Analysis of the stress-strain state of the spine model with posterior fusion in the treatment of scoliotic deformities in children

Background. Mathematical modeling of the correction of scoliotic deformities of the spine makes it possible to analyze the effectiveness of various methods of treatment without surgical intervention. In the study of traction, mainly experimental methods were used. The purpose was to investigate the stress-strain state of the spine models with varying degrees of scoliotic deformity during posterior spinal fusion. Materials and methods. Deformities of the spine of 40, 70 and 100° were modeled, with posterior spondylodesis of the Th1-Th12 vertebrae. A load of 300 N was used. Results. With a deformity of 40°, the most stressed are the areas of frontal plane curve. For the upper vertebrae Th1-Th4, a more even distribution of stress over the vertebral body is observed. For Th5-Th10 vertebrae, the concave side of the vertebral bodies is more stressed. In the thoracic spine, the more stressed vertebrae are Th2 and Th5. The main load is borne by the fixing structure, in which the level of stress is significantly higher than in the bone structures of the vertebrae. In the posterior supporting complex of the vertebrae, the stress concentration areas are located at the points where fixing screws enter the bone. An increase in the magnitude of the scoliotic deformity of the spine up to 70° causes an increase in the level of stresses in all elements of the model, with the exception of Th9-Th10 vertebrae. With a deformity of 100° in the posterior supporting complex of the vertebrae, the stress concentration areas are located at the points where fixing screws enter the bone. The stress level of 116.0 MPa exceeds the ultimate strength of the cortical layer of the bone tissue of the spine, which can lead to microdamage of the bone tissue and loosening of the screws. Conclusions. For all values of scoliotic deformity of the spine, the most stressed are Th4 and Th5 vertebrae. A decrease in the degree of deformity has a significant effect on the stress-strain state of the spinal column. In the Th4 vertebral body, the level of stresses with a deformity of 100° is more than twice as high as with a deformity of 70°, and more than 4 times higher than with a deformity of 40°. In the body of the Th5 vertebra, the stress level with a deformity of 70° is 1.5 times less than with a deformity of 100°, and with a deformity of 40°, it is 3 times less. The level of stress in the Th1-Th5 vertebral bodies is higher than that of Th6-Th12. In the posterior supporting complex, at the points where screws enter the bone, the maximum stress value at a deformity of 40° is 34.0 MPa, which is not critical for the bone tissue. With a deformity of 70°, the stresses are 85.0 MPa, which can exceed the ultimate strength for the cortical bone and lead to microdestruction of the bone tissue in the screw-bone contact area. With a deformity of 100°, the stresses are equal to 116.0 MPa, which exceeds the ultimate strength for the cortical bone and can lead to microfracture in the screw-bone contact area.

Features of walking in patients with knee arthrosis before and after arthroplasty according to the GAITRite system

Background. Hardware examinations are the key to standardizing the assessment of the patient’s condition, they reduce the doctor’s error, make it possible to obtain digital material, which can be used to determine the functional ability of the patient. One of such studies is the GAITRite system, the purpose of which is to assess the parameters of a person’s walking. The study was aimed to determine the basic parameters of walking in patients with gonarthrosis before and after the endoprosthesis. Materials and methods. There were examined 23 patients with gonarthrosis after unilateral endoprosthesis. The studies carried out concern the analysis of temporal, geometric parameters of walking, as well as the assessment of the functional ability of patients with degenerative diseases of the hip joint before treatment and one year after arthroplasty. Results. Before treatment for knee arthrosis, patients experience a violation of walking in the form of asymmetry of steps. There is a decrease in the time of support on the foot of the impaired limb and, therefore, an increase in the time of transfer of the foot of this limb. Changes in the impaired limb are reflected in the opposite one. After surgery, the changes in the parameters of walking in patients were as follows: an increase in the time of support on the prosthetic limb, and, therefore, a decrease in the time of support on the foot of the opposite limb that manifested in an increase in the symmetry of the parameters of steps. Reduction of pain syndrome and restoration of limb support ability increase the indicator of gait functionality. Osteoarthritis is a systemic disease and develops more often in both knee joints, and other structures of the skeleton are often involved in the degenerative process. Therefore, in elderly patients, FAP after arthroplasty reaches only satisfactory values. We examined patients after endoprosthesis on one knee joint, and this does not always give the expected good result immediately. Conclusions. Instrumental methods of studying patients’ gait make it possible to determine the degree of impairment of dynamics. Knee arthroplasty eliminates pain and restores limb resistance, which improves gait. This method of assessing walking allows determining the degree of recovery of patients and to adjust the need for further methods of correcting walking or a plan for further treatment.

Surgical treatment of patients with extra-articular fractures of the distal humerus

Background. The article deals with extra-articular fractures of the distal humerus, according to the АО/ASIF classification, which includes types 12A–C, depending on the plane of the fracture and the nature of the fragment displacement. The purpose was to study the features of the lower third humeral fractures and to conduct a comparative analysis of the outcomes of surgical treatment. Material and methods. One hundred and twenty-seven patients with extra-articular fractures of the distal humerus were under observation. For retrospective analysis, they were divided into a comparison group (n = 92) who underwent traditional bone osteosynthesis and a study group (n = 35) in whom a rod-type external fixation device developed by us was used. The short- and long-term functional results were studied using the Mayo Elbow Performance Score. Results. Various indicators, established by us for comparison, and treatment outcomes were analyzed in 101 patients (comparison group — 68 people, study group — 33). Many values of these parameters were quite comparable in terms of the age, gender, hospitalization terms, duration of surgeries, etc., but the revealed differences in indicators still did not reach the level of statistical reliability (p > 0.05). Evaluation of the clinical use of the device proposed by us showed restoration of the humeral anatomy, quite comparable to that in bone osteosynthesis, and the achievement of the final result of treatment. However, the number of complications by type and by total number was significantly higher (4.5 times; p ˂ 0.001) in the comparison group, where it accounted for the largest share of cases of neuropathies (16.18 %), nonunions (8.82 %), elbow contractures (8.82 %) and heterotopic ossification (4.42 %). The final score on the Mayo Elbow Performance Score in the comparison group was 84.9 ± 10.2 points, in the study group — 92.6 ± 3.7 points. At the same time, the total number of positive treatment outcomes after bone osteosynthesis was 66.18 %, after transosseous osteosynthesis — 81.82 %. Conclusions. The analysis of the data obtained allows us to recommend a method of minimally invasive osteosynthesis with a rod device of external controlled fixation as a method of choice for wider clinical use in the treatment of patients with lower third humeral fractures.

Treatment outcomes in humeral fractures of different location (review)

The choice of treatment (open reduction and internal fixation) for a humeral fracture with a plate versus an intramedullary nail is highly debated. We compared outcomes (fracture union, reoperation, and adverse events) of intramedullary nailing and plate fixation in patients with proximal humeral, humeral shaft, and distal humeral fractures. No significant differences were found between intramedullary nailing and plate fixation for fracture union, reoperation, or adverse events in patients with proximal humeral or humeral shaft fractures. There is a scarcity of evidence comparing intramedullary nailing and plating for distal humeral fractures. No recommendations can be given from current evidence. Surgeons may have to continue to use discretion based on their personal preference, experience as well as patient’s characteristics and fracture features before more high-quality evidence is available.

Analysis of long-term results of surgical treatment of acromioclavicular dislocation

Background. Acromioclavicular dislocation is a fairly common traumatic injury of the musculoskeletal system, and according to different authors varies from 2 to 26.1 % dislocations of other localizations, and is about 10 % of all acute injuries of the shoulder girdle, taking 3rd place after dislocations of shoulder and forearm. The social significance of this damage is determined by the occurrence mainly among young working-age men. The work was aimed to identify factors that cause unsatisfactory anatomical and functional results after surgical treatment of acromioclavicular dislocations. Materials and methods. This retrospective study (2015–2020) included 93 patients who had surgical intervention for acromioclavicular dislocation. Surgical stabilization of the acromial end of the clavicle was done by Hook Plate and by Weber technic. Results. The outcome of research shows that 49.5 % of cases had good results, 31.2 % — satisfactory, and 19.3 % — poor. There is a direct correlation between unsatisfying outcome and increased severity of the injury. The study found that 9.7 % of unsatisfying results were associated while using Weber’s technic in the Tossy II, while in Tossy III, it was 27.0 %. A similar correlation was found while using Hook Platе, in the case of Tossy II, unsatisfying results were in 15.8 % of cases and Tossy III — 29.4 %. Conclusions. The reason for the unsatisfying results of the surgical acromioclavicular dislocations treatment is the severity of damage and the absence of an algorithm for diagnosis and management of this injury. In Tossy III dislocations, the use of stabilization methods as Weber’s technic, Hook Plate, or suturing damaged acromioclavicular ligaments did not demonstrate satisfying effectiveness.

Comparative analysis of the validity of goniometric, inclinometric, and radiographic methods to measure ankle joint dorsiflexion

Background. The search for an optimal method to assess the amplitude of ankle joint dorsiflexion remains topical for scientific discussions. The purpose of the research was to analyze the validity of goniometric and inclinometric methods for measuring the scope of ankle joint (AJ) dorsiflexion compared to radiological data. Materials and methods. The research included 25 healthy and physically active people (50 ankle joints), 18 men and 7 women with an average age of 25.8 ± 5.2 years; their mean body mass index was 25.01 ± 5.01 kg/m2. Ankle dorsiflexion measures were obtained in a weight-bearing lunge position using a double-plane goniometer and inclinometer, then compared with X-ray data. The measurement results were evaluated by descriptive statistics. Results. Mean values of AJ dorsiflexion obtained with a double-plane goniometer were 37.62 ± 5.56°; with an inclinometer — 40.61 ± 5.15°; radiological results — 23.69 ± 7.25°. Their difference was significant (p < 0.001). The mean variability index for the radiological method was 0.31 prevailing over goniometric (0.15) and inclinometric (0.13) methods (p < 0.001). X-ray ima-ging of a weight-bearing AJ at its maximum dorsiflexion raises the indicator of a talus-first metatarsal angle. Conclusions. The values of the dorsiflexion angle parameters of an AJ, measured using goniometric and inclinometric methods, significantly exceed those obtained by X-ray imaging. Higher variation index for radiological imaging demonstrates better reproducibility of inclinometry and goniometry when evaluating AJ dorsiflexion. A weight-bearing AJ radiogram at maximum extended position demonstrates an increase in a talus-first metatarsal angle compared to normal values that should be considered when interpreting the results of X-ray imaging of an AJ dorsiflexion.

Morphological and morphometric changes of bone tissue in patients with osteoporosis and osteomalation

Bone tissue was studied in 56 postmenopausal women (mean age 62.30 ± 2.74 years), of which 46 patients who worked in unfavorable working conditions had a decreased bone mineral density (BMD) (osteoporosis (OP) — in 31 women, osteomalacia (OM) — in 13); 10 women had no metabolic changes in bone tissue (BT). A BT scan fragment was obtained during surgery for a fracture of the femoral neck. Non-decalcified QD sections were prepared, the functional activity of the QD cell nuclei was determined using the method of differential staining of nuclei with different functional activity. Morphological changes in OP and OM have both common features and differences. The common is the thinning of the bone rods, the expansion of the canals of osteons, the presence of cell-free areas, and cell-free lacunae. In contrast to OP, OM presents with the thickness and area of the osteoid increase, a less pronounced decrease in oxyphyllin matrix, a higher functional activity of BT cells. A decrease in BMD and the occurrence of low-energy fractures may result not only from OP but also OM. When prescribing treatment, it is necessary to carry out diffe-rential diagnostic measures that determine the cause of the decrease in bone mass.

Studying the strength of the tibia during the replacement of a post-resection defect with a segmental allograft using locked intramedullary nailing (experimental clinical study)

Background. To achieve success in the incorporation of allografts and bone of the recipient, many factors are taken into account, which can be divided into two main groups: those related to sterilization and processing of the bone allograft and factors affecting the reliability of implant fixation in the bone of the recipient. The second important factor is the method for fixing the allografts and the bone of the recipient. The purpose was to determine the mechanical properties of bone after segmental bone alloplasty. Materials and methods. Female patient Sh., 30 years old, diagnosed with osteosarcoma of the left distal tibia T2N0M0 GIII, degree II, clinical group II, underwent polychemotherapy courses, surgical intervention according to the developed method. The tumor was removed en block, a post-resection defect was replaced with an articulating segmental bone allograft, fixed to the recipient’s bone through a stepped osteotomy and an intramedullary locked nail. Bone autografts were additionally placed into the area of the allograft contact with the recipient’s bone. After 2 years, the patient underwent surgery: amputation at the left third of the thigh. Radiographically, fusion of the allograft and the recipient’s bone was noted. An experimental study of the tensile strength of the tibia after segmental alloplasty of a post-resection defect was carried out using the developed surgical technique and a segmental allograft. Results. To compare the results of an experimental study of the tibia preparation after segmental bone alloplasty, data about the values of the ultimate strength of the bone tissue under compression and bending loads were selected. As shown by the experiment, the ultimate strength of the tibia preparation after its bone alloplasty was 51.82 MPa. This value corresponds to the minimum ultimate strength of a compact bone in bending — 51 MPa. Although this is twice as low as the maximum value of the ultimate strength of a compact bone in bending (133 MPa), it should be borne in mind that all the given reference values were obtained when testing intact preparations of a compact bone. Conclusions. The use of a segmental bone allograft to replace a post-resection defect in a long bone with its fixation to the recipient’s bone through a stepped osteotomy and locked intramedullary nailing with additional bone autoplasty in the area of the allograft contact with the recipient’s bone makes it possible to obtain in the osteotomy zone the bone, the ultimate strength of which corresponds to that of the intact tissue.

The historical example of economic effect resulted from complex interagency interaction in pre-emergency medical care for injured in traffic accident

The work emphasizes the urgency of this problem, the importance of timely and high-quality pre-hospital assistance to victims of road accidents. The purpose was to show the importance of complex, interagency interactions in helping victims on motorways. The existing different tactical schemes to assist victims at the pre-hospital stage were analyzed. The success of the European countries in reducing the level of road accidents has shown their negative consequences compared to the Ukrainian current indicators. Also, the historical example of the constitutional result from the introduction of several provisions and actions in 1985 and 1986 in the USSR to improve pre-emergency care for the injured on the highways. As a result of the introduction of the provisions, the savings from pre-hospital losses amounted to 96.85 % of the total loss of fatalities on motorways. These data show the need to improve the universal organizational scheme of assistance to victims at the pre-hospital stage in Ukraine, which requires significant attention from state structures of different levels.

Simulation of double-leg stance in conditions of limited hip mobility

Hip osteoarthritis is one of the most common and disabling conditions affecting the elderly. Coxarthrosis is accompanied by impairment of the amortization properties of cartilage, its thinning and destruction, the appearance of pain syndrome, impaired motor functions due to a decrease in muscle strength and the development of stable flexion-adduction contractures, which change congenital motor programs, and, with a prolonged course of degenerative disease, lead to the formation of pathological habits. Objective: to determine the required strength of the muscles of the lower limb in conditions of limited hip mobility to support an upright posture in double-leg stance. Materials and methods. The work of the muscles of the lower extremities under conditions of restricted hip mobility was simulated using the OpenSim 4.0 software. It is based on the ToyLandingModel, which has contact geometry objects to fix the model on the support area. Four models were created: norm (without limitation of joint mobility), model 2 — adduction of 5°, model 3 — adduction of 7°, flexion of 10°, model 4 — adduction of 10°, flexion of 20°, shortening of the femur bones by 2 cm. Results. It was found that with insignificant adduction contractures of the hip joint, the work of the muscles of the lower limb changes slightly during double-leg stance. With flexion-adduction contractures, changes are observed in almost all muscles of the lower limb. There are some peculiarities in the work of muscles under contractures. All the muscles around the thigh reduce the strength necessary to maintain balance, while the lower leg muscles, on the contrary, increase the required strength several times. For example, m.medial gastrocnemius with flexion-adduction contracture and limb shortening develops10 times higher compensatory force (200 N) than in normal conditions (20 N), and although muscle resources are 1500 N, it is very demanding to maintain an upright posture. Similarly, m.tibialis posterior require an increase in strength (threefold), but the antagonist muscle m.tibialis anterior, on the contrary, reduces the force of contraction by an average of 100 N. Conclusions. According to the data of the conducted modeling of double-leg stance with limited hip mobility, it was proved that an increase in limited movements changes the nature of muscle contraction of the entire lower limb and pelvis. The analysis of the obtained results showed that restriction of movements reduces the required force of muscle stabilization around the hip joint, and increases the required force of contraction of the leg muscles. That is, there is an imbalance in the muscles.