Female Femur Research Articles

Does commonly used femoral components of total knee arthroplasty fit well in the Indian population?

Background20 % of patients remain dissatisfied post-Total Knee Arthroplasty. We intend to find the correlation between sizes of commonly used femoral components and morphometric data of distal femur in Indian population. Materials and methodsProspective observational study in 178 knees (178 individuals) was conducted on Magnetic Resonance Imaging scans (Axial section). The anteroposterior dimension at intercondylar notch (AP), anteroposterior dimension on the medial (MAP) and lateral (LAP) femoral condyle, total mediolateral width (ML), width of medial condyle (MLM), lateral condyle (MLL) and intercondylar distance (ICD) and aspect ratio (AR) were measured on males and females separately. These measurements were then analyzed keeping in view the available sizes of three latest knee arthroplasty systems (Attune CR, Next Gen II, Genesis II) to look for correlation and best fitting system. ResultsOn observation between values of male and female femur, a significant difference was seen in all the parameters (p-value<0.0001) except ICD (p-value 0.6591). On scatter plots, Attune was found to be nearer to the line of best fit compared to other two implant companies in both males and females. Outliers were highest in cases of NextGen II (45 % in males and 46 % in females) whereas it was lowest in the case of Attune (12.5 %in males and 41 % in females). ConclusionAttune CR was seen to fit best in the Indian population followed by Genesis II and NextGen II. These femoral implants are designed as per the sizes of the Western population and the Caucasians are oversized for the Indian subcontinent, especially female patients, thus needing improvement in design/sizes. Level of evidenceIII.

Mechanical effect of changed femoral neck ante-version angles on the stability of an intertrochanteric fracture fixed with PFNA: A finite element analysis

ObjectiveChange of femoral neck ante-version angle postoperatively due to inadequate reduction could result in unsatisfying treatment outcome of intertrochanteric fracture. However, the influence of increased or decreased femoral neck ante-version on the biomechanical stability of the bone-implant complex has rarely been studied. MethodsA finite element model of a complete normal human femur with normal femoral neck ante-version as 13° was established accurately by scanning a 64 year old female femur. The models of 31-A1.1 intertrochanteric fractures with different femoral neck ante-version angles of 3°, 5.5°, 8°, 10.5°, 13°, 15.5°, 18°, 20.5°, 23° were created. They were assembled with a proximal femoral nail anti-rotation (PFNA) device. The biomechanical differences with varying femoral neck ante-version angles were compared using finite element analysis method. ResultsAs the femoral neck ante-version angle gradually increased from 13° to 23°with a gradient of 2.5°, the peak von Mises stress was gradually increased from 137.82 MPa to 276.02 MPa. Similarly, the peak von Mises stress was gradually increased from 137.82 MPa to 360.12 MPa with the femoral neck ante-version angle decreased from 13° to 3°. When decreased ante-version angle of 7.5° and increased ante-version angle of 10° will exceed the yield strength of femoral (240.32 MPa), the risk of femoral fracture will increase significantly. The maximum displacement of the femur was significantly reduced for increased ante-version models than for decreased ante-version models, whether the changes of ante-version angles were 2.5°, 5°, 7.5° or 10°. The maximum stress of PFNA was found in the intersection of main nail and helical blade, and became greater gradually as the ante-version angle increased or decreased with a gradient of 2.5°. The maximum stress of PFNA was presented in the model 5.5° with the maximum stress of 724.42 MPa (near to the yield strength of titanium alloy of 700–1000 MPa), producing the breakage risk of PFNA. The maximum displacement of the PFNA was significantly reduced for increased ante-version models than for decreased ante-version models, whether the changes of ante-version angles were 2.5°, 5°, 7.5° or 10°. ConclusionBased on the results of present study, it was demonstrated that the anatomical reduction of femoral neck ante-version was vital to secure the optimal stability. Abnormal femoral ante-version could increase the potential risk of failure for intertrochanteric fracture after PFNA. The stability of increased femoral ante-version (less than 10°) was superior to the stability of decreased ante-version (less than 5°) for the cases of difficulty to acquire anatomical reduction. The clinical implication of the finding was that increased femoral neck ante-version had an advantage of mechanical stability towards the decreased femoral neck ante-version for the cases of comminuted intertrochanteric fracture and failure of anatomical reduction.

Osteoblastgenic and Osteogenic Effects of KY-273 with CDK8/19 Inhibitory Activity in Bone Marrow Mesenchymal Stem Cells and Female Rats.

Osteoporosis is caused by imbalance between osteogenesis and bone resorption, thus, osteogenic drugs and resorption inhibitors are used for treatment of osteoporosis. The present study examined the effects of (R)-4-(1-hydroxyethyl)-3-{4-[2-(tetrahydropyran-4-yloxy)ethoxy]phenoxy}benzamide (KY-273), a diphenyl ether derivative, on CDK8/19 activity, osteoblast differentiation and femoral bone using micro-computed tomography in female rats. KY-273 potently inhibited CDK8/19 activity, promoted osteoblast differentiation with an increase in alkaline phosphatase (ALP) activity, and gene expression of type I collagen, ALP and BMP-4 in mesenchymal stem cells (ST2 cells). In female rat femur, ovariectomy decreased metaphyseal trabecular bone volume (Tb.BV), mineral content (Tb.BMC), yet had no effect on metaphyseal and diaphyseal cortical bone volume (Ct.BV), mineral content (Ct.BMC) and strength parameters (BSPs). In ovaries-intact and ovariectomized rats, oral administration of KY-273 (10 mg/kg/d) for 6 weeks increased metaphyseal and diaphyseal Ct.BV, Ct.BMC, and BSPs without affecting medullary volume (Med.V), but did not affect Tb.BV and Tb.BMC. In ovariectomized rats, alendronate (3 mg/kg/d) caused marked restoration of Tb.BV, Tb.BMC and structural parameters after ovariectomy, and increased metaphyseal but not diaphyseal Ct.BV, Ct.BMC, and BSPs. In ovaries-intact and ovariectomized rats, by the last week, KY-273 increased bone formation rate/bone surface at the periosteal but not the endocortical side. These findings indicate that KY-273 causes osteogenesis in cortical bone at the periosteal side without reducing Med.V. In conclusion, KY-273 has cortical-bone-selective osteogenic effects by osteoblastogenesis via CDK8/19 inhibition in ovaries-intact and ovariectomized rats, and is an orally active drug candidate for bone diseases such as osteoporosis in monotherapy and combination therapy.

A phylogeny of Carrerapyrgota Aczél (Diptera, Pyrgotidae)

Carrerapyrgota Aczél, 1956 is a Neotropical Diptera genus within Pyrgotidae. Currently, the genus comprise four species: C. miliaria Aczél, 1956 (type species), C. personata (Lutz &amp; Lima, 1918), C. aczeli Mello, Lamas &amp; Rafael, 2010, and C. bernardii Mello, Lamas &amp; Rafael, 2010. This study investigates the phylogenetic relationships among Carrerapyrgota species, aiming to establish their monophyly as a genus. To achieve this, we conducted phylogenetic analyses based on 22 external morphological characters of adults, emploing the principle of parsimony. Analyses using both equal and implied character weighting support the monophyly of the genus, based on the following apomorphies: absence of the postscutellum, R₂₊₃ with spurious apical vein, lower calypter with a longitudinal row of bristles, and the presence of a posterior longitudinal groove on the female fore femur. The species C. aczeli, C. bernardii, and C. miliaria form a monophyletic group, supported by the synapomorphic condition of a spot on the forehead. Within this group, C. bernardii and C. miliaria are sister species, sharing the synapomorphic condition of a less sclerotized M vein, after dm-cu compared to the anterior region, as well as the homoplastic condition of a spot on the median occipital sclerite. This phylogenetic analysis reaffirms the synonymy proposed by Bernardi (1990), which treats Anapyrgota Steyskal, 1967, as a junior synonym of Carrerapyrgota. The evolutionary relationship among the species of the genus is represented as (C. personata (C. aczeli (C. bernardii, C. miliaria))). Furthermore, this study includes an updated distributional map for the genus, featuring the first record of Pyrgotinae in the Andean region.

Systems genetics and bioinformatics analyses using ESR1-correlated genes identify potential candidates underlying female bone development

Estrogen receptor α (ESR1) is involved in E2 signaling and plays a major role in postmenopausal bone loss. However, the molecular network underlying ESR1 has not been explored. We used systems genetics and bioinformatics to identify important genes associated with Esr1 in postmenopausal bone loss. We identified ~2300 Esr1-coexpressed genes in female BXD bone femur, functional analysis of which revealed ‘osteoblast signaling’ as the most enriched pathway. PPI network led to the identification of 25 ‘female bone candidates’. The gene-regulatory analysis revealed RUNX2 as a key TF. ANKRD1 and RUNX2 were significantly different between osteoporosis patients and healthy controls. Sp7, Col1a1 and Pth1r correlated with multiple femur bone phenotypes in BXD mice. miR-3121-3p targeted Csf1, Ankrd1, Sp7 and Runx2. β-estradiol treatment markedly increased the expression of these candidates in mouse osteoblast. Our study revealed that Esr1-correlated genes Ankrd1, Runx2, Csf1 and Sp7 may play important roles in female bone development.

Morphological and genetic variability of Cotesia tibialis species complex (Hymenoptera: Braconidae: Microgastrinae)

Cotesia tibialis is a gregarious koinobiont parasitoid of lepidopteran larvae. Due to the wide range of variability of some morphological traits, several new species were already described from the C. tibialis complex. Nixon left open the possibility that there are more by recognizing two seasonal forms. To investigate whether there are hidden taxa within C. tibialis, of 14 samples we analysed morphological characters such as the colouration of female hind femora and male antennae, and the colour and structure of the mass cocoons. The results of the analyses of the colouration of female hind femora and cocoons refute the previously defined forms within C. tibialis. Using the method of geometric morphometrics to investigate the shape of the females’ fore wings, we also did not find support of the existence of two seasonal forms of C. tibialis. Finally, applying the mitochondrial barcoding region COI the genetic differences between selected C. tibialis morphotypes were analysed. Based on both morphological and molecular analyses, one morphotype obtained from smoke-white cocoons was completely discriminated against all others, indicating that it is a potentially new species, or one of those already described which Nixon returned to C. tibialis as a synonym. The status of the other 13 morphotypes is still unclear and requires further analyses.

RF36 | PSUN77 Female Dexras1 WT &amp; KO Mice Fed a High Fat Diet Do Not Have Different Body Compositions nor Bone Densities

Abstract Glucocorticoids are a frequently prescribed class of medications, widely used for their anti-inflammatory and immunosuppressive effects. However, long term usage of glucocorticoids is associated with a variety of adverse effects, including adrenal suppression, increased adiposity, and decreased bone density. DEXRAS1, also known as RASD1, is a member of the Ras family of GTPases that is upregulated by glucocorticoids. In in vitro experiments, DEXRAS1 has been shown to promote differentiation of adipocytes and decrease differentiation of osteoblasts. Studies conducted in male Dexras1 knockout (KO) and wild type (WT) mice treated with dexamethasone found decreased body weight and visceral fat, and increased bone density in KO mice when compared to WT mice; together, these experiments suggest that the removal of the Dexras1 gene can prevent glucocorticoid-induced osteoporosis and fat-accumulation.A major limitation of the aforementioned studies is that they were performed using only male mice, despite well-known sex related differences in body composition and bone density. On average, females have a higher percentage of body fat and lower bone density. While obesity is prevalent across all sexes, osteoporosis is 4 times more common in females. Therefore, in order to better understand sex as a biological variable on the effects of the Dexras1 gene, we compared female Dexras1 KO and WT mice fed a high-fat diet (HFD) containing 45 kcal% fat over the course of 14 weeks. Body composition was assessed by quantitative magnetic resonance. Bone morphometry was analyzed with micro-CT, and bone density was analyzed with micro-CT and dual-energy x-ray absorptiometry (DXA) scans of female murine femurs. Interestingly, there were no differences in the overall body weight, fat mass, nor lean mass over this period between WT and KO female mice. Similarly, the female Dexras1 KO and WT mice mice showed no differences in their bone density, cortical thickness, and average trabecular separation. Since there was no difference in the fat mass, it is not surprising that there was also no difference in bone density, as they are often inversely related. These data in conjunction with previous experiments on male mice suggest that sex strongly impacts the phenotype observed as a result of knocking out the Dexras1 gene. The mechanisms underlying differential regulation between the sexes is unclear, and could include differences in sex hormones, the presence of estrus cycle in females, differences in stress response, or even differences in microbiome. Consequently, more studies are necessary to fully understand the function and regulation of Dexras1. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 12:36 p.m. - 12:41 p.m.

Estimasi Tinggi Badan berdasarkan Panjang Tulang Femur pada Mahasiswa Suku Bugis Universitas Muslim Indonesia

Identification is an important examination in determining a person's identity in forensic anthropology. One of the parameters that can be used to determine a person's biological profile is height. Estimation of height based on the length of the femur is the most widely used method, because it has a significant correlation coefficient value to height. The purpose of this study was to determine the estimation of height based on the length of the femur in the Bugis. This research is a descriptive analytic study with a cross sectional approach to 40 students of the Faculty of Medicine UMI who are Bugis ethnicity with purposive sampling technique. Data analysis was performed by using Pearson correlation test and simple linear regression test. The results obtained that the mean height of the male is 171.42 ± 5.63, the female is 153.91 ± 6.18, the mean length of the right femur for the male is 44.54 ± 3.20 and the left is 44.32 ± 3.19, while the length of the left femur for women is 37.15 ± 3.12, and the right is 37.18 ± 3.05. With Pearson correlation analysis, obtained r value between 0.828 and 0.928 which indicates a significant correlation. The regression formula obtained between the length of the left femur and height in men is Height = 100,627 + 1,597 x (Left Femur for Men), while for the right femur, Height = 98,772 + 1,631 x (Right Femur for Men). The regression formula for the length of the female left femur and height is Height = 92.891+1.643 x (Female Left Femur) while the length of the female right femur is Height = 88.528+1.758 (Female Right Femur). This formula can be used on the Bugis. Height can be estimated by measuring the length of the femur using a linear regression equation.

S-allylmercapto-N-acetylcysteine protects bone cells from oxidation and improves femur microarchitecture in healthy and diabetic mice.

Oxidative stress is involved in the deterioration of bone quality and mechanical strength in both diabetic and aging adults. Therefore, we studied the ability of the antioxidant compound, S-allylmercapto-N-acetylcysteine (ASSNAC) to protect bone marrow stromal cells (BMSCs) from advanced glycation end-products (AGEs) cytotoxicity and improve bone microarchitecture of adult healthy and obese/diabetic (db/db) female mice. ASSNAC effect on AGEs-treated cultured rat BMSCs was evaluated by Neutral Red and XTT cell survival and reactive oxygen species (ROS) level assays. Its effect on healthy (C57BL/6) and obese/diabetic (C57BLKS/J Leprdb+/+; db/db) female mice femur parameters, such as (1) number of adherent BMSCs, (2) percentage of CD73+/CD45- cells in bone marrow (BM), (3) glutathione level in BM cells, and (4) femur microarchitecture parameters by microcomputed tomography, was studied. ASSNAC treatment protected BMSCs by significantly decreasing AGEs-induced ROS production and increasing their cellular resistance to the cytotoxic effect of AGEs. ASSNAC treatment of healthy female mice (50 mg/kg/day; i.p.; age 12-20 weeks) significantly increased the number of BMSCs (+60%), CD73+/CD45- cells (+134%), and glutathione level (+110%) in the femur bone marrow. Furthermore, it increased the femur length (+3%), cortical diameter (+3%), and cortical areal moment of inertia (Ct.MOI; +10%) a surrogate for biomechanical strength. In db/db mice that demonstrated a compromised trabecular bone and growth plate microarchitecture, ASSNAC treatment restored the trabecular number (Tb.N, +29%), bone volume fraction (Tb.BV/TV, +130%), and growth plate primary spongiosa volumetric bone mineral density (PS-vBMD, +7%) and thickness (PS-Th, +18%). In conclusion, this study demonstrates that ASSNAC protects bone marrow cells from oxidative stress and may improve bone microarchitecture in adult healthy and diabetic female mice.

Influence of the PFNA screw position on the risk of cut-out in an unstable intertrochanteric fracture: a computational analysis

The position of the lag screw in the femoral head is a key factor to cut-out, the most reported complication in the internal fixation of intertrochanteric fractures. Considering that the best position for the lag screw remains controversial, the aim of this study was to evaluate the influence of different lag screw positions on the risk of cut-out of an unstable intertrochanteric fracture fixed with a Proximal Femoral Nail Anti-Rotation (PFNA) implant. The relationship between cut-out and the tip-apex distance (TAD) or the calcar referenced tip-apex distance (CalTAD) was also investigated.Finite element models of one male and one female femur treated with a PFNA implant were developed considering the lag screw positioned centrally and inferiorly on the anteroposterior view, and for each of these, the screw tip at 4 discrete positions along its longitudinal axis. All 8 positions simulated for each femur considered the lag screw in a centre position on the lateral view. The risk of cut-out was evaluated for two loading conditions assuming it is related with high compressive strains.The bone region at the fracture line, near the tip of the missing medial fragment, was always the most concerning regarding high compressive strains. The inferior positioning of the lag screw reduced the volume of bone susceptible to yielding compared to the centre positioning. The deep placement of the screw tip improved the outcome for both centre and inferior positions.The results suggested the inferior and deep placement of the screw to be the best position to reduce the risk of cut-out. The volume of bone susceptible to yielding was found not to be correlated to TAD or CalTAD, suggesting that further investigation is necessary to identify other, more reliable, predictors of cut-out.

Gut microbiome depletion and repetitive mild traumatic brain injury differentially modify bone development in male and female adolescent rats

Dysregulation of the gut microbiome has been shown to disrupt both bone formation and bone resorption in several preclinical and clinical models. However, the role of microbiome in adolescent bone development remains poorly understood. This effect of disrupted bone development may be more pronounced during adolescence, when bone development is vulnerable to environmental stimuli and external insults (e.g., antibiotic treatment and traumatic brain injury), as this is a critical window of development. Therefore, in this study, we sought to investigate the effect of repetitive mild traumatic brain injury (RmTBI) and gut microbiome depletion by antibiotic treatment on femur length and bone density in male and female adolescent Sprague Dawley rats. Rats were randomly assigned to receive standard or antibiotic autoclaved drinking water and to receive sham or RmTBIs injuries. Using micro-computed tomography (μCT), we found sexually dimorphic changes in adolescent bone development in response to microbiome depletion and RmTBI. Specifically, gut microbiome depletion stunted femur growth in males and altered cross sectional bone area (CSA), bone area fraction, and the bone volume of low and mid density bone in the distal metaphyseal region of the femur. Conversely, RmTBI and antibiotic treatment individually disrupted bone growth, bone area fraction, and bone volume of high-density bone within the distal metaphyseal region of the femur in females, but not when combined. Therefore, findings from this study indicate that gut microbiome and RmTBI may alter bone development in a sex-dependent manner during adolescence.

English

BACKGROUND Femur is the longest and strongest bone of the human body. It also takes relatively longer time to disintegrate after death, hence morphometric analysis of skeletal remains of femoral head can be considered for the determination of age and sex for forensic expert, anthropologist as well as anatomist. The present study was an attempt to establish sex of a skeleton by the help of femoral head diameters which will be of great help in medico-legal and anthropometric studies. METHODS The present study was carried out in the S C B Medical College Cuttack from May 2019 to June 2020 by taking 84 dried and intact femora. The vertical head diameter of femoral head and head circumference were measured by the vernier’ s caliper and measuring tape in centimeters. RESULTS The result showed significant difference in the head circumference and the vertical diameter of head of femur of the male and female femora. It was found that the mean femoral head circumference of the male was 13.296 cm with a “S.D” of 0.8694 cm and female was 12.023 cm with a “S.D” of 0.73 cm and vertical diameter of male was 4.1520 cm with a “SD” of 0.3635 cm and that of female femora was 3.7231 cm with a “S.D” of 0.2264 cm respectively. CONCLUSIONS There was a significant difference in the head circumference and the vertical diameter of head of femur of the male and female femora which determines sexual dimorphism. KEY WORDS Anthropometry, Medico-Legal, and Standard Deviation (SD)

A comparison between Asians and Caucasians in the dimensions of the femoral isthmus based on a 3D-CT analysis of 1189 adult femurs

IntroductionFor successful intramedullary implant placement at the femur, such as nailing in unstable proximal femur fractures, the use of an implant that at least reaches or exceeds the femoral isthmus and yields sufficient thickness is recommended. A number of complications after intramedullary femoral nailing have been reported, particularly in Asians. To understand the anatomical features of the proximal femur and their ethnic differences, we aimed to accurately calculate the femoral isthmus dimensions and proximal distance of Asians and Caucasians.MethodsIn total, 1189 Asian and Caucasian segmented 3D CT data sets of femurs were analyzed. The individual femoral isthmus diameter was precisely computed to investigate whether gender, femur length, age, ethnicity or body mass index have an influence on isthmus diameters.ResultsThe mean isthmus diameter of all femurs was 10.71 ± 2.2 mm. A significantly larger diameter was found in Asians when compared to Caucasians (p < 0.001). Age was a strong predictor of the isthmus diameter variability in females (p < 0.001, adjusted r2 = 0.299). With every year of life, the isthmus showed a widening of 0.08 mm in women. A Matched Pair Analysis of 150 female femurs showed a significant difference between isthmus diameter in Asian and Caucasian femurs (p = 0.05). In 50% of the cases the isthmus was found in a range of 2.4 cm between 16.9 and 19.3 cm distal to the tip of the greater trochanter. The female Asian femur differs from Caucasians as it is wider at the isthmus.ConclusionsIn absolute values, the proximal isthmus distance did not show much variation but is more proximal in Asians. The detailed data presented may be helpful in the development of future implant designs. The length and thickness of future standard implants may be considered based on the findings.

Variation of the Three-Dimensional Femoral J-Curve in the Native Knee

The native femoral J-Curve is known to be a relevant determinant of knee biomechanics. Similarly, after total knee arthroplasty, the J-Curve of the femoral implant component is reported to have a high impact on knee kinematics. The shape of the native femoral J-Curve has previously been analyzed in 2D, however, the knee motion is not planar. In this study, we investigated the J-Curve in 3D by principal component analysis (PCA) and the resulting mean shapes and modes by geometric parameter analysis. Surface models of 90 cadaveric femora were available, 56 male, 32 female and two without respective information. After the translation to a bone-specific coordinate system, relevant contours of the femoral condyles were derived using virtual rotating cutting planes. For each derived contour, an extremum search was performed. The extremum points were used to define the 3D J-Curve of each condyle. Afterwards a PCA and a geometric parameter analysis were performed on the medial and lateral 3D J-Curves. The normalized measures of the mean shapes and the aspects of shape variation of the male and female 3D J-Curves were found to be similar. When considering both female and male J-Curves in a combined analysis, the first mode of the PCA primarily consisted of changes in size, highlighting size differences between female and male femora. Apart from changes in size, variation regarding aspect ratio, arc lengths, orientation, circularity, as well as regarding relative location of the 3D J-Curves was found. The results of this study are in agreement with those of previous 2D analyses on shape and shape variation of the femoral J-Curves. The presented 3D analysis highlights new aspects of shape variability, e.g., regarding curvature and relative location in the transversal plane. Finally, the analysis presented may support the design of (patient-specific) femoral implant components for TKA.

English

BACKGROUND The peculiar waddling gait of a female attracts most of the anatomists to measure and compare the neck-shaft angle (NSA) of the femora. The femoral neck shaft angle is greater in women due to greater pelvic breadth and shorter femur. Neck-shaft angle was measured by the angle that the neck makes with the shaft of the femur and it is measured on the ventral surface of femur taking the long axis of femoral neck with the long axis of the proximal end of the femur. It gives information about the race it belongs to and normally measures 120° to 140°. The intention of this study was to establish the femoral neck shaft angle variations in adult male and female for medico-legal and anthropometric studies. METHODS This cross-sectional study was conducted on 84 adult human femora of unknown sex in the anatomy department, Sriram Chandra Bhanja (SCB) Medical College, Cuttack, Odisha, from May 2018 to April 2019. We included all the femora which were free of damage or deformity and fully ossified indicating adult bone. Femora with any pathological changes i.e., cortical bone deterioration, extreme osteophyte activity, osteoarthritis and fracture etc. were excluded from the study. The NSA was measured by protractor and goniometer. RESULTS In the present study the NSA range for the right femur of male was 108° - 135° and for the right femur of females 117° - 135°. The left male femur was 118° - 135° and the left female femur was 120° - 135°. The mean neck shaft angle of male femora was 125.9° and the female femora was 125.7°. These measurements show that the values were more in males than the females. The value of the present study was statistically significant between male and female i.e., P &lt; 0.0001. CONCLUSIONS These measurements are important in the medico-legal cases, reconstructive orthopaedic surgeries, hip replacement surgeries and also while constructing suitable prosthesis. This will also be helpful in the detection of sex by anatomists and forensic experts. KEY WORDS Neck Shaft Angle, Medico-Legal, Anthropometry and Goniometer

Supplemental medial small fragment fixation adds stability to distal femur fixation: A biomechanical study

Introduction: Bridge plating of distal femur fractures with lateral locking plates is susceptible to varus collapse, fixation failure, and nonunion. While medial and lateral dual plating has been described in clinical series, the biomechanical effects of dual plating of distal femur fractures have yet to be clearly defined. The purpose of this study was to compare dual plating to lateral locked bridge plating alone in a cadaveric distal femur gap osteotomy model.Materials and Methods: Gap osteotomies were created in eight matched pairs of cadaveric female distal femurs (average age: 64 yrs (standard deviation ± 4.4 yrs); age range: 57–68 yrs;) to simulate comminuted extraarticular distal femur fractures (AO/OTA 33A). Eight femurs underwent fixation with lateral locked plates alone and were matched with eight femurs treated with dual plating: lateral locked plates with supplemental medial small fragment non-locking fixation. Mechanical testing was performed on an ElectroPuls E10000 materials testing system using a 10 kN/100 Nm biaxial load cell. Specimens were subject to 25,000 cycles of cyclic loading from 100-1000 N at 2 Hz.Results: Two (2/8) specimens in the lateral only group failed catastrophically prior to completion of testing. All dual plated specimens survived the testing regimen. Dual plated specimens demonstrated significantly less coronal plane displacement (median 0.2 degrees, interquartile range [IQR], 0.0–0.5 degrees) compared to 2.0 degrees (IQR 1.9-3.3, p = 0.02) in the lateral plate only group. Dual plated specimens demonstrated greater bending stiffness compared to the lateral plated group (median 29.0 kN/degree, IQR 1.5–68.2 kN/degree vs median 0.50 kN/degree, IQR 0.23–2.28 kN/degree, p = 0.03).Conclusion: Contemporary fixation methods with a distal femur fractures are susceptible to mechanical failure and nonunion with lateral plates alone. Dual plate fixation in a cadaveric model of distal femur fractures underwent significantly less displacement under simulated weight bearing conditions and demonstrated greater stiffness than lateral plating alone. Given the significant clinical failure rates of lateral bridge plating in distal femur fractures, supplemental fixation should be considered, and dual plating of distal femurs augments mechanical stability in a clinically relevant magnitude.

Sex-specific versus standard posterior cruciate-substituting total knee prosthesis

Background The introduction of sex-specific (SS) knee prosthesis designs was an approach to offer more sizing options and is based on the anatomic sex differences. These SS components were though to provide better fitting to female femora and consequently improve the clinical outcome. Materials and methods In the period between February 2011 and March 2013, a prospective superiority randomized controlled clinical trial was conducted to compare the clinical outcome of SS versus the standard posterior stabilized (PS) knee prosthesis in women. The primary outcome measure was the postoperative range of knee flexion, and the secondary outcome measure was the knee function as reflected on the performance of daily activities. The OXFORD Knee Score, Knee Society Score, and Knee Society Score for function were recorded preoperatively and then at 3, 12 months, and annually thereafter. Female patients with degenerative or inflammatory arthritis who were 50 years or older and their knee deformities were totally articular were included. A total of 64 patients with 80 knees were enrolled in this trial, and 40 knees were allocated to each group. Knees in the SS group had total knee arthroplasty using SS knee prosthesis, with SS femoral component (the experimental group), whereas knees in the PS group had standard PS knee design with standard femoral component (the control group). Equal randomization (1 : 1 ratio) was undertaken according to a computer-generated randomization table. Results The mean preoperative knee flexion range of motion (ROM) was 110 and 108° in the SS and PS groups, respectively. At the latest follow-up, the mean postoperative knee flexion ROM was 115 and 113° the SS and PS groups, respectively. The mean improvement in the knee flexion ROM in both groups was 5° (range: 0–25), with no statistically significant difference between the two groups. All knees except one had full extension. No statistically significant difference was observed between the two groups when the OXFORD Knee Score, the Knee Society Score, and the Knee Society Score for function were compared. Conclusion No clinical advantage was observed in the ROM or function between knees that received SS knee prosthesis when compared with those who received PS knee implants. The SS total knee arthroplasty though designed to provide better fitting to the female distal femur does not provide any clinical advantage over the standard PS knee prosthesis. A logic question is whether a separate implant is required for women or modifications to the knee prostheses geometry and more sizes are required to accommodate all patients? Level of evidence Level II.

Removal of cement-augmented screws in distal femoral fractures and the effect of retained screws and cement on total knee arthroplasty: a biomechanical investigation

BackgroundGiven the increasing number of osteoporotic fractures of the distal femur, screw augmentation with bone cement is an option to enhance implant anchorage. However, in implant removal or revision surgeries, the cement cannot be removed from the distal femur without an extended surgical procedure. Therefore, the aims of this study were to investigate (1) whether cement augmentation has any influence on screw removal and removal torque, and (2) whether the implantation of a femoral component of a knee arthroplasty and its initial interface stability are affected by the remaining screws/cement.Material and methodsEight pairs of fresh-frozen human female cadaveric distal femurs (mean age, 86 years) with a simulated AO/OTA 33 A3 fracture were randomized in paired fashion to two groups and fixed with a distal femoral locking plate using cannulated perforated locking screws. Screw augmentation with bone cement was performed in one of the groups, while the other group received no screw augmentation. Following biomechanical testing until failure (results published separately), the screws were removed and the removal torque was measured. A femoral component of a knee arthroplasty was then implanted, and pull-out tests were performed after cement curing. Interference from broken screws/cement was assessed, and the maximum pull-out force was measured.ResultsThe mean screw removal torque was not significantly different between the augmented (4.9 Nm, SD 0.9) and nonaugmented (4.6 Nm, SD 1.3, p = 0.65) screw groups. However, there were significantly more broken screws in in the augmented screw group (17 versus 9; p < 0.001). There was no significant difference in the pull-out force of the femoral component between the augmented (2625 N, SD 603) and nonaugmented (2653 N, SD 542, p = 0.94) screw groups.ConclusionThe screw removal torque during implant removal surgery does not significantly differ between augmented and nonaugmented screws. In the augmented screw group, significantly more screws failed. To overcome this, the use of solid screws in holes B, C, and G can be considered. Additionally, it is possible to implant a femoral component for knee arthroplasty that retains the initial anchorage and does not suffer from interference with broken screws and/or residual cement.Level of Evidence 5

Local bone quality measure and construct failure prediction: a biomechanical study on distal femur fractures

IntroductionThe aim of this investigation was to better understand the differences in local bone quality at the distal femur and their correlation with biomechanical construct failure, with the intention to identify regions of importance to optimize implant anchorage.Materials and methodsSeven fresh–frozen female femurs underwent high-resolution peripheral quantitative computed tomography (HR-pQCT) to determine bone mineral density (BMD) within three different regions of interest (distal, intermedium, and proximal) at the distal femur. In addition, local bone quality was assessed by measuring the peak torque necessary to break out the trabecular bone along each separate hole of a locking compression plate (LCP) during its instrumentation. Finally, biomechanical testing was performed using cyclic axial loading until failure in an AO/OTA 33 A3 fracture model.ResultsLocal BMD was highest in the distal region. This was confirmed by the measurement of local bone quality using DensiProbe™. The most distal holes represented locations with the highest breakaway torque resistance, with the holes on the posterior side of the plate indicating higher values than those on its anterior side. We demonstrated strong correlation between the cycles to failure and local bone strength (measured with DensiProbe™) in the most distal posterior screw hole, having the highest peak torque.ConclusionThe local bone quality at the distal femur indicates that in plated distal femur fractures the distal posterior screw holes seem to be the key ones and should be occupied. Measurement of the local bone strength with DensiProbe™ is one possibility to determine the risk of construct failure, therefore, thresholds need to be defined.

Unique Morphology of Intraoperative Measurement of Distal Femur in Northern Malaysian Females and its Correlation With Total Knee Arthroplasty Implant Sizing

Unique Morphology of Intraoperative Measurement of Distal Femur in Northern Malaysian Females and its Correlation With Total Knee Arthroplasty Implant Sizing