Femoral Head Diameter Research Articles

Association Between Hip Translation and Hip Rotation and Anatomy: A Pilot Quasi-static MRI Study.

There is little known about translation of the hip and the relationship with hip rotation and morphology in asymptomatic patients. (1) Femoral head would exhibit significant translations in asymptomatic hips, (2) femoral head translations would correlate to femoral rotations, and (3) range of femoral head translations would correlate to hip morphology. Cross-sectional study; Level of evidence, 3. A total of 11 individuals (age, 23-47 years; 64% female) with asymptomatic hips underwent hip magnetic resonance imaging (MRI) in the following postures: neutral (supine), midflexion, maximum-flexion, internal rotation, internal rotation + midflexion, internal rotation + maximum-flexion, adduction, flexion-abduction-external rotation (FABER), extension, and lateral abduction. All rotations were passive. MRI-generated 3-dimensional hip models were used to quantify femoral rotations and translations. Femoral head diameter, acetabular diameter, lateral center-edge angle, alpha angle, femoral anteversion, acetabular version and inclination, and neck-shaft angle were measured from MRI. A t test was used if measured translations were statistically significant. Linear regression was used to assess the associations between translation and rotation. Pearson correlation was used to assess the relationships between hip anatomy and range of femoral head translations. In all tested positions, the femoral head translated anteriorly by 2 ± 1 mm (maximum 5 mm, P < .001), posteriorly by 1 ± 1 mm (maximum 6 mm, P < .001), superiorly by 2 ± 2 mm (maximum 7 mm, P < .001), inferiorly by 2 ± 2 mm (maximum 6 mm, P < .001), laterally by 1 ± 1 mm (maximum 4 mm, P < .001), and medially by 2 ± 1 mm (maximum 5 mm, P < .001), relative to the rested supine position. Femoral flexion was associated with posterior translation of the femoral head (P = .038). Femoral abduction was associated with medial translation of the femoral head (P = .042). Higher femoral anteversion and smaller alpha angle were associated with a higher total magnitude of femoral head translation in the anterior-posterior direction (P < .04). Smaller femoral anteversion, higher acetabular inclination, smaller lateral center-edge angle, and lower neck-shaft angle were associated with a higher total magnitude of femoral head translation in the superior-inferior direction (P ≤ .03). Our study demonstrated that, during passive physiologic movement, asymptomatic hips on average translated up to 2 mm (with up to 7 mm maximum translation in some positions), which is potentially related to hip rotations and morphology. Further investigations are warranted to understand the normal and pathologic hip translations and their impact on hip function (ie, instability and impingement).

Radiological and Anthropometrical Analysis of the Hip Joint Using Computed Tomography Scan in North Indian Population

Abstract Background: Anthropometric research on the hip joint has significant clinical implications, including (1) implant design and (2) avoiding implant mismatch complications, such as aseptic loosening and incorrect load distribution, which are mainly unknown in North India. The aim of this research is to ascertain the anatomical differences in the normal hip joint across individuals in North India and to statistically compare the results with global data. Materials and Methods: We used one hip topogram and one axial segment of the femoral head to analyze 100 people (35 females and 65 males) with normal hips between the ages of 20 and 65. In both sexes and on both sides, we determined the means of the following measurements: femoral head diameter (HD), femoral neck width (NW), femoral neck length, acetabular angle of sharp, femoral version, horizontal offset, acetabular version, and vertical offset. Results: The following are the mean parameters that were observed: (a) neck shaft angle (NSA) - 128.93°, (b) femoral HD = 4.29 cm, (c) femoral NW = 2.97 cm, (d) femoral neck length = 3.61 cm, (e) Acetabular angle of Sharp - 33.01°, (f) Acetabular version = 20.44°, (g) femoral Version = 21.57°, (h) horizontal offset = 3.62 cm, and (i) Vertical offset = 4.43 cm. Conclusion: The NSA and acetabular angle of sharp were 5°–6° more when compared to the western population while horizontal and vertical offset is comparatively less than Western population and in the Indian NSA was higher for North Eastern population than the North Indian population. The residual parameters were comparable to those found in Western literature.

A Study on Imaging Risk Factors for Hip Osteoarthritis.

Due to low prevalence and few studies, the morphologic risk factors for hip osteoarthritis (HOA) in Chinese population remain unknown. The purpose of this study was to investigate the relationship between 10 radiographic parameters measured via anteroposterior pelvic X-ray radiography and HOA in Chinese population. Thirty-three patients who required total hip arthroplasty for unilateral HOA (2017-2022) and 132 healthy individuals were selected for this case-control study. We measured 10 radiological parameters via anteroposterior pelvic X-ray radiography, which were sharp angle, center edge angle, sourcil angle, neck shaft angle, α angle, pelvic height, pelvic width, femoral head diameter, femoral neck width, and ratio of the femoral head diameter to the femoral neck width. After measurements were obtained, logistic regression analysis was utilized to calculate the adjusted odds ratios (ORs) for confounding variables such as age, sex, and body mass index (BMI). Receiver operating characteristic (ROC) curves were utilized to determine the proportional risk contribution (PRC) of each radiographic factor. After adjustment for confounding factors, individuals with a larger sourcil angle (SA) (OR = 4.89, 95% CI 1.66-14.42, p = 0.004), larger α angle (OR = 4.14, 95% CI 1.53-11.23, p = 0.005), and wider femoral neck (OR = 5.27, 95% CI 1.50-18.51, p = 0.01) were found to have a greater risk of developing HOA. Among all radiographic parameters, the SA demonstrated the greatest risk contribution (PRC = 13.695%). Radiographic parameters correlate with the incidence of HOA. The SA is probably the most powerful of all the parameters related to HOA.

Three-dimensional analysis of age and sex differences in femoral head asphericity in asymptomatic hips in the United States.

The sphericity of the femoral head is a metric used to evaluate hip pathologies and is associated with the development of osteoarthritis and femoral-acetabular impingement. To analyze the three-dimensional asphericity of the femoral head of asymptomatic pediatric hips. We hypothesized that femoral head asphericity will vary significantly between male and female pediatric hips and increase with age in both sexes. Computed tomography scans were obtained on 158 children and adolescents from a single institution in the United States (8-18 years; 50% male) without hip pain. Proximal femoral measurements including the femoral head diameter, femoral head volume, residual volume, asphericity index, and local diameter difference were used to evaluate femoral head sphericity. In both sexes, the residual volume increased by age (P < 0.05). Despite significantly smaller femoral head size in older ages (> 13 years) in females, there were no sex-differences in residual volume and aspherity index. There were no age-related changes in mean diameter difference in both sexes (P = 0.07) with no significant sex-differences across different age groups (P = 0.06). In contrast, there were significant increases in local aspherity (maximum diameter difference) across whole surface of the femoral head and all quadrants except the inferior regions in males (P = 0.03). There were no sex-differences in maximum diameter difference at any regions and age group (P > 0.05). Increased alpha angle was only correlated to increased mean diameter difference across overall surface of the femoral head (P = 0.024). There is a substantial localized asphericity in asymptomatic hips which increases with age in. While 2D measured alpha angle can capture overall asphericity of the femoral head, it may not be sensitive enough to represent regional asphericity patterns.

Can necrotic depth be a substitute of necrotic volume to predict collapse progression in osteonecrosis of the femoral head?

Although some patients may experience collapse progression while others may not in post-collapse osteonecrosis of the femoral head (ONFH) with a necrotic lesion located within the weight-bearing part of the acetabulum (Type B/C1), few studies have focused on the natural course after collapse. This study aimed to clarify the correlation between necrotic volume (NV) and necrotic depth (ND) in predicting collapse progression in patients with post-collapse ONFH Type B/C1. We retrospectively reviewed 54 hips with post-collapse ONFH Type B/C1 from 52 consecutive patients who were conservatively followed up for more than 1 year. We measured the amount of femoral head collapse using biplane radiographs at each follow-up period, and produced Kaplan-Meier survival curves with collapse progression (≥ 1 mm) as the endpoint. We compared NV and ND, which were calculated as the ratio of the distance from the articular surface of the femoral head to the deepest point of a necrotic lesion to the femoral head diameter in the mid-coronal slice of T1-weighted magnetic resonance imaging (MRI). We observed collapse progression in 31 hips (57.4%). The NV and ND were significantly greater in hips with collapse progression than in those without collapse progression (p = 0.0127 and 0.0047, respectively). Necrotic volume was significantly correlated with ND (rs = 0.56, p < 0.0001). This study suggests that necrotic depth on the mid-coronal slice of T1-weighted MRI can be a substitute for necrotic volume to predict collapse progression in ONFH Type B/C1.

Paper 18: The Pendulum Has Swung: A 14-Year Analysis of Patients Presenting for Failed Hip Arthroscopy Shows Rising Incidence of Cam Over-Resection and Decreasing Incidence of Under-Resection

Background: There is a paucity of literature regarding prevalence of femoral resection in the setting of revision hip arthroscopy. Few studies have examined different types of resections and their presentation. Purpose: To describe the prevalence of femoral resection types in the setting of revision hip arthroscopy for residual femoroacetabular impingement syndrome (FAIS) symptomatology. Methods: A search of the institutional prospective registry was performed for patients who presented for evaluation of failed previous arthroscopy between February 2008 and June 2022, and subsequently underwent revision arthroscopy. AP and Dunn view radiographs were reviewed from our study population. On the basis of measurements on both radiographs, patients were divided into 3 categories: overresection (OR) in which the resection measured 5% or more of the femoral head diameter, underresection (UR) in which residual CAM morphology was found (alpha angle &gt;60°), and neutral resection, alpha angle less than 60° and no overresection. Both AP and Dunn radiographs were used to identify over- and under- resections. Results: A total of 622 hips were reviewed and measured on both AP and Dunn radiographs. Of the 622 hips, there were 373 right and 249 left hips. The average age was 33.7 ± 12.0, and the average body mass index (BMI) was 26.0 ± 5.2. Three hundred sixty-five hips were classified as UR and 265 hips as OR. The mean prevalence rates from 2008 to 2022 for neutral resection, over-resection and under-resection were 48.1%, 20.3%, and 31.6%, respectively. The prevalence rates of UR have decreased since 2008, while prevalence rates of OR have increased concomitantly. The steadily decreasing prevalence rates of UR was negatively correlated with the increasing OR ((R=-0.829, P&lt;.0001), as well as with neutral resections (R=-0.735, P=0.002). The ratio of UR to OR reversed entirely, from 4:1 in 2010, to 1: 2.3 ( P &lt; 0.00001) in 2020. Conclusions: Amongst patients presenting for failed hip arthroscopy over the last 14 years, the pendulum has swung from under-resection towards over-resection. Indeed, as of 2020, over-resections were more than twice as common as under-resections. This may be a result of heightened awareness in FAIS, and previous literature emphasizing the risks of under-resection. As we gain increased understanding of the risks of over-resection, the findings of this study highlight the importance of achieving an anatomical spherical resection.

Social inequality and body mass differences in two post‐Medieval Dutch populations

AbstractAdult body mass is largely related to nutrition levels, which can be affected by external stressors, such as diet, environment, and disease. High‐status and low‐status groups likely had very different nutrition and stress experiences, which might result in differences in population's body mass. Since inequality between social statuses prevailed in Europe in the post‐Medieval period, did these differences result in body mass variations between high‐status and low‐status populations in the Netherlands? In order to answer this question, this research compared body size of two post‐Medieval urban skeletal collections with different social statuses from the Eusebius cemetery of two cemeteries of the 17th–19th centuries: the Arnhem and the Broerenkerk church of Zwolle, the Netherlands. Social statuses of the two collections are estimated based on the burial locations, grave goods, and historical records. Body mass was estimated using both femoral head diameter method and stature/bi‐iliac breadth method. Results have shown no statistically significant differences in body mass between the two samples. Therefore, this research suggests that inequality in post‐Medieval Dutch society did not result in observable population body mass differences in the skeletal collections of different social status groups. It cannot, however, prove that social inequality in populations did not impact body size or health more broadly.

Factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head.

This study aimed to identify factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head (ONFH) and to identify patients who would benefit from surgical treatment. This study included 41 patients (56 hips) with type B ONFH with a minimum follow-up of threeyears. Based on a ≥ 3mm collapse progression in ONFH, we categorised patients into two groups: collapse progression and no collapse progression. Sagittal and coronal computed tomography images were used to measure the necrotic region relative to the intact femoral head diameter. The ratios of the necrotic regions of transverse and vertical diameter in coronal and sagittal images are defined as mediolateral transverse and mediolateral vertical, anteroposterior transverse and anteroposterior vertical, respectively. Demographic data and these imaging findings were compared between the two groups. We established a cut-off value for predicting collapse progression through receiver operating characteristic analysis and determined survival rates. Type B ONFH had a 17.8% collapse progression rate. The mediolateral transverse, mediolateral vertical, anteroposterior transverse, and anteroposterior vertical were significantly higher in the collapse progression group (P < 0.01). Mediolateral transverse was an independent risk factor of collapse progression (hazard ratio, 1.27; 95% confidence interval, 1.03-1.57; P = 0.03), with an optimal cut-off of 45.6%. The 5-year survival rates with collapse progression as the endpoints were 57.0 and 94.9% in the mediolateral transverse of ≥ 45.6 and < 45.6%, respectively. A mediolateral transverse of ≥ 45.6% predicts collapse progression in patients with type B ONFH.

Evaluation of the proximal femur using the digital photographs: Does change in proximal femur position due to anteversion affect the measurement of the size of the femoral head diameter?

A plain pelvic radiograph is usually conducted with the lower limbs in internal rotation. This is to correct the anteversion of the femur. However, in the fracture neck of the femur, internal rotation of the fractured limb is avoided, because it would be painful. We examined the effect of correction of anteversion or otherwise on the diameter of the head of the femur using imaging. This study aimed to determine if there was a significant difference between the femoral head diameter at two different positions, at the normal anatomical position (without correcting the anteversion) and at the corrected anteversion position. It also aimed to document the correlation and the statistical significance between the differences in the size of the diameter at these two different positions with the anteversion angles of the femoral bone. Two sets of digital photographs of the proximal part of 55 non-sexed, non-paired femoral bones were taken. Images obtained were at two positions: normal anatomical (with anteversion uncorrected) and anteversion corrected positions. The diameters of the head of the femur were documented at these two different positions. The anteversion angles and actual femoral head (AFH) diameters were also measured and documented. The femoral head diameters at anatomical positions were persistently larger than those measured after the anteversion was corrected, except in three femoral bones (5%) where no differences were observed. The difference in the two measurements was statistically significant to the anteversion angle of the femoral bone. (P = 0.0005). The means of the two sets of measurements were statistically different from each other. Pairwise correlation showed that both were strongly associated with the AFH diameter but the measurements from images with corrected anteversion had a higher value (0.8166) than the measurements from normal anatomical position (0.7526). The correction of femoral anteversion produced femoral head size measurements that were closer to AFH diameters compared to those without the correction of the femoral anteversion. Femoral anteversion should always be corrected as per protocol.

Intraoperative live measurement of femoral head size for acetabular cup sizing: simple, accurate, and green!

Templating is the first step in achieving a successful total hip arthroplasty. We hypothesize that native head size is highly correlated with implanted cup size. Therefore, the purpose of this study is to look for a correlation between sizes of the intra-operative measurement of the femoral head and the implanted cup. This is a monocentric observational study conducted from December 2018 till January 2023. All patients admitted for a primary total hip arthroplasty were included and retrospectively reviewed. Intra-operative femoral head measurement, radiographic femoral head diameter, templated (planned) cup size, and definitive implanted cup size were recorded. The sample included 154 patients (85 female and 69 males) with a mean age of 66.2 ± 10.4years. There were 157 THA cases; 82 on the right side and 75 on the left side. The native head size and acetate template on digital radiographs were the most significantly positively correlated with cup size (P < 0.0001) while the radiological head size was significantly negatively correlated with cup size (P = 0.009). The implanted cup was on average 2 ± 2mm bigger than the native head size measured intra-operatively. The native femoral head diameter measured intra-operatively is a simple and reliable tool to help the surgeons choose the proper size of the acetabular cup, preventing complications during surgery hence optimizing results post operatively. This technique would contribute to a more ecofriendly orthopaedic reconstructive surgery.

Determination of preoperative risk factors for iliopsoas tendonitis after total hip arthroplasty: Asimulation study.

This study aims to identify preoperative risk factors for iliopsoas tendonitis after total hip arthroplasty, a complication typically attributed to acetabular cup position and orientation, using a validated iliopsoas impingement detection simulation. Analyzing CT scans and X-rays of 448 patients using a validated preoperative planning protocol, patients were simulated for iliopsoas impingement and categorized into at-risk and not at-risk groups based on a prior validation study, with a 23% at-risk incidence. Implementing a propensity score matching algorithm to reduce covariate imbalance, we identified factors that may exacerbate risk of iliopsoas tendonitis. Parameters that were investigated included standing pelvic tilt, functional femoral rotation, and the difference between the planned acetabular cup diameter and native femoral head diameter (ΔC-NFH). Comparing pelvic tilt, we found a significant difference between the groups (at-risk: -6.0°, not at-risk: -0.7°; p << 0.01). A similar trend was noted for ΔC-NFH (at-risk: +5.7 mm, not at-risk: +5.1 mm; p = 0.01). Additional simulations of at-risk patients indicated increased anteversion of the acetabular cup reduces impingement risk more effectively than medialisation. These findings suggest that spinopelvic parameters may exacerbate iliopsoas irritation risk, underscoring their importance in preoperative planning and patient expectation management. Similar findings of a greater than 6 mm difference between cup size and native femoral head diameter being a significant risk for iliopsoas tendonitis have been observed before, underscoring its potential veracity. These results may provide surgeons with a simple threshold that can be used in determining a cup size to reduce the risk of iliopsoas tendonitis.

Cemented dual-mobility constructs in uncemented revision acetabular components.

Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m2 (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97). There were nine cemented DM cup revisions: three for periprosthetic joint infection, three for acetabular aseptic loosening from bone, two for dislocation, and one for a broken cup-cage construct. The two-year survivals free of aseptic DM revision and dislocation were both 92%. There were five postoperative dislocations, all in patients with prior dislocation or abductor deficiency. On radiological review, the DM cup remained well-fixed at the cemented interface in all but one case. While dislocation was not eliminated in this series of complex revision THAs, this technique allowed for maximization of femoral head diameter and optimization of effective acetabular component position during cementing. Of note, there was only one failure at the cemented interface.

Assessment of polyethylene wear in dual mobility implant for Asians on various head-to-liner ratios: A finite-element analysis

Based on several references, Asians carry out several daily activities that are different from Westerners, which require a greater range of motion. Because of that, a dual mobility (DM) implant was created that was adapted to the activities of Asian people. One of the factors that might shorten the life of a hip implant is wear. Simulations of wear that are based on computation can guide product design to reduce the amount of adhesive and abrasive wear. Even though advanced modeling approaches have been established, a great deal of wear is still not understood, especially regarding the metal-on-polyethylene articulations found on DM cups. It is critical to examine the wear on the DM cup's head-to-liner ratio to determine the proper head diameter and liner thickness for this DM cup. In this work, wear was analyzed using finite-element analysis and compared between three different femoral head diameters matched with different thicknesses of the polyethylene liner on DM cups. Wear was analyzed throughout the regular walking cycle at each head-to-liner ratio. The findings of this study can be used to develop a dual-mobility artificial hip joint for Asians with the slightest wear.

Morphological Characteristics of the Vietnamese Adult Human Acetabulum Using Multiplanar Reconstruction Computed Tomography in Total Hip Replacement Surgery.

The anatomical parameters of the acetabulum vary among races and geographical regions. Multislice Computed Tomography (CT) has proven to be a practical approach to assess morphological parameters of the acetabulum. The purpose of this study was to explore morphological characteristics of the acetabulum measured by CT scans in Vietnamese adults. Thirty-five consecutive patients aged 18 years and older received indications and eligibility for total hip replacement surgery. Sixty-three acetabulum were examined with multislice computed tomographic system (CT) with multiplanar reconstruction (MPR). Measured morphometric parameters of acetabulum included acetabular inclination angle (AIA), acetabular anteversion angle (AAA), acetabular angle of sharp (AAS), sagittal acetabular angle (SAA), acetabular horizontal offset (AHO), transverse acetabular ligament anteversion (TALA), transverse acetabular ligament inclination (TALI), acetabular depth (ADe), acetabular depth ratio (ADr) and acetabular diameter (ADi). The mean values of acetabular diameter, femoral head diameter, AIA, AAA, AAS, SAA, TALA, TALI, AHO, ADe, ADr were 50.22±3.56 mm, 43.54±3.68 mm, 40.27±5.09 mm, 13.30±5.54 mm, 39.46±5.41 mm, 26.38±9.01 mm, 9.49±3.92 mm, 47.70±6.73 mm, 3.06±0.37 mm, 18.62±2.95 mm and 309.60±41.87 mm. Our initial data has showed morphological characteristics of the acetabulum in Vietnamese adults, different from the populations from other parts of world. Also, significant correlation between the orientation of the acetabulum and the transverse acetabular ligament was documented.

Effect of geometrical, operational and material parameters in the lubrication regime of hard-on-hard hip implants

The lubrication regime of a hip implant is influenced by various parameters, including material, geometry, roughness, relative angular movement, and loading circumstances. These factors impact friction and wear performance, ultimately limiting the implant's longevity. In this study, a ball-on-plane model is considered to predict the lubrication regime across the entire gait cycle for the metal-on-metal and ceramic-on-ceramic hip implants. According to ISO 14242-1, a normal walking gait cycle is considered for the loads and rotations in the hip implant for this study. A comprehensive analysis is done to estimate the lubrication regime by considering different material combinations, body weights, femoral head sizes, clearances, and roughness across the entire gait cycle. The correlation coefficients show that the geometrical parameters are dominant in affecting the lubrication film thickness compared to the operational and material parameters. The femoral head size and body weight are found to be the most dominant and least dominant parameter respectively. Among the hard-on-hard tribo-pairs, ceramics operate predominantly in the full-film lubrication regime compared to metals due to its fine surface finish. The present research suggests that in order to maximise the longevity of a hip implant, an orthopaedic surgeon should choose one with a larger femoral head diameter, less clearance, and an ultra-fine surface finish, regardless of any material tribo-pair.

Morphometry of proximal femur in South Indian Population

Background: Proximal femur analysis plays a vital role in orthopedic surgery, implant design, fracture care, and research. Studying this complex bone helps surgeons select the right implants, plan fracture treatment, and understand bone strength. This growing field improves clinical outcomes and enhances scientific knowledge. Our study analyzes the morphometry of proximal femur, particularly the head and neck, to further explore its implications. Aims and Objectives: To study the morphometric measurements of the proximal end of the femur quantitatively in the South Indian population from the dry femora available in the Department of Anatomy, Government Medical College, Kottayam. Materials and Methods: This cross-sectional study was conducted in 101 dry femora available in the Department of Anatomy, Government Medical College, Kottayam. The measurements were taken with digital Vernier calipers and a goniometer. All continuous variables were expressed as mean with standard deviation. Statistical differences between the right and left sides were analyzed with Student’s independent sample t-test (for parametric variables) and Mann–Whitney U test (for non-parametric variables). Results: The mean vertical and anteroposterior diameter of the femoral head, superior and inferior length of the femoral head, the anteroposterior and vertical diameter of the femoral neck, superior and inferior lengths of the femoral neck, neck-shaft angle, and intertrochanteric length were 39.61±3.29 mm, 40.17±3.14 mm, 33.01±3.6 mm, 23.88±4.32 mm, 24.22±3 mm, 29.59±3 mm, 21.75±3.81 mm, 32.03±5.58 mm, 124.11±6.37, 60.31±7.33 mm, respectively. There was a statistically significant difference in the mean of neck anteroposterior diameter and neck-shaft angle between the right and left sides where the left side had the higher value. Conclusion: Notable skeletal metric variations exist amidst different populations. Proximal femoral dimensions can be acquired through either manual means or radiological information. These measurements can be used in designing orthopedic implants for the South Indian population.

The impact of femoral head size on the wear evolution at contacting surfaces of total hip prostheses: A finite element analysis

Total Hip Arthroplasty has been a revolutionary technique in restoring mobility to patients with damaged hip joints. The introduction of modular components of the hip prosthesis allowed for bespoke solutions based on the requirements of the patient. The femoral stem is designed with a conical trunnion to allow for assembly of different femoral head sizes based on surgical requirements. The femoral head diameters for a metal-on-polyethylene hip prosthesis have typically ranged between 22 mm and 36 mm and are typically manufactured using Cobalt–Chromium alloy. A smaller femoral head diameter is associated with lower wear of the polyethylene, however, there is a higher risk of dislocation. In this study, a finite element model of a standard commercial hip arthroplasty prosthesis was modelled with femoral head diameters ranging from 22 mm to 36 mm to investigate the wear evolution and material loss at both contacting surfaces (acetabular cup and femoral stem trunnion). The finite element model, coupled with a validated in-house wear algorithm modelled a human walking for 10 million steps. The results have shown that as the femoral head size increased, the amount of wear on all contacting surfaces increased. As the femoral head diameter increased from 22 mm to 36 mm, the highly cross-linked polyethylene (XLPE) volumetric wear increased by 61% from 98.6 mm3 to 159.5 mm3 while the femoral head taper surface volumetric wear increased by 21% from 4.18 mm3 to 4.95 mm3. This study has provided an insight into the amount of increased wear as the femoral head size increased which can highlight the life span of these prostheses in the human body.

Distances and angles in standing long-leg radiographs: comparing conventional radiography, digital radiography, and EOS

ObjectiveDistances and angles measured from long-leg radiographs (LLR) are important for surgical decision-making. However, projectional radiography suffers from distortion, potentially generating differences between measurement and true anatomical dimension. These phenomena are not uniform between conventional radiography (CR) digital radiography (DR) and fan-beam technology (EOS). We aimed to identify differences between these modalities in an experimental setup.Materials and methodsA hemiskeleton was stabilized using an external fixator in neutral, valgus and varus knee alignment. Ten images were acquired for each alignment and each modality: one CR setup, two different DR systems, and an EOS. A total of 1680 measurements were acquired and analyzed.ResultsWe observed great differences for dimensions and angles between the 4 modalities. Femoral head diameter measurements varied in the range of > 5 mm depending on the modality, with EOS being the closest to the true anatomical dimension. With functional leg length, a difference of 8.7% was observed between CR and EOS and with the EOS system being precise in the vertical dimension on physical-technical grounds, this demonstrates significant projectional magnification with CR-LLR. The horizontal distance between the medial malleoli varied by 20 mm between CR and DR, equating to 21% of the mean.ConclusionsProjectional distortion resulting in variations approaching 21% of the mean indicate, that our confidence on measurements from standing LLR may not be justified. It appears likely that among the tested equipment, EOS-generated images are closest to the true anatomical situation most of the time.

Is sexual dimorphism in morphometric variables of the proximal femur moderated by age in adulthood? A cross-sectional study in Ghana

Ageing may impact proximal femoral morphometry in both males and females. However, it is not clear whether the observed sexual dimorphism is attributable to an ageing effect in the post-pubertal period. The potential effect of ageing on sexual dimorphism in the proximal femur is most significantly relevant for forensic and osteoarchaeological research. The study was cross-sectional and comprised 123 participants (females = 72 and males = 51), who were recorded between January 2017 and June 2018 at the Korle-Bu Teaching Hospital. The study participants were aged between 31 and 79 years. The femoral head diameter, the femoral neck diameter, the femoral neck-shaft angle, and the femoral hip axis length were measured from the right side by radiographic technique and following standard osteometry methods. The femoral head-neck ratio was then calculated. All measurements were taken twice and then averaged. The (mean ± SD) femoral head diameter was higher in males (5.1 ± 0.56 cm) than in females (4.8 ± 0.51 cm) with a moderate effect size (p = 0.023, Hedge’s g = 0.56). Similarly, the femoral neck diameter was higher in males (4.0 ± 0.52 cm) than in females (3.8 ± 0.48 cm) with a small effect size (p = 0.025, Hedge’s g = 0.40). The femoral head axis length increased by 0.03 cm annually in males. The observed sexual dimorphism in the femoral head and neck diameters could not, however, be attributable to the ageing effect. Ageing may not have an impact on sexual dimorphism in the femoral head and neck diameters among persons older than 30 years in the Ghanaian population.

A glimpse into the body shape and limb proportions of enslaved Africans from Lagos, Portugal (15th–17th centuries)

AbstractAt the beginning of the Portuguese maritime expansion (15th century), ships loaded with various goods, including sub‐Saharan enslaved individuals, began to arrive in Portugal. In 2009, osteoarchaeological remains of these individuals were recovered for the first time in Valle da Gafaria, Lagos. Attending to their African origin and given that several studies have shown that the human body generally conforms to Bergmann's and Allen's rules, in this study, the physique of 63 adult individuals from the Valle da Gafaria site is tested against ecogeographical predictions. For that purpose, body shape (assessed by the femoral head diameter to femoral length index) and intralimb proportions (brachial and crural indices) were compared with those of 200 identified Portuguese skeletons. Results showed that the Lagos females' body shape and intralimb proportions differed significantly from those of the Portuguese, being more ‘tropically adapted’ (i.e., more ‘linear’ body shape with elongated distal limb segments). For the Lagos' males, the reduced sample size advises caution in the interpretation of the results. Although the specific origin of the Lagos individuals is not yet known, and different individuals may have come from relatively different regions of sub‐Saharan Africa, with specific climatic adaptations, the results generally agree with the ecogeographical expectations. This study not only allows for the first glimpse into the body shape and limb proportions of enslaved Africans arriving in Portugal but also confirms that morphometric analyses of the long bones may be a valuable complement to investigate the latitude origin of an osteoarchaeological assemblage.