History of biomechanical research at the Ilizarov Centre (to the 100th anniversary of Academician G.A. Ilizarov)

Background. Biomechanical studies of both the Ilizarov apparatus itself and the physiological system “apparatus – limb” occupy a significant place in the history of the formation and elaboration of the Ilizarov method, developed in the middle of the last century at the Kurgan Research Institute of Experimental Traumatology and Orthopaedics (nowadays – the world-famous Centre named after its creator). The analysis of the history of biomechanical research in the formation of Ilizarov method is not without interest.The aim. To analyze the history and stages of development of biomechanical research in order to substantiate the effectiveness of the Ilizarov method of transosseous osteosynthesis.Results. The national medical industry did not produce the appropriate equipment for biomechanical research in the early 1970s. That is why a group of engineers was included into the Laboratory of Clinical Physiology and Biomechanics (established in 1971) of the Ilizarov Centre, which created equipment for studying the processes in the tissues of the limbs and in the structure of the Ilizarov apparatus itself during its traction and compression impact on biological structures. The community of physicians, scientists and engineers made it possible to overcome a number of difficulties and problems. In their scientific publications and dissertations, the laboratory staff paid great attention to biomechanical research during transosseous osteosynthesis with the Ilizarov apparatus. At present, the staff of the Ilizarov Centre continues the traditions established by G.A. Ilizarov. For the first time in our country, a computer 3D video analysis of the kinematics and kinetics of orthopedic patients gait was introduced; it was supplemented with embedded software for the preparation of a clinical report of human gait biomechanics.Conclusions. The initial stage of the biomechanical research at the Ilizarov Centre included the creation of the research equipment. Subsequently, the biomechanical studies carried out by the staff of the Centre for almost half a century have shown an applied and functional result of the realization of general biological regularities of the Ilizarov’s discovery. At present, the biomechanical research continues at a higher level with the use of modern high-tech equipment

Numerical Analysis of Liquid Menisci in the EFG Technique

This chapter is devoted to the analysis of the behavior of the profile curves of the melt menisci for the sapphire crystal growth by edge-defined film-fed growth (EFG) technique. The menisci of the shaped crystals with capillary channels, fibers, and tubes (including cases of outer and inner circular menisci) are considered. Also, we investigated the profile curves of menisci both in the cases of the positive and negative angles between profile curve and the working edge of the die. The cases of outer and inner circular menisci of the tubular crystals and menisci at capillaries and fibers are considered

Sapphire shaped crystals for laser-assisted cryodestruction of biological tissues

We have developed cryo-applicators based on the sapphire shaped crystals fabricated using the edge-defined film-fed growth (EFG) and noncapillary shaping (NCS) techniques. Due to the unique physical properties of sapphire: i.e. high thermal, mechanical, and chemical strength, impressive thermal conductivity and optical transparency, these cryo-applicators yield combination of the tissue cryo-destruction with its exposure to laser radiation for controlling the thermal regimes of cryosurgery, and with the optical diagnosis of tissue freezing. We have applied the proposed sapphire cryo-applicators for the destruction of tissues in vitro. The observed results highlight the prospectives of the sapphire cryo-applicators in cryosurgery

Vasodilator effect of vascular endothelial growth factors (VEGF) in the conditions of bone tissue formation by the method of discrete traction in congenital segmental pathology

The development of the limbs in patients with congenital segmental defects is associated with defects in the vascular system of the same segment. In this case, vascular endothelial growth factors that participate in physiological angiogenesis may have effect on bone tissue formation in ontogenesis and participate in endochondral ossification. In this regard, the aim of the study was to compare the quantitative changes in growth factors (VEGF) and the contractile properties of arterioles under conditions of discrete distraction for congenital pathology of the lower leg bones. Materials and methods Subjects of the study were 12 patients with congenital pseudarthrosis of the lower leg (ICD-10 Q 74.0). Their serum was analyzed using an enzyme immunoassay. Microcirculation in the calf skin was examined by laser flowmetry (BLF21, Transonic Systems Inc., USA). We used the findings obtained from the study of blood serum in 103 somatically healthy people for control. Results Significant imbalance in serum concentrations of endothelial factors and their receptors was detected in the subjects with congenital pathology. As a result of surgical treatment, the imbalance of secretion of vascular growth factors and their receptors increased. Vasodilator effect in the precapillary vessels in the zone of the operated segment in patients with congenital pathology was not revealed by surgical intervention

Regional hemodynamics in patients with femoral shaft nonunions treated with combined external fixation and intramedullary nail

Objective The purpose of the study was to explore peripheral hemodynamics in patients with femoral shaft nonunions treated with combined external fixation and intramedullary nail. Material and methods Two groups of patients were identified. Group I included 11 patients with a deformity at the apex of nonunion treated with consecutive combined osteosynthesis. Group II consisted of 15 patients with nonunions and femoral shortening treated with synchronous combined distraction-compression osteosynthesis. Methods of examination comprised duplex ultrasound of veins and paraosseous vessels at the regeneration site (HITACHI HI Vision Avius), USDG (ANGIO-PLUS, Moscow) and tetrapolar rheovasography (RVG) of lower limbs (Rheograph RGPA-6/12, Taganrog). Results and discussion Volumetric blood flow of the femur and tibia measured postoperatively with RVG showed no differences in the intact and operated limb whatever technique was applied. In all patients, major blood flow was recorded at stages of combined fixation and Ilizarov fixation, linear systolic velocity and pulsatility index were not significantly different from normal and intact limb values, hemodynamic criteria of vasoconstriction of major vessels were not identified. The steal syndrome of distal segments due to functional bypass was observed in patients with unstable metal constructs and did not aggravate after surgical treatment in Group I. Duplex ultrasound scan of the femoral shaft cortical bone showed expressed arterial and venous color map in all patients with high peripheral indices reflecting vascular tone and measuring PI = 12 ± 3.5; RI = 0.9 ± 0.1. Conclusion No significant hemodynamic changes were detected in major arteries during treatment of patients with femoral nonunions using combined techniques of external fixation and intramedullary nail. Vasodilatation of veins recorded during treatment of patients with femoral nonunions using combined techniques of external fixation and intramedullary nail was determined as a risk factor for venous thromboembolism. A local increase in the arterial and venous paraosseous blood flow was recorded at the cortical site of nonunion with combined intramedullary osteosynthesis

Biomedical applications of sapphire shaped crystals

We have proposed novel medical instrument

Analysis of the Degree of Involvement of the Lower Limb Muscles in the Pathological Process in Adolescents with Idiopathic Scoliosis

Background. The problem of the effect of adolescent idiopathic scoliosis on the functional condition of the lower limb muscles is still highlighted insufficiently.Aim. Analysis of the degree of involvement of the lower limb muscles in the pathological process in adolescents with idiopathic scoliosis.Methods. A comparative analysis has been made on the results of examination of 209 adolescents: 25 adolescents with idiopathic scoliosis; 170 normal adolescents; 14 adolescents with congenital scoliosis. The moments of force ofthe lower limb muscles were evaluated using dynamometric stands. Electrophysiological characteristics of the lower limb muscles were registered by the method of global and stimulation electroneuromyography.Results. The decrease in the amplitude of voluntary EMG of the femoral muscles in adolescents with idiopathic and congenital scoliosis is accompanied by dropping the moments of force relative to the values of the control group. The leg muscles are characterized by the preservation of the values of force at the level of normal test subjects under the conditions of the reduced voluntary EMG of high frequency. The amplitude of the M-responses of the indicator muscles and the values of the excitation propagation velocity along the motor fibers were also preserved. There are no statistically significant correlations between the amount of the spine deformity, on the one hand, and the values of asymmetry of the characteristics of the muscles in adolescents with idiopathic scoliosis.Conclusion. In adolescents with idiopathic scoliosis the function of femoral muscles is decreased, and there is no relationship between the amount of the spine deformity and the values of asymmetry of the characteristics of the lower limb muscles. The similar character of muscle function changes in adolescents with idiopathic and congenital scoliosis can testify that the cause of the observed changes is not the disease etiology, but the insufficient level of motor activity

Treatment of patients with caudal regression syn- drome: a systematic review of the literature

Objective. To analyze and summarize the data of modern literature on the issues of surgical treatment and natural course of the spine and spinal cord pathology in patients with various types of caudal regression syndrome (CRS). Material and Methods. A systematic review of the literature on the issue of treatment of the spine and spinal cord pathology in patients with CRS was performed. Selection criteria were: articles for the period 2002–2022, original studies of populations/patients with various forms of CRS with a description of treatment methods and long-term results of treatment or observation. A total of 28 articles on the treatment of various forms of CRS with the described results of treatment of 212 patients were analyzed: 29 patients with CRS in combination with open neural tube defects and 183 patients with closed forms of CRS. Evaluation criteria included number of patients, gender, type of spinal cord pathology, type of sacral agenesis, presence of the spine and lower extremities deformities, concomitant pathology, operations performed and their complications, and results. Results. The studied patients underwent the following surgeries on the spine and spinal cord: untethering of the spinal cord, correction and stabilization surgeries on the spine, plasty of the spinal cord herniation, plasty of the terminal meningocele, and removal of the presacarial volumetric mass. The greatest number of complications occurred after operations on the spine and sacrum. The majority of patients (67 %) with sacral agenesis by the end of the follow-up period (average 14 years) walked independently or with the help of devices, and a minority of them (33 %) could not walk. More than half of patients with CRS (67 %) had a neurogenic bladder, urinary incontinence, or suffered from a chronic urinary tract infection. Fecal incontinence and constipation were less common (46 %). Conclusions. Patients with CRS have a good potential for improvement/recovery of walking and pelvic organ dysfunction. This is extremely important to timely carry out multimodality treatment of patients with CRS who have neurosurgical, orthopedic, urogenital and colorectal problems in CRS, and to start early motor rehabilitation and physiotherapy

In vitro terahertz spectroscopy of gelatin-embedded human brain tumors - a pilot study

We have performed the in vitro terahertz (THz) spectroscopy of human brain tumors. In order to x tissue

In vitro terahertz spectroscopy of malignant brain gliomas embedded in gelatin slab

In our work, we have performed in vitro terahert