Using preoperative planning software to assess the effect of head length on prosthetic range of motion in a high-risk population: a three-dimensional modeling study.

PURPOSE: Concurrent use of minus heads with tapered stems in total hip arthroplasty (THA) decreases the prosthetic range of motion (pROM). Three-dimensional preoperative templating can simulate the location of the impingement by taking the hip through a virtual pROM. This enables surgeons to simulate how modifying the type of implant, orientation, and position influences impingement. We hypothesized that CT-based modeling would result in a decrease in the pROM, thereby increasing the risk of impingement when minus heads are used. METHODS: Forty-three patients who underwent robotic-assisted primary THAs were included. Prosthetic head diameter (32/36-mm) and head length (minus/zero/plus) were the predictors. Maximum external rotation at full hip extension and internal rotation at 90° and 100° of flexion prior to prosthetic impingement were the outcome variables. A CT-based preoperative planning software was used for pROM estimation and impingement detection. RESULTS: Significant decreases in pROM were found for both head diameters as the head length decreased and was more pronounced in external rotation during full hip extension (changes of 2.8-3.4° for the 32-mm head and 1.6-2.8° for the 36-mm head (p = 0.00011)). The magnitude of loss in pROM when using a minus head was larger than the gain provided by a plus head in tapered stems (p < 0.0001). CONCLUSION: Head length affects the offset and pROM. When the use of minus heads or smaller heads is indicated, 3D preoperative templating for assessing postoperative pROM and impingement provides surgeons with options to consider alternate surgical plans offering additional assurance and protection from dislocation.

High femoral offset as a risk factor for aseptic femoral component loosening in cementless primary total hip arthroplasty.

PURPOSE: Lateralized stems in primary cementless total hip arthroplasty (THA) showed to be associated with aseptic femoral loosening. However, femoral head length also affects femoral offset but was not considered so far. This study analyzed the impact of high femoral offset (hFO) combinations, formed by lateralized stems or large femoral head lengths, on aseptic femoral component loosening. METHODS: Retrospective cohort study was performed including all patients that underwent primary cementless THA at our institution between July 2004 and December 2016. Patients were screened for aseptic femoral component loosening and grouped in aseptic loosening (AL) and non-aseptic loosening (nAL) group. Medical records were screened; implant details were noted and classified in hFO and standard femoral offset (sFO) combinations. Supposed risk factors for aseptic loosening were analyzed. RESULTS: Two thousand four hundred fifty-nine THA could be included, containing 14 THA (0.6%) with aseptic femoral component loosening. The AL group contained 11 hFO combinations (78.6%), whereas in the nAL group, 1315 hFO combinations (53.8%) were used. Subgroup analysis showed significant difference between two groups for hFO combinations (p = 0.014), age (p = 0.002), NSAR (p = 0.001), and bilateral THA on same day (p = 0.001). The multiple logistic regression analysis showed that hFO combination was the only variable for increased probability of aseptic loosening (OR, 3.7; p = 0.04). CONCLUSION: High femoral offset combinations, formed by lateralized stems or large femoral head lengths in our collective of standard straight stems implanted by an anterior approach, show a 3.7-fold increased probability for aseptic femoral component loosening. Adjustment of the postoperative protocol may be considered in these cases to ensure proper stem ingrowth.

The Impact of Varying Femoral Head Length on Hip External Rotation During Posterior-approach Total Hip Arthroplasty.

Background: Prior investigations of total hip arthroplasty (THA) have studied the effects of prosthetic femoral head size and stem offset on hip range of motion (ROM), impingement risk, and overall hip stability to optimize the return to activities of daily living. However, the relationship between femoral head length and hip ROM, specifically external rotation (ER), has not been evaluated. The aim of our study was to intraoperatively assess how femoral head length affects hip ROM during a posterior approach THA. Methods: Thirty-two patients undergoing a primary elective THA through a posterior approach were prospectively included. After final femoral stem insertion, femoral head trials were performed using the targeted head length, followed by the shorter (-3.0 to -3.5 mm) and longer (+3.0 to +4.0 mm) head length configurations. At each length, hip ER was measured using an intraoperative goniometer from an imageless navigation system. ER values across the three head lengths were compared using a repeated-measures analysis of variance and paired t-tests. Results: Varying femoral head lengths demonstrated a statically significant and reproducible effect on intraoperative ER range (analysis of variance; P < .001) in each patient. An increased femoral head length (mean 3.4 mm) significantly decreased (P < .001) ER range by 10.8 ± 3.3° while a shortened femoral head length (mean 3.5 mm) significantly increased (P < .001) the ER ROM by 6.0 ± 3.8°. Conclusions: The results of this study demonstrate the sensitivity of hip ROM to incremental changes in femoral head length. As ER is important for activities of daily living, inadvertent lengthening should be avoided.

Anthropometric and Physiologic Parameters in Cleft Neonates: A Hospital-Based Study.

The oro-facial morphology is greatly affected in neonates with a cleft lip and palate. The initial evaluation of neonate's body and maxillary arch dimensions is important for treatment planning and predicting growth in cleft patients. The objective of this study was comparative evaluation of the anthropometric and physiologic parameters of cleft and non-cleft neonates in a hospital-based set up. This cross sectional study was conducted on 88 cleft and non-cleft neonates (n = 44 in each group) aged between 0 and 30 days after obtaining approval from the institutional ethics committee and positive written informed consent from their parents. Neonates' body weight, body length, head length, head circumference, and maxillary arch dimensions were measured. Maxillary arch dimensions were measured on dental casts with digital sliding calipers. Statistical analyses performed using the independent t-test and one-way ANOVA analysis were followed by Bonferroni correction for post-hoc comparison. The results showed statistically significant differences in birth weight (p < 0.0001), head length (p < 0.01), head circumference (p < 0.007), and maxillary arch dimensions (p < 0.0001) between cleft and non-cleft neonates. These findings suggest that cleft neonates had significant anthropometric and physiologic variations than non-cleft neonates.

Cephalofacial differences between males 18 years of age and 20-30 years of age / Diferencias cefalofaciales entre hombres de 18 años y de 20-30 años

SUMMARY: The human skull is comprised of many flat and irregular bones, divided into two groups: cranial and facial bones. The size, shape and growth of the human skull are the product of many interrelated internal and external factor interactions. The purpose of the present study was to explore the systematic differences in cephalofacial size and shape classification between two measured groups of different ages and different period of done measurements. Five cephalofacial variables and four cephalofacial indexes were measured on 795 entities of the Kosovo Albanian population in two different timelines; 401 male entities aged 20-30 years old were measured during the timeline 1997-1999, while 394 male entities aged 18 years old were measured during the timeline 2016-2018. The gained data were analyzed in terms of basic descriptive statistical parameters and the percentage of distribution of results. The most pronounced differences between the age groups of 18 year-olds and the age group of 20-30 year-olds, are mainly emphasized in the morphological height of the face, total facial index and transverse cephalic index. While in other dimensions, the distribution of results is very similar. Differences between groups can be justified by the age at which the growth of the cephalofacial bones ends and the influence of external factors such as nutritional and socio-economic factors.

RESUMEN: El cráneo humano está compuesto por huesos planos e irregulares, divididos en dos grupos: huesos craneales y faciales. El tamaño, la forma y el crecimiento del cráneo humano son el producto de muchas interacciones de factores internos y externos interrelacionados. El propósito del presente estudio fue explorar las diferencias sistemáticas en la clasificación de tamaño y forma cefalofacial entre dos grupos de diferentes edades y en diferentes períodos de mediciones. Se midieron cinco variables cefalofaciales y cuatro índices cefalofaciales en 795 entidades de la población albanesa de Kosovo en dos líneas de tiempo diferentes. Se midieron 401 entidades masculinas de 20 a 30 años. Durante el periodo 1997-1999 se medieron 401 entidades masculinas de 20 a 30 años, mientras que 394 entidades masculinas de 18 años se se midieron durante el periodo 2016-2018. Los datos obtenidos se analizaron en términos de parámetros estadísticos descriptivos básicos y el porcentaje de distribución de los resultados. Las diferencias más pronunciadas entre los grupos de edad de 18 años y el grupo de 20-30 años, se enfatizan principalmente en la altura morfológica de la cara, índice facial total e índice cefálico transversal. Mientras que en otras dimensiones, la distribución de resultados es muy similar. Las diferencias entre grupos pueden estar asociadas a la edad en la que finaliza el crecimiento de los huesos cefalofaciales y la influencia de factores externos, tal como aspectos nutricionales y socioeconómicos.

Ancient to modern secular changes in the cranial/cephalic index in Korea: historical brachycephalization and recent debrachycephalization.

We investigated changes in the cranial/cephalic index of the Korean population in millennia, centuries, and recent decades. Secular changes of Korean's cephalic index in history were studied using the data of archaeology literature and our measurement data of different adult skull sets for the fifteenth-nineteenth century Joseon people, the Korean War victims (1950-1953), and the Korean skeletons collected by medical schools in the 1960s. A change in head shape during the last century was also estimated by the analysis on Korean cephalometric datasets of Korean Research Institute of Standards and Science. In brief, over the past 2000 years, the crania of Korean people have steadily changed from mesocephalic to brachycephalic, mainly due to the cranial length shortening. Brachycephalization accelerated at the beginning of the twentieth century and continued until the early twenty-first century, largely caused by increased cephalic breadth. We also note that debrachycephalization began in birth cohorts around 1965 for males and around 1970 for females. Taken together, we figure out that the head shape of Korean people has been gradually shortened over millennia and then has undergone dramatic shortening in the last century. In recent decades, however, the changing pattern has reversed to debrachycephalization, for which we discussed about the possible causes in the present report.

Micromotion at the head-stem taper junction of total hip prostheses is influenced by prosthesis design-, patient- and surgeon-related factors.

Taper junctions of modular hip prostheses are susceptible to fretting and crevice corrosion. Prevalence and significance increase for cobalt-chromium heads assembled on titanium-alloy stems. Retrieval and in-vitro studies have identified micromotion between the taper components to accelerate the corrosion process. The aim of this study was to identify the most critical factors contributing to increased micromotion, which is most likely influenced by design-, patient- and surgeon-related aspects. Micromotion between head and stem taper surfaces was measured for different taper surface topographies and load orientations. Consecutive visual images were recorded through windows in the head component. By image matching analysis the local micromotions at the taper junction between head and stem tapers were determined. To extend the findings to taper regions not visible through the windows, finite element models were generated. The models were further utilized to investigate the influence of head length, taper angle difference and assembly force on micromotion. Significantly higher micromotion (+20%) was found under varus loading (7.1 µm) in comparison to valgus loading (5.9 µm). Smooth and microgrooved stem tapers exhibited equal amounts of micromotion. The numerical model revealed head tilting and recurring taper contact changes in terms of cyclic engagement/disengagement during the loading sequences. Especially long heads (+240%) and low assembly forces (+53%) were found to substantially increase micromotion (from 2.7 µm to 9.3 µm and from 4.1 µm to 8.8 µm, respectively). This study accentuates the susceptibility of taper junctions to a variety of factors, which need to be appreciated in preoperative planning and surgical procedure to reduce the amount of micromotion and such minimize the risk of critical corrosion.

The effect of altering head length on corrosion using a material loss method.

INTRODUCTION: Corrosion at head neck taper junctions in total hip arthroplasty has increasingly been reported in the literature. Debate persists as to the exact causes and clinical significance of corrosion. Increased offset and head length has been correlated with an increased risk of tribocorrosion due to an adverse mechanical environment. The purpose of this study is to assess the effect of head length on corrosion of a metal-on-polyethylene articulation. METHODS: Retrievals from a single institution of 28-mm cobalt chromium alloy heads with a 12/14 taper from a single manufacturer were studied. Corrosion of femoral head bores were studied utilising a material loss method. Testing was performed using co-ordinate measuring for maximum linear wear depth. RESULTS: 56 heads were examined with lengths of either -3, 0, +4 or +8 mm and all had been in situ for a minimum of 2 years. There were no significant differences in mean maximum linear wear depth (MLWD) (p = 0.6545). There was no correlation found between MLWD and the time implants were in situ (Spearman coefficient -0.1157) and no significant difference seen between high or standard offset stems (p = 0.1336). CONCLUSION: In contrast to studies using qualitative methodologies, there was no correlation between head length and material loss when confined to a 28-mm head. Broad application of this outcome should be cautioned against as this study examined 1 taper construct and a metal-on-polyethylene articulation.

Genetic Mapping of Head Size Related Traits in Common Carp (Cyprinus carpio).

Head size is important economic trait for many aquaculture fish which is directly linked to their carcass yield. The genetic basis of head size trait remains unclear in many widely cultured fish species. Common carp (Cyprinus carpio) is one of the most widely studied fish due to its importance on both economic and environmental aspects. In this study, we performed genome-wide association study using 433 Yellow River carp individuals from multiple families to identify loci and genes potentially associated with head size related traits including head length (HL), head length/body length ratio (HBR), eye diameter (ED), and eye cross (EC). QTL mapping was utilized to filter the effects of population stratification and improve power for the candidates identification in the largest surveyed family with a published genetic linkage map. Twelve SNPs showed significant for head size traits in GWAS and 18 QTLs were identified in QTL mapping. Our study combining both GWAS and QTL mapping could compensate the deficiency from each other and advance our understanding of head size traits in common carp. To acquire a better understanding of the correlation between head size and body growth, we also performed comparisons between QTLs of head size traits and growth-related traits. Candidate genes underlying head size traits were identified surrounding the significant SNPs, including parvalbumin, srpk2, fsrp5, igf1, igf3, grb10, igf1r, notch2, sfrp2. Many of these genes have been identified with potential functions on bone formation and growth. Igf1 was a putative gene associated with both head size and body growth in Yellow River carp. The teleost-specific igf3 was a candidate head size related gene, related to both HL and HBR. Our study also indicated the importance of Igf signaling pathway for both growth and head size determination in common carp, which could be potentially used in future selective breeding in common carp as well as other species.

Cephalic Index in Indigenous Tharu Community.

INTRODUCTION: Cephalic index is an important parameter for differentiation of race and sex which varies significantly on the basis of hereditary, geographical, racial, sexual and other factors. It is a morphometric expression of different forms of head. The objective of this research was to evaluate the cephalic index of people of indigenous Tharu community of Biratnagar, Nepal and to determine different head types. METHODS: A cross-sectional study was conducted in which maximum head length and breadth of 100 adult Tharu people living in Biratnagar were measured using spreading caliper and scale. The cephalic index was obtained from these values using Hrdlicka's method. RESULTS: The mean cephalic index of the study population was 75.99±4.97. The mean cephalic indices of males and females were 76.22±5.14 and 75.78±4.85 respectively. The most common head type observed was dolichocephalic type 47 (47%). It was followed by mesocephalic type 37 (37%), brachycephalic type 13 (13%) was less common and least common was hyperbrachycephalic type 3 (3%). CONCLUSIONS: Long head (dolichocephalic) type is more common in Tharu population in both the genders, whereas, broad head (brachycephalic and hyperbrachycephalic) type is present in very few people.

Estimation of Body Height from Head Length among Dental Students of a Dental College.

INTRODUCTION: Body height is an important measure of physical identity. Height exhibits a dimensional relationship with various parts of the body. This relationship helps to calculate height from dismembered and mutilated body parts in forensic examinations. As the cranial dimensions are more reliable and precise means of predicting the stature, this study was undertaken to find the relation between head length and height and to derive a regression formula for the estimation of height from head length among dental students. METHODS: This descriptive cross-sectional study was conducted among 150 dental students of age group 18-21 years in the Department of Anatomy, Kantipur Dental College Teaching Hospital and Research Center, Basundhara, Kathmandu. The head length was measured with the help of spreading caliper. Height was measured with the help of a standard height measuring instrument. The head length and the height of the students were measured in centimeters. Data obtained were analyzed to find the correlation between head length and height and to derive a regression equation for the estimation of height. RESULTS: A significant positive correlation was observed between head length and height (r=0.734, P<0.001). The regression equation for body height and head length including both sexes and all age groups of dental students was found to be y=12.9+8.45x where x is head length and y is body height. CONCLUSIONS: It was observed in the present study that there was a significant positive correlation between height and head length in all the age groups indicating that head length is a reliable indicator in estimation of height.

Exploring the newborn head diameters in relation to current obstetric forceps' dimensions: A systematic review.

OBJECTIVE: The aim of this study was to systematically search the literature for studies that reported term neonate head size and shape, in an attempt to determine the most appropriate dimensions for the obstetric forceps. STUDY DESIGN: We searched the Ovid Medline, Ovid Embase and Ebscohost CINAHL databases from inception to February 2016. We predefined inclusion criteria to identify studies in which head width and length of asymptomatic, term neonates were measured soon after birth using direct, non-photographic methods A bespoke quality assessment score was used to evaluate the identified studies. RESULTS: Seven studies were identified which measured head width (biparietal diameter) in 551 neonates; giving a mean value of 94.0mm (range 90.7mm-95.5mm). We identified one study which measured head length (mentovertical diameter) in 38 neonates; which gave a mean value of 134.5mm (range 129mm-139mm). CONCLUSION: This data, in conjunction with measurements of Neville Barnes' and Wrigley's forceps from our previous study, indicates current obstetric forceps' blades are too long, and close together. Potentially, this could be contributing to neonatal and maternal injuries associated with operational vaginal deliveries.

The study of cephalic index in North Indian population / Estudio de Índice cefálico en una población del norte de India

Cephalic index (CI) and head shape are greatly affected by geographical, sex, age and racial factors. Such data is of great medico legal and forensic importance which indicates that cephalic index can be used as marker of ethnicity. There is less published literature about cephalic index of Punjab population. Hence, we undertook this study to document the cephalometric characteristics and gender differences in cephalic index of Punjabi community. Head length, head breadth and CI were determined for 500 medical students (17­23 years) of Punjab. The mean cephalic index for males was 80.52 and for females 84.32 which was statistically significant. On comparison with the existing literature the Punjabi community can be categorized as Brachycephalic/ Hyperbrachicephalic. This is of immense value in forensic science for facial reconstruction of disputed identity, orthodontics, different oral & maxillofacial surgery or craniofacial surgery, paleoanthropology and phylogeography.

El índice cefálico (IC) y la forma de la cabeza se ven afectados en gran medida por las regiones geográficas, el sexo, la edad y los factores raciales. Este tipo de dato son de gran importancia legal y forense dado que el IC puede ser utilizado como marcador de la etnia. Hay escasa literatura publicada sobre el IC de la población de Punjab. Por lo tanto, se realizó este estudio para documentar las características cefalométricas y las diferencias de sexo en el IC de una comunidad Punjabi. La longitud y ancho la cabeza, junto al IC, fueron determinados en 500 estudiantes de medicina (17­23 años) de Punjab. El IC medio para los hombres fue de 80,52 y para las mujeres 84,32, lo que fue estadísticamente significativo. En comparación con la literatura existente, la comunidad Punjab puede ser categorizada como braquicefálica/ hiperbraquicefálica. Esta información es de importancia para las ciencias forenses en relación a la reconstrucción facial con fines de identificación, como así también para la cirugía oral, maxilofacial, craneofacial, la paleoantropología y la filogeografía.

Neurocranial morphology of the albanian kosovo population / Morfología neurocranial de la población albanesa de kosovo

The purpose of this research publication in reference to the morphological features of the head of a Kosovo Albanian population takes us one step further toward studying the anthropological status of Kosovo Albanian population. Three cephalofacial variables were measured in 754 Kosovo subjects, between 18-35 years of age, 561 male and 193 female. The categorization of the head size of the treated subjects was done based on the head length (G-Op), head width (Eu-Eu), and head height (V-Po), according to the Lebzelter-Saler scale (head length and width) and Routil scale (head height). Results show that the head of the male subjects was characterized by long (50.1%), large (49.7%) and medium high head (46%), whereas, female subjects was characterized by a medium long (50.3%), medium large (50.8%) and low head type (41%). In general, the morphologic results of the head, match the results of the other authors, who found similarities between the morphologic features of the Dinaric type (Iliric) and Albanian population.

El propósito de esta investigación referente a las características morfológicas de la cabeza en la población albanesa de Kosovo, es un paso más en el estudio de su condición antropológica. Se midieron tres variables cefalofaciales en 754 sujetos de Kosovo entre 18­35 años de edad, correspondientes a 561 hombres y 193 mujeres. La categorización del tamaño de la cabeza fue realizada en base a la longitud de la cabeza (G­Op), ancho de la cabeza (Eu­Eu), y altura de la cabeza (V­Po) de acuerdo a la escala Lebzelter­Saler (longitud y ancho de la cabeza) y la escala Routil (altura de la cabeza). Los resultados muestran que la cabeza de los hombres se caracterizó por ser larga (50,1%), de gran tamaño (49,7%) y altura media (46%), mientras que en las mujeres se caracterizó por una longitud media (50,3%), tamaño medio (50,8%) y altura baja (41%). En general, los resultados morfológicos de la cabeza, concuerdan con los resultados de otros autores que encontraron similitudes entre las características morfológicas del tipo Dinárico (Ilírics) y la población albanesa.

Estimation of stature and age from head dimensions in Indian population / Estimación de la estatura y edad a partir de dimensiones de la cabeza en población india

Body segments exhibit consistent ratios with stature, age, gender and race. Thus prediction of stature from cranial remains is vital in establishing the identity of an unknown individual in natural calamities and archaeological exploration where entire body skeleton is not available. Little is known about the cranial dimensions in Indian population. Hence the study was carried out to predict stature, age and sex for solving medico-legal problems, anthropological complexities and archaeological investigations. Undergraduate students in the age group of 17-26 years of CSM Medical University, UP, India were selected as subjects because of easy access. Cranial dimensions of the subjects were measured by spreading calliper and Todd' head spanner. Heights of subjects were measured by standing height measuring instrument in similar anatomical position and at fixed time to avoid diurnal variation. The correlation and regression analyses and statistical analyses carried out here is most important to anthropologists and forensic science experts to facilitate them to solve complicated medico-legal problems.

Los segmentos corporales presentan proporciones de acuerdo a estatura, edad, sexo y raza. Así, la predicción de medidas de los restos craneales es vital para determinar la identidad de un individuo en desastres naturales, como también, en la investigación arqueológica en los casos cuando no se encuentra disponible el esqueleto completo. Existe escasa información acerca de las dimensiones craneales en la población de la India. El presente estudio se llevó a cabo para predecir la estatura, edad y sexo con el propósito de asistir en la resolución de problemas médico-legales, las complejidades antropológicas y las investigaciones arqueológicas. Como sujetos de estudio fueron seleccionados, debido a su fácil contribución, estudiantes universitarios entre 17 a 26 años de edad de la CSM Medical University, UP, India. Las dimensiones craneales de los sujetos se midieron mediante caliper digital deslizante y llave de Todd. Las alturas de los sujetos fueron tomadas por medición en posición anatómica de pie y en el tiempo fijado para evitar la variación diurna. Los análisis de correlación y regresión además de los análisis estadísticos realizados son importantes para antropólogos y expertos en las ciencias forenses con el propósito de facilitar y resolver complejos problemas médico-legales.

Study of cephalic index in Indian students / Estudio del índice cefálico en estudiantes Indios

Cephalic index is important parameter for deciding race and sex of an individual whose identity is unknown. Cephalic index and head shape are greatly affected by geographical, sex, age and racial factors. Present study aimed at working out cephalic index in Indian students. 100 students were taken as subjects and head length, head breadth were measured. Indian males had mean cephalic index of 77.92 and they were mesocephalic and females had mean cephalic index of 80.85 and they were brachycephalic. The comparison was statistically significant. The data is utmost important in forensic medicine, anthropology and in genetics.

El índice cefálico es un parámetro importante para determinar la raza y el sexo de un individuo cuya identidad es desconocida. El índice cefálico y la forma de la cabeza se ven afectados en gran medida por la geografía, el sexo, la edad y factores raciales. El presente estudio tuvo como objetivo la elaboración de índice cefálico de estudiantes indios. Cien estudiantes fueron tomados como sujetos de estudio, y fue medida la longitud y amplitud de la cabeza. Los hombres indios tuvieron una media del índice cefálico de 77,92 correspondiente a individuos mesocéfalos, mientras que las mujeres tuvieron una media del índice cefálico de 80,85 siendo braquicéfalas. La comparación fue estadísticamente significativa. Los datos obtenidos son de importancia para la medicina forense, la antropología y la genética.