Mathematical modeling of the stress-strain state of the "bone-implant" system during the osteosynthesis with a philos with polylactic acid implants.

OBJECTIVE: The aim: To study was to use mathematical modeling in assessing the stress-strain state of the bone-implant system during plate osteosynthesis with a PHILOS plate of a proximal humerus fracture with polylactic acid implants. PATIENTS AND METHODS: Materials and methods: Two bone-implant systems with a three-fragment humerus fracture according to the Neer classification (type 11-C1 according to the AO / ASIF classification) were selected for the study, one of which was with additional reinforcement of the head fragment with two polylactic acid implants (PLA - polylactide Ingeo™ Biopolymer 4032D). Sawbones (Europe AB, Malmö, Sweden) built the humeral model on 3D scanning of the composite model № 3404 of the left humerus. RESULTS: Results: A comparative analysis of the obtained results of mathematical modeling of the stress-strain state of the bone-implant systems showed that with given constraints (hand abduction to 90°), the use of two polylactic acid implants can reduce the stress in the plate and screws, respectively, by 11% and 6% . CONCLUSION: Conclusions: The use of polylactic acid implants during osteosynthesis of three- and four-fragment fractures of the proximal humerus, especially in the case of osteoporosis, allows providing for the reinforcement of metal structures and supporting of the articular surface without deterioration of fixation rigidity.

Usage of histological methods in determining the prescription of kidney injuries in forensic medical practice.

OBJECTIVE: Introduction: The article presents data from literary sources and a statistical analysis of our own research on the nature, mechanism and prescription of kidneys injury in case of mechanical trauma and the absence of alcohol intoxication. The aim: To study the dynamics of changes in the histological parameters of the kidneys injured tissues in case of mechanical trauma depending on the prescription of injury. PATIENTS AND METHODS: Materials and methods: The material of the study was the kidneys tissue of 48 males and females aged from 20-60 who died at known and unknown time in the presence and absence of alcohol in the blood. We used histological, histochemical methods, and carried out the analysis of results. RESULTS: Results: The obtained results showed that during the mechanical injury of kidneys there often developed a capsule and a parenchyma with hematoma in the area of injury. Our records showed that during the first 6 hours after injury, there appeared a hematoma in the center of the injury. Hemolysis of the erythrocyte particles was observed in the center of the hematoma. There were also isolated leukocytes and fibrin tissues closer to the edge of the hematoma. CONCLUSION: Conclusions: The obtained results indicate that there are several histological changes in the damaged kidneys tissues area which directly depend on the time which passed from the moment of injury.

Dynamics of biochemical markers of connective tissue metabolism in patients with knee osteoarthritis during conservative treatment with laser therapy.

OBJECTIVE: Introduction: The biochemical markers of the connective tissue metabolism in blood serum may characterize the disturbances in inflammatory, destructive processes, and also serve the criteria for diagnostic evaluation of the state of cartilage and bone tissue of the joints in knee osteoarthritis to control the effectiveness of conservative treatment. The aim: determination of biochemical markers of connective tissue metabolism in the blood of patients with the 1st and 2nd stages of knee osteoarthritis in order to prove the effectiveness of the complex conservative treatment of patients with the use of low-intensity infrared laser radiation. PATIENTS AND METHODS: Materials and methods: During the study we examined 80 patients with the 1st and 2nd stages of knee osteoarthritis according to the Kellgren and Lawrence classification. Some patients were prescribed diclofenac sodium and glucosamine hydrochloride, others were prescribed an additional course of laser therapy. RESULTS: Results: At the end of the treatment the group of patients with knee osteoarthritis who were treated with the use of laser therapy, diclofenac sodium and glucosamine hydrochloride, showed a decrease in the content of the following blood serum components: glycoproteins (by 28.9 %), sialic acids (by 28.8 %), chondroitinsulfates (by 91.3 %) due to chondroitin-6-sulfate, activity of alkaline phosphatase (by 36.1 %) compared with the indicators before treatment. CONCLUSION: Conclusions: a more significant decrease in the inflammation and destruction of the cartilage tissue of the affected joints was observed during knee osteoarthritis treatment with the use of laser therapy than without it.

Biochemical markers of connective tissue metabolism in rats' blood serum with experimental knee osteoarthritis and their dynamics during conservative treatment.

OBJECTIVE: Introduction: There are many methods for diagnosis and treatment of knee joints osteoarthritis in modern orthopedics. The infrared radiation is one of the most popular and effective methods though it needs experimental substantiation on rats. The aim: Experimental definition of the effectiveness of the proposed method of conservative treatment of knee joints osteoarthritis using sodium diclofenac, glucosamine hydrochloride and infrared laser radiation, on the basis of biochemical markers of connective tissue metabolism in rats. PATIENTS AND METHODS: Materials and methods: Experimental studies were performed on 40 white male rats. A part of rats received infrared laser radiation in addition to diclofenac sodium and glucosamine hydrochloride. RESULTS: Results: Using a complex of infrared laser radiation and glucosamine hydrochloride and diclofenac sodium in conservative treatment of rats with experimentally induced knee joints osteoarthritis rats after 24 days of treatment. Treatment with the above-mentioned scheme resulted in a significant reduction in the content of glycoproteins (28.5%), chondroitin sulfates (26.1%), alkaline phosphatase activity (32.3%), and I and II fractions of glycosaminoglycans, namely chondroitin-6- (28.7%) and chondroitin-4-sulfate (40.3%). Moreover, these indicators of the studied markers approached the level of intact animals. CONCLUSION: Conclusions: Changes in biochemical markers of connective tissue in rats during experimental knee joints osteoarthritis indicated a higher efficiency of the treatment regimen with the use of low-intensity infrared laser radiation compared with exclusively drug therapy.