Diagnostic technique for joint implant with metal friction pair
SUBSTANCE: invention refers to medical equipment tests, namely to production tests of joint implants with a metal friction pair the state of which is assessed in the course of testing with using electric (electrically resistive) diagnostic techniques. The diagnostic technique for joint implants with the metal friction pair consisting in the fact that the implant is mounted in a test bench loaded with axial force; a lubricant layer is formed between surfaces of the implant components, and the physical characteristics of the surface layer of the components in the friction zone are measured. Small AC current is passed through the friction zone of the implant; a temporary function of complex impedance of the implant tribocoupling is recorded; it uses its active and reactive component parameters to show an actual thickness of the lubricant layer and a lubricant type prevailing in the tribocoupling and a friction regimen. The actual technical condition of the joint implant tribocoupling is assessed by a ratio of the time intervals when the active part of the complex impedance is more than the reactive part to the total measurement time.
EFFECT: invention provides shortening the test time, assessing the real time of the contact of the friction surfaces, increasing the produced valid signal power and noise stability, in obtaining the objective initial diagnostic information from the friction zone in order to predict a durability of the joint implant with the metal friction pair.
The invention relates to the field of testing of medical equipment, namely to production testing issue joint endoprosthesis with a metal bearing couple, a condition in which the test process is evaluated by applying electric (electroresistive) methods of diagnosis.
From the existing prior art discloses the method of diagnosis of hip arthroplasty with a metal bearing couple. Method for the diagnosis of hip arthroplasty with a metal bearing couple is that the endoprosthesis is fixed in the test bench, load axial force, form a lubricating layer between the surfaces of the components of the endoprosthesis and determine the physical characteristics of the surface layer of components in the friction zone. Axial force is applied perpendicular to the surface of the prosthesis is passed through the friction zone of the endoprosthesis small value stable electric current, caused by a current register and is proportional to the electrical resistance to a voltage drop in the friction zone in the form of the time function, the parameters fluctuations which estimate the actual friction in the endoprosthesis. Against time the integrity of the lubricating layer is determined by the time function of the resistance to General lie�neither the measurements assess the actual technical state of the elements of triborate parts of the prosthesis in the process of testing (see RF patent №2435551, IPC A61F 2/32, publ. 2011).
The disadvantage of this method is that the measurement of DC does not provide the necessary sensitivity and speed of measurement, as the processes occurring at the micro level in the friction zone, have a very low duration. Thus, the accuracy of diagnosing the above method is limited.
The problem to be solved by the invention is to improve the quality of diagnosis by obtaining a greater quantity and quality of information from the zone of friction triborate of the prosthesis joint.
This is achieved in that in the method of diagnosing joint endoprosthesis with a metal friction pair, which consists in that the endoprosthesis of the hip or shoulder joint is fixed to the test bench, load axial force, form a lubricating layer between the surfaces of components of the implant and determine the physical characteristics of the surface layer of components of the implant joint, unlike the prototype is passed through the friction zone of the endoprosthesis small value alternating electric current, caused by a current register and is proportional to the total electric with�rotellini the voltage drop in the friction zone in the form of the time function, in the parameters fluctuations which assess the actual technical condition of triborate of the prosthesis joint.
The technical result obtained by the implementation of the described invention, is to reduce the test time, the assessment of the real-time contact interaction of surfaces of friction, to increase the capacity allocated to the desired signal, its noise immunity and in the formation of an objective source of diagnostic information from the zone of friction to predict the longevity of the prosthesis joint with metal bearing couple.
The invention is illustrated by drawings. Fig.1 is a diagram of the contacting surfaces of the prosthesis when the liquid friction. Fig.2 is a schematic diagram of the contacting surfaces of the prosthesis under mixed friction. Fig.3 is a diagram of the contacting surfaces of the prosthesis, with the boundary friction mode. Fig.4 is illustrated the essence of the diagnostic parameter. Fig.5 shows a diagram of a device for carrying out the method.
The method is as follows. The joint endoprosthesis, consisting of a metal glenoid bowl 3 legs and 1 with femoral head 2, installed in a test stand, which is a container 6 made of non-conductive mate�IALA and filled with a dielectric liquid 4, separating the contacting surface of the prosthesis joint. Under a load when testing lubricating fluid is extruded from the zone of friction, changes its thickness and there is a change of mode of friction from liquid to mixed and boundary. The resistance of the contact area is defined by the expression (1)
where Z(t) - total impedance, Ohms;
R(t) is the resistance in Ohms;
X(t) is the reactance in Ohms.
Full impedance when liquid (2) and the semi-liquid lubricant (3) is described by the following expression
where R - resistance lubricant layer, Ohm;
SSM - capacity lubricating layer, Φ;
ω - cyclic frequency of the applied voltage, Hz;
R1 is the resistance of the contact metal to metal, Ohm;
R2 - resistance of the lubricating boundary layer at the friction.
In this case,
where S is the surface area, m2;
d - the distance between the surfaces, m;
ρ is the specific conductivity, Ohm·m;
ε0- electric constant, Φ/y;
εr- the relative permittivity of the medium between the plates.
Analyzing the numerator of the reactive part of the expression (2) we get that
Substituting known values (ε0=8,85·10-12Φ/m; for silicone oils εr=2,2%, ρ=1013Ohm·m) and comparing the active and reactive parts of the impedance, we get
The expression (7) is valid for frequencies where
When the liquid friction of fluctuations in the temporal function of the electrical impedance Z(t) is negligible. During the transition to the semi-liquid friction point contacts occur parts in the friction zone. This leads to a sharp decrease of the reactance of the impedance X(t) and additional fluctuations of the function Z(t). If the condition of the contacting surfaces in the friction zone of the endoprosthesis of inferior quality, the contact surfaces occurs more frequently and the point contacts longer. Such processes occur in the mode of boundary friction when a lubricant is almost forced out of the friction zone and the function of the electrical complex impedance is determined mainly active SOP�the resistance R(t). To the fluctuations of the function Z(t) will also lead to local inhomogeneities of the surface friction (abrasion and hooks, the results of the adhesion interactions of the contacting surfaces, contamination of the lubricant (synovial fluid) and the rheological properties of the lubricant. The articular Cup of the prosthesis 3 is fixed in the holder 5, which is rotated by the actuator 7, simulating the rotational movement of the joint.
Loading is carried out adjustable axial force (the value of which varies depending on the type and size of prosthesis) applied perpendicular to the surface of the base. To create such a load is used as the loading device 13, which allows in manual mode to set the current value of the axial force, the current collector 12 is connected to the leg prosthesis 1, remove a signal is transmitted to the divider 10.
The time function of the voltage divider 10 is proportional to the electrical resistance of the friction zone and reflects the actual process of microconductivity in the friction zone of the endoprosthesis. The voltage divider supplied from the generator 11 and the divider is fed to a digital oscilloscope 8 which in turn is connected to the computer 9. The parameters of the fluctuation of the measured function of resistance Z(t) will characterize the real macro - and microgeometry its�STV contacting surfaces and friction regime as a whole. As a diagnostic parameter is proposed to use the normalized integral time electrical contacting, K, units.
where Tand- time of measurement, C;
nT- the number of segments in tribounit of the prosthesis, corresponding to R(t)-X(t)≥0 at time Tand, ed;
tn(K)i- the start time (the end of) the i-th segment corresponding to the condition R(t)-X(t)≥0, s
Varying from 0 when the liquid lubricant to 1 under boundary lubrication, the parameter K is a statistical estimate of the likelihood of microconductivity in tribounit of the prosthesis joint. Thus, the parameters of active and reactive components of the resistance are judged on the actual thickness of the lubrication layer and dominant in the tribounit the form of lubrication and friction, with respect to the time intervals, in which the active part of the complex impedance of more reactive to total measurement time estimate of the actual technical state of triborate of the prosthesis joint. The difference between the active and reactive components of the contact resistance is determined by the parameter of the normalized integral time electrical contacting K.
According to the obtained value To the conclusion about the mode of friction in the endoprosthesis, the state macro - and microgeometry of contacting de�Aley, about the likelihood of future use of the prosthesis or its rejection. The reference values for implants are determined on the basis of statistical processing of the results of endurance tests for implants of various sizes.
Thus, the technical result obtained by the implementation of the described invention, is to reduce the test time, the assessment of the real-time contact interaction of surfaces of friction, to increase the capacity allocated to the desired signal, its noise immunity and in the formation of an objective source of diagnostic information from the zone of friction to predict the longevity of the prosthesis joint with metal bearing couple.
Method of diagnosing joint endoprosthesis with a metal friction pair, which consists in that the endoprosthesis is fixed in the test bench, load axial force, form a lubricating layer between the surfaces of the components of the endoprosthesis and determine the physical characteristics of the surface layer of components in the friction zone, characterized in that, through the friction zone of the endoprosthesis small value alternating electric current, record the time function of the complex impedance of triborate of the endoprosthesis, the parameters of active and reactive components koto�Oh is judged on the actual thickness of the lubrication layer and dominant in the tribounit the form of lubrication and friction, in this respect the time intervals, in which the active part of the complex impedance of more reactive to total measurement time estimate of the actual technical state of triborate of the prosthesis joint.
SUBSTANCE: stimulating the excised liver regeneration is ensured by a 70% hepatectomy into a laboratory animal on the second day of the experiment. A liver regeneration stimulator is presented by L-norvaline administered intragastrically in a daily dose of 10.0 mg/kg every 46 hours for the first 7 days of the experiment.
EFFECT: method provides the effective stimulation of the excised liver regeneration evidenced by reducing the animals' lethality, improved hepatic microcirculation, reduced manifestation of cytolysis and enhanced synthetic function of the liver.
2 tbl, 1 ex
SUBSTANCE: limb ischemia is simulated in a male Wistar rat anaesthetised with chloral hydrate in a dose of 250-300 mg/kg by the surgical removal of femoral, popliteal arteries and the front shin artery. That is followed by introducing a prepared mononuclear fraction of the autologous bone marrow in a dose of 4×106 cells in an amount of 200 mcl. The above is introduced into the ischemic limb from two points in an amount of 100 mcl each. One point is found directly under the femoral arch paravasally within the anatomical position of collaterals of the inner iliac artery and its branches. The other point is located in the calf muscle on an anteriolateral surface of the midleg.
EFFECT: more effective experimental treatment ensured by stimulating the collateral blood flow in the ischemic limb and improving the arterial blood flow from the proximal to distal parts of the limb.
1 ex, 1 tbl
SUBSTANCE: method consists in a single administration of a mixture consisting of a rat's homogenised myocardial tissue - 25%, egg albumin - 25% and Freund's adjuvant - 50%, into old male rats. The method involves administering in an amount of 0.3 ml into 5 injection points: intraperitoneally, into inguinal and axillary regions from the left and right.
EFFECT: being easy to reproduce and cost efficient, the method is effective for creating a model aiming at a possibility of studying the pathogenesis, preventing and treating cardiopathy.
2 dwg, 1 tbl, 1 ex
SUBSTANCE: phantom test consists of two parts being a single whole. One part has a constant longitudinal height, while the other part has a continuously varying longitudinal height forming a wedge. On the side of the wedge, there are calibrated notches.
EFFECT: more accurate determination of the bone mineral density by X-ray images formed with the help of a general-application X-ray machine, and simplifying the design.
SUBSTANCE: invention refers to medicine, particularly to gastroenterology, pathologic physiology, and concerns simulating acute pancreatitis. To this effect, the method involves ligaturing the main truck of the excretory duct of the pancreas, administering an aggressive solution into the pancreatic duct system, and removing the ligature. The aggressive solution represents 1% chenodeoxycholic acid with 5% sodium hydrogen carbonate in an equal proportion in an amount of 0.3-0.5 ml at 10-15 mg/kg of the animal's body weight.
EFFECT: method enables developing a model of acute fatty, hemorrhagic or mixed pancreatitis in the animal that makes it applicable for improving the known methods for conservative and radical methods of treating.
SUBSTANCE: invention refers to medicine, particularly to ophthalmology, and concerns simulation in vivo of cortical cataract. That is ensured by a double-side surgical sympathectomy by excising a superior cervical sympathetic ganglion.
EFFECT: by simplicity and effectiveness of modulation, the method provides forming the cortical lens-form opacity, which is morphologically and immunohistochemically identical to lens cell changes in age-related lens opacity in a human.
6 dwg, 2 tbl
SUBSTANCE: during the trial rabbits are given the inhibitor preparation lynestrenol in vivo endogastrically with the daily dose of 110 mkg/kg of animal body weight in the course of 14, 21 or 28 days.
EFFECT: invention makes it possible to use lynestrenol as positive control of lower activity of glycoprotein-P for prediction of inclusion of studied medicinal agents into substrates of a transporter protein.
SUBSTANCE: cecum lymphoma is modelled by the introduction of 2,4,6-trinitrobenzosulfonic acid to a rat in a dose of 0.1-0.15 ml, diluted in 0.1-0.15 ml of a 50% ethanol solution. Introduction is realised into a submucosal layer of the cecum cupola 2-3-times daily for 2-3 weeks.
EFFECT: creation of an adequate model of the cecum lymphoma.
SUBSTANCE: to correct pathologic changes in the condition of viable offspring under a cytostatic impact the medication glutoxim is introduced to female rats in a dose of 50 mcg/kg 5 days before and 5 days after the introduction of the cytostatic medication vepesid. The latter is introduced once intravenously in a maximal tolerable dose, equal to 30 mg/kg. It has been established that glutoxim can be applied as means for the correction of pathologic changes in the viable offspring of rats, obtained from coupling 3 months after the cytostatic impact.
EFFECT: application of glutoxim as the means of corrective therapy makes it possible to increase efficiency and reduce its side effects.
SUBSTANCE: method is realised by the intravenous allogeneic transplantation of multipotent mesenchymal stromal cells (MMSC) and hematopoietic stem cells (HSC) to laboratory mice one hour after irradiation. HSC are obtained from the placenta of female mice at the 14-day gestation term. MMSC are introduced in a dose of 6.5 mln cells/kg, with HSC being introduced in a dose of 400 thousand cells/kg.
EFFECT: invention makes it possible to extend the arsenal of means, capable of providing the regeneration potential of the spleen tissues, as well as to increase the regeneration of main morphometric spleen indices after exposure to a radiation load.
SUBSTANCE: invention refers to medicine. What is described is a cage for total extended long bone defect restoration representing a hollow cylinder made of a carbon-carbon composite walls of which are perforated with multiple through holes providing surrounding tissue adhesion and blood vessel penetration inside the cylinder. An inner lumen of the cage is filled with a xenogenic osteoplastic material with an axial through hole used to facilitate a fixation procedure.
EFFECT: cage makes it possible to deliver the osteoplastic material to the defect region, prevents its migration and enables improving the results of the long bone defect correction outcome by the reliable fixation of the osteoplastic material within the defect region due to optimum strength characteristics of an outer support frame, the effective regeneration within the defect region by the osteoplastic material, the absence of adverse effects of the long-term implantation, and as a result no necessity to remove the cage, and ensured possibility of the intraoperative adjustment of the cage size depending on the defect size.
SUBSTANCE: what is described is a biomaterial having a multi-dimensional structure and comprising differentiated MSCs tissue and demineralised bone matrix, wherein the above demineralised bone matrix is dispersed in the differentiated MSCs tissue; a method for preparing and using the same is also presented.
EFFECT: biomaterial is processed as needed and has the mechanical properties required for implantation into the natural involved region.
17 cl, 6 dwg, 2 ex
SUBSTANCE: group of inventions relates to medicine. A knitting device for knitting a human or an animal joint contains at least one anchor part and at least one support part and additionally contains two rod-like anchor parts and one support part. In its general depth (D), measured from a proximal surface to a distal end of the knitting device, the knitting device is oriented parallel to the direction (I) of implantation, and in its general width (W) and the thickness profile (T1 and T2) the knitting device is oriented perpendicular to the direction (I) of implantation. The anchor part and the support part are alternating or are made with a possibility of alternation along the width (W), with the thickness (T1) of the said at least one anchor part being larger than the thickness (T2) of the said at least one support part. The said at least one anchor part contains a material which is liquidised, with the material, which is liquidised, representing a thermoplastic material and being located on the surface of the anchor part or inside a perforated envelope, forming a part of the anchor part. The said surface of the anchor part or the said perforated envelope is placed on the knitting device in such a way that they are capable of coming in contact with the bone tissue in the process of implantation. The support part is placed between the anchor parts, and the anchor part has a depth which is larger than the depth of the support part. The support part, if possible together with the anchor part, forms a concave profile of the device and in this way limits an osteoconduction area. The method of knitting the human or animal joint in accordance with the first version contains the following stages: provision of the availability of the said knitting device, preparation of at least one of joined surfaces and introduction of the knitting device in such a way that the said at least one anchor part comes in contact with the bone tissue in the area of the said at least one prepared surface to be joined. A sage of introduction includes the supply of energy to the proximal surface of the knitting device due to its connection to a vibration or rotation drive or to a source of energy of electromagnetic radiation of visible or infrared range in the process of introduction or after the introduction and switching on a drive or a source for the time sufficient for liquidising of at least part of the material to be liquidised and penetration of the liquidised material into the said bone tissue, where after solidification the liquidised material forms with the said bone tissue a compound with the positive tightness. In accordance with the second version the method contains the following stages: provision of availability of the said knitting device, preparation of at least one of the joined surfaces and introduction of the knitting device in such a way that the said at least one anchor part comes in contact with the bone tissue in the area of the said at least one prepared surface to be joined. In accordance with the third version the method contains the following stages: provision of availability of the said knitting device, fixation of the joined surfaces in a preliminarily specified mutual position, introduction of the knitting device between the fixed surfaces to be joined and release of fixation of the surface to be joined. A set of instruments for knitting a synovial human or animal joint contains vibroinstrument or a pusher and the said knitting device or a part of the said device, installed or to be installed on th distal end of the vibroinstrument or pusher.
EFFECT: inventions provide the joint immobilisation to a degree sufficient for doing without additional fixing elements, optimal osteoconduction between two bones of the joint and preferably optimal osteointegration into the bone tissue with a possibility of application in minimally invasive surgery.
21 cl, 20 dwg
SUBSTANCE: invention relates to medicine, namely to maxillofacial surgery and traumatology and can be applied for formation of antimicrobial coating in manufacturing titanium-based intra-tissue endoprostheses. For this purpose preliminary preparation of silver-containing solution, preliminary preparation of implant surface and coating formation are carried out. In the process of preparation of silver-containing solution first hydroxyapatite powder is placed into 0.04% solution of AgNO3. After that, powder is kept in air at room temperature for the time necessary for qualitative soaking of hydroxyapatite particles with AgNO3 solution. Then, sediment is filtered and washed with hot water, and dried at 200°-300°C for 4-6 hours and annealed at 600°-700°C for 2-3 hours. Preliminary preparation of implant surface is performed by jet processing of surface with electrocorundum powder under pressure. Formation of coating is carried out by plasma sputtering of first titanium sublayer and then silver-containing hydroxyapatite powder. Plasma sputtering of titanium sublayer is performed at voltage 35 V, current intensity 450 A, distance of sputtering 100 mm and titanium powder dispersion 100-120 mcm, consumption of argon being 55-60 l/min. Plasma sputtering of silver-containing hydroxyapatite powder is performed at current intensity 450 A, voltage 36 A, distance 80 and 120 mm, dispersion 70-75 mcm and argon consumption 65-70 l/min.
EFFECT: method ensures obtaining implant coating, contributing to fast and reliable osteointegration of the implant due to formation of developed surface morphology and creation of antimicrobial effect in tissues adjacent to endoprosthesis.
4 tbl, 2 dwg
SUBSTANCE: invention relates to a method of producing oxidation-resistant ultrahigh molecular weight polyethylene (UHMWPE) material. The method involves forming UHMWPE with an additive and treatment with gamma-rays or an electron beam. Exposure is carried out on air under normal atmospheric conditions with a dose of 2-40 Mrad. The exposed head has oxidation index after artificial ageing which is equal to or lower than that of standard UHMWPE material sterilised with gamma-rays.
EFFECT: UHMWPE material exhibits improved wear resistance and good resistance to oxidation.
48 cl, 5 tbl, 5 ex
SUBSTANCE: invention refers to medicine. What is described is an implanted multilayer chondral reparation flap showing biological compatibility and physiological resorption, and what is also described is a method providing surgical management in situ for intra-articular regeneration of cartilaginous tissue in joint damages and/or defects. The chondral reparation flap comprises a first external cell-impermeable layer and a second external cell-permeable layer adapted for placement in an immediate proximity from a subchondral bone on a wound portion, and also a cartilage-forming matrix located between the first and second layers. The cartilage-forming matrix represents an accepting medium for diffusion of autologous stem cells and contains chemical components promoting formation of a hyaline-like cartilage in the presence of said autologous stem cells. The method prevents a fibrous cartilaginous replacement tissue from forming within the injury region.
EFFECT: method provides autologous compositions which when used in a combination with the reparation flap form the medical system for formation of the replacement hyaline-like intra-articular cartilage.
17 cl, 7 dwg, 1 ex
SUBSTANCE: invention refers to medicine. An implant to be inserted between vertebral bodies comprises a first contact surface adjoining one of the adjacent vertebral bodies and a second contact surface adjoining another adjacent vertebral body, and forms a power transmission chain between the adjoining surfaces of the adjacent vertebral bodies in which at least one elastically adjustable element is located. The implant is compounded with at least one first portion of the implant and one second portion of the implant being rearranged with respect to each other in the direction of its longitudinal axis. Each of the implant portions represents a tubular sleeve. At least of the implant portions has the elastically adjustable element integrated in its wall and formed by cross shifted slots.
EFFECT: invention provides lower load of end plates of the vertebral body.
15 cl, 18 dwg
SUBSTANCE: invention refers to medicine. An acromialclavicular disc implant represent an oval plate tapered towards the bottom enclosing a clavicle and an acromion placed between its articular surfaces.
EFFECT: invention provides improved joint function recovery and prevented ankylosis by replacing an injured acromialclavicular disc.
5 cl, 3 dwg
SUBSTANCE: invention relates to medicine. Endoprosthesis contains element (4) made with possibility of connection with lower bone and having surface (44) of sliding on its upper side, element (1) made with possibility of connection with upper bone and having surface (11) of sliding on its lower side, and intermediate link (2), on whose upper and lower sides there is one surface (21, 24) of sliding, which together with surfaces (11, 44) of sliding of said elements (1, 4) in each case determine surfaces of movement for support. Surfaces (21, 24) of sliding of intermediate link (2) have different contours. Frame (3) is made two-zone: with located on perimeter belt zone and adjoining it anti-expansion zone, involving lateral surfaces of intermediate link (2) and is placed on intermediate link (2) in such a way that does not have contact with surfaces of movement, determined by surfaces (11, 44) of sliding with different contours.
EFFECT: invention ensures endoprosthesis higher reliability of enduring high loading without deformation preserving several degrees of freedom.
13 cl, 7 dwg
SUBSTANCE: implant consists of two bars and coupling. Bar with bearing bone thread on one end, on end with metric thread has coaxial hexahedral opening for butt-end spanner and through axial opening for guide pin, which opens in hexahedral opening. Second bar, with conically narrowing and sharpened end, and end with metric thread, has longitudinal semi-circular gaps on lateral surface of conically narrowing and sharpened end. Opposite ends with metric thread of bars are connected by coupling.
EFFECT: invention ensures substitution of considerable defect of distal part of radial bone with simultaneous arthrodesis in wrist joint.
2 cl, 1 dwg
FIELD: medical engineering.
SUBSTANCE: system has endoprosthesis having rod introduceable into intramedullary canal and rasp shaped like the rod. The rasp is usable for preparing cavity for introducing the rod. The rasp has toothless profile part within the basic segment of its length. The rod has at least one longitudinal rib in the area matching the toothless rasp profile part. The toothless rasp profile part has no rib matching the rod rib at least in the basic segment of rasp length.
EFFECT: high reliability in fitting prosthesis.
13 cl, 3 dwg