinness is associated with low resistance to axial forces (CSA) and bending load (Z and CSMI) in adult eumenorrheic women. LM seems to be a key determinant of FN geometry in underweight women.

Importance of Restoration of Proximal Femur Geometry in the Management of Intertrochanteric Fractures using Dynamic Hip Screw in Egyptian population

Importance of Restoration of Proximal Femur Geometry in the Management of Intertrochanteric Fractures using Dynamic Hip Screw in Egyptian population

Risk factors for cut-out failure of Gamma3 nails in treating unstable intertrochanteric fractures: An analysis of 176 patients

BackgroundCut-out failure is one of the most common complications in the Gamma3 nail fixation system. The purpose of this retrospective study was to determine pre-operative or intra-operative risk factors for cut-out failure of lag screws in unstable, intertrochanteric fractures fixed with short Gamma3 nails. MethodsOne hundred and seventy-six patients over 60 years of age, with unstable intertrochanteric fractures (AO/OTA 31-A2, 31-A3) treated with short Gamma3 nails were included in this study. All patients completed a minimum of 1-year follow-up. Analysis of post-operative radiographs included assessment for cut-out failure of lag screw, appropriateness of the entry point, posterior lag screw axis, fracture gaps, posterior displacement of the proximal fragment, and tip-apex distance. ResultsOf the 176 patients in this study, 22 patients were identified with cut-out failure. Multivariate logistic regression analysis revealed that improper entry point in an antero-posterior projection (odds ratio 10.39, 95% confidence interval 1.74–78.4), posterior displacement distance of the proximal fragment in a lateral projection (odds ratio 1.35, 95% confidence interval 1.17–1.59), and female sex (odds ratio 17.14, 95% confidence interval 1.88–876.11) were correlated with cut-out failure. ConclusionThis study emphasizes the importance of an optimal position of reduction in the lateral projection in reducing the risk of cut-out failure. In addition, sex difference in bone mineral density, proximal femur geometry, and the bone strength in elderly females may explain why female sex is a risk factor.

Evaluation of the proximal femur geometry in patients with elderly osteoporotic hip fractures

Objective: To investigate the relationship between the proximal femur geometry and elderly osteoporotic hip fractures. Methods: From May 2015 to December 2015, 137 patients with elderly osteoporotic hip fractures were involved.69 cases were in the fracture group and 68 cases were in the control group.CT scan were performed on all patients and the proximal femur geometry parameters were measured, including the neck width (NW), neck length (NL), neck shaft angle (NSA), femur head diameter (FHD), head height (HH) and Offset.Statistical analysis was performed between two groups. Results: The results of single factor analysis showed that age, sex, NL, FHD, NSA and Offset had significantly differences between two groups (P<0.05). The multiple Logistic regression analysis showed that age, sex, NL and NSA were independent risk factor for the hip fractures.The ROC curve analysis showed that area under curve (AUC) were 0.818, 0.818 and 0.725, respectively. Conclusions: The patients with older age, longer NL and larger NSA might be prone to hip fracture and it was an effective and feasible method to reconstruct and measure the CT data of the proximal femur with Mimics software.

Türk Toplumunda Proksimal Femurun Geometrik Özelliklerinin Radyolojik Değerlendirilmesi

Objective : The aim of this study is to assess different features of the proximal femoral geometry of the Turkish population to build a database for surgeons and implant manufacturers. Methods : 380 (190 male, 190 female) antero-posterior direct radiography of pelvis of 40-80 years old patients were reviewed retrospectively. The femoral head diameter, horizontal offset, neck shaft angle, femoral neck width, femoral neck length and the femoral axis length were measured. Results : In both genders, there was statistically significant difference between right and left hips at femoral head diameters and horizontal offset of hip. No significant difference was detected at the measurements of neck-shaft angle, femoral neck width, femoral neck length and femoral neck axis length. Conclusion : Male population most of the time present higher average values than the female population. This study may offer a data base for surgeons and manufacturers who deal with proximal femoral bone surgery.

Bone-specific Physical Activity Questionnaire (BPAQ) Score Associations with Proximal Femur Geometry from DXA-derived 3D Analysis

Bone-specific Physical Activity Questionnaire (BPAQ) Score Associations with Proximal Femur Geometry from DXA-derived 3D Analysis

Femoral Head Fovea Capitis Variant Configurations and Age Related Changes- A Radiological Study

Background: Many studies in the literature focused on the proximal geometry of the femur using cadaveric samples, X-rays or computed tomography, demonstrated substantial differences in the proximal femoral geometry in different patient groups. Many radiological parameters have been introduced in the literature to aid in diagnosis and surgical interventions. Objectives: We aimed to assess the diameter of the femoral head fovea capitis in both genders with different age groups and to record their variant configurations. Patients and Methods: Six-hundred true pelvis anteroposterior radiographs of patients were divided into three different age groups. Results: In group 1, the general average values of fovea capitis index (FCI) in both female and male genders were 25.35% ± 4.12% and 26.82 ± 4.81%, respectively (P = 0.08). The general average FCI value of both sides was 26.08% ± 4.46%. In group 2, the general average values of FCI values in both female and male genders were 26.69% ± 5.27% and 26.88% ± 4.77%, respectively (P = 0.43). The general average FCI value of both sides was 26.78% ± 4.93%. In group 3, the general average values of FCI value in both female and male genders were 28.86% ± 4.98% and 29.16% ± 3.82%, respectively (P = 0.27). The general average value of both sides was 28.93% ± 4.40%. Conclusion: Fovea capitis size increases with aging process. It has four different configurations. Further clinical studies should be conducted to correlate the different configurations with other femoral head pathologies and anatomical variations.