SummaryA country-specific FRAX model has been developed for the Ukraine to replace the Austrian model hitherto used. Comparison of the Austrian and Ukrainian models indicated that the former markedly overestimated fracture probability whilst correctly stratifying risk.IntroductionFRAX has been used to estimate osteoporotic fracture risk since 2009. Rather than using a surrogate model, the Austrian version of FRAX was adopted for clinical practice. Since then, data have become available on hip fracture incidence in the Ukraine.MethodsThe incidence of hip fracture was computed from three regional estimates and used to construct a country-specific FRAX model for the Ukraine. The model characteristics were compared with those of the Austrian FRAX model, previously used in Ukraine by using all combinations of six risk factors and eight values of BMD (total number of combinations =512).ResultsThe relationship between the probabilities of a major fracture derived from the two versions of FRAX indicated a close correlation between the two estimates (r > 0.95). The Ukrainian version, however, gave markedly lower probabilities than the Austrian model at all ages. For a major osteoporotic fracture, the median probability was lower by 25% at age 50 years and the difference increased with age. At the age of 60, 70 and 80 years, the median value was lower by 30, 53 and 65%, respectively. Similar findings were observed for men and for hip fracture.ConclusionThe Ukrainian FRAX model should enhance accuracy of determining fracture probability among the Ukrainian population and help to guide decisions about treatment. The study also indicates that the use of surrogate FRAX models or models from other countries, whilst correctly stratifying risk, may markedly over or underestimate the absolute fracture probability.

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Radial head fractures are becoming a major public health problem and are an increasingly important target for both clinical and mechanical researchers. In this work, comparative biomechanical analyses of the stress–strain state of a healthy elbow joint and elbow joints with radial head compression from 2 to 5 mm due to injury are performed. Three-dimensional models of the elbow joint with cartilage surfaces and ligaments were constructed based on the results of computed tomography. This study is focused on an elbow joint range of motion ranging from 0° to 120° flexion. Analysis of the stress–strain state of cartilage and ligaments under the influence of functional loads is conducted using a finite element method (FEM) and the ABAQUS software package. The results show that with increasing compression of the radial head, contact stress increases at the olecranon, which can lead to cartilage damage. Analysis of displacement shows that compression of the radial head during full extension of the elbow joint leads to an increased humeral shift from 1.14° ± 0.22 in the healthy joint to 10.3° ± 2.13 during 5-mm compression of the radial head. Mathematical modeling performed in this study proved that reducing the height of the radial head and the contact area between the radial head and the humeral head led to increased medial collateral ligament stresses of up to 36 ± 3.8 MPa. This work confirmed that the head of the radius is the main stabilizing structure of the elbow joint and that the medial collateral ligament is the second structure responsible for valgus stability of the elbow joint.

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Worldwide, the number of hip fractures, the most important osteoporotic complication in the elderly, continues to increase in line with the ageing of the population. In some countries, however, including the Ukraine, data on the incidence of hip fracture are limited. This article describes the first analysis to characterize the incidence of hip fracture in the Ukrainian population from the age of 40 years. It is based on data from two regional studies, namely, the Vinnitsa city study and the STOP study, which were performed during 1997–2002 and 2011-2012 years, respectively. Hip fracture incidence rates were demonstrated to increase with increasing age. The rates were higher among younger men than women, however, with a female preponderance from the age of 65 years upwards. The incidence of hip fractures in Ukraine is 255.5 per 100,000 for women aged 50 years and older and 197.8 per 100,000 for men of the corresponding age. Overall, the incidence of hip fracture was comparable with data from neighboring countries, such as Poland and Romania. Hip fractures constitute a serious healthcare problem in Ukraine, and changes in healthcare are required to improve the management and long-term care of osteoporosis and its complications.

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The EMG pattern in the elbow flexors during the performance of relatively slow (non-ballistic) targeted flexor and extensor movements with different velocities and amplitudes and subsequent fixation of a reached position was studied in healthy humans. Using a servocontrolled mechanostimulator, steady external loading was applied to the arm, which provided performance of the movements and their termination exclusively by the flexor activity, leaving the extensors passive. In all cases, even at very slow movements, EMG activity of the flexors at transition of the joint from one equilibrium state to another was shown to contain a clear dynamic phase followed by a phase of stationary activity. The level of the latter, generated during fixation of a reached position, was practically independent of the amplitude of a movement within the 0-60* range of the joint angles. Thus, the force developed by the flexors at the dynamic EMG phase became fixed when a new equilibrium joint position was reached and did not decrease in the course of a considerable drop in the efferent activity level, when the stationary phase of this activity began. The dynamic EMG phase included two components. The first component was related to leaving the equilibrium state with a certain acceleration, while the second component was probably involved in the velocity control and stoppage of the joint in a new equilibrium position. We suppose that retention of the joint in the equilibrium state is not provided exclusively by formation of a certain equilibrium level of efferent activity (as it is postulated by the equilibrium point hypotheses); it results from some coordinated modifications of the dynamic muscle activity that provide achievement of equilibrium in a certain position within a certain stage of the movement.

Резюме. Переломи проксимального відділу стегнової кістки (ППВСК) є одним із найбільш тяжких усклад-нень остеопорозу, що має важливе медико-соціальне й економічне значення. Загальновідомо, що їх час- Àêòóàëüí³ñòüНа сьогодні системний остеопороз залишається важливою медико-соціальною проблемою у зв'язку зі збільшенням у популяції осіб старших вікових груп і тяжкими медико-соціальними наслідками захворю-вання [1-5], що пов'язані з низькоенергетичними переломами. До основних остеопоротичних перело-мів відносять переломи тіл хребців, проксимального відділу плечової кістки, дистального відділу кісток пе-редпліччя та переломи проксимального відділу стег-нової кістки (ППВСК). Останні є найбільш складни-ми, пов'язані з підвищенням рівня захворюваності й смертності, а також зі збільшенням матеріальних витрат на лікування й реабілітацію хворих [3,4]. Зде-більшого ППВСК виникають у результаті падіння, хоча іноді -спонтанно. Загальновідомо, що ризик падіння збільшується з віком, більшою мірою -в жі-нок. Близько однієї третини осіб літнього віку пада-ють щороку, 5 % отримують переломи різної локалі-зації, а 1 % -переломи стегнової кістки. До 20 % осіб із ППВСК помирають протягом першого року після перелому (близько 30 % -від наслідків самого пере-лому, решта -від супутніх захворювань), і менше по-ловини серед тих, хто не помирає, відновлюють свій функціональний стан до рівня, що був до виникнення перелому [1,2].