Naming Homo erectus: A review.

Following the discovery of hominin fossils at Trinil (Java, Indonesia) in 1891 and 1892, Eugène Dubois named a new species, now known as Homo erectus. Although the main historical events are well-known, there appears to be no consensus regarding two important aspects of the naming of the species, including what constitutes the original publication of the name, and what is the name-bearing type specimen. These issues are addressed in this paper with reference to original sources and the International Code of Zoological Nomenclature. Our review confirms earlier studies that cite the published quarterly fieldwork report covering the 3rd quarter of 1892 as the original publication naming the species erectus. However, until recently, the correct publication year of 1893 has consistently been cited as 1892, and it has rarely been recognized that the author of the publication was anonymous, even though the author of the species is specifically named. Importantly, Dubois assigns all three hominin fossils found at Trinil up to that moment to the new species, explicitly stating that they belong to a single individual. The three fossils, a molar, a calotte, and a femur, therefore jointly constitute the original holotype. However, the femur most likely derives from younger strata than the other hominins and shows fully modern human-like morphology, unlike subsequently discovered H. erectus femora. Moreover, there is no consensus over the affinities of the molar, and if it is H. erectus rather than an extinct ape, there is no evidence that it belongs to the same individual as the calotte. Excluding these two fossils from the holotype, the calotte is the appropriate fossil to retain the role as name-bearing specimen.

3D Slicer open-source software plug-in for vector-based angle calculation of canine hind limb alignment in computed tomographic images.

BACKGROUND: Severe and complex angular limb deformities in dogs require accurate morphological assessment using diagnostic imaging to achieve successful orthopedic surgery. Computed tomography (CT) is commonly used to overcome projection errors in two-dimensional angular measurements of dog hindlimb alignment. Three-dimensional volume rendering (VR) techniques permit virtual positioning and variable projection, but the final CT-image that defines the projection plane for angular measurements remains two-dimensional. OBJECTIVE: We wanted to develop a true three-dimensional open-source technique to measure the alignments of the hind limbs of dogs in CT scanners. METHODS: We developed an open-source 3D Slicer plug-in, to perform angular measurements using vector calculations in three-dimensional space. In 113 CT-scans of canine pelvic limbs, femoral torsion, femoral varus, femorotibial rotation, tibial torsion, tibial varus and tibiotalar rotation angles were calculated and compared to an already validated technique using VoXim®. RESULTS: Reference points were identified and measurements were possible in the 113 acquisitions. The greatest difference between the two techniques was 1.4° at only one tibial torsion angle. Mean values for all Bland-Altman plots did not show significant differences and were less than 0.07° for all comparisons. DISCUSSION: Based on these results we considered angular measurements of canine hind limb alignment in CT scans using the 3D Slicer extension program sufficiently accurate for clinical orthopedic and surgical purposes in veterinary medicine. CONCLUSION: With our open-source 3D Slicer extension software, we provide a free accessible tool for veterinary orthopedic surgeons and thus we hope to improve angular measurements in CT-scans of canine hind limb deformities through true three-dimensionality.

Significant difference in femoral torsion between coronal plane alignment of the knee type 1 and 4.

PURPOSE: The purpose of this study was to find out whether the torsions of the femur and tibia are dependent on the coronal plane alignment of the knee (CPAK) type. METHODS: Five hundred patients (1000 legs) were included, who received a whole leg standing three-dimensional (3D) radiograph using EOS imaging (EOS Imaging, Paris, France). SterEOS software was used for digital reconstruction. Femoral and tibial torsions were determined by analysing 3D reconstructions of each leg. Femoral torsion was defined as the angle between the femoral neck axis (FNA) and the posterior condylar axis (PCA). Tibial torsion was defined as the angle between the axis tangent to the posterior part of the tibia plateau and the transmalleolar axis. Arithmetic hip-knee-ankle angle (aHKA) and joint-line obliquity (JLO) were also determined, allowing each leg to be assigned one of nine possible phenotypes according to CPAK. RESULTS: The mean femoral torsion in CPAK type 1 was significantly higher (+ 2.6° ± 0.8°) than in CPAK type 4 (p = 0.02). All other CPAK types did not differ in the degree of femoral torsions. No differences could be demonstrated for the tibial torsion. CONCLUSION: There is a correlation between the coronal alignment of the lower limb and femoral torsion. This may provide the basis for extending the CPAK classification beyond the coronal plane. LEVEL OF EVIDENCE: Level III.

Novel radiologic indices for stem type decision in total hip arthroplasty in patients with metaphyseo-diaphyseal mismatched Dorr A proximal femur.

BACKGROUND: In metaphyseo-diaphyseal (M-D) mismatched Dorr A femurs, it is difficult to achieve proper fixation with a type 1 stem. Proper interpretation of the geometry of the femur is integral at the preoperative stage in an M-D mismatched femur, but there has been a scarcity of studies on the radiologic indices. Therefore, we analyze the previous radiologic indices and suggest the novel ones for M-D mismatched femurs. METHODS: Our study was a retrospective review of preoperative radiographs of patients who underwent total hip arthroplasty with the smallest type 1 stem or with type 3 C stem at a single institution from July 2014 to March 2022. A Type 3 C stem was used when the smallest type 1 stem failed to achieve metaphyseal fixation. One hundred twenty-six patients were categorized into two main groups. Canal-flare index, canal-calcar ratio, modified morphological cortical index, and two novel indices (lesser trochanter-to-distal ratio-α and -ß [LDR-α and -ß]) were assessed on preoperative pelvic radiographs. RESULTS: Multivariate and ROC analysis demonstrated that high LDR-ß (Exp[B]: 485.51, CI: 36.67-6427.97, p < 0.001) was associated with a more mismatched tendency group and had clinically acceptable discriminatory power (AUC: 0.765, CI: 0.675-0.855, p < 0.001) between the two cohorts. CONCLUSION: Correct assessment of preoperative femoral morphology would be fundamental in the selection of a suitable stem. The ratio based on 3 cm below the lesser trochanter of the femur seemed crucial. We recommend evaluating the newly described radiological index preoperatively in M-D mismatched Dorr A femur for planning precisely and selecting a proper stem.

Anatomical Diversity in Femur bones: Understanding the Morphological Variability for Surgical and Prosthetic Applications / Diversidad Anatómica en Huesos Fémur: Comprensión de la Variabilidad Morfológica para Aplicaciones Quirúrgicas y Protésicas

SUMMARY: The femur, the body's longest bone, plays a critical role in orthopaedics and radiology. Understanding its anatomy, particularly the neck-shaft angle (NSA), is vital for diagnosing bone issues and designing hip implants. While some Asian populations' femur measurements have been studied, there is a research gap concerning Sri Lankans. This study aimed to fill this gap by examining the proximal femur's anatomy in the Sri Lankan population. We analysed 45 adult human femurs (26 right, 19 left) of unknown sex, ethically sourced from the University of Sri Jayewardenepura. Femurs with fractures or pathologies were excluded. Precise measurements were recorded using digital vernier callipers, with millimetre accuracy. Parameters included mean femoral length, vertical and transverse femoral head diameters, neck axis and neck length. Each measurement was taken three times to minimize subjectivity. Right femurs had a mean length of 42.8 mm (SD±2.64), while left femurs measured 43.53 mm (SD±3.27). Mean NSA was 125.78º (SD±4.45) for left femurs and 127.59º (SD±2.06) for right. Mean femoral head diameters were 4.09mm (SD±0.30) (right) and 4.12mm (SD±0.31) (left). Mean anterior neck lengths of the right and left were 2.61 (SD±0.54) and 2.71(SD±0.50) respectively. Comparing our findings with other Asian populations highlighted significant variations in femur measurements. These discrepancies emphasize the need for population-specific data for orthopaedic interventions and raise questions about the suitability of imported prosthetics. Differences in femur length, neck length, and NSA between sides suggest potential challenges in using implants designed for one side on the other. This study underscores the necessity of population-specific data in orthopaedics, as femur measurements differ even among Asian populations. Further research and statistical analysis are essential for tailoring orthopaedic solutions to individual populations. The findings also suggest a potential need for locally manufactured prosthetics to better suit the Sri Lankan population.

El fémur, el hueso más largo del cuerpo, desempeña un papel fundamental en ortopedia y radiología. Comprender su anatomía, en particular el ángulo cuello-diáfisis (NSA), es vital para diagnosticar problemas óseos y diseñar implantes de cadera. Si bien se han estudiado las medidas del fémur de algunas poblaciones asiáticas, existe un vacío en la investigación sobre los habitantes de Sri Lanka. Este estudio tuvo como objetivo examinar la anatomía del fémur proximal en la población de Sri Lanka. Analizamos 45 fémures humanos adultos (26 derechos, 19 izquierdos) de sexo desconocido, obtenidos éticamente de la Universidad de Sri Jayewardenepura. Se excluyeron fémures con fracturas o patologías. Se registraron mediciones precisas utilizando calibradores vernier digitales, con precisión milimétrica. Los parámetros incluyeron la longitud femoral media, los diámetros vertical y transversal de la cabeza femoral, el eje del cuello y la longitud del cuello. Cada medición se tomó tres veces para minimizar la subjetividad. Los fémures derechos tuvieron una longitud media de 42,8 mm (DE ± 2,64), mientras que los fémures izquierdos midieron 43,53 mm (DE ± 3,27). La NSA media fue de 125,78º (DE±4,45) para el fémur izquierdo y de 127,59º (DE±2,06) para el derecho. Los diámetros medios de la cabeza femoral fueron 4,09 mm (DE ± 0,30) (derecha) y 4,12 mm (DE ± 0,31) (izquierda). Las longitudes medias del cuello anterior de la derecha y la izquierda fueron 2,61 (DE ± 0,54) y 2,71 (DE ± 0,50) respectivamente. La comparación de nuestros hallazgos con otras poblaciones asiáticas destacó variaciones significativas en las medidas del fémur. Estas discrepancias enfatizan la necesidad de datos específicos de la población para las intervenciones ortopédicas y plantean dudas sobre la idoneidad de las prótesis importadas. Las diferencias en la longitud del fémur, la longitud del cuello y la NSA entre lados sugieren posibles desafíos al utilizar implantes diseñados para un lado en el otro. Este estudio subraya la necesidad de datos específicos de la población en ortopedia, ya que las mediciones del fémur difieren incluso entre las poblaciones asiáticas. Es esencial realizar más investigaciones y análisis estadísticos para adaptar las soluciones ortopédicas a poblaciones individuales. Los hallazgos también sugieren una posible necesidad de prótesis fabricadas localmente para adaptarse mejor a la población de Sri Lanka.

Bleeder's Femur: The Proximal Femoral Morphology in Hemophilic Patients Who Underwent Total Hip Arthroplasty.

INTRODUCTION: Patients with hemophilia (PWH) constantly suffer hemarthrosis, which leads to deformity of the hip joint. Therefore, PWH who are going to receive total hip arthroplasty (THA) should be exclusively treated before the surgery with careful measurement of their proximal femur. Hence, we conducted a retrospective study to explore the anatomical parameters of and differences in the proximal femur in hemophilic patients who underwent THA. METHODS: The retrospective study comprised data of adult patients who received total hip arthroplasty from 2020 to 2022 in the research center. Patients having a diagnosis of hemophilic arthritis and received THA were included in experimental group, and patients with hip arthritis or femoral head necrosis were taken as control group. Parameters including femoral offset, neck-shaft angle (NSA), medullary cavity of 20 mm above mid-lesser trochanter level (T+20), mid-lesser trochanter level (T), and 20 mm blow it (T-20), and canal flare index (CFI), femoral cortical index (FCI) were measured on X-ray and CT images with PACS by two independent doctors. Data was analyzed by SPSS 20. Kolmogorov-Smirnov test was used to test data normality. Student's t-test was performed between PWH and control group. p < 0.05 was considered statistically significant. RESULTS: Among the 94 hips, 39 (41.5%) were included in group hemophilia and 55(58.5%) in control group. The mean age of the patients was 49.36 ± 12.92 years. All cases were male patients. Data demonstrated significantly smaller femoral cortical index (FCI), femoral offset, medullary cavity of 20 mm above mid-lesser trochanter level, mid-lesser trochanter level, and 20 mm below it, and neck-shaft angle (NSA) was obviously larger in PWH than control group (p < 0.05). No significant difference was found in canal flare index (CFI). CONCLUSION: Hemophilic patients undergoing THA were prone to longer and thinner proximal femur. Preoperative morphological analysis of femur is recommended.

Variation of Mid shaft Antero-posterior and Transverse Diameter of Femur in Bangladeshi People.

Femoral morphometric variation is a dynamic system for different region, which is influenced by geographical, physiological and environmental factors, due to the adaptation, functional and remodeling responses of bones. This descriptive cross-sectional study was conducted on 150 (64 right and 86 left) fully ossified dry human femur of Bangladeshi people to find out the variation of mid shaft antero-posterior and transverse diameter of femur. Sample was collected in the Department of Anatomy, Mymensingh Medical College (MMC), Bangladesh from January 2019 to December 2019. All samples were assessed to eliminate fractured, pathologically damaged and remodeled bones. The diameters were measured with the help of digital Vernier slide calipers. The mean±SD mid shaft antero-posterior diameter of right and left femur were 25.03±2.86 mm and 25.54±2.65mm respectively. The mean±SD transverse diameter of right and left femur was 24.24±2.43mm and 24.54±2.38mm respectively. The knowledge of variations in the parameters of dry femora will help the orthopedicians for the treatment and management of femoral shaft fracture. These data also provide information about mid shaft diameter of femur of Bangladeshi people and to compare these data to those from various other races. Thus it could contribute for the design of well-fitting prosthesis which suits the Bangladeshi population. This value may be considered while making a best-fit femoral prosthesis.

Proximal radiolucent lines around fully hydroxyapatite-coated tapered femoral stems: should we be concerned?

INTRODUCTION: Radiolucent lines occasionally develop around the proximal aspect of fully hydroxyapatite (HA)-coated tapered femoral stems after total hip arthroplasty (THA). It was hypothesised that distal wedging of stems may predispose to proximal radiolucent line formation, which may negatively impact clinical outcome. METHODS: All primary THA performed with a collarless fully HA-coated stem that had a minimum of 1 year of radiographic follow-up were identified in a surgical database (n = 244). Radiographic measures of proximal femoral morphology and femoral canal fill at the middle and distal thirds of the stem were analysed for association with the presence of proximal radiolucent lines. Linear regression was used to explore any association between radiolucent lines and patient reported outcome measures (PROMs), available in 61% of patients. RESULTS: Proximal radiolucent lines developed in 31 cases (12.7%) at final follow-up. Dorr A femoral morphology and increased canal-fill at the distal ⅓ of the stem correlated with the development of radiolucent lines (p < 0.001). No correlation was observed between pain or PROMs and the presence of proximal radiolucent lines. DISCUSSION: We observed an unexpectedly high incidence of proximal femoral radiolucent lines about collarless fully HA coated stems. Distal-only implant wedging in Dorr A bone may compromise proximal fixation. Although this finding did not correlate with short-term outcomes, the long-term clinical impact requires further study.

A review of the distal femur in Australopithecus.

In 1938, the first distal femur of a fossil Australopithecus was discovered at Sterkfontein, South Africa. A decade later, another distal femur was discovered at the same locality. These two fossil femora were the subject of a foundational paper authored by Kingsbury Heiple and Owen Lovejoy in 1971. In this paper, the authors discussed functionally relevant anatomies of these two fossil femora and noted their strong affinity to the modern human condition. Here, we update this work by including eight more fossil Australopithecus distal femora, an expanded comparative dataset, as well as additional linear measurements. Just as Heiple and Lovejoy reported a half-century ago, we find strong overlap between modern humans and cercopithecoids, except for inferiorly flattened condyles and a high bicondylar angle, both of which characterize modern humans and Australopithecus and are directly related to striding bipedalism. All other measured aspects of the femora are by-products of these key morphological traits. Additional fossil material from the early Pliocene will help to inform the evolution of the hominin distal femur and its condition in the Pan-Homo common ancestor that preceded bipedal locomotion.

Femora of women with premature ovarian insufficiency exhibit reduced strength and misalignment with the transmitted vertical forces from the upper body.

BACKGROUND: Women with premature ovarian insufficiency (POI) lack oestrogen, which is a key determinant of bone growth, epiphyseal closure, and bone tissue organisation. Although dual-energy X-ray absorptiometry (DXA)-derived areal bone mineral density (BMD) remains the gold standard for fracture risk evaluation, it does not fully characterise the skeletal abnormalities present in these women. Hence, we aimed to assess hip/femur anatomy, strength, and geometry and femoral alignment using advanced hip analysis (AHA). METHODS: We conducted a cross-sectional, case-control study including 89 women with spontaneous normal karyotype POI (s-POI) or iatrogenic POI (i-POI), aged 20-50 years compared with 89 age- and body mass index (BMI)-matched population-based female controls. Hip anatomy, strength, geometrical parameters, and femur alignment were measured using hip DXA images and Lunar AHA software. Femoral orientation angle (FOA) was quantified as the overall orientation of the femur with respect to the axis of the forces transmitted from the upper body. RESULTS: The median age of POI diagnosis was 35 (18-40) years; the mean POI duration at the time of DXA was 2.07 (range 0-13) years, and 84% of POI women received oestrogen therapy. Areal BMD at all sites was significantly lower in the POI group (all P < .05). Indices of compressive and bending strength were lower in women with POI compared with controls, specifically the cross-sectional area (CSA, mm2) and section modulus (SM, mm3) (139.30 ± 29.08 vs 157.29 ± 22.26, P < .001 and 665.21 ± 129.54 vs 575.53 ± 150.88, P < .001, respectively). The FOA was smaller (124.99 ± 3.18) in women with POI as compared with controls (128.04 ± 3.80; P < .001) at baseline and after adjusting for height and femoral neck BMD. CONCLUSION: Alongside lower BMD at multiple sites, the femora of women with POI demonstrate reduced strength and a misalignment with forces transmitted from the upper body. Further research is needed to establish the role of these newly identified features and their role in fracture risk prediction in this population.

Surface morphology of osteochondral grafts harvested from femoral condyles with free-hand technique: a cadaveric study.

PURPOSE: The purpose of this cadaver study was to examine the surface morphology of the osteochondral grafts harvested from the femoral condyles using the free-hand graft harvesting technique. MATERIALS AND METHODS: One hundred osteochondral grafts were harvested with 6.5 mm chisels at ten different donor sites using the free-hand technique in five paired knee specimens (Mean age: 56.4 years). The cartilage and subchondral bone surface angles were measured through multiplanar reconstruction computerized tomography examination. The cartilage thickness was measured with a MicroScribe G2X digitizer with an accuracy of 0.02 mm. An acceptable congruity could be obtained when these plugs were transferred to a perpendicular socket (articular step-off of less than 1 mm and 0.5 mm) was evaluated. RESULTS: Four plugs were damaged or broken during harvesting due to technical difficulties; thus remaining 96 plugs were analyzed. The cartilage thickness varied between 1.36 mm and 3.26 mm across the donor sites. The cartilage was the thinnest in the medial intercondylar notch and thickest in the lateral supracondylar notch. Twenty of ninety-six plugs (20.8%) had unacceptable cartilage surface inclination according to the > 0.5 mm protrusion criteria. Of these plugs, 14 were harvested from the lateral intercondylar notch, whereas five of 96 plugs (5.2%) had unacceptable cartilage surface inclination according to the > 1 mm protrusion criteria. Of these plugs, all were harvested from the lateral intercondylar notch. CONCLUSIONS: High rates of unacceptable plugs (up to 100%) might be harvested from the lateral intercondylar notch. In large chondral lesions that require multiple plugs, lateral and medial supracondylar ridges were the best donor sites for perpendicular plug harvesting, whereas lateral intercondylar notch should be avoided.

Anatomic Referencing Restores the Anatomy of the Distal Femur with Less Compromise.

Historically, anterior referencing and posterior referencing are two specific techniques that surgeons can use for proper sizing of the femoral component in total knee arthroplasty (TKA). In this review, we introduce the concept of "anatomic referencing" which has become useful with more incremental sizes of the femoral component to more perfectly match the native anatomy of each patient and reduce overstuffing of the patellofemoral joint and medial-lateral (ML) overhang. Fifty consecutive TKA cases were reviewed where the novel anatomic referencing technique was used. Lateral radiographic projections were obtained preoperatively and postoperatively. The posterior condylar offset (PCO) was evaluated on the lateral radiographs by measuring the distance between the tangent line of the femoral diaphysis posterior cortex and the posterior condylar margin. PCO ratio (PCOR) was calculated by dividing the PCO by the distance between the posterior condylar border and a tangent line along the anterior cortex of the femoral diaphysis. Forty-five patients (50 TKAs) were reviewed. Average age of the patients was 70.34, range: 47-91. There were 19 males and 26 females reviewed in this series. On average, the delta PCOR was 0.022 (standard deviation = 0.032; min: -0.049, max: 0.082). When grouping our results into three main groups: < -0.03, -0.03 to 0.03, and > 0.03, we found that 62% fell within the -0.03 to 0.03 range. There was no statistically significant difference in delta PCOR between standard and narrow implants (p = 0.418). The proposed novel anatomic referencing technique has allowed for proper sizing of patients' femurs in the anteroposterior and ML direction while avoiding component overhang or the need for component downsizing to obtain a proper ML fit. This radiographic review confirmed this to be a highly accurate and reproducible technique.

An evolutionary perspective to intramedullary nail fit - comparing present-day data with a historical specimen collection.

Manufacturers aim to design implants fitting for the broadest possible population segment. Due to the scarcity of available morphological data of intact long bones, anatomical collections of historical bone specimens may represent valuable additional sources. Previous work on femoral morphology measurements suggests that historical specimens are widely consistent with data from present-day populations. This study aimed to investigate whether this also applies to the anatomical fitting of a clinically used femoral nail. Nail fit was computer-graphically quantified through virtual implantation into CT-based 3D models of 52 femora, comprising a subset representative of the present-day Caucasian population (n = 31), a subset from a historical medieval European bone collection (n = 20), and additionally, a dataset from a natural ice mummy from the Neolithic period. Nail fit was assessed by nail protrusion (area and distance) to the inner cortex surface and the distal nail tip's position in the medullary canal. Assessed measurements and parameters of the present-day Caucasian subset were mostly consistent with those of the medieval European subset. After adjusting for multiple testing, only the distance from lateral nail entry point to shaft axis remained significantly (p = 0.03) different when comparing our modern and medieval subsets. Subsequent bivariate (Spearman) correlation analyses for both subsets (modern and medieval) combined showed that of the three variables representing basic demographic parameters, individual age, biological sex, and femur length, most statistically significant associations to the examined nail fit measurements were found for age (six measurements at a level of p < 0.05), however, with a relatively weak monotonic correlation (rho values ranging between ±0.31 and ±0.37). The measurements for the Iceman's femur lie within the range of the modern and historical subgroups, but in some cases, differ by more than one standard deviation from the mean. Our results confirm previous findings, suggesting that more recent historical bone specimen collections may indeed be a convenient and easily accessible source of new 3D morphological data and complement existing data to be used for the development of femoral nails.

Biomechanical and taxonomic diversity in the Early Pleistocene in East Africa: Structural analysis of a recently discovered femur shaft from Olduvai Gorge (bed I).

Recent Plio-Pleistocene hominin findings have revealed the complexity of human evolutionary history and the difficulties involved in its interpretation. Moreover, the study of hominin long bone remains is particularly problematic, since it commonly depends on the analysis of fragmentary skeletal elements that in many cases are merely represented by small diaphyseal portions and appear in an isolated fashion in the fossil record. Nevertheless, the study of the postcranial skeleton is particularly important to ascertain locomotor patterns. Here we report on the discovery of a robust hominin femoral fragment (OH 84) at the site of Amin Mturi Korongo dated to 1.84 Ma (Olduvai Bed I). External anatomy and internal bone structure of OH 84 were analyzed and compared with previously published data for modern humans and chimpanzees, as well as for Australopithecus, Paranthropus and Homo specimens ranging from the Late Pliocene to Late Pleistocene. Biomechanical analyses based on transverse cross-sections and the comparison of OH 84 with another robust Olduvai specimen (OH 80) suggest that OH 84 might be tentatively allocated to Paranthropus boisei. More importantly, the identification of a unique combination of traits in OH 84 could indicate both terrestrial bipedalism and an arboreal component in the locomotor repertoire of this individual. If interpreted correctly, OH 84 could thus add to the already mounting evidence of substantial locomotor diversity among Early Pleistocene hominins. Likewise, our results also highlight the difficulties in accurately interpreting the link between form and function in the human fossil record based on fragmentary remains, and ultimately in distinguishing between coeval hominin groups due to the heterogeneous pattern of inter- and intraspecific morphological variability detected among fossil femora.

CT measurements of the proximal femoral medullary cavity in healthy adults: a cross-sectional study.

Objectives: To analyse the proximal femoral morphology on three-dimensional reconstructed imagery to explore the factors influencing the relevant parameters. METHODS: The cross-sectional study was conducted at Peking University Third Hospital in northern China from January 2019 to August 2020, and comprised healthy adults who underwent computed tomography scanning. Three-dimensional computed tomography reconstruction of the proximal femoral medullary cavity was performed using Mimics 22. The anatomical parameters related to total hip arthroplasty were measured to examine the relationship among gender, age and femoral length. Data was analysed using SPSS 20. RESULTS: Of the 63 adults, meaning 126 hips, 21(33.3%) were males, meaning 42 (33.3%) hips, and 42(66.6%) were females, meaning 84(66.6%) hips. The overall mean age was 51.5±23.1 years (range: 23-68 years). The inflection point of the medullary cavity curved at 5-10mm distal to the lesser trochanteric line. Most horizontal plane parameters significantly differed between men and women (p<0.05), with the mean medullary cavity being wider in men than women. There was a significant difference between the genders in the sagittal anterior-posterior diameter of the canal flare index (p<0.05). Age was negatively correlated with the coronal medial-lateral diameter and coronal lateral diameter of canal flare index. In the coronal and sagittal planes, there was a positive correlation between the metaphysis and diaphysis, and the coronal and sagittal planes were positively correlated with the orthogonal plane. CONCLUSIONS: Femoral morphology could be influenced by gender and age. Morphological changes of the proximal femoral medullary cavity were not present in a single plane, but were affected by multiple planes. When the diameter of one plane became larger, its orthogonal plane concomitantly increased.

Análisis Morfológico y Biométrico de la Fóvea de la Cabeza del Fémur / Morphological and Biometric Analysis of the Fovea for Ligament of Head of Femur

En la literatura actual se encuentra escasa información referente a la fóvea de la cabeza del fémur (fóvea de la cabeza del hueso fémur). Este estudio tuvo como propósito recolectar datos morfológicos y biométricos respecto a la fóvea de la cabeza del fémur y reconocer variaciones que podrían ser de utilidad en las diversas patologías de la región. Se utilizaron 46 huesos fémures humanos pertenecientes al Departamento de Ciencias Básicas de la Universidad de La Frontera, Chile. Para la medición de datos se utilizó material ad hoc y los datos fueron analizados el programa Excel y los softwares ImageJ e Image Pro Plus. La longitud promedio de los huesos fémures fue de 43,8 ± 2,9 cm; el ángulo de torsión del cuello fue de 23,0 ± 2,0°. En el 100 % de las muestras se observó una fóvea en el cuadrante posteroinferior de la cabeza del fémur. El área promedio de la fóvea de la cabeza del fémur fue de 1,51 ± 0,7 cm2. El perímetro fue de 4,72 ± 1,0 cm; la forma de la fóvea fue: 60,9% ovalada, 23,9% triangular y 15,2 % circular, teniendo como base la fórmula derivada del índice craneal, dejando la fórmula como feret mínimo/feret máximo, con el cual los valores mayores a 0,8 se clasificaban como circulares y los menores como ovalados. Conocer la ubicación de la fóvea de la cabeza del fémur adquiere implicancia médica, ya que una fóvea en posición anormalmente alta, en imágenes radiológicas, es un indicador de displasia pélvica. La importancia de las variaciones de la fóvea de la cabeza del fémur debe ser más investigadas para una correcta comprensión de las patologías que afectan a la cabeza femoral.

SUMMARY: In the current literature there is little information regarding the fovea for ligament of head of femur. The aim of this study was to collect morphological and biometric data regarding the fovea for ligament of head of femur and recognize variations that could be useful in the various pathologies of the region. Forty six human femur bones belonging to the Department of Basic Sciences of the University of La Frontera, Chile were used. For data measurement, ad hoc material was used and the data were analyzed with the Excel program and the ImageJ and Image Pro Plus software. The average length of the femur bones was 43.8 ± 2.9 cm; the neck torsion angle was 23.0 ± 2.0°. In 100% of the samples, a fovea was observed in the posteroinferior quadrant of the head of femur. The average area of the fovea for ligament of head of femur was 1.51 ± 0.7 cm3. The perimeter was 4.72 ± 1.0 cm; The shape of the fovea was: 60.9% oval, 23.9% triangular and 15.2% circular, based on the formula derived from the cranial index, leaving the formula as minimum feret/maximum feret, with which the values greater than 0.8 were classified as circular and those less as oval. Knowing the location of the fovea for ligament of head of femur acquires medical implications, since a fovea in an abnormally high position, in radiological images, is an indicator of pelvic dysplasia. The importance of variations in the fovea for ligament of head of femur must be further investigated for a correct understanding of the pathologies that affect the femoral head.

Five or more gender- and size-diverse customizations of distal femur prostheses are needed to improve fit for Chinese knees.

PURPOSE: Mismatch between partial imported prostheses and Chinese anatomy affects the clinical outcome of the procedure. The purpose of this study was to measure the anatomical dimensions of Chinese distal femurs to provide guidance for the design of more compatible distal femoral prostheses. METHODS: A total of 406 healthy distal femurs were reconstructed and measured. Consistency of these measurements and differences in sides, gender, and populations were examined. Parameter correlations were analyzed, and pairs with strong correlations underwent linear regression analysis. The design of distal femoral prostheses was referenced from the results of K-means and hierarchical clustering analysis. RESULTS: Ten parameters were measured, including the trans-epicondylar axis, width of the distal femur (ML), anteroposterior diameter of the distal femur (AP), etc. The intra-class correlation coefficient ranged from 0.795 to 0.999 for intra-observer consistency, and from 0.796 to 0.998 for inter-observer consistency. Males exhibited significantly larger parameters than females, except for the posterior condylar angle (all P values < 0.05). Compared to other populations, substantial differences were observed for most parameters, such as ML, AP, width of lateral femoral condyle, etc. (all P values < 0.05). Clustering analysis suggested that distal femoral prostheses should include at least five sizes to adequately accommodate the sampled population. ML sizes for males were 68, 70, 83, 73, and 89 mm, and for females 64, 65, 71, 67, and 77 mm. AP sizes for males were 56, 60, 60, 64, and 64 mm, and for females 48, 52, 54, 57, and 58 mm. CONCLUSIONS: Chinese distal femur morphology, as analyzed using 3D techniques, varies significantly between genders and when compared with international data. For improved patient fit, the creation of five or more distal femur prostheses, diversified by gender and size and informed by the associated morphological parameters, is recommended. LEVEL OF EVIDENCE: IV.

Palaeobiological inferences of "rauisuchians" Fasolasuchus tenax (Los Colorados Fm., Argentina) and Prestosuchus chiniquensis (Santa Maria Super sequence, Brazil) from the Middle-Upper Triassic of South America based on microstructural analyses.

"Rauisuchia" is a non-monophyletic group of quadrupedal and carnivorous pseudosuchians that inhabited the entire world during the Middle-Upper Triassic period (Anisian/Ladinian-Rhaetian). In South America, "rauisuchians" reached the largest sizes among continental carnivores. Despite their important ecological role, some aspects of their palaeobiology have been poorly examined. Here, we study appendicular bones, dorsal ribs and osteoderms of two genera, the Argentinean Fasolasuchus tenax (PVL 3850, holotype) and the Brazilian Prestosuchus chiniquensis (SNSB-BSPG AS XXV) respectively. The femur of F. tenax is formed by laminar fibrolamellar bone, which is composed of non-fully monorefringent woven-fibred matrix and primary osteons; the dorsal rib has a Haversian bone composition with an external fundamental system recorded and the osteoderm is formed by well-organised parallel-fibred bone. The femur, humerus and fibula of P. chiniquensis are mostly composed of strongly arranged parallel-fibred bone and a laminar vascularisation. The minimal ages obtained correspond to 9 years for F. tenax (based on the maximum number of growth marks in the osteoderm) and 4 years for P. chiniquensis (obtained from the highest count of growth marks in the femur and in the humerus). F. tenax attained somatic and skeletal maturity, while P. chiniquensis was near to reaching skeletal and sexual maturity, but it was somatically immature. The overall rapid growth rate and the high and uniform vascularisation seems to imply that these features are common in most of "rauisuchians", except in P. chiniquensis.

Evolution of posture in amniotes-Diving into the trabecular architecture of the femoral head.

Extant amniotes show remarkable postural diversity. Broadly speaking, limbs with erect (strongly adducted, more vertically oriented) posture are found in mammals that are particularly heavy (graviportal) or show good running skills (cursorial), while crouched (highly flexed) limbs are found in taxa with more generalized locomotion. In Reptilia, crocodylians have a "semi-erect" (somewhat adducted) posture, birds have more crouched limbs and lepidosaurs have sprawling (well-abducted) limbs. Both synapsids and reptiles underwent a postural transition from sprawling to more erect limbs during the Mesozoic Era. In Reptilia, this postural change is prominent among archosauriforms in the Triassic Period. However, limb posture in many key Triassic taxa remains poorly known. In Synapsida, the chronology of this transition is less clear, and competing hypotheses exist. On land, the limb bones are subject to various stresses related to body support that partly shape their external and internal morphology. Indeed, bone trabeculae (lattice-like bony struts that form the spongy bone tissue) tend to orient themselves along lines of force. Here, we study the link between femoral posture and the femoral trabecular architecture using phylogenetic generalized least squares. We show that microanatomical parameters measured on bone cubes extracted from the femoral head of a sample of amniote femora depend strongly on body mass, but not on femoral posture or lifestyle. We reconstruct ancestral states of femoral posture and various microanatomical parameters to study the "sprawling-to-erect" transition in reptiles and synapsids, and obtain conflicting results. We tentatively infer femoral posture in several hypothetical ancestors using phylogenetic flexible discriminant analysis from maximum likelihood estimates of the microanatomical parameters. In general, the trabecular network of the femoral head is not a good indicator of femoral posture. However, ancestral state reconstruction methods hold great promise for advancing our understanding of the evolution of posture in amniotes.

A web application for sex and stature estimation from radiographic proximal femur for a Thai population.

In both forensic and archaeological domains, the discovery of incomplete human remains is a frequent occurrence. Nevertheless, the estimation of biological profiles from such remains presents a challenge due to the absence of crucial skeletal elements, such as the skull and pelvis. This study aimed to assess the utility of the proximal femur in the forensic identification process by creating a web application for osteometric analysis of the proximal femur. The aim was to determine the sex and stature of an individual from radiographs of the left anteroposterior femur. To accomplish this, an automated method was developed for acquiring linear measurements from radiographic images of the proximal femur using Python tools. The application of Hough techniques and Canny edge detection was utilized to generate linear femoral dimensions from radiographs. A total of 354 left femora were radiographed and measured by the algorithm. The sex classification model employed in this study was the Naïve Bayes algorithm (accuracy = 91.2 %). Results indicated that Gaussian process regression (GPR) was the most effective method for estimating stature (mean error = 4.68 cm, SD = 3.93 cm). The proposed web application holds the potential to serve as a valuable asset in the realm of forensic investigations in Thailand, particularly in the estimation of biological profiles from fragmentary skeletal remains.