Morphometric study of the fetal development of the human hip joint: significance for congenital hip disease.

Hip joints (280) from 140 human fetuses, obtained from abortions and deaths in the perinatal period, were studied. The fetuses ranged from 8.7 to 40 cm in crown-rump length and are believed to be between 12 and 42 weeks in age. The joints were dissected, morphology inspected, and measurements taken of the depth and diameter of the acetabulum, the diameter of the femoral head, length and width of the ligament of the head, the neck-shaft, and torsion angles of the proximal femur. Regression models were fitted to determine which would best predict the growth pattern. Multivariate analysis of variance showed no significant differences between males and females or between the right and left sides. Acetabular depth was shown to be the slowest-growing hip variable, increasing less than fourfold in the period studied. Acetabular indices less than 50 percent indicate a shallow socket at term. Femoral head and acetabular diameter demonstrated a strong relationship (r = 0.860) and in many joints the femoral head diameter exceeded that of the acetabulum. Considerable variability was demonstrated in both femoral angles. The femoral angles showed only low correlation with the other hip variables. These observations indicate that soft tissue structures about the joint must play an important role in neonatal joint stability. The explanation of greater female and left side involvement in congenital hip disease must lie in factors other than growth changes of hip dimensions. Neither angle appears to be a useful indicator of normal joint development.     

Anterior femoral curvature: Its probable basis and utility as a criterion of racial assessment

Stewart ('62) and Walensky ('65) indicated that while the metrical expression of anterior femoral curvature alone will not always differentiate between Whites, American Negroes, and North American Indians, it was very useful as a racial criterion in combination with observed traits such as torsion, pilastry, and cross-sectional shape. Seven additional North American Indian groups reported here, representing both pre-Columbian and post-contact times, upheld the observation that anterior femoral curvature is a useful feature of racial assessment for Negroes, Whites and North American Indians. However, two South American groups studied (Ecuador and Peru) were only slightly more curved than American Negroes, and were less curved than Whites and North American Indians. The metrical expression of anterior femoral curvature therefore is not a useful feature of racial assessment for separating these two South American Indian groups from Whites and American Negroes. Femora of American Negro and White individuals with low ponderal indices were found to be less bowed than the norms for their race; individuals with high ponderal indices were more bowed than the norm for their race. The assumed genetic basis for expression of anterior femoral curvature suggested by Stewart ('62) and Walensky ('65) seems to be a feature of human plastic response to body weight rather than to temporal, clinal, postural or equestrian influences.     

Testing assumptions of the Gilbert and Gill method for assessing ancestry using the femur subtrochanteric shape

In 1990, Gilbert and Gill proposed a simple metric technique using femoral subtrochanteric anteroposterior and mediolateral diaphyseal diameters for discriminating between Native American and American Black and White femora in medicolegal and bioarchaeological contexts. However, there are several inherent assumptions in the method that may affect its validity. The assumptions include minimal sexual dimorphism, temporal and geographical homogeneity within populations, and that differences between populations in femoral subtrochanteric size and shape are primarily due to genetic variation. In this study, these assumptions are tested using femora from seven populations (African, American Black, American White, Australian, Native American, Hispanic, and Polynesian). The results indicate that sexual dimorphism and geographical and temporal heterogeneity in proximal femur diaphyseal shape within Native Americans are not great enough to significantly affect the validity of the Gilbert and Gill method (GGM). Variation between populations is most likely due to combined genetic and environmental factors, but differences in proximal femur shape between Native Americans and American Blacks/Whites are sufficient to allow accurate discrimination between these groups. Caution, however, must be taken during investigations where populations other than Native Americans or American Blacks/Whites are present, and therefore, the GGM may have limited forensic anthropological application in many parts of the world.     

Cortical bone distribution in the femoral neck of strepsirhine primates

The thickness of the inferior and superior cortices of the femoral neck was measured on X-rays of 181 strepsirhine primate femora representing 24 species. Neck length, neck depth and neck-shaft angle were also measured. The strength of the femoral neck in frontal bending was estimated by modeling the neck as a hollow cylinder, with neck depth as the outer diameter and cortical thickness representing the superior and inferior shell dimensions. Results indicate that the inferior cortex is always thicker than the superior cortex. The ratio of superior to inferior cortical thickness is highly variable but distinguishes two of the three locomotor groups in the sample. Vertical clingers and leapers have higher ratios (i.e., a more even distribution of cortical bone) than quadrupeds. The slow climbers tend to have the lowest ratios, although they do not differ significantly from the leapers and quadrupeds. These results do not confirm prior theoretical expectations and reported data for anthropoid primates that link greater asymmetry of the cortical shell to more stereotypical hip excursions. The ratio of superior to inferior cortical thickness is unrelated to body mass, femoral neck length, and neck-shaft angle, calling into question whether the short neck of strepsirhine primates acts as a cantilever beam in bending. On the other hand, the estimated section moduli are highly correlated with body mass and neck length, a correlation that is driven primarily by body mass. In conclusion, we believe that an alternative interpretation to the cantilever beam model is needed to explain the asymmetry in bone distribution in the femoral neck, at least in strepsirhine primates (e.g., a thicker inferior cortex is required to reinforce the strongly curved inferior surface). As in prior studies of cross-sectional geometry of long bones, we found slightly positive allometry of cortical dimensions with body mass.     

Some anthropometric studies of the femur of the male West Malaysian Chinese

Measurements and indices were made on 120 male West Malaysian Chinese femora. The findings are compared with appropriate ones from some Eastern and Western series. The Chinese femur is smaller than all the other groups listed except for the Japanese femur. There is a high degree of significance between the maximum and bicondylar lengths of the Chinese femur against those of the Australian aborigine, Maori and White American. The head of the femur is greater in the Maori and White American than the Chinese. The platymeric index is nearly as high as the White American. The difference in the robusticity index of the femur between the Australian aborigine, Maori, White American and the present series is small. The collodiaphyseal angle of the Chinese femur is large being greater than the Australian aborigine, Finn and White American. The angle of torsion of 11.8° is within the range for Westerners with a high incidence of retroversion unlike the Australian aborigine and Maori where no retroversion is seen. Although most of the means of the measurements and indices of the femur show a highly significant difference between the present series and some of the other groups listed there is a wide overlap for measurements of the Chinese femur to be used for racial identification.     

Subject-specific hip geometry and hip joint centre location affects calculated contact forces at the hip during gait

Hip loading affects the development of hip osteoarthritis, bone remodelling and osseointegration of implants. In this study, we analyzed the effect of subject-specific modelling of hip geometry and hip joint centre (HJC) location on the quantification of hip joint moments, muscle moments and hip contact forces during gait, using musculoskeletal modelling, inverse dynamic analysis and static optimization. For 10 subjects, hip joint moments, muscle moments and hip loading in terms of magnitude and orientation were quantified using three different model types, each including a different amount of subject-specific detail: (1) a generic scaled musculoskeletal model, (2) a generic scaled musculoskeletal model with subject-specific hip geometry (femoral anteversion, neck-length and neck-shaft angle) and (3) a generic scaled musculoskeletal model with subject-specific hip geometry including HJC location. Subject-specific geometry and HJC location were derived from CT. Significant differences were found between the three model types in HJC location, hip flexion–extension moment and inclination angle of the total contact force in the frontal plane. No model agreement was found between the three model types for the calculation of contact forces in terms of magnitude and orientations, and muscle moments. Therefore, we suggest that personalized models with individualized hip joint geometry and HJC location should be used for the quantification of hip loading. For biomechanical analyses aiming to understand modified hip joint loading, and planning hip surgery in patients with osteoarthritis, the amount of subject-specific detail, related to bone geometry and joint centre location in the musculoskeletal models used, needs to be considered.     

Moment coefficients of skewness in the femoral neck cortical bone distribution of BAR 1002’00

The cortical bone distributions in the femoral necks of apes and humans differ as a result of different loading environments caused by the realignment of the hip abductor apparatus. Femoral neck cortical bone in extant humans is very thin superiorly and thicker inferiorly, while the cortical bone in apes tends to be more uniformly thick. The unique internal anatomy of extant humans allows inferences to be made about primary locomotor function from incomplete femora. Here the differences in cortical bone distributions are quantified using moment coefficient of skewness. Skewness coefficients at two locations along the neck of the 6 million years old African femoral specimen BAR 1002’00 were compared to samples of 9 extant adult humans and 10 adult chimpanzees. The skewness coefficients of cortical bone in the femoral neck of BAR 1002’00 are more similar to those of chimpanzees than to humans, although the contrast is less pronounced in the region closer to the neck-shaft junction than more proximally toward the femoral head; this pattern indicates that in at least one respect this specimen attributed to Orrorin tugenensis manifests structural features suggesting influences of a hip abductor apparatus that had not yet evolved to the same extent as in extant humans.     

内蒙古和林格尔土城子农业人群与林西井沟子游牧人群股骨中部的生物力学对比

肢骨的形态结构可以反映人类进化、古代人群的生存适应性活动和生存环境等重要信息。基于“骨骼功能适应”和“杠杆原理”,有学者对不同生计方式的古代人群下肢股骨开展了大量的研究工作,但是,国内外尚未有关于农业人群和游牧人群股骨之间差异性研究的报道。本文选取两个具有代表性的古代人群,即内蒙古和林格尔土城子戍边农业人群和内蒙古林西井沟子游牧人群进行对比研究。通过对股骨骨干中部横断面生物力学分析发现,农业人群股骨粗壮度与游牧人群之间具有显著差异。前者的平均粗壮度较大,后者女性组下肢骨的活动强度明显较小,这可能与游牧人群经常从事骑马活动而下肢骨活动强度相对较少有关。农业人群股骨指数的变异范围均大于游牧人群,这可能与前者男性的士兵身份有关;同时,也提示土城子男性组股骨所反映的行为活动信息并不代表真正意义上的纯农业人群下肢骨行为模式,而是一种农业和士兵行为的混合模式。在性别分工上,井沟子组的男女性均从事骑马活动,两侧股骨受力较为一致,在两侧不对称性程度和骨干横断面形状上的男女差异不大;男性股骨的粗壮度要明显大于女性,这与井沟子组男性还从事一定的狩猎行为有关。与游牧人群女性较为纤细的股骨不同,土城子组女性作为典型的农业人群代表,其下肢骨整体的活动强度较大,几乎与同组的男性和井沟子组男性相当,组内的性别差异相对较小;骨干横断面形状的显著性差异说明,土城子组内部男性和女性的行为活动方式存在明显的性别分工。本文研究结果说明农业人群女性的下肢骨活动强度较大,在行为活动方式上,戍边农业人群具有更为明显的性别分工。     

Variation in the number of presacral vertebrae in bantu-speaking South African Negroes

Variation in number of presacral vertebrae (PSV) was examined in 462 vertebral columns in four populations drawn from tribal groups of Southern African Negroes. The total incidence of numerical variants (23 PSV and 25 PSV) was 19% in males and 12.1% in females. Males have a higher frequency of 25 PSV and females a higher frequency of 23 PSV, a sex difference reported by previous workers. Significant differences in the incidence of 25 PSV in males were present between S.A. Negroes, American Negroes and other racial groups. The total number of variants (23 PSV and 25 PSV) is significantly higher in S.A. Negro males (and higher but not significantly in females) than in the other groups; owing mainly to the findings in the Nguni-speaking sub-samples of the S.A. Negro. These findings support a previous suggestion based on combined-sex data that the frequency of numerical variations of PSV are characteristic of a population. It is suggested here that such frequencies are even more characteristic when males and females are considered separately.     

Morphology of Liberian Negro deciduous teeth I. Odontometry

An odontometric study of the deciduous teeth of 21 Liberian Negro children is reported. These data were obtained from dental casts alone. Statistical comparisons were made of the mesiodistal diameter alone with two American White populations and the three Japanese populations. Maxillary teeth, with the exception of the cuspids were larger in the Negro sample, while only the Negro mandibular molars were significantly wider. This situation resulted in an alteration of Negro maxillary tooth size order. Comparisons were made with other populations reported in the literature which led us to stress the fact that, as yet, no satisfactory sample of deciduous tooth measurements are available for any population. A discussion of tooth form differences stresses the point that teeth differ in both attributes of form, i.e., in shape as well as in size between the several major racial groups. The processes by which these shape differences are brought about were discussed and it was suggested that differing relative growth rates may well be one cause. An allometric analysis of fetal molar tooth growth showed, again, that a sharp interphase occurs in all teeth, with a subsequent decrease in specific growth rate. This interphase corresponds to the initiation of cuspal calcification.     

An evaluation of race and sex identification from cranial measurements

A total of 104 adult human crania (95 American Indian and 9 Labrador Eskimo) are used in this evaluation of a discriminant functional analysis for determining race and sex from eight cranial measurements. The methods used are those given by Giles and Elliot ('62). The study shows that non-deformed American Indian crania are racially misclassified as American White and Negro in 35.6% of the cases when using this metrical method. Deformed Indian crania are racially misclassified 60.0% and 4.4% of the time as White and Negro respectively. The determination of sex on male crania, regardless of deformation, is as accurate as, or better than, the visual method of identification. The female crania, however, are shown to be incorrectly sexed in nearly 50% of the cases, with one non-deformed group (Palus) running as high as 80.0%. This evaluation suggests, therefore, that discriminant functional analyses for race and / or sex determinations are not applicable to problems of human identification unless the crania are from that population on which these functions were established.     

Sex and race differences in finger ridge-count correlations

Correlations between ridge-counts on the ten fingers were compared by race and sex in 11 samples representing Negroes and Caucasians: five from subsaharan Africa, one American Black, three European, one American White and one from India. The samples of European ancestry showed no consistent sex difference in mean correlation, although female American Whites significantly exceeded males. In three of the six Negro samples and in the Parsis of India males showed significantly higher average correlations than females. The pattern of sex and race differences suggests that the sex chromosomes, particularly the Y chromosome, play a role in dermal ridge development.     

Brief communication: Sex determination accuracy of the minimum supero-inferior femoral neck diameter in a contemporary rural Guatemalan population

One hundred and fourteen femora (75 male and 39 female) derived from a contemporary rural Guatemalan population were studied to test the ability of the minimum supero-inferior femoral neck diameter as a sex indicator. With the discriminant functions previously developed from North American modern populations, a maximum of only 36% correctly sexed femora was obtained, with correct percentages as low as 4%. A new discriminant function for the Guatemalan rural population is presented, with a total of 89.5% correctly classified individuals. It is suggested that poor physical growth of the rural Guatemalan population, due to a stressful environment, can explain part of the metric differences observed between the North American and rural Guatemalan populations.     

Ceramic cups for hip endoprostheses. 6: Cup design, inclination and antetorsion angle modify range of motion and impingement]

The present investigation focuses on total hip replacement using ceramic acetabular components. The relationship between the position of the cup and the range of motion (ROM) was investigated. A limited range of motion may cause impingement, which is defined as contact between the femoral neck and the rim of the acetabular cup. Impingement may result in wear, chipping, fracture or dislocation of the femoral head. Joint movements were simulated in a three-dimensional CAD program. The results obtained underscore the importance of correct positioning and design of the cup for achieving a ROM as close to the physiological situation as possible. With ceramic cups, the inclination angle should not be more than 45 degrees, and the antetorsion angle between 10 and 15 degrees. If the cup is too vertical, the risk of dislocation and fracture of the ceramic increases. If, on the other hand, the angle of inclination is too small, flexion and abduction will be greatly limited. The study shows that acetabular components with non-recessed ceramic inserts should not be used. Slight recession of the insert helps to avoid impingement. The ROM is reduced and the risk of impingement appreciably increased when mushroom-shaped femoral heads (XL heads) or ceramic inserts protected by a polyethylene ring are used.     

Sex assessment of the femur: a test of a new method.

Simple and multiple discriminant functions using mid-shaft femoral circumference for the determination of sex were used to test a sexing method recently proposed by Black. The method was able to correctly assign sex for 82% of the sample, which consisted of 115 North American White femora of verified age and sex. Circumference proved as accurate as any other criteria that have been used in sexing the femur. This suggests a usefulness beyond the limited archaelogical scope originally proposed by Black.     

The dermatoglyphics of American Negroes

Digital and palmar dermatoglyphics of 184 male and 224 female normal American Negroes were evaluated for digital patterns, digital ridge counts, palmar patterns, palmar main line terminations, accessory triradii and palmar creases. All subjects were seven year olds examined and found free of chronic or other genetic diseases. The results were presented for the left and right hand for the most part comparable to those of the African and other American Negro groups reported earlier. The distributions of the various dermatoglyphic features among the Negroes taken as a group were compared to those of the other racial groups and their differences were discussed.     

Subject-specific hip geometry affects predicted hip joint contact forces during gait

Hip loading affects bone remodeling and implant fixation. In this study, we have analyzed the effect of subject-specific modeling of hip geometry on muscle activation patterns and hip contact forces during gait, using musculoskeletal modeling, inverse dynamic analysis and static optimization. We first used sensitivity analysis to analyze the effect of isolated changes in femoral neck-length (NL) and neck-shaft angle (NSA) on calculated muscle activations and hip contact force during the stance phase of gait. A deformable generic musculoskeletal model was adjusted incrementally to adopt a physiological range of NL and NSA. In a second similar analysis, we adjusted hip geometry to the measurements from digitized radiographs of 20 subjects with primary hip osteoarthrosis. Finally, we studied the effect of hip abductor weakness on muscle activation patterns and hip contact force. This analysis showed that differences in NL (41-74 mm) and NSA (113-140 degrees ) affect the muscle activation of the hip abductors during stance phase and hence hip contact force by up to three times body weight. In conclusion, the results from both the sensitivity and subject-specific analysis showed that at the moment of peak contact force, altered NSA has only a minor effect on the loading configuration of the hip. Increased NL, however, results in an increase of the three hip contact-force components and a reduced vertical loading. The results of these analyses are essential to understand modified hip joint loading, and for planning hip surgery for patients with osteoarthrosis.     

Height and weight growth patterns of school age deaf children

Distance and velocity curves for height and weight were analyzed in a mixed longitudinal sample of American White, American Negro and Mexican-American deaf children 6 through 17 years of age. The heights of deaf boys and girls are, on the average, consistently below an accepted pediatric standard from six through ten years of age. Between 11 and 17 years, deaf White and Negro boys approximate the standard, while White and Negro girls are at or slightly below the standard. Deaf Mexican-American children are consistently below the height standard. For body weight, deaf boys are at or slightly below the standard from 6 to 11 years, and are at or slightly above the weight standard from 12 to 17 years of age. White and Negro deaf girls generally approximate the weight standard from eight years of age on. Mexican-American deaf girls are consistently below the standard until 13 years of age, while between 14 and 17 years they are at or above the standard. Height and weight velocity curves for deaf children parallel closely the incremental standards of Falkner ('62). The height velocity curve, however, appears to peak, on the average, about one year earlier in deaf children.     

During sideways falls proximal femur fractures initiate in the superolateral cortex: Evidence from high-speed video of simulated fractures

Results of recent imaging studies and theoretical models suggest that the superior femoral neck is a location of local weakness due to an age-related thinning of the cortex, and thus the site of hip fracture initiation. The purpose of this study was to experimentally determine the spatial and temporal characteristics of the macroscopic failure process during a simulated hip fracture that would occur as a result of a sideways fall. Twelve fresh frozen human cadaveric femora were used in this study. The femora were fractured in an apparatus designed to simulate a fall on the greater trochanter. Image sequences of the surface events related to the fractures were captured using two high-speed video cameras at 9111 Hz. The videos were analyzed with respect to time and load to determine the location and sequence of these events occurring in the proximal femur. The mean failure load was 4032 N (SD 370 N). The first surface events were identified in the superior femoral neck in eleven of the twelve specimens. Nine of these specimens fractured in a clear two-step process that initiated with a failure in the superior femoral neck, followed by a failure in the inferior femoral neck. This cadaveric model of hip fracture empirically confirms hypotheses that suggested that hip fractures initiate with a failure in the superior femoral neck where stresses are primarily compressive during a sideways fall impact, followed by a failure in the inferior neck where stresses are primarily tensile. Our results confirm the superolateral neck of the femur as an important region of interest for future hip fracture screening, prevention and treatment research.     

Classification and misclassification in sexing the Black femur by discriminant function analysis

Stepwise discriminant function analysis for sex assessment was applied to 130 North American Black femora. The measurements included femoral length and three midshaft dimensions likely to be preserved in archaeologically derived and forensic remains. The method correctly assigned sex for 76.4% of the sample (range 70.8–81.5%). This compares favorably with results achieved with other skeletal parts; it also compares favorably with results using the femur in sexing other racial groups. Among our other conclusions are: (1) a “general size factor” is one of major significance in correct classification and in misclassification of sex, and most misclassified individuals are anomalous for this factor; (2) the inconsistency in the relation between circumference and femoral length, which characterizes the remaining misclassified individuals, suggests that anomalous functional demands of body weight/musculature are at fault, and affect circumference more than length; and (3) discriminant function analysis of the same variables in Whites produced similar results, suggesting that sex overrides race in sex assessment; this was confirmed by cross-validating the predictive accuracy of Black discriminant function coefficients on White data, and vice versa.