Femoral Shape Research Articles

Image based quantification of the proximal femur shape deformities in 3D by using the contralateral healthy shape structure: A preliminary study

As a result of the several hip joint disorders seen on the hip joint components, shape deformities occur in the morphological structure of the proximal femurs and femoral heads. Quantification of the shape deformities in related hip joint components is a crucial task since it may provide assistive information to clinical experts and surgeons in clinical treatment, assessment and prognosis processes. In this article, a preliminary study handling the 3D shape deformity quantification of the abnormal proximal femurs is presented. The shape deformity of the abnormal proximal femurs in bilateral hip joint images are quantified directly by using the morphological structure of the contralateral healthy proximal femurs without a need for a statistical shape model. For this purpose, segmentation maps of the bilateral proximal femurs are registered in 3D by performing a rigid transform method, and the regions outside the intersection volume are quantified as the shape deformities. To evaluate the proposed study, a total of 13 bilateral hip magnetic resonance imaging (MRI) sequences of 13 patients with Legg-Calve-Perthes disease (LCPD) were used. The deformity ratios observed in experiments are quite promising and consistent with the Waldenstrom classification system stages of the LCPD. The shape deformity ratios of the pathological proximal femurs in 3D were quantified as 18.02% (±04.84), 26.41% (±07.54), 31.21% (±11.07), and 36.84% (±09.33), respectively for the Initial, Fragmentation, Reossification, and Remodelling stages of LCPD in this preliminary study.

Hydroxyapatite-coated compaction short stem represents a characteristic pattern of peri-prosthetic bone remodelling after total hip arthroplasty.

We aimed to investigate the differences in peri-prosthetic bone remodelling between the full hydroxyapatite (HA)-collared compaction short stem and the short tapered-wedge stem. This retrospective cohort study enrolled 159 consecutive patients (159 joints) undergoing total hip arthroplasty (THA) using the full HA compaction short (n = 64) and short tapered-wedge (n = 95) stems. Body mass index (BMI), peri-prosthetic bone mineral density (BMD), and clinical factors, including the Japanese Orthopaedic Association score and the University of California Los Angeles (UCLA) activity score were assessed and compared. Stem related complications were seen in three cases. Both groups showed similar peri-prosthetic BMD changes. Peri-prosthetic BMD was almost maintained in the distal femur and Gruen zone 6 with both type of stems, but significant BMD loss was found in zones 1 and 7 in both groups and in zone 2 of the full HA compaction stem group. No significant correlations were found between the proximal femoral BMD changes and the age, BMI, and UCLA score in both the full HA compaction and tapered-wedge stem groups. Femoral bone shape affected the peri-prosthetic BMD changes in the tapered-wedge stem group but not in the full HA compaction group. The stem collar of the full HA compaction stem did not affect peri-prosthetic BMD, but unique bone remodelling in the calcar region was observed in 27.6% cases. A significant difference in the peri-prosthetic BMD changes at Gruen zone 2 was found in patients with or without thigh pain. Peri-prosthetic bone remodelling remained unaffected by clinical and radiographic factors after THA with the new short full HA compaction stem. Therefore, this new stem may be useful in a variety of cases.

Results of Early Proximal Femoral Osteotomy at Skeletal Maturity in Legg-Calvé-Perthes Disease: Implication for the Bypass of Fragmentation Stage.

The aim was to assess the long-term radiographic outcomes of patients with Legg-Calvé-Perthes disease following an early proximal femoral osteotomy (PFO) performed in avascular necrosis stage or early fragmentation stage. In this retrospective study, we analyzed data of 65 patients aged above 6 years at the time of diagnosis with unilateral Legg-Calvé-Perthes disease, following early PFO performed at our institution between 1979 and 2013. We observed the presence of bypassing fragmentation stage, which was classified into complete and incomplete. We compared radiographic outcomes between patients with bypass of fragmentation stage (26 hips) and those without (31 hips). Regarding skeletal maturity, the hips were graded according to the femoral head shapes: spherical, ovoid, or flat. The mean age at diagnosis was 7.9 years (range: 6.0 to 11.9 y). The average follow-up period was 11.8 years (range: 5.9 to 22.9 y). Fragmentation bypass occurred in 40.5% (26/65) of patients, with 8 (12.3%) "undetermined" cases. Patients who completely or partially bypassed fragmentation experienced significantly less severe lateral pillar collapse (P=0.016). The femoral head was also significantly more spherical in patients with bypass (P=0.024). Our results show that 40.5% of patients who underwent early PFO bypassed the fragmentation stage. The degree of lateral pillar collapse was lower in patients with bypass. In addition, there were significantly more patients with more spherical femoral head in the bypass group. Level IV-case series.

¿Se puede predecir el pronóstico de la cadera contralateral tras una artroplastia total de cadera?

IntroductionCoxarthrosis is one of the most frequent and disabling pathologies. 20% of individuals over 60 years of age will develop symptomatic coxarthrosis and 10% of them will need a hip replacement; it is probably one of the orthopaedic procedures that most increases quality of life. When we recommend arthroplasty in clinical practice, patients often ask about the prognosis of their other hip. Will it deteriorate in the same way? Will it be necessary to replace it? When?The aim of the study is to determine if there is any variable or radiological sign that predicts the medium-term prognosis of the contralateral hip after total hip arthroplasty. Material and methodsA retrospective review of patients who underwent total hip arthroplasty in our hospital during 2011 and 2012 was carried out, with a total of 543 patients.The coxarthrosis degree at X-ray was determined at the time of the first arthroplasty and at regular intervals during follow-up, according to the JOA and Tönnis classifications, analyzing each of the items included in these classifications. Its relation with the progression of osteoarthritis and the need of contralateral hip replacement was established. Results and conclusionsA progression of osteoarthritis of the contralateral hip could be expected in the next 3 years in 10% of patients. This progression will be greater and faster in those with JOA grade III–IV/Tönnis grade II–III, especially, in those with greater joint narrowing and femoral head shape score, and can reach between 25 and 30% of patients. The initial JOA/Tönnis degree is a predictive factor for requiring a hip replacement on the contralateral side.

Impact of proximal femoral shape on leg length discrepancy after total hip arthroplasty

To investigate the effect of different proximal femoral shapes on leg length discrepancy(LLD) after total hip arthroplasty(THA). Total 131 patients with osteoarthritis or osteonecrosis received unilateral biological total hip arthroplasty from June 2013 to June 2019. All patients' age, sex, side and pelvis anteroposterior digital radiography were retraspectively analyzed. There were 69 males and 62 females, 57 cases of left hip and 74 cases of right hip. The age ranges from 25 to 89 with an average age of 62 years. There were 48 cases of osteoarthritis and 83 cases of osteonecrosis. In this study, femoral cortical index (FCI) was used as the classification of proximal femoral shape, and bilateral lower limb length differences were measured by preoperative and postoperative pelvis anteroposterior digital radiography. Grouping according to FCI:> 0.6 was Dorr A group, 0.5 to 0.6 was Dorr B group, <0.5 was the Dorr C group, and the relationship between proximal femur morphology and the leg length discrepancy after total hip arthroplasty was determined. The postoperative average FCI was(0.56±0.08) mm and the median LLD was 5.10 mm (IQR -1.00 to 8.80 mm). Three groups were divided according to the level of FCI, and there were no statistically significant differences in gender, age, side, diagnosis and intraoperative fracture rate distribution among three groups. FCI>0.6, the postoperative LLD was 6.30 mm (IQR 1.00 to 10.95 mm). When FCI was 0.5 to 0.6, the postoperative LLD was 5.85 mm(IQR-0.55 to 8.90 mm). FCI<0.5, the postoperative LLD was 1.95 mm(IQR -2.50 to 6.68 mm). LLD comparison of different proximal femoral shape was statistically significant (P<0.05). High FCI increases the risk of lower extremity prolongation after surgery on the affectedside, while low FCI reduces the risk of lower extremity prolongation after surgery on the affected side. The surgeon can assess the shape of the proximal femur of the patient preoperatively and inform the patient in advance of possible changes in leg length of both lower extremities after total hip replacement.

Vertical clinging and leaping induced evolutionary rate shifts in postcranial evolution of tamarins and marmosets (Primates, Callitrichidae)

BackgroundCallitrichids comprise a diverse group of platyrrhine monkeys that are present across South and Central America. Their secondarily evolved small size and pointed claws allow them to cling to vertical trunks of a large diameter. Within callitrichids, lineages with a high affinity for vertical supports often engage in trunk-to-trunk leaping. This vertical clinging and leaping (VCL) differs from horizontal leaping (HL) in terms of the functional demands imposed on the musculoskeletal system, all the more so as HL often occurs on small compliant terminal branches. We used quantified shape descriptors (3D geometric morphometrics) and phylogenetically-informed analyses to investigate the evolution of the shape and size of the humerus and femur, and how this variation reflects locomotor behavior within Callitrichidae.ResultsThe humerus of VCL-associated species has a narrower trochlea compared with HL species. It is hypothesized that this contributes to greater elbow mobility. The wider trochlea in HL species appears to correspondingly provide greater stability to the elbow joint. The femur in VCL species has a smaller head and laterally-oriented distal condyles, possibly to reduce stresses during clinging. Similarly, the expanded lesser trochanters visible in VCL species provide a greater lever for the leg retractors and are thus also interpreted as an adaptation to clinging. Evolutionary rate shifts to faster shape and size changes of humerus and femur occurred in the Leontocebus clade when a shift to slower rates occurred in the Saguinus clade.ConclusionsBased on the study of evolutionary rate shifts, the transition to VCL behavior within callitrichids (specifically the Leontocebus clade) appears to have been an opportunity for radiation, rather than a specialization that imposed constraints on morphological diversity. The study of the evolution of callitrichids suffers from a lack of comparative analyses of limb mechanics during trunk-to-trunk leaping, and future work in this direction would be of great interest.

Mobility in Ancient Egypt from the shape and strength of the femurs

The aim of the study was to establish the degree of robustness and to infer the level of mobility of a group from ancient Thebes (Middle Egypt). Seventy-one left femurs of adult individuals from the 1st century AD from the tomb of Monthemhat (Luxor) were studied. Metrical, non-metrical variables, shape and size indices of femur were considered. Stature, body mass and Body Mass Index were calculated. All variables showed higher values in males, the vertical diameter of the femoral head was the variable with the highest sexual dimorphism. Non-metric variables also indicated low robustness, with heterogeneous sex distribution. The robustness, pilastric and platymeric indices indicated that the values were close to those of gracile populations in both sexes. Subtrochanteric size and shape showed no sexual dimorphism. The robustness, size and shape in the middle of the diaphysis suggested a mobility related to a daily occupation without intense physical activity in the legs. The results indicate a profile of low robustness, relative sedentarism with apparent sexual division in daily activities.

Influence of gender and age on distal femur shape. Are there any relevant differences?

Objective: Evaluate the possible sex differences in the shapeof the distal femur and the age group influence on morphometry.Methods: Five measurements on 124 knees wereevaluated using magnetic resonance imaging, 62 male and62 female. The age ranged between 40 and 80 years, and thepatients were divided into two age groups. Three factors wereanalyzed, allowing the bone classification regarding its width,shape, and symmetry. Results: The male group showed absolutemeasurements greater than the female, but there wereno sex differences in the shape of the knee. Younger patientshad more trapezoidal knees and a higher rate of asymmetrybetween condyles. After analyzing the factors, regardingtheir width, 31 knees were considered standard, 47 narrow,and 46 wide. As for the shape of the knee, 12 were consideredstandard, 58 rectangular, and 54 trapezoidal. About the condylessymmetry, 23 were classified as symmetrical and 101asymmetrical. There was a great interpersonal variation in theshape of the knee, regardless of the sex. Conclusion: The shapeof the distal femur presents great interpersonal variation,going beyond the simple division between wide or narrow.This variation is influenced by the patients’ age, but not thesex. Level of evidence: 4

Comparison of radiographic and tomographic evaluations for measurement of the Canal Flare Index in dogs

ABSTRACT The outcome of total hip arthroplasty (THA) in dogs is directly related to surgical planning. Templating of radiographs prior to THA should help the surgeon anticipate prosthesis size and femoral shape allowing canal fill of the proximal metaphysis by the implant ensuring primary stable fixation. The canal flare index (CFI) obtained from radiograph has been used as a measure of risk of complications for the technique in human beings and dogs. However, standard radiographs only provide limited data for the selection of cementless prostheses and the assessment of their fit within the femoral canal, due to factors like radiographic magnification and femoral rotation. Therefore, three-dimensional evaluation based on computed tomography (CT) may be a better tool for CFI measurement. The aim of this study was to compare anatomical measurement with CFI values obtained from craniocaudal radiography and CT. Craniocaudal radiographs using a horizontal radiographic beam (CR), CT, and anatomical macroscopic measurements (A) were obtained from 45 femurs from 23 canine cadavers. The differences between the values of CFI obtained from radiograph (CFI-R), computed tomography on transverse (CFI- TT) and longitudinal axis (CFI-TL) compared to the CFI obtained from macroscopic measurements - gold standard - (CFI-A), and 95% limits of agreement (LOA) between the values, were evaluated by the Bland-Altman method. Dimensions obtained from CT techniques had a greatest mean difference from anatomical and CFI values were also different (P=0.032). Under the experimental conditions, the craniocaudal radiograph, provided the most accurate measurement of the CFI (mean difference: 0.087 ± 0.42).

Limits to the exaggeration and diversification of a male sexual trait in the false blister beetle Oedemera sexualis

AbstractDifferentiation in sexual traits among populations is one of the major predictions of theories of sexual selection and sexual conflict. A balance between maximizing reproductive benefits and minimizing survival costs could explain variation in sexual traits within and between populations. The false blister beetle Oedemera sexualis (Coleoptera: Oedemeridae) has exaggerated sexual traits, that is, sexually dimorphic hindlegs. In this study, we characterized scaling relationships in populations of O. sexualis to evaluate the determinants of sexual trait variation in the species. We quantified sexual dimorphism in body size and hindleg sizes in three representative populations based on distance measurements and an elliptical Fourier analysis. We found significant variation in the degree of sexual dimorphism for body and hindleg sizes among populations. In particular, differentiation in the male hind femur shape, especially the femur width, was conspicuous. Scaling relationships between male hind femur width and body size were best described by logistic models, showing that increases in male hind femur width were constrained for large individuals in all three populations. The degree of constrained growth of the hind femur width differed among populations in accordance with the population means, while the basal growth rates did not. Populations with smaller mean values for sexual traits showed more limited sexual trait exaggeration, contrary to the predictions based on resource competition among body parts. The latitudinal cline in femur widths suggests that environmental constraints on exaggeration might be responsible for sexual trait diversification in O. sexualis.

Comparative sexual selection in field and laboratory in a guild of sepsid dung flies

Phenomenological and behavioural studies have greatly advanced the study of natural selection. Field studies of selection well appraise the natural situation, but is this also true for laboratory studies, which are typically more mechanistic? We compared precopulatory sexual selection (mating differential based on pairing success) in field and laboratory of several closely related, ecologically similar black scavenger dung flies (Diptera: Sepsidae). Selection on fore femur (sexual trait) and wing size (nonsexual trait) and shape varied considerably among seven species and continental populations in agreement with variation in their mating system and sexual size dimorphism. Selection on trait size was mostly positive or nil, but never significantly negative, implying mating advantages of large males in most species. Strongest selection was found in species/populations with male-biased size dimorphism, associating evolutionary shifts from female- to male-biased dimorphism with intensified sexual selection for large male size by adding male –male competition to a mating system previously driven primarily by female choice. Although sexual selection on shape was closely aligned with allometric shape variation, selection on fore femur shape was more consistent than selection on wing shape, which was absent in most species. Sexual selection intensities, but not necessarily the underlying behavioural mechanisms, were overall similar in field and laboratory, suggesting that laboratory assessments well represent the natural situation. If this conclusion can be generalized, it would lend credence to the strategy of using controlled laboratory mating studies to better understand natural selection, behaviour and ecology, at least for smaller animals that can be held in captivity.

New femoral remains of Nacholapithecus kerioi: Implications for intraspecific variation and Miocene hominoid evolution

The middle Miocene stem kenyapithecine Nacholapithecus kerioi (16–15 Ma; Nachola, Kenya) is represented by a large number of isolated fossil remains and one of the most complete skeletons in the hominoid fossil record (KNM-BG 35250). Multiple fieldwork seasons performed by Japanese–Kenyan teams during the last part of the 20th century resulted in the discovery of a large sample of Nacholapithecus fossils. Here, we describe the new femoral remains of Nacholapithecus. In well-preserved specimens, we evaluate sex differences and within-species variation using both qualitative and quantitative traits. We use these data to determine whether these specimens are morphologically similar to the species holotype KNM-BG 35250 (which shows some plastic deformation) and to compare Nacholapithecus with other Miocene hominoids and extant anthropoids to evaluate the distinctiveness of its femur. The new fossil evidence reaffirms previously reported descriptions of some distal femoral traits, namely the morphology of the patellar groove. However, results also show that relative femoral head size in Nacholapithecus is smaller, relative neck length is longer, and neck–shaft angle is lower than previously reported for KNM-BG 35250. These traits have a strong functional signal related to the hip joint kinematics, suggesting that the morphology of the proximal femur in Nacholapithecus might be functionally related to quadrupedal-like behaviors instead of more derived antipronograde locomotor modes. Results further demonstrate that other African Miocene apes (with the exception of Turkanapithecus kalakolensis) generally fall within the Nacholapithecus range of variation, whose overall femoral shape resembles that of Ekembo spp. and Equatorius africanus. Our results accord with the previously inferred locomotor repertoire of Nacholapithecus, indicating a combination of generalized arboreal quadrupedalism combined with other antipronograde behaviors (e.g., vertical climbing).

Sex differences in diet and life conditions in a rural Medieval Islamic population from Spain (La Torrecilla, Granada): An isotopic and osteological approach to gender differentiation in al-Andalus.

Gender differentiation can influence the diet, physical activity, and health of human populations. Multifaceted approaches are therefore necessary when exploring the biological consequences of gender-related social norms in the past. Here, we explore the links between diet, physiological stress, physical activity, and gender differentiation in the Medieval Islamic population of La Torrecilla (Granada, Spain, 13th-15th century AD), by analyzing stable isotope patterns, stature, and long bone diaphyseal measurements. The sample includes 96 individuals (48 females, 48 males) classified as young and middle adults (20-34 and 35-50 years of age respectively). Diet was reconstructed through the analysis of δ13 C and δ15 N. Stature, humeral and femoral diaphyseal shape and product of diaphyseal diameters served as proxies of physiological stress and physical activity. Isotopic ratios suggest a substantial dietary contribution of C4 plants (e.g., sorghum, millet), a variable access to animal proteins, and no differences between the sexes. Sexual dimorphism in stature derives from a markedly low female stature. Long bone diaphyseal properties suggest that men performed various physically stressful activities, whereas women were involved in less physically demanding activities (possibly related to household work). Gender differentiation in La Torrecilla was expressed by a possibly differential parental investment in male versus female offspring and by culturally sanctioned gender differences in the performance of physical tasks. Diet was qualitatively homogenous between the sexes, although we cannot rule out quantitative differences. Our results shed new light on the effects of gender-related social norms on human development and lifestyle.

A novel approach for computerized quantitative image analysis of proximal femur bone shape deformities based on the hip joint symmetry

As a result of most of the bone disorders seen in hip joints, shape deformities occur in the structural form of the hip joint components. Image-based quantitative analysis and assessment of these deformities in bone shapes are very important for the evaluation, treatment, and prognosis of the various hip joint bone disorders. In this article, a novel approach for the image-based computerized quantitative analysis of proximal femur shape deformities is presented. In the proposed approach, shape deformities of the pathological proximal femurs were quantified over the contralateral healthy proximal femur shape structure of the same patient in 2D by taking the hip joint symmetry property of human anatomy into consideration. It is based on the idea that if the right and left proximal femurs in bilateral hip joints are highly symmetrical and also if one of the proximal femurs is healthy and the contralateral one is pathological, the non-overlapping bone shape regions can represent the deformities in pathological proximal femurs when both proximal femurs are registered to overlap each other. In the methodological process of the proposed study, a set of image preprocessing operations was primarily performed on the raw magnetic resonance imaging (MRI) data. Then, the segmented proximal femurs in bilateral hip joint images were automatically aligned with the Iterative Closest Point (ICP) rigid registration method. Following the registration, a set of image postprocessing operations was performed on the images of proximal femurs aligned. In the quantification phase, the bone shape deformities in pathological proximal femurs were quantified simply in terms of the mismatching area in 2D by measuring a shape variation index representing the total bone shape deformity ratio. To evaluate the proposed quantitative shape analysis approach, bilateral hip joints in a total of 13 coronal MRI sections of 13 patients with Legg-Calve-Perthes disease (LCPD) were used. Experimental studies have shown that the proposed approach has quite promising results in the quantitative representation of the pathological proximal femur shape deformities. Furthermore, consistent results have been observed for the Waldenström classification stages of the disease. The shape deformity ratios in pathological proximal femurs were quantified as 9.44% (±1.40), 18.38% (±6.30), 24.73% (±12.42), and 27.66% (±10.41), respectively for the Initial, Fragmentation, Reossification, and Remodelling stages of LCPD with the quantification error rates of 0.29% (±0.16), 0.58% (±0.71), 1.12% (±0.82), and 0.80% (±0.98). Additionally, a mean error rate of 0.65% (±0.68) was observed for the quantified shape deformity ratios of all samples.

Minimum 10 years clinical results of an anatomical short stem with a proximal hydroxyapatite coating

Objectives The CentPillar stem (Stryker Orthopaedics), an anatomical short stem, was designed to match the proximal femoral canal shape in both patients with normal hips and those with developmental dysplasia of the hip (DDH). The long-term outcomes of the CentPillar stem was examined herein. Methods In total, 222 hips that underwent total hip arthroplasty using the CentPillar stem were analyzed. DDH was the main reason for surgery (79.3%). Implant survivorship was assessed using Kaplan–Meier analysis. For radiographic evaluation, stress shielding was assessed using the Engh classification. For functional evaluation, patients’ ability to perform deep hip bending activities (sit on the floor, squat, and sit straight) was assessed. Results During a median follow-up of 13.1 years, 2 stem revisions were performed (aseptic loosening and late hematogenous periprosthetic infection), and the overall cumulative implant survival rate was 99.0% at 15 years. In the radiographic evaluation, grade >3 stress shielding was found in only one hip. More than 80% of the patients were able to perform each of the three deep hip bending activities. Conclusions Good fixation at the proximal part of the femur was obtained, and the implant survival rate of the CentPillar stem was excellent during a long-term follow-up.

Supplementation of Screw-Rod C1-C2 Fixation With Posterior Arch Femoral Head Allograft Strut.

Numerous C1-C2 fixation techniques exist for the treatment of atlantoaxial instability. Limitations of screw-rod and sublaminar wiring techniques include C2 nerve root sacrifice and dural injury, respectively. We present a novel technique that utilizes a femoral head allograft cut with a keyhole that rests posteriorly on the arches of C1 and C2 and straddles the C2 spinous process, secured by sutures. To offer increased fusion across C1-C2 without the passage of sublaminar wiring or interarticular arthrodesis. A total of 6 patients with atlantoaxial instability underwent C1-C2 fixation using our method from 2015 to 2016. After placement of a C1-C2 screw/rod construct, a cadaveric frozen femoral head allograft was cut into a half-dome with a keyhole and placed over the already decorticated dorsal C1 arch and C2 spinous process. Notches were created in the graft and sutures were placed in the notches and around the rods to secure it firmly in place. The femoral head's shape allowed for creation of a graft that provides excellent surface area for fusion across C1-C2. There were no intraoperative complications, including dural tears. Postoperatively, no patients had sensorimotor deficits, pain, or occipital neuralgia. 5 patients demonstrated clinical resolution of symptoms by 3 mo and radiographic (computed tomography) evidence of fusion at 1 yr. One patient had good follow-up at 1 mo but died due to complications of Alzheimer disease. The posterior arch femoral head allograft strut technique with securing sutures is a viable option for supplementing screw-rod fixation in the treatment of complex atlantoaxial instability.

Influence of preoperative femoral orientation on radiographic measures of femoral head height in total hip replacement

BackgroundIn total hip arthroplasty the surgeon aims to restore the biomechanics of the joint. Femoral height has the greatest influence on restoring limb length and contributes equally to the restoration of femoral head centre. On X-ray, the level of femoral neck resection is most often referenced off the upper border of lesser trochanter. Less frequently, femoral head centre is referenced from the tip of the greater trochanter. The error in measurement of femoral height resulting from unknown femoral rotation is crucially important and can result in inappropriate surgical planning for implant selection and placement. It is unknown which reference produces lower error. MethodsA sample of femoral shapes was generated using a femoral statistical shape model. These were placed in a range of orientations in terms of external rotation and flexion, at intervals of 10°. Simulated X-rays were then produced and the distances from the tip of either greater or lesser trochanter to femoral head centre were measured. FindingsAlthough using greater trochanter as a reference demonstrated greater errors at the extremes, both techniques resulted in errors of 7–8 mm with 20° of both femoral external rotation and flexion. InterpretationModerate degrees of femoral external rotation combined with flexion can result in unsatisfactory errors when templating limb length. There should be greater focus and an agreed definition for femoral height. There is a clinical need for a method with a lower error in determining true femoral height and the level of neck resection.

Morphology of Proximal Femur in South-West Coast of India.

Introduction:With a higher proportion of young individuals undergoing uncemented hip arthroplasty, a close match in the dimension of the proximal femur and the implanted prosthesis is paramount. This is a study to gain insight into geographical variation in proximal femur morphology to determine the reference values to design uncemented femoral stems for a south Indian population, and also the effect of ageing and gender on the proximal femur morphology.Materials and Methods:The study comprised of two groups. For the first group, 50 unpaired dry femur bones were obtained from adult human cadavers; and the second group was a clinical group of 50 adult patients. Standardised radiographic techniques were used to measure the extra-cortical and intra-cortical morphometric parameters. Based on these, dimensionless ratios were calculated to express the shape of the proximal femur. The data were expressed in terms of mean and standard deviation and a comparison made with other studies.Results:A significant difference was noted across various population subsets within the Indian subcontinent and also in comparison to the Western population, suggestive of regional variation. The measurements made in cadaveric bone differed significantly from those in live patients, especially the femoral head diameter and extra-cortical and intra-cortical width. Femoral offset, head height and diameter were significantly less in females.Conclusion:The south Indian population needs customised implants with an increase in neck shaft angle and a decrease in intra-cortical and extra-cortical width for press fit in hip arthroplasty. The variation between the two sexes must also be accounted for during prosthesis design.

Combining shape and intensity dxa-based statistical approaches for osteoporotic HIP fracture risk assessment

Aiming to improve osteoporotic hip fracture risk detection, factors other than the largely adopted Bone Mineral Density (BMD) have been investigated as potential risk predictors. In particular Hip Structural Analysis (HSA)-derived parameters accounting for femur geometry, extracted from Dual-energy X-ray Absorptiometry (DXA) images, have been largely considered as geometric risk factors. However, HSA-derived parameters represent discrete and cross-correlated quantities, unable to describe proximal femur geometry as a whole and tightly related to BMD. Focusing on a post-menopausal cohort (N = 28), in this study statistical models of bone shape and BMD distribution have been developed to investigate their possible role in fracture risk. Due to unavailable retrospective patient-specific fracture risk information, here a surrogate fracture risk based on 3D computer simulations has been employed for the statistical framework construction. When considered separately, BMD distribution performed better than shape in explaining the surrogate fracture risk variability for the analysed cohort. However, the combination of BMD and femur shape quantities in a unique statistical model yielded better results. In detail, the first shape-intensity combined mode identified using a Partial Least Square (PLS) algorithm was able to explain 70% of the surrogate fracture risk variability, thus suggesting that a more effective patients stratification can be obtained applying a shape-intensity combination approach, compared to T-score. The findings of this study strongly advocate future research on the role of a combined shape-BMD statistical framework in fracture risk determination.

Chronological and regional variation in developmental stress and behavior of Early and Late Neolithic Cis-Baikal hunter-gatherer juveniles: Insights from diaphyseal cross-sectional geometry

This study explores growth (increase in size) and development (change in structure and function) in Middle Holocene Cis-Baikal hunter-gatherer populations to evaluate chronological and regional variation in developmental health and juvenile behavior using post-cranial Cross-Sectional Geometry (CSG). It also evaluates whether sexual differences in size and habitual behavior were evident by the end of adolescence. Age and body size standardized femur, tibia, and humerus midshaft CSG are used to test for differences between Early Neolithic (EN) and Late Neolithic (LN) juveniles from different micro-regions. Regression of these measures on radiocarbon date tests for differences within archaeological periods.EN individuals younger than 16 years, particularly those from the Angara River Valley, exhibit lower measures of cross-sectional size/ rigidity than LN juveniles. EN individuals older than 6 years, especially those from the Southwest Baikal had less circular lower limbs and higher humerus percent cortical area than LN individuals. Age standardized cross sectional size/ rigidity decline throughout both the EN and the LN, suggesting decrease in body size during both archaeological periods, whereas changes in femur shape are consistent with increases in juvenile mobility throughout the EN. By the end of adolescence, sexual dimorphism is emerging but not fully established in lower and upper limb robusticity and shape.The lower cross-sectional area and bending rigidity support higher levels of developmental stress in the EN compared to the LN period, whereas less circular lower limb indices suggest higher terrestrial mobility in the EN. These differences may reflect may a higher risk of resource scarcity in the EN, which resulted in higher mobility and greater involvement of juveniles in harvesting aquatic resources. Declines in body size within both archaeological periods emphasize the cyclical nature of developmental stress, perhaps due to declines in resource abundance. The presence of incipient sexual dimorphism by the end of adolescence is consistent with individuals beginning to assume adult roles.