Hydrolysis of Bone-Replacing Materials Based on Polylactic Acid and Containing Hydroxyapatite in an In Vitro Experiment.

We studied the features of hydrolytic degradation of polylactic acid (PLLA) implants depending on their structural filling with hydroxyapatite (HA). The resistance to in vitro hydrolysis was tested for the following samples: PLLA without HA (control; group 1), PLLA/HA 25 wt% (group 2), and PLLA/HA 50 wt% (group 3). Samples were incubated at 37°C. In the hydrolysate, lactate, calcium ions, and inorganic phosphate were determined. Additionally, the time of appearance of visual deformation and sample disintegration was recorded. PLLA degradation was higher in samples saturated with HA. The highest resistance to deformation was noted for samples without HA. Samples with a PLLA/HA 50 wt% demonstrated the maximum degradation of PLLA in combination with lower resistance to deformation and the highest bioavailability of calcium and phosphate. Group 2 samples are most promising for clinical use.

Model of Osteomyelitis in Rats.

We developed a rat model of chronic osteomyelitis of the femur caused by Staphylococcus aureus. The clinical, histomorphological, and laboratory signs were compared in rats with osteomyelitis (infected) and control animals receiving saline. On day 21 after infection, clinical, histomorphological, and laboratory signs of chronic osteomyelitis were found in experimental rats.

[The Optimization of Amount of Laboratory Analyses in the Federal Orthopedic Clinic].

The article presents the analysis of efficiency of medical services support related to laboratory analyses in case of alteration of system of Federal clinic financing. The analysis was implemented using the example of functioning of three departments of endoprosthesis replacement of the Federal State Budget Institution "The Academician G. A. Ilizarov Russian Research Center 'Restorative Traumatology and Orthopedics' " in 2013-2015. It is established that during examined period in the structure of laboratory analyses of the Center decreasing of total number of prescriptions to all types of laboratory analyses occurred. The observed decreasing of laboratory analyses had no impact to quality of treatment of patients of the departments of endoprosthesis replacement. In particular, percentage of post-surgery complications among patients of these departments was decreasing during the examined period. The study demonstrated that to the end of 2015 decreasing of average costs in rubles per patient of departments of endoprosthesis replacement related to laboratory analyses occurred up to 20.28% as compared with 2013. The proposals were made concerning structuring of laboratory analyses for patients with endoprosthesis replacement of large joints.

[The complex correction of the pathophysiological disorders in the patients presenting with orthopedic and traumatological problems with the application of the electromagnetic waves of the terahertz range at the radiation frequencies of nitric oxide]. / Kompleksnaia korrektsiia patofiziologicheskikh narushenii u ortopedotravmatologicheskikh bol'nykh s primeneniem élektromagnitnykh voln teragertsovogo diapazona na chastotakh izlucheniia oksida azota.

Experimental and clinical studies have shown that a skeletal trauma causes a whole complex of pathophysiological disorders, both local and systemic. The main factors determining the severity of the trauma, as well as the nature of the course of the post-traumatic period, are the degree of hypoxia (acidosis), hypercoagulation and immune disorders. To influence these pathophysiological disorders in the patients presenting the with skeletal traumas, various approaches have been proposed, including the use of antihypoxants and antioxidants, the methods and means for the stimulation and support of the immune system, medications to regulate hemostasis. According to the literature publications, terahertz-frequency therapy is presently regarded as a promising method the minimally invasive interference in the metabolic processes proceeding in the tissues of the musculoskeletal system. The analysis of the literature data and clinical observations indicate that electromagnetic waves of the terahertz range are efficient in the treatment of many chronic diseases when applied both as monotherapy and in combination with other physical methods and medications strengthening and consolidating the therapeutic effect of the latter. The electromagnetic waves of the terahertz range are currently used in medicine as a biophysical factor for the correction of the microcirculatory disorders. It has been shown that the use of these waves for the combined restorative treatment of the patients suffering fractures of the limb bones not only improves the dynamics of fracture consolidation symptoms but also contributes to the prevention of posttraumatic complications (thrombosis, ossification of soft tissues). However, the experience with the application of the electromagnetic waves of the terahertz range waves in clinical traumatology and orthopedics is rather modest. The analysis of the results of fundamental research and experience with the application of electromagnetic waves in the terahertz range has shown that the systemic effects produced by the waves of this range promote the correction of such pathophysiological disorders as hypoxia, hypercoagulation, and impaired immunity. Given that these disorders develop during the post-traumatic period in the patients presenting with severe multiple and combined traumas, it can be assumed that the use of electromagnetic waves of the terahertz range for the the combined treatment of these patients provides a very promising tool for the stimulation of the reparative processes especially bearing in mind that the first results described in the literature, look quite optimistic. The investigation into the mechanisms regulating the regenerative capacity of connective tissue, the creation of the scientifically-sound foundations for its management with the help of the modern electronics devices is a promising task for the developers of the new biomedical technologies.

A Technique for In Vitro Studying of the Permeability of the Spinal Cord Dura Mater.

We propose an in vitro method for studying permeability of spinal cord dura mater for components of autological serum using an original device. Sixty native samples of the spinal cord dura mater obtained from 12 mongrel dogs were used for testing of the device. The coefficient of permeability variation (V) for blood serum substances did not exceed 5% in most cases excluding lactate (V=8.03%). Analysis of spinal cord dura mater permeability in vitro for various substances using the developed device provides reproducible results with acceptable variability (5-10%).

[THE PERMEABILITY OF DURA MATER OF SPINAL CORD CANINE FOR LOW-MOLECULAR AGENTS OF BLOOD SERUM].

We studied dura mater (DM) permeability of spinal cord canine in vitro for the low-molecular components of blood serum - urea, creatinine, glucose, lactate, cholesterol, calcium, and inorganic phosphate. We evaluated DM permeability for high-molecular compound of blood serum - albumin as a comparison marker. As established, most of the studied components had the permeability within 8-15 %. Maximum DM permeability was found for lactate (33.6 %), minimum one - for cholesterol (1.3 %). The permeability for urea and for creatinine was 8.0 and 7.5 %, respectively; and herewith the permeability non-linear dependence on the initial substrate concentration in blood serum was observed. DM threshold permeability for urea was 4.83 mmol/L, for creatinine - 97 µmol/L. The functional characteristics of DM permeability can be determined by its structural features - close packing of fibrillar structures connective tissue, high content of sulfated glycosaminoglycans, and the absence of non-sulfated ones.

[THE DYNAMICS OF ENERGY SUBSTRATE CHANGES IN MICE MUSCLES AND LIVER AFTER SKELETAL INJURY THROUGH LIMB GRAVITATION UNLOADING].

The authors studied the content of creatine phosphate, creatine and glycogen in skeletal muscles and that of glycogen in the liver of mice from three experimental groups. The animals of Group 1 (n = 18) underwent leg bone fracture modeling; those of Group 2 (n = 18) - modeling of limb gravitation unloading by their weight-bearing deprivation; the animals of Group 3 (n = 18) after modeling a leg bone fracture underwent weight-bearing deprivation in the model of gravitation unloading. As for Comparison Group, the same parameters studied in the intact animals at the age of two (n = 14) and three (n = 12) months. The authors found the decrease in the total content [creatine phosphate+creatine] and glycogen level in skeletal muscles of Group 1 and 2 mice in the process of the experiment, that was not observed in Group 3 mice. They concluded that the special features of the changes in the studied substrates of Group 3 mice were the consequence of the compensation of the increased energy due to injury by hypofunction of the muscle as a result of its gravitation unloading.

[The laboratory biochemical markers of severity of trauma in acute period after multiple fractures of bones of extremities].

The article presents results of studying alterations of biochemical indices of blood serum in 47 patients of both genders with multiple fractures of bones of lower extremities occurred in period up to 5 days after trauma. All examined patients were allocated in 5 groups: group I (n=10, average age 41±9 years) - patients received during 24 hours after trauma; group II (n=10, average age 42±7 years) - patients received during 24-48 hours after trauma; group III (n=10, average age 42±6 years) - patients received after 72-96 hours after trauma; group IV (n=8, average age 43±6years) - patients received 72-96 hours after trauma; group V (n=9 average age 39±8 years) - patients received after 96-120 hours after trauma. It is established that in examined patients the higher level of lactate (rate 0.745) and increased activity of aspartate aminotransferase (rate 0.553) are established most often. The high rate of increasing of activity of creatinine phosphatase was marked. The reliable correlation dependence on treatment period had three indices: total creatinine kinase, r=-0.534 (p=0.03); total protein, r=-0.477 (p=0.02) and lactate, r=0.406 (p=0.04). It was established also that average periods of treatment of received patients with both increased activity of total creatine kinase and level of lactate or decreased level of total protein, were reliably higher than average periods of treatment of patients with normal indices at the moment of reception into hospital. These three indices can be included into listing of tests for evaluation of trauma severity in patients with multiple fractures of bones of lower extremities with possibility of application of these tests as additional criteria of monitoring under management of patients in post-traumatic period.

Serum Concentration of Growth Factors in Dogs under Different Conditions of Distraction Osteogenesis.

Concentrations of insulin-like growth factors 1 and 2 (IGF-1 and IGF-2), stem cell factor (SCF), vascular endothelial growth factor (VEGF), and transforming growth factor ß1 (TGF-ß1) were measured in the blood serum of dogs subjected to experimental lengthening of shin bones. In animals subjected to shin bone lengthening at a rate of 1 mm/day in 4 steps, the concentrations of SCF and TGF-ß1 significantly increased in the middle of distraction and IGF-1 concentration increased by the end of distraction. In animals subjected to lengthening at a rate of 1.5 mm/day in 6 steps, the levels of IGF-1 and TGF-ß1 significantly increased in the middle of distraction and the concentration of IGF-2 at the end of distraction. In animals subjected to lengthening at a rate of 3 mm/day in 120 steps, the concentrations of IGF-1 and TGF-ß1 significantly decreased in the middle of distraction and concentrations of IGF-1, VEGF, and TGF-ß1 increased by the end of distraction.

[METABOLIC STATUS OF PATIENTS OF DIFFERENT AGE GROUPS ON THE STAGES OF OSTEOARTHRITIS].

This study investigated the biochemical parameters of blood and urine in patients with osteoarthritis in the stages of the pathological process in different age groups. The patients of all age groups in the stages of osteoarthritis demonstrated metabolic acidosis, activation of the antioxidant system and increase in acute phase proteins. In addition to the total for all age groups metabolic shifts the characteristic age-related changes were observed: activated reaction of lipid peroxidation in middle-aged patients and negative calcium balance, with increasing energy metabolism disorders in elderly patients.

[EVALUATION OF RENAL FUNCTION IN PATIENTS WITH SPINAL CORD INJURY].

A comprehensive evaluation of renal function in 59 patients with spinal cord injury was performed. Excretory urography, biochemical and ion-selective analysis of serum and daily urine were used. Excretory urography had showed a reduction in the cumulative and excretory renal functions, which was accompanied by an increase in glomerular filtration rate, regardless of the level of damage and the period of traumatic disease. Excretory renal function has undergone a number of changes: 1) decrease in clearance of nitrogenous components; 2) an increase in clearance of mineral components in acute phase; 3) decrease in the rate of calcium excretion. Spinal cord injury contributed to an increase in the stimulating effect of aldosterone on the distal tubules of nephrons function of the kidneys, manifested in the form of increased excretion of potassium in the urine. In case of injury of the cervical and thoracic spine, significant increase in the K/Na coefficient was determined in acute phase, in patients with lumbar spine injury - in the late period.

[THE SEARCH AFTER PROGNOSTIC TESTS OF DEVELOPMENT OF UROLITHIASIS OF PATIENTS WITH VERTEBRO-CEREBROSPINAL TRAUMA].

The article presents analysis of alterations of biochemical indicators in blood serum and day urine of 22 patients in acute and early periods after vertebro-cerebrospinal trauma. Out of total number of patients in 10 (main group) in post-traumatic period urolithiasis developed In 12 patients no signs of urolithiasis were detected These examinedpatients were included into comparative group. The reference group was composed with 20 healthy individuals. The concentration of urea, creatinine, uric acid, calcium and inorganic phosphate in blood serum and day urine were detected In patients of main group statistically significant increasing of levels of urea and creatinine was detected in blood serum relative to patients of comparative group. In examined patients of main group clearance of urea was reliably lower than both values of comparative group (up to 2.55 times; p < 0.05) and indicators of reference group (up to 3.75 times; p < 0.05). In patients of this group, clearance of uric acid also had reliable differences from indicators both in comparative group and reference group. Therefore, in patients in acute and early periods of vertebro- cerebrospinal trauma expressed disorders of biochemical indicators of blood serum and urine that can be referred to predictors of risk of development of urolithiasis in the following. The most informative tests were increasing of concentration of urea in blood serum more than 5.30 mmol/l (ratio of likelihood ofpositive test--4.26) and decreasing of clearance of uric acid and urea.

[Potential biochemical factors for the development of urolithiasis in patients with spinal cord injuries].

A comparative analysis of biochemical parameters of blood serum and daily urine in patients with urolithiasis developed after spinal cord injury (study group--35 patients) and patients without development of the disease (comparison group--20 patients) was performed. It was found that patients after spinal cord injury have developed productive azotemia, which led to the disruption of renal excretory function (accumulation of urea and creatinine in blood, and lowering their clearance). Against this background, there is violation of excretion of uric acid, magnesium, decreased sensitivity of the renal tubules to aldosterone (in patients with nephrolithiasis K/Na ratio in urine was lower). As a result, patients have decreased reabsorption of sodium and water retention, increased urine osmolality; against the background of electrolyte imbalance in urine, this leads to the formation of stones. In patients with spinal cord injuries, main trigger mechanism of formation of urinary stones was excessive posttraumatic azotemia. The high concentration of the products of protein-nitrogen catabolism in the serum of patients in the acute and early periods of spinal cord injury may be unfavorable criterion determining the significant risk of developing of kidney stones.

[Lipid peroxidation in the rat liver following skeletal injury].

We assessed the concentrations of the products of lipid peroxidation (conjugated dienes--CD, malone dialdegide--MDA), the activity of catalase and the total lipids in the rat liver following tibial fractures. The experiment was carried out using sixty adult male Wistar rats. In group 1 (n = 30), tibial fractures were modeled and fixed with the apparatus of external fixation. In control group 2 (n = 30), the external apparatus was applied to the tibias but the fractures were not modeled. In group 1 animals, the absolute concentrations of CD and MDA were statistically reduced at each time-point studied. The concentration of CD in group 2 was significantly lower on day 3 while the level of MDA up to day 14 of the experiment than in the intact rats. The level of total lipids on days 3 and 7 was decreased in group 1 while in group 2 it was lower than the intact values on days 3 through 14. The catalase activity in group 1 was statistically elevated from day 7 of the experiment as compared to the intact rats. No significant changes in the activity of catalase were found in group 2 at all time-points of the experiment.

[Liver functional state after fractures of leg bones in mice].

The content of glycogen and lipids in the liver, relative liver weight, the volume of hepatocytes and their nuclei, nucleocytoplasmic index, content binucleated hepatocytes, the chemical composition of the bones of the injured limb segment was studied after 3, 7, 28 days after the fracture of the leg bone after fracture leg bone with background carbon tetrachloride intoxication in mice CBA (n = 134). After the fracture revealed functional changes in the liver at all stages of the experiment. The decrease in the liver glycogen content and lipids in the bone of the injured limb segment--collagen and phosphate--was found after fracture leg bone of against the background liver failure. Found that during the recovery period after leg bone fracture liver condition affects mineral and organic composition of the bone injured limb segment.

[Morphometric parameters of hepatic lobule vessels in mice during the restorative period after leg injury].

The diameters of the hepatic lobule vessels (interlobular veins, central veins, interlobular arteries, intralobular sinusoidal capillaries, interlobular bile ducts) were been studied 3, 7 and 28 days after shin bones fracture in CBA mice (n=30). Most pronounced changes of morphometric parameters indicative of hemodynamic disturbances, were found 3 days after the trauma. The increase of the diameter of central, interlobulat veins and sinusoidal capillaries took place, together with the decrease of the diameter of interlobular arteries, which, probably, promoted the reduction of arterial blood supply. The tendency for normalization of the diameter of interlobular veins, arteries and bile ducts was detected 28 days after the start of an experiment. However, the diameter of the central veins and sinusoidal capillaries remained significantly higher than in control group. Thus, it was found that the leg bone fracture was accompanied by the changes of morphometric parameters of the hepatic lobule, mediated by the organ response to injury.

[The characteristics of chemical composition of content of unicameral bone cysts depending on their growth stage].

The article deals with the results of study of chemical composition of solitary cysts and blood serum of 27 patients. The results demonstrated that qualitative composition of f content of unicameral bone cysts is identical to chemical composition of blood serum. The results of analysis of total proteolysis activity and acid phosphatase activity in content of cysts can be used as criteria to determine the stage of cyst growth and to evaluate the effectiveness of applied treatment.

Kinetic characteristics of myosin ATPase in dog skeletal muscles after shin bone fracture.

Kinetic characteristics of myosin from dog anterior tibial and gastrocnemius muscles after shin bone fracture were studied. Myosin affinity for ATP increased in muscles of the injured and contralateral limbs.

Accumulation of calcium, phosphate, and collagen in bones and accumulation of creatine in muscles of mice with acute hepatic intoxication during shin fracture healing.

The intensity of calcium and phosphate accumulation in regenerating bone tissue decreased significantly during the posttraumatic period in 54 male CBA mice with acute hepatic intoxication. The formation of organic components of the bone decreased to a lesser degree. Creatine metabolism in the muscles of damaged segment virtually did not change.

[Biochemical parameters in the prediction of the course of osteoreparative processes in skeletal injury].

A mathematical analysis was made to examine changes in the biochemical parameters of blood and daily urine in patients with closed shin fractures in the early posttraumatic period in order to determine the most important markers for the evaluation of the course and the prediction of the duration of osteoreparative processes.