Antropological measurement of the calcaneus.

Transfer of the forces from the trunk to the lower extremities end on calcaneus which transports these forces to the pad, and that is why it is very important to research this bone. This study was done on 57 calcaneal bones of the osteological collection of the Department of Anatomy "Drago Perovic" Zagreb School of Medicine and Department of Anatomy Osijek School of Medicine. The intention was to notice the regularity of the relations between specific dimensions and bone mass and structure, which is of great importance for understanding interrelation between biomechanical parameters of calcaneus and development of involutive changes. In this study geometrical parameters of the calcaneus have been defined, so length of the whole bone and especially frontal and back part, width, height, weight of dry bone, volume, geometrical surface of lateral and longitudinal cross section have been measured on every anatomical specimen. --Mean value, standard deviation and standard error have been calculated for every measured parameter. Positive correlation between most of the parameters of the calcaneus and negative correlation between specific weight and surface of cross section have been found. Coefficient of variation is the highest for weight, and the smallest for width.

Real mineral density of the sternum.

Mineral density of the sternum is insufficiently known. The aim of this research was to investigate mineralisation of the sternum and collect normative data on mineral density of the standard male and female sternum in elderly people (average age of female samples was 64 and male's was 62 years). The research was conducted on 93 cadaveric sternums, 56 male and 37 female samples. To determine regional mineral density of the sternum each sample was cut into six bony segments (Figure 1). Mineral density of every segment was determined using the method of ashing. Male sternums were on average denser than female ones in all segments. Average mineral density of the manubrium in women was 0.169 g/cm3 and 0.220 g/cm3 in men. Average mineral density of the body of the sternum also showed existence of sex difference; it was 0.160 g/cm3 in women and 0.227 g/cm3 in men. Both male and female sternums showed identical mineral density distribution. Mineral density of the manubrium and the body was roughly equal, while the analysis of longitudinal segments showed that the central part of both the manubrium and the body of the sternum was denser than lateral parts. Complex determination of the real mineral density for defined segments of the sternum and analysis of the obtained results were used to create the map of mineral density of the sternum in men and women (Figure 2). Maximum density values were four times greater than minimum density values for analysed samples. These data showed that osteoporosis also occurs on the sternum. Loss of structure and lower mineral density decrease the sternum quality and increase the risk of sternal dehiscence after median sternotomy.

Morphometric characteristics of thyroid cartilage in people of Eastern Croatia.

The aim of this research was to describe thyroid cartilage morphometry in the population of Eastern Slavonia in detail. The research was carried out on 68 samples of adult thyroid cartilages. There was statistically significant difference between all analysed parameters in male and female samples, except for the distance between the superior horns tips. All parameters had greater values in men, except for the thyroid angle, which was greater in women. There was significant correlation between most of the measured parameters. The strongest correlation was noticed in the distance between the horns at all measured levels and between the pairs of parameters measured for the left and right side respectively. The difference of our results in comparison to the results obtained by other researchers is probably caused by the fact that the measurements were taken on the samples obtained from different populations.

Vasculometry of upper and lower extremities in correlation with development of pathologic conditions like the diabetic foot.

We assume that the vascular apparatus of the lower limb did not evolutionary adapt to leg mass and volume. The lower limb is greater in length and volume that the upper limb, and therefore the arteries should have a bigger diameter and cross-sectional area. During pathoanatomic autopsies at the Department of Pathology of University Hospital Center Osijek we have taken segments of 1 cm of length from the subclavian, femoral, radial and tibial artery. Our sample contained segments from 51 bodies, 24 female and 27 male. We have measured leg and arm length and circumference. From these data the idealized limbs volume was calculated by geometric approximations to a cone fragment. The relation between idealized leg and arm volume and arterial cross-sectional area were calculated. For statistical analysis, Student's t-test was used. At the Department of Radiology of the University Hospital Center Osijek we measured the diameter of subclavian and femoral artery in systole and diastole in 41 patients (21 female and 20 male) by Color Doppler ultrasound, and the circumference and length of upper and lower limb was measured. There is a slightly difference between the diameter and cross-sectional area of subclavian and femoral artery. Leg length was for 48.5% bigger than arm length and the difference in volume between upper and lower limb is significantly different. The foot has four to five times greater volume than the arm, and is vascularised by an arterial tree of similar diameter. This fact proves our hypothesis that the blood supply to the lower limbs compared to the mass of tissue is smaller.

Morphometry of the pelvic ring in definition of biomechanical factors influencing the type of pelvic fracture.

The aim of the study was to supplement data on pelvic morphology and structural geometry. Using these data, a mathematical and biomechanical model was constructed. The research was divided into two parts. The first part comprised radiogrammetric analysis of pelvic morphology and geometry based on 60 AP x-rays of male and female pelvises. The spatial definition of the pelvis was given by three transverse and one sagittal diameter. Transverse diameters were measured at the level of iliac wings, at the narrowest supraacetabular portion and on the line passing through the center of both femoral heads. The fourth diameter was the height of the pelvis. Geometric properties and structure of pelvic bones and position of muscles in relation to bone elements of the pelvis were analyzed in the second part. Knowing geometric dimensions of the pelvis and the body weight, it is possible to calculate the magnitude of gravitational forces acting upon certain pelvic portions. This biomechanical model serves for simulation of operative methods of fixation and allows search for the optimal solution, which is stable enough to withstand all the forces acting upon fragments of a fractured pelvic ring.

Analysis of muscle forces acting on fragments in pelvic fractures.

CT was used in 50 adult pelvic fractures to determine the size and the position of relevant muscles with regard to bony elements in order to calculate muscle forces acting upon certain pelvic portions. Muscle length was measured to calculate muscle volume and physiological muscle cross-section. Among others, the size and direction of muscle forces were calculated for iliac, pubic and ischiadic fractures. The strongest muscle acting in iliac fractures is m. gluteus medius. The strongest upward pulling of iliac bone fragments is exerted by the erector muscles, while the major anterior, medial and downward pulling is performed by the iliopsoas muscle. In pubic bone fractures, eight muscles push bone fragments downward, the strongest among them being m. adductor magnus. Two muscles pull them upwards: m. rectus abdominis and m. obliquus externus. Nine muscles are responsible for downward displacement of bone fragments in ischiadic fractures, but the strongest is m. semitendinosus. Calculation of moments of muscle forces acting upon bone fragments using CT of pelvic fractures gives additional data for planning of optimal operative treatment that can guarantee stable fixation in individual patients.

Biomechanical model of the diabetic foot.

In this work, a two dimensional (2D) finite element foot model was established from magnetic resonance imaging (MRI) of a male subject. The model comprises first medial planar cross-section through the foot, representing the foot in standing posture. For specified external load, the stress and strain distribution field under foot structure are determined. The material characterization of foot structure components are stronger related to diabetic phenomena. The new material model for soft tissue based on mixture theory is proposed. The linear finite element model replaced by nonlinear counterpart with segment-to-segment contact element.

Supracondylar fractures of the humerus in children caused by traffic.

A sample of 38 patients aged under 14 treated at the Surgery Clinic of the University Hospital Osijek has been used in showing therapeutic guidelines supported by patients' functional status after the completed treatment. The patients suffered from supracondylar fractures caused by traffic accidents and classified into three types according to Gartland. Not a single patient with neurocirculatory disturbances has been registered. The most common treatment was a conservative one while more than half of the patients with fractures from type III underwent surgery. The duration of immobilization approximated three weeks whereas patients' recovery considering their functional status has justified the choice of the treatment. However, a lot can be done in the field of prevention, which would greatly decrease the frequency of such injuries.

Quantification model for muscular forces and momentums in human lower extremities.

The possibility of calculating muscular forces and momentums and their influence on skeleton was evaluated in this study by means of computerized tomography performed on a living person. Through this, the surface and corrected surface for each muscle cross section area were obtained, the distance from muscular centroide to the neutral bone axis was measured, and muscular force and muscular momentum on the bone were determined. Muscular momentum on the bone was obtained by multiplication of the muscular force and the distance between muscular centroide and neutral bone axis. The use of computerized tomography, as a method for creating a model for quantification of muscular forces and momentum, was proven to be reliable according to exactness in evaluation of all human lower extremity structures which is the basis for muscular biomechanical characteristic calculations.

The cancellous bone multiscale morphology-elasticity relationship.

The cancellous bone effective properties relations are analysed on multiscale across two aspects; properties of representative volume element on micro scale and statistical measure of trabecular trajectory orientation on mesoscale. Anisotropy of the microstructure is described across fabric tensor measure with trajectory orientation tensor as bridging scale connection. The scatter measured data (elastic modulus, trajectory orientation, apparent density) from compression test are fitted by stochastic interpolation procedure. The engineering constants of the elasticity tensor are estimated by last square fitt procedure in multidimensional space by Nelder-Mead simplex. The multiaxial failure surface in strain space is constructed and interpolated by modified super-ellipsoid.

Morphometric analysis of the sternum.

Sternum has a great clinical significance, considering that median sternotomy is the most common surgical approach used in cardiac surgery. The aim of this study is to standardize the sternum according to size, shape and sex and to obtain ranges of the "standard sternum". The study was done on 55 male and 35 female sterna of the average age of 65. Complex morphometric analysis of breadth, length and thickness of the sterna were performed on sternal segments which were defined by costal notches. Morphometric analysis shows that the general sternum structure in the females and in the males is equal. The standard dimensions of female and male sternum were determined. Standardization according to shape suggests that there is one standard sternum shape present in more than 2/3 of analysed samples of both sexes.

Foot anthropometry and morphology phenomena.

Foot structure description is important for many reasons. The foot anthropometric morphology phenomena are analyzed together with hidden biomechanical functionality in order to fully characterize foot structure and function. For younger Croatian population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot structure descriptors are influenced by many factors, as a style of life, race, climate, and things of the great importance in human society. Dominant descriptors are determined by principal component analysis. Some practical recommendation and conclusion for medical, sportswear and footwear practice are highlighted.

Morphological classification and sexual dimorphism of hyoid bone: new approach.

Hyoid bone is a part of viscerocranium placed between the tongue root and thyroid cartilage to which it is connected by thyrohyoid membrane. Widely accepted morphological classification does not exist. Sexual dimorphism was analysed in this study and new guidelines for anatomical classification of hyoid bones based on anthropometric parameters were given. Total number of analysed bones was 70. The bones were classified into three groups: symmetrical U-type, symmetrical V-type and asymmetrical type according to the angle between greater horns and the proportion of greater horns length. In the females incidence of asymmetrical type is considerably higher than in the males, while the incidence of symmetrical V-type is lower The angle value that is on average higher in males may be the parameter indicating that in puberty hyoid bone, still not completely ossified, to some extent follows development of thyroid cartilage because of their close anatomical relation.

The ventilatory patterns of the left upper lobe of lung.

Having knowledge on models of the bronchial tree branching, is of a special interest for clinical and surgical pulmology, because the hemilobectomy, segmentectomy and subsegmentectomy are always determined by intralobar, intrasegmental and intrasubsegmental bronchial ramification. Investigations were performed on 100 lungs of children and adults of both sexes, one day to 85 years old, randomly chosen. There are two main types of branching of the left upper lobe bronchus: the bifurcation pattern as dominant model in 74% and the trifurcation model found in 26%. Out of 100 lungs studied, 21 lungs had the ventilatory variations of the bronchopulmonary segments. The classification and categorization of the ventilatory of bronchopulmonary segments of the left upper lobe of lung were made. This classification contains 5 categories and 8 subcategories.

Circadian rhythm of blood leptin level in obese and non-obese people.

Leptin, an adipose tissue hormone, has circadian variations in its secretion. Aims of this study were to show how circadian rhythm depends on fat tissue distribution in obese and non-obese subjects. The research was carried out on 70 subjects (37 men and 33 women) with an average body mass index (BMI) of 25.22 kg/m2. Concentration of leptin in blood was measured at 8.30 a.m., 12.30 p.m. and 6.30 p.m. Basal leptin level correlated strongly with all isolated regions of subcutaneous fat tissue in women and obese subjects. Circadian changes of blood leptin level in non-obese people are more significant than these changes in obese people. Differences in circadian pattern of leptin secretion between obese and non-obese subjects were probably caused by enlarged volume of subcutaneous fat tissue in obese people. Lean subjects have subcutaneous fat in physiological range which allows influence of some hormones (insulin or cortizol) or food intake on leptin secretion.

Holistic approach to functional anatomy of the injured ankle joint.

Talocrural joint injuries are among the most common injuries of the joints and therefore there is a need for a holistic approach to analysis of morphology, biomechanics and visualization of the talocrural joint ligamentary apparatus in different positions. The research was carried out on 20 fresh and conserved anatomical specimens of the lower leg on which X-ray, computed tomography, ultrasonography and stress analysis were performed before and after the lesion of ligaments. Also the gait of 130 adults without (100) and with ligament and joint capsule lesion (30) was analyzed by infrared telemetry. After complete discission of the lateral ligaments, arthrography and CT could register the lesion, while X-ray and ultrasonography could not detect it. Gait analysis of healthy and injured leg showed that the injured leg was significantly less loaded.