RU2778604C1 - Implant for metaphyseal fixation of the tibial component of the knee joint endoprosthesis and a holder for its installation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to the field of medicine, namely traumatology and orthopedics, and is used in primary or revision endoprosthetics in patients with bone marginal and central metaphyseal defects in the implantation zone. An implant is proposed for metaphyseal fixation of the tibial component of the knee joint endoprosthesis in the form of a hollow truncated cone, having an upper edge of a larger diameter than the lower edge of a smaller diameter, with a central hole for the rod of the tibial component of the endoprosthesis, with a wall of porous metal. From the upper edge of the hollow truncated cone, cutouts extend downwards to interact with the projection of the tibial component plateau. The inner surface of the hollow truncated cone has projections. The implant wall is made of porous titanium nickelide (NiTi). On the inner side surface of the hollow truncated cone, along one diametrical line passing through the central axis at an equal distance between the cutouts, at the level of the lower edge of the cutouts, there are recesses for interaction with the balls of the working part of the holder. On the inner lateral surface, the hollow truncated cone has sections with stepped projections: the upper sections start from the upper edge of the larger diameter of the hollow truncated cone, the stepped projections of the upper sections have a length equal to the distance between the cutouts and end above the edge of the recesses at a distance of 1/10 of the height of the implant, the lower section is located below the edge of the recesses at a distance of 1/10 of the height of the implant and it reaches the lower edge of the smaller diameter of the hollow truncated cone, has circular stepped projections. The diameter of the circular stepped projections gradually decreases in the direction from the upper edge of the larger diameter of the hollow truncated cone to the lower edge of the smaller diameter. The verges of the edges of the hollow truncated cone are rounded. The holder for the installation of the above implant includes a handle and a lower working part. The working part has the shape of a truncated cone, immersed in the implant in the form of a hollow truncated cone. On the side of the larger base of the truncated cone of the holder, there is a circular limiter with a diameter exceeding the diameter of the larger base of the truncated cone and a rod. A central cylindrical hole passes through a truncated cone, a circular limiter and a rod. Between the central cylindrical hole and the side wall of the truncated cone there are blind channels with rolled exit holes on the outer side surface of the wall of the truncated cone. The blind channels are located perpendicular to the longitudinal axis of the holder, oppositely along one diametrical line located between the projections on the outer side surface of the truncated cone. The projections on the outer side surface of the truncated cone are located under a circular limiter, correspond in shape, size and location to the cutouts of the implant. The blind channels have fixation elements in the form of springs acting on the balls with the possibility of their partial exit from the rolled holes of the blind channels to interact with the recesses on the inner side surface of the implant. In the central part of the rod, riffling is performed on the outer side surface, a rectangular through hole is located at the opposite end of the rod, to which the central cylindrical hole reaches, a circular groove is made for the coupling balls, followed by a square four-sided end of the rod interacting with the coupling. The coupling has an external cylinder with circular ribs on the surface, a thrust ring on the side of the working end of the holder and an internal two-stage cylinder, between which a return spring is installed. The outer cylinder is installed with the possibility of movement along the inner cylinder, which at the first stage from the side of the working end of the holder has a larger outer diameter than at the second stage, which forms a cavity with the outer cylinder for the return spring. A through hole passes through the inner cylinder, having from the working end a section with a cross section in the shape of a square, corresponding in shape to the square tetrahedral end of the rod, on two opposite walls of which cylindrical holes with an inner annular projection for balls interacting with the circular groove of the rod are made opposite each other when it is installed in the coupling. The section of the through hole with a cross section in the shape of a square turns into a cylindrical section. The second stage of the inner two-stage cylinder of the coupling exits from the outer cylinder of the coupling and has an external thread on this section from the side of the transverse handle, for interaction with it. The transverse handle on the working side has a cylindrical hole with a thread in the lower part in the center for connection to the section of the second stage of the two-stage cylinder of the coupling with an external thread coming out of the coupling. In the upper part, in the center of the transverse handle, there is a first round impact pad with an entrance hole into a cylindrical inner cavity for installing a rod-shaped handle with upper and lower pads. A movable hammer in the form of a dumbbell is placed on the handle rod. A cylindrical thickening is made on the handle rod in front of the lower platform. The lower platform has the shape of a rectangular parallelepiped with a length different from the width, with rounded ends, with a central through cylindrical hole connecting the rounded ends of the parallelepiped. On the edges of the central through hole there are balls protruding from the rolled holes, between which a spring with the possibility of partial stroke is installed. The rounded ends of the parallelepiped of the lower handle pad have a width equal to the diameter of the cylindrical thickening of the handle. The balls from the rolled holes interact with the support slots on the side surface of the cylindrical inner cavity of the transverse handle. The cylindrical inner cavity has a diameter equal to the length of the parallelepiped at the level of the central through hole, a height equal to the height of the parallelepiped. The cylindrical inner cavity has on the inner side surface two support slots located along one diametrical line in the direction of the central longitudinal axis of the transverse handle for interaction with balls placed in rolled holes on the rounded ends of the parallelepiped of the lower handle pad when it is rotated 90°. The inlet to the cylindrical inner cavity and the inner cavity are connected to the lateral surface of the transverse handle by a cutout having a width equal to the diameter of the cylindrical thickening of the handle and a height equal to the total height of the cylindrical thickening of the handle and the height of the cylindrical inner cavity. The surface of the transverse handle, except for the first round impact pad, is covered with heat-resistant rubber.

EFFECT: inventions make it possible to securely and stably fix the implant on the holder, achieve the correct location during installation, without limiting visual control, reduce the time and cost of the operation and simplify it as a whole.

8 cl, 21 dwg, 1 ex

Description

SUBSTANCE: group of inventions refers to medicine, namely to traumatology and orthopedics, and is used in primary or revision arthroplasty in patients with bone marginal and central metaphyseal defects in the implantation area to create maximum congruence of the surface of the acceptor bone and the seating surface of the tibial component of the knee joint endoprosthesis for by creating an additional fixation zone.

Endoprosthetics of the knee joint is a technology for the treatment of diseases of the knee joint, including the replacement of the articulating surfaces of the tibia, femur and patella with artificial ones. It allows you to effectively relieve the patient of pain in the knee joint in the terminal stages of arthrosis and significantly improve the quality of life. The terms of functioning of an artificial knee joint are decades, however, in a certain percentage of cases, complications develop that require repeated intervention - revision arthroplasty. As a rule, after removal of a compromised implant, defects in the bone bed remain, requiring reconstruction for a high-quality installation of a revision endoprosthesis. To replace bone defects, bone auto- and allografts are used, which is associated with the risk of transmission of infectious diseases, rejection and lysis of the donor bone. The use of blocks and augments made of steel and its alloys also has its drawbacks associated with early rejection due to poor quality of the remaining bone, which occurs in 8% of cases and leads to instability of the revision endoprosthesis. To improve the results of revision arthroplasty, the concept of zonal fixation was formulated, according to which at least two of the three zones (diaphyseal, metaphyseal and epiphyseal) are required for good and long-term fixation of the revision endoprosthetics. At the same time, in 94% of cases, during revision arthroplasty, one has to deal with bone defects in the epiphysis of the tibia and femur. This fact determines the mandatory use of metaphyseal fixators and diaphyseal rods when performing revision knee arthroplasty.

Most orthopedic systems for revision arthroplasty consist of many modular elements. One of such elements is an implant for metaphyseal fixation of the tibial component of the knee joint endoprosthesis. It is represented by devices that have the shape of a truncated cone of a round or elliptical shape, gradually decreasing in diameter to the hole for the rod (pedicle) of the tibial component, have a smooth inner surface and a porous outer surface, which can be stepped and is made of metal or metal alloys. Implants for metaphyseal fixation provide secondary biological fixation of the endoprosthesis due to on-grow or in-grow osseointegration (depending on the type of coating) due to the porous outer coating, which increases the stability of the implant and its service life.

In the Japanese patent JP 2017-508562 A dated March 30, 2017, M. class. A61F 2/28, A61F 2/38 describes a cone that is inserted into the prepared tibia, having the shape of a round truncated cone with an axial through cavity or the shape of an ellipse with open ends. The housing is made of multilayer and has an outer part and an inner part made of a porous material with different pore sizes and an intermediate part made of metal. For the intermediate part, the outer part and the inner part, Ti6Al4V titanium alloy, well known in medicine, is used. The layers that form the body are combined by sintering. The intermediate part has a metal structure that can mechanically resist the stress transmitted to the inner part on one side and the outer part on the other side.

The proximal edge of the body of the truncated cone has one or two U-shaped notches located symmetrically with respect to the central axis of the truncated cone. The lateral wall of the truncated cone between the notches is thinner anteriorly than the posterior wall to facilitate centering of the implant during surgery.

The truncated cone is placed in the bone defect of the tibia and the prosthesis shaft is inserted.

The tibial component has a tibial plateau with protrusions on the underside cooperating with the U-shaped notches of the truncated cone and a shaft passing through it along the central axis if the truncated cone has a circular cross section or offset to the left or right if the cross section is elliptical depending on the location replacement bone defect.

Inject cement into the cavity of the truncated cone, which combines the rod, the tibial component and the truncated cone. The protrusions on the underside interacting with the U-shaped cutouts of the truncated cone are partially covered with cement.

Analog has the following disadvantages:

- complex manufacturing technology due to the need to sinter three different parts of the body;

- the impossibility of modeling a truncated cone intraoperatively due to the internal intermediate part made of cast metal T16Al4V;

- insufficient regeneration of bone tissue due to the lack of a through porous structure of a truncated cone;

- this type of truncated cone cannot be used for unlimited bone defects and defects of the third type according to the AORI classification, since it does not provide sufficient rotational stability;

- Excessive rise in price due to the method of manufacture.

Known design of the cone, described in US patent US 8506645 B2 dated August 13, 2013, IPC A61F 2/32, issued by Zimmer. The patent describes a cone intended for implantation in the proximal part of the tibia, depending on the location of the defect, used in knee prostheses. The invention describes a template used temporarily to try on and evaluate the correct fit within the bone, as well as a holder used to hold, insert and remove the template.

The cone is made of an elliptical annular body made of a porous material based on tantalum, since it resembles bone and approaches the physical and mechanical properties of bone better than other materials. The use of such a metal allows increased bonding to adjacent bone, allowing the bone to grow into its highly porous surface, which increases the strength of the bone. The cone conforms to the patient's anatomy and can be of different sizes depending on the specific size of the patient's bone structure.

The distal part of the cone may have depressions and steps. In its central part, the cone has a hollow end opening a canal into which the rod of the tibial component is inserted.

Bone cement may be inserted between the hollow central canal and the nail to provide greater stability for filling the tibia.

The walls of the annular body have a substantially uniform thickness except for a small area of lesser thickness on the front wall. A portion of the reduced thickness is needed to provide space for the tibial base plate rods of the knee prosthesis.

The outer surface of the housing has a downward slope (taper) of approximately 19°. Such constrictions reproduce the constrictions commonly found in the corresponding regions of the human proximal tibia. The dimensions of the cone can vary in length, width and height.

Prior to taper installation, a taper template is used as a test to ensure that the permanent taper fits correctly into the cavities. There are two main differences between a template and a sleeve. First, to allow the surgeon to visualize how the augment fits into the cavity, the template can be made of transparent or photoelastic polyphenylsulfone material. Secondly, the template has a set of grooves on the inner medial surface and the inner lateral surface. These grooves are designed to interact with the ribs on the holder. The holder is designed to facilitate the insertion and removal of the cone template into/out of the cavity in order to determine the correct fit and size match between the cavity and the template.

However, this design has several disadvantages:

- due to the low modulus of elasticity of the porous tantalum cone, bone fractures occur during its implantation, which requires careful preparation of the bone bed using high-speed drills. This leads to an increase in the time of the operation and the risk of complications, as well as the cost of treatment;

- if necessary, remove the porous tantalum cone, its strength properties do not allow it to be destroyed, which leads to the formation of severe iatrogenic bone defects and makes it difficult to perform a second operation;

- insufficient hygroscopicity of the porous tantalum cone does not allow reliable cement fixation of the tibial component;

- the absence of an open-cell and asymmetric structure in the porous tantalum cone prevents and slows down the process of osseointegration;

- the complexity of manufacturing using physical vapor deposition (PVD) manufacturing technology greatly increases the cost of porous tantalum (Trabecular Metal™).

The closest is the design of the implant, selected as a prototype, described in US patent 20130172892 A1, published July 4, 2013, IPC A61B 17/16, A61F 2/38. The present invention relates to surgical instruments and implants for use in total revision knee replacement procedures.

The implant for metaphyseal fixation of the tibial component of the knee endoprosthesis is made hollow in the form of a truncated cone with an upper diameter larger than the lower diameter. The implant in the lower part may have a cylindrical section with a diameter equal to the lower diameter of the truncated cone, which improves stability. It has a central hole for the stem of the tibial component of the endoprosthesis. The body wall of the truncated cone of the implant consists of one layer or two layers: the inner one is made of titanium, the outer one is made of porous titanium. Cutouts extend downward from the upper edge to interact with the projection of the plateau of the tibial component. When the wall is made of porous titanium, the notch can be corrected by cutting with a standard surgical instrument. On the inner surface, projections in the form of ribs are made, going from top to bottom to improve the connection with cement or other adhesive filling the truncated cone.

The prototype has the following disadvantages:

- the impossibility of modeling the truncated cone of the implant intraoperatively due to the internal intermediate part made of cast metal Ti6Al4V;

- insufficient regeneration of bone tissue due to the lack of a porous structure of a truncated cone, in the presence of a layer of titanium;

- the absence of an internal porous structure, as a result of insufficient hygroscopicity of the material, does not allow reliable cement fixation of the tibial component;

- the available side cutouts limit the use of this implant in conjunction with tibial components from other manufacturers;

- complexity in manufacturing and a long production time increase the final cost of the product several times.

A known design of the impactor is described in US patent 20130172892 A1, published July 4, 2013, IPC A61B 17/16, A61F 2/38. The present invention relates to surgical instruments and implants for use in total revision knee replacement procedures. The impactor is used when installing an implant in the cavity of the proximal part of the tibia, described in the same patent and having an oval body shape. The impactor consists of a handle and a working part containing an enlarged shaft area, and a head part having the shape of the inner surface of the implant reduced by 0.762 mm. The proximal surface of the implant is in contact with the lower surface of the oval platform, which is free from the head part attached to it. On the oval site, the surgeon can apply pressure transmitted to the implant to align it and place it in the cavity. Since the head part imitates the shape of the internal surface of the implant, it has corresponding conical slopes of the side surface areas, except for the front surface, which is perpendicular to the bottom surface of the oval platform. The head part of the impactor, which has a shape corresponding to the implant, must also have the appropriate size. There should be four impactors in the toolbox. The impactor may have a handle made of aluminum or other metal or plastic, a working part made of polymers or metals.

Disadvantages of analogue:

- does not allow you to set the trajectory of the implant;

- requires additional control during implantation;

- the inability to evenly and coaxially strike when installing the implant.

The trial implant insertion tool described in US Pat. No. 20130172892 A1, published July 4, 2013, IPC A61B 17/16, A61F 2/38, is the prototype for our proposed implant holder.

The invention described in the prototype relates to surgical instruments for bone preparation for use in revision knee arthroplasty procedures.

A multifunctional tool is described, which contains a drive and a large number of elements attached to it, providing the entire technological chain for installing a knee joint endoprosthesis.

For the prototype, the element for installing a trial implant in the tibial component of the knee joint was selected, after reaming its channel, expanding and creating a conical central cavity with a cone expander. The cone dilator is disconnected from the extension, leaving its head in the bone. The trial implant element is assembled to be inserted into the formed central conical cavity in the tibia.

The element for installation and extraction contains a handle, with a shock platform at the top, and a lower end that interacts with the groove of the trial implant. At the lower end there is a protrusion extending radially from the housing having the shape of a groove on the upper surface of the side wall opposite the extraction groove, preventing rotation of the housing relative to the implant. The trial implant is connected to the shaft of an elongated dilator head left slidably in the bone. The trial implant has the shape and dimensions of a truncated cone, as described in the prototype. A groove runs on the inner side surface of the wall, which ensures the extraction of the trial implant. In the lower part of the trial implant, above the cylindrical section, a protrusion passes inside, which serves to transfer the force from the shock pad of the body to the trial implant when it is installed in the bone cavity. On the outer side surface, there are locking slots that cut into the bone when a trial implant is inserted into the cavity.

The handle has fixing elements in the form of round recesses on the side flat surface, and on the other surface there are marks of the immersion depth indicator.

Prototype Disadvantages:

- the absence of a quick-release connection at the end of the instrument and, as a result, the possibility of quickly changing the configuration of a part of the instrument, if necessary, changing the cutter to an implant placement tool suitable for one handle/handle;

- the absence of a restrictive platform for establishing the extreme position of the implant during installation;

- the impossibility to apply blows evenly and coaxially when installing the implant in the bone space prepared by the cutter, due to the lack of a movable hammer;

- the complexity of manufacturing and the availability of implant templates/analogues/measuring devices significantly increase the total cost of the installation tool.

Purpose of the group of inventions: creation of a set of devices for installing a universal, intraoperatively modeled implant that provides reliable cementless fixation using a quick-release holder that ensures accuracy and reliability of implant positioning in knee arthroplasty in patients with bone marginal and central metaphyseal defects.

The purpose is achieved by an implant for metaphyseal fixation of the tibial component of the knee joint endoprosthesis in the form of a hollow truncated cone, having an upper edge of a larger diameter than the lower edge of a smaller diameter, with a central hole for the shaft of the tibial component of the endoprosthesis, with a porous metal wall. From the upper edge of the truncated cone, cutouts extend downward to interact with the protrusion of the plateau of the tibial component, the inner surface of the truncated cone has protrusions.

The implant wall is made of porous titanium nickelide (Porous NiTi) with a porous permeable structure - a porosity of 40-70% with a pore size of 50-100 microns. On the inner side surface of the hollow truncated cone, along one diametral line passing through the central axis at an equal distance between the cutouts, at the level of the lower edge of the cutouts, there are recesses for interacting with the balls of the working part of the holder.

On the inner side surface, the hollow truncated cone has sections with stepped protrusions. The upper sections start from the upper edge of the larger diameter of the truncated cone, have a length equal to the distance between the notches and end above the edge of the recesses at a distance of 1/10 of the implant height. The lower section is located below the edge of the recesses at a distance of 1/10 of the implant height and reaches the lower edge of the smaller diameter of the hollow truncated cone, has circular stepped protrusions. The diameter of the circular stepped protrusions gradually decreases in the direction from the upper edge of the larger diameter of the truncated cone to the lower edge of the smaller diameter. The edges of the edges of the truncated cone are rounded.

The implant has a maximum height of a hollow truncated cone of 50 mm and an internal diameter of the lower hole of 16 mm for the possibility of modeling the implant intraoperatively for a tibial component of any size.

The hollow truncated cone of the implant may be round or elliptical.

The implant has two to four lateral cutouts for interaction with the protrusions of the tibial component.

The total number of stepped protrusions on the inner surface of the hollow truncated cone in the upper and lower sections is from 2 to 10 with a protrusion height of 4 to 10 mm.

The side walls of the hollow truncated cone are directed at an angle of 0° to 20° to the central axis of the implant.

Novelty of the implant:

- the implant wall is made of porous titanium nickelide (Porous NiTi) with a porous permeable structure - a porosity of 40-70% with a pore size of 50-100 microns. The material is highly porous, has high biocompatibility, which promotes the growth of osteoblasts and bone osteoclasts in the open pores of the implant, better than any coating or rough surface finish that is mentioned by world famous manufacturers. The hygroscopicity of porous titanium nickelide material is several times better than that of porous tantalum (Trabecular Material™) and provides reliable cementation.

- on the inner side surface of the hollow truncated cone, along one diametral line passing through the central axis at an equal distance between the cutouts, at the level of the lower edge of the cutouts, there are recesses for interacting with the balls of the working part of the holder, which allows you to simply, quickly and reliably fix the implant on the holder and to carry out its introduction and installation into the cavity prepared by the cutter with the possibility of the same simple and quick disconnection after installation, which affects the reduction of operation time.

- on the inner side surface of the truncated cone has sections with stepped protrusions. The upper sections start from the upper edge of the larger diameter of the hollow truncated cone, have a length equal to the distance between the cutouts and end above the edge of the recesses at a distance of 1/10 of the implant height. The lower section is located below the edge of the recesses at a distance of 1/10 of the implant height and reaches the lower edge of the smaller diameter of the hollow truncated cone, has circular stepped protrusions. The diameter of the circular stepped protrusions gradually decreases in the direction from the upper edge of the larger diameter of the truncated cone to the lower edge of the smaller diameter. The presence of steps on the inner surface of the truncated cone increases the area of contact with the cement, especially in the lower part of the cone, and creates a more reliable support for the stabilization of the implant, which reduces the likelihood of movement of the implant, increasing its stability in the bone. Additionally, there is a uniform redistribution of the load from the tibial plateau, which allows you to increase the load on the joint as a whole.

- the edges of the edges of the truncated cone are rounded to facilitate the introduction of the implant into the cavity.

- the implant has a maximum height of the truncated cone of 50 mm and an internal diameter of the lower hole of 16 mm for the possibility of modeling the implant intraoperatively for the tibial component of any size, which allows it to be used with tibial components of the most famous manufacturers of knee prostheses and, if necessary, adjust the size of the implant during the operation individually according to patient, which reduces the risk of resorption and significantly reduces the time for surgery.

- hollow truncated implant cone, can be round or elliptical. The shape of the implant depends on the condition of the bone and the cavity formed during the operation, and can be chosen before the operation, but sometimes corrected intraoperatively.

- the implant has from two to four side cutouts for interaction with the protrusions of the tibial component. This makes it possible to use it with knee endoprostheses from different manufacturers that produce a tibial component with a different number and configuration of protrusions.

- the total number of stepped protrusions on the inner surface of the hollow truncated cone in the upper and lower sections is from 2 to 10 with a protrusion height of 4 to 10 mm. The number of steps depends on the size of the implant and the height of the protrusions, which positively affects the interaction with the cement inside, increasing its adhesion.

- the side walls of the truncated cone are directed at an angle from 0° to 20° to the central axis of the implant. The walls repeat the shape of the cavity formed for the installation, taking into account the anthropometric features of the tibia. Such narrowing reproduces the configuration of the tibial metaphysis, allowing it to be filled with the implant as efficiently as possible.

The purpose is also achieved by the fact that a holder is used to install the implant. The holder includes a handle with a striking platform at the top, a lower working part immersed in the implant cavity, having fixation elements interacting with elements located on the inner side surface of the implant, protrusions on the outer side surface for the mating parts of the implant.

The working part has the shape of a truncated cone, immersed in the implant in the form of a hollow truncated cone. On the side of the larger base of the truncated cone of the holder, there is a circular limiter with a diameter exceeding the diameter of the larger base of the truncated cone and a rod. A central cylindrical hole passes through a truncated cone, a circular limiter and a rod.

Between the central cylindrical hole and the side wall of the truncated cone there are blind channels with rolled outlet holes on the outer side surface of the wall of the truncated cone. Blind channels are located perpendicular to the longitudinal axis of the holder, opposite along one diametral line located between the protrusions on the outer side surface of the truncated cone. The protrusions on the outer side surface of the truncated cone are located under the circular limiter and correspond in shape, size and location to the implant cutouts. Fixation elements in the form of springs are installed in the blind channels, acting on the balls with the possibility of their partial exit from the rolled holes of the blind channels to interact with the recesses on the inner side surface of the implant.

Corrugation is made in the central part of the rod on the outer side surface. At the opposite end of the rod there is a rectangular through hole, which reaches the central cylindrical hole, a circular groove is made for the clutch balls, followed by a square tetrahedral end of the rod interacting with the clutch.

The coupling has an external cylinder with circular ribs on the surface, a thrust ring on the side of the working end of the holder and an internal two-stage cylinder between which a return spring is installed. The outer cylinder is mounted with the possibility of movement along the inner cylinder, which at the first stage from the side of the working end of the holder has a larger outer diameter than at the second stage, which forms a cavity for the return spring with the outer cylinder. A through hole passes through the inner cylinder, having a section with a section in the form of a square at the working end, corresponding in shape to the square tetrahedral end of the rod, on two opposite walls of which cylindrical holes are made opposite each other with an internal annular protrusion for balls interacting with the circular groove of the rod, when installed in the clutch. A section of a through hole with a cross section in the form of a square passes into a cylindrical section. The second stage of the inner two-stage clutch cylinder comes out of the outer clutch cylinder and has an external thread in this area from the side of the transverse handle to interact with it.

The transverse handle on the working side has a cylindrical threaded hole in the lower part in the center for connection with the section of the second stage of the two-stage clutch cylinder with an external thread coming out of the clutch. In the upper part in the center of the cross handle there is a first round impact platform with an inlet into a cylindrical inner cavity for installing a rod-shaped handle with an upper and lower platform. A movable hammer in the form of a dumbbell is placed on the handle shaft. A cylindrical thickening is made on the handle rod in front of the lower platform. The lower platform has the shape of a rectangular parallelepiped with a length different from the width with rounded ends, with a central through cylindrical hole connecting the rounded ends of the parallelepiped. At the ends of the central through hole, balls protruding from the rolled holes are placed, between which a spring is installed with the possibility of a partial stroke. The rounded ends of the parallelepiped of the lower platform of the handle have a width equal to the diameter of the cylindrical thickening of the handle, the balls from the rolled holes interact with the support grooves on the side surface of the cylindrical inner cavity of the transverse handle. The cylindrical inner cavity has a diameter equal to the length of the parallelepiped at the level of the central through hole, a height equal to the height of the parallelepiped. The cylindrical inner cavity has on the inner side surface two support grooves located along one diametral line in the direction of the central longitudinal axis of the transverse handle for interacting with the balls placed in the rolled holes on the rounded ends of the parallelepiped of the lower platform of the handle when it is rotated by 90°.

The inlet to the cylindrical inner cavity and the inner cavity are connected to the side surface of the transverse handle by a cutout having a width equal to the diameter of the cylindrical thickening of the handle and a height equal to the total height of the cylindrical thickening of the handle and the height of the cylindrical inner cavity. The surface of the transverse handle, except for the first round shock pad, is covered with heat-resistant rubber.

The working part of the holder in the form of a truncated cone may have a round or elliptical shape of the bases and side walls directed at an angle from 0° to 20°.

The holder has from two to four protrusions on the outer side surface of the truncated cone of the working part.

The novelty of the holder.

The working part has the shape of a truncated cone, immersed in the implant in the form of a hollow truncated cone. This allows for maximum contact area for uniform force transfer from the holder to the implant. Allows you to control the position of the metaphyseal fixator during impaction, evaluate the position of the resulting assembly to select the correct position of the implant, which allows you to avoid deviations and positioning of the tibial component of the joint endoprosthesis.

On the side of the larger base of the truncated cone of the holder, there is a circular limiter with a diameter exceeding the diameter of the larger base of the truncated cone and a rod. The limiter allows you to maintain the depth of immersion of the implant into the cavity prepared for its installation, which contributes to the exact location inside the bone.

A central cylindrical hole passes through a truncated cone, a circular limiter and a rod. At the opposite end of the rod there is a rectangular through hole, which is reached by a central cylindrical hole. The central cylindrical hole is designed for coaxial installation of the cone with a holder along the shank of the reamer used to guide the shaft of the tibial component and a conical cutter used to form the hole for the implant/cone of the tibial component. A rectangular through hole at the end of the rod and an internal through hole are used for the convenience of washing and disinfecting the working part of the tool.

Between the central cylindrical hole and the side wall of the truncated cone there are blind channels with rolled outlet holes on the outer side surface of the wall of the truncated cone. Blind channels are located perpendicular to the longitudinal axis of the holder, opposite along one diametral line located between the protrusions on the outer side surface of the truncated cone. Fixation elements in the form of springs are installed in the blind channels, acting on the balls with the possibility of their partial exit from the rolled holes of the blind channels to interact with the recesses on the inner side surface of the implant. This connection makes it possible to simply and securely connect the implant and holder. Serves for holding and moving the implant, as well as for manipulations during its installation.

The protrusions on the outer side surface of the truncated cone are located under the circular limiter and correspond in shape, size and location to the implant cutouts. The protrusions during installation in the implant exclude its rotation relative to the holder. The protrusions are made of stainless steel and have a smooth surface and are limited by the thickness of the implant, which facilitates the advancement of the implant into the cavity during its installation.

Corrugation is made in the central part of the rod on the outer side surface. For a comfortable, non-slip grip and hold by the clinician.

At the opposite working end of the end of the rod, there is a circular groove for the balls of the clutch, followed by a square four-sided end of the rod, which interacts with the clutch.

The coupling has an external cylinder with circular ribs on the surface, a thrust ring on the side of the working end of the holder and an internal two-stage cylinder between which a return spring is installed. The outer cylinder is mounted with the possibility of movement along the inner cylinder, which at the first stage from the side of the working end of the holder has a larger outer diameter than at the second stage, which forms a cavity for the return spring with the outer cylinder. A through hole passes through the inner cylinder, having a section with a section in the form of a square at the working end, corresponding in shape to the square tetrahedral end of the rod, on two opposite walls of which cylindrical holes are made opposite each other with an internal annular protrusion for balls interacting with the circular groove of the rod, when installed in the clutch. A section of a through hole with a cross section in the form of a square passes into a cylindrical section. The second stage of the inner two-stage clutch cylinder comes out of the outer clutch cylinder and has an external thread in this area from the side of the transverse handle to interact with it. Thanks to this, the working end of the instrument can be easily disconnected from the handle using a coupling if it is necessary to improve the view of the surgical field or free up space for the use of other instruments. A through hole in the inner cylinder, having a section in the form of a square, makes it possible to exclude the rotation of the square tetrahedral end of the rod, which ensures the reliability of the connection, and the second stage of the inner cylinder provides a connection with the cross handle.

The transverse handle on the working side has a cylindrical threaded hole in the lower part in the center for connection with the section of the second stage of the two-stage clutch cylinder with an external thread coming out of the clutch. In the upper part in the center of the cross handle there is a first round impact platform with an inlet into a cylindrical inner cavity for installing a rod-shaped handle with an upper and lower platform. A movable hammer in the form of a dumbbell is placed on the handle shaft. If necessary, the doctor can hold the instrument by the cross handle and effortlessly insert the additional handle of the movable hammer to place the implant. The upper platform allows you to strike on its surface and is a limiter, preventing the movable hammer from emigrating from the handle.

A cylindrical thickening is made in front of the lower platform on the handle shaft, which corresponds to the inlet to the cylindrical inner cavity of the transverse handle and limits the movement of the lower platform of the handle when it is installed in the cylindrical inner cavity, providing the desired position of the lower platform before turning it.

The lower platform has the shape of a rectangular parallelepiped with a length different from the width with rounded ends, with a central through cylindrical hole connecting the rounded ends of the parallelepiped. At the ends of the central through hole, balls protruding from the rolled holes are placed, between which a spring is installed with the possibility of a partial stroke. The rounded ends of the parallelepiped of the lower platform of the handle have a width equal to the diameter of the cylindrical thickening of the handle, the balls from the rolled holes interact with the support grooves on the side surface of the cylindrical inner cavity of the transverse handle. The cylindrical inner cavity has a diameter equal to the length of the parallelepiped at the level of the central through hole, a height equal to the height of the parallelepiped. The cylindrical inner cavity has on the inner side surface two support grooves located along one diametral line in the direction of the central longitudinal axis of the transverse handle for interacting with the balls placed in the rolled holes on the rounded ends of the parallelepiped of the lower platform of the handle when it is rotated by 90°. The shape of the bottom platform of the handle provides connection with the transverse handle through a cylindrical inner cavity made to fit its shape and dimensions. When the handle is installed, when the bottom platform is turned, the balls are pushed into the rolled holes, compressing the spring, and when the support grooves on the side surface of the cylindrical inner cavity of the transverse handle are reached, the balls are pushed out of the holes under the influence of the spring and fix the bottom platform.

The inlet to the cylindrical inner cavity and the inner cavity are connected to the side surface of the transverse handle by a cutout having a width equal to the diameter of the cylindrical thickening of the handle and a height equal to the total height of the cylindrical thickening of the handle and the height of the cylindrical inner cavity. The surface of the transverse handle, except for the first round shock pad, is covered with heat-resistant rubber. When installing the handle, the insertion of the lower platform of the handle is carried out through the side cutout by the smaller side wall of the parallelepiped until the cylindrical thickening of the handle stops against the wall of the inlet into the cylindrical inner cavity, after which the handle is rotated by 90°. The balls located on the roundings of the walls fall into the thrust grooves of the side wall of the cavity and fix the position of the handle quickly and reliably.

The working part of the holder in the form of a truncated cone may have a round or elliptical shape of the bases and side walls directed at an angle from 0° to 20°. The holder has from two to four protrusions on the outer side surface of the truncated cone of the working part. These elements of the working part of the holder correspond to the shape and dimensions of the implant for fast and reliable fixation on the instrument and installation.

Conducted patent studies on subclasses IPC A61F 2/38, IPC A61B 17/16 and analysis of scientific and medical information reflecting the existing level of designs for primary or revision arthroplasty in patients with bone marginal and central metaphyseal defects did not reveal devices identical to those proposed. Thus, the proposed devices are new. The relationship and interaction of the essential distinguishing features of the proposed devices ensure the achievement of a new technological medical result in solving the intended purpose, namely, an increase in the effectiveness of treatment due to the manufacture and use of an implant made of porous titanium nickelide, which makes it possible to individually model the shape and dimensions intraoperatively, reliable stable fixation and ease of installation implant using a holder, which can significantly reduce the time of operation and overall costs.

Thus, the proposed technical solution has an inventive step.

The proposed devices are industrially applicable in the field of practical health care, since their manufacture is available at the current level of development of the medical industry.

The set of essential features of the invention allows to obtain a new technical result:

- the use of porous materials based on an alloy of nickelide titate allows you to easily and quickly, without reducing the strength of the implant, give shape and size intraoperatively, as well as adapt to tibial components of any manufacturer;

- increase the stability of fixation of the cement and the tibial component with the implant by increasing the area of uniform contact and adhesion with the internal circular stepped protrusions;

- the proposed design of the implant and holder make it possible to securely and stably fix the implant when positioning the implant in space in all directions and not restrict visual control during installation, simplify and reduce the time for the operation.

The group of inventions is illustrated by the illustrations shown in Fig. 1-21.

On FIG. 1 implant view 3D.

On FIG. 2 view of the implant from above.

On FIG. 3 view of the implant from the front.

On FIG. 4 view of the implant along A-A in the context of the side cutouts.

On FIG. 5 view of the implant along B-B in the context of the recesses for the balls.

On FIG. 6 view holder 3D.

On FIG. 7 front view of the holder.

On FIG. 8 view of the holder in section along В-В.

On FIG. 9 side view of the holder.

On FIG. 10 is a sectional view of the holder in G-D.

On FIG. 11 local view D of the connection of the handle and the handle from the section along B-B in an enlarged size.

On FIG. 12 local view E of the connection of the handle with the coupling and the rod from the section along В-В in an enlarged size.

On FIG. 13 local view F of the truncated cone of the working part of the holder from the section along B-B in an enlarged size.

On FIG. 14 local view And the connection of the handle and the handle from the section along G-G in an enlarged size.

On FIG. 15 Panoramic teleroentgenogram (stiching) of the left knee joint of patient L. in direct projection.

On FIG. 16 radiograph of the left knee joint of patient L. in lateral projection.

On FIG. 17 fitting of the implant to the tibial component of the endoprosthesis.

On FIG. 18 Modeling the side cutouts of the implant with wire cutters to adapt to the tibial component.

On FIG. 19 simulation of the height of the implant after its installation, the protruding parts are resected with an oscillatory saw.

On FIG. 20 x-ray of the knee joint in the direct projection of the patient L. three days after the installation of the implant.

On FIG. 21 x-ray of the knee joint in the lateral projection of the patient L. three days after the installation of the implant.

The implant for metaphyseal fixation of the tibial component of the knee endoprosthesis has the shape of a hollow truncated cone 1 with an upper edge of a larger diameter 2 than the lower edge of a smaller diameter 3, with a central hole 4 for the stem of the tibial component of the endoprosthesis. The wall of the hollow truncated cone 1 is made of porous metal, namely, porous titanium nickelide (NiTi) with a porous permeable structure with a porosity of 40-70% with a pore size of 50-100 μm. From the upper edge 2 of the truncated hollow cone 1 go down cutouts 5 to interact with the protrusion of the tibial component. On the inner side surface of the truncated hollow cone, along one diametral line passing through the central axis at an equal distance between the cutouts 5, at the level of the lower edge of the cutouts 5, recesses 6 are located for interacting with the balls 7 of the working part of the holder 8. On the inner side surface there is a hollow truncated cone 1 has sections with stepped protrusions: the upper sections 9 start from the upper edge of the larger diameter 2 of the hollow truncated cone 1, the stepped protrusions 10 of the upper sections 9 have a length equal to the distance between the cutouts 5 and end above the edge of the recesses 6 at a distance of 1/10 of the height of the implant; the lower section 11 is located below the edge of the recesses 6 at a distance of 1/10 of the height of the implant and reaches the lower edge of the smaller diameter 3 of the hollow truncated cone 1. The lower section 11 has circular stepped protrusions 12, the diameter of the stepped protrusions 12 gradually decreases in the direction from the upper edge of the larger diameter 2 of the hollow truncated cone 1 to the lower edge of the smaller diameter 3, the edges of the edges 3 and 2 of the hollow truncated cone are rounded.

The implant has a maximum height of a hollow truncated cone h equal to 50 mm and an inner diameter d of the lower hole of 16 mm for the possibility of modeling the implant intraoperatively for a tibial component of any size.

Hollow truncated cone 1 may be round or elliptical.

The implant has from two to four side cutouts 5 for interaction with the protrusions of the tibial component.

The total number of stepped protrusions 10 and 12 on the inner surface of the hollow truncated cone 1 in the upper sections 9 and lower section 11 is from 2 to 10 with a protrusion height of 4 to 10 mm.

The side walls of the truncated cone 1 can be directed at an angle α from 0° to 20° to the central axis of the implant.

The holder 8 has a working part in the form of a truncated cone 13, immersed in a hollow truncated cone 1 of the implant. On the side of the larger base of the cone 13 there is a circular stop 14 with a diameter greater than the diameter of the larger base of the cone 13 and the rod 15 of FIG. 6. A central cylindrical hole 16 of FIG. 10. Between the central cylindrical hole 16 and the side wall of the truncated cone 13 there are blind channels 17 with rolled outlets on the outer side surface of the wall of the truncated cone 13 FIG. 8, FIG. 13. Blind channels 17 are located perpendicular to the longitudinal axis of the holder, opposite along one diametral line located between the protrusions 18 on the outer side surface of the truncated cone 13. The protrusions 18 on the outer side surface of the truncated cone 13 are located under the circular limiter 14, Fig. 7, FIG. 9 correspond in shape, size and location to the cutouts 5 of the hollow truncated cone 1 of the implant of FIG. 1. Fixation elements in the form of springs 19 are installed in the blind channels 17, acting on the balls 7 with the possibility of partially exiting the rolled holes of the blind channel 17, interacting with the recesses 6 on the inner side surface of the implant. eight.

In the central part of the rod 15 on the outer side surface there is a corrugation 20 FIG. 9. At the opposite end of the rod 15 there is a rectangular through hole 21, to which the central cylindrical hole 16 reaches, a circular groove 22 is made for the balls 23 of the coupling 24 of FIG. 12. The circular groove 22 is followed by a square tetrahedral end 25 of the rod 15 interacting with the coupling 24 of FIG. 12. The clutch 24 has an outer cylinder 26 with circular ribs on the surface, a thrust ring on the side of the working end of the holder and an inner two-stage cylinder between which a return spring 27 is installed. of the working end of the holder has a larger outer diameter than in the second stage 29, which forms with the outer cylinder 26 a cavity 30 for the return spring 27 of FIG. 12. A through hole passes through the inner cylinder, having a section with a section in the form of a square 31 from the working end, corresponding in shape to the square tetrahedral end of the rod 25. On two opposite walls of which cylindrical holes 32 are made opposite each other with an internal annular protrusion for the balls 23 of the coupling 24 interacting with the circular groove 22 of the rod 15 when it is installed in the sleeve 24 FIG. 12. The section of the through hole with a section in the form of a square 31 passes into a cylindrical section 33. The second stage of a smaller diameter 29 of the inner two-stage clutch cylinder 24 comes out of the outer cylinder of the clutch 24 and has an external thread 34 in this section from the side of the transverse handle 35, for interaction with her Fig. 12.

The transverse handle 35 on the working side has in the lower part in the center a cylindrical threaded hole 36 for connection with the second stage section 29 of the two-stage clutch cylinder 24 with an external thread 34 coming out of the clutch 24 of FIG. 12.

In the upper part in the center of the transverse handle 35 is the first round striking platform 37 with an inlet 38 into a cylindrical inner cavity 39 for installing a handle in the form of a rod 40 with the upper 41 and lower 42 platforms FIG. 7, FIG. 11, Fig. 14. On the shaft 40 of the handle is placed a movable hammer 43 in the form of a dumbbell with a longitudinal central hole 44 FIG. 10 mounted for free movement along the shaft 40 of the handle and impact on the first round impact pad 37 of the transverse handle 35 to advance the implant. The upper platform 41 of the handle has the shape of a cylinder and serves as a second impact platform for the action of the movable hammer 43 from below in the opposite direction to remove the implant if necessary or to strike from above. In front of the lower platform 42, a cylindrical thickening 45 is made on the rod 40 of the handle. 7. The lower platform 42 has the shape of a rectangular parallelepiped with a length different from the width with rounded ends, with a central through cylindrical hole 46 connecting the rounded ends of the parallelepiped of the lower platform 42. balls 47, between which the spring 48 is installed with the possibility of partial stroke. Fig. 11, Fig. 14. The rounded ends of the parallelepiped of the lower platform 42 of the handle 40 have a width equal to the diameter of the cylindrical thickening of the handle 45, the balls 47 from the rolled ends of the hole 46 interact with the support grooves 49 on the side surface of the cylindrical inner cavity 39 of the transverse handle 35. The cylindrical inner cavity 39 has a diameter equal to the length box of the bottom platform 42 at the level of the central through cylindrical hole 46, the height is equal to the height of the box FIG. 14. The cylindrical inner cavity 39 has on the inner side surface located along one diametral line in the direction of the central longitudinal axis of the transverse handle 35 two support grooves 49 to interact with the balls 47 placed in the rolled ends of the cylindrical hole 46 on the rounded ends of the parallelepiped of the lower platform 42 of the handle 40 when rotated through 90°. The inlet 37 into the cylindrical inner cavity 39 and the inner cavity 39 are connected to the side surface of the transverse handle 35 by a cutout 50 having a width equal to the diameter of the cylindrical thickening of the rod 45 of the handle 40 and a height equal to the total height of the cylindrical thickening of the rod 45 of the handle 40 and the height of the cylindrical inner cavity 39 . 11. The surface of the cross handle 35, except for the first round impact pad 37, is covered with heat-resistant rubber.

The working part of the holder in the form of a truncated cone 13 may have a round or elliptical shape of the bases and side walls directed at an angle from 0° to 20°.

The holder has from two to four protrusions on the outer side surface of the truncated cone of the working part.

The surface of the handle is covered with heat-resistant Eurosil rubber. The holder can be made of stainless steel, titanium alloy.

The assembly of the holder is carried out as follows.

The holder 8 has a working part in the form of a truncated cone 13 with a circular limiter 14, to install it at the desired level, the rod 15 in the form of a single block. The working part is connected by means of a rod 15 with the transverse handle 35 through the clutch 24. To do this, grab the outer cylinder 26 of the clutch 24 by hand and pull it towards the working end of the holder, at this time the cavity 30 moves under the return spring 27, which creates additional space above the holes 32 to move the balls 23 at the moment of entry of the square tetrahedral end 25 of the rod 15. The balls 23 are installed on two opposite walls of the section of the through hole with a section in the form of a square 31 inside the holes with an internal annular protrusion 32, which limits their exit into the through hole with a section in the form square 31 of the coupling 24. When the outer cylinder 26 is displaced and the size of the cavity 30 is reduced, which leads to compression of the return spring 27, at the moment of which a square tetrahedral end is inserted into the through hole of the section with a section in the form of a square 31 of the first stage of the inner cylinder 28 of the coupling 24 25 rod 15. The outer cylinder 26 of the clutch 24 is released and it returns to its original position under the influence of the return spring 27, while the balls 23 from the holes 32 under the influence of the outer cylinder 26 of the clutch 24 move in the opposite direction and fall into the circular groove 22 of the rod 15 and fix it. From the opposite end of the coupling 24, onto the cylindrical section 33 of the second stage with an external thread 34 coming out of it, a handle 35 is screwed, having for this purpose a hole 36 with a thread in the lower part in the center. 6, FIG. 12.

If it is necessary to extend the tool, an additional handle is inserted into the cutout 50 located in the center of the upper part of the handle 35, connected to the inner cavity 39 and the outer side surface of the handle 35. The handle consists of a rod 40 on which there is a movable hammer 43 and two platforms 41 and 42. The upper platform 41 is used for hitting with a movable hammer from below if it is necessary to remove the implant, as well as for hitting from above when installing the implant. The bottom platform 42 has the shape of a parallelepiped with rounded ends, on top of which there is a cylindrical thickening 45 on the rod 40. A central through hole 46 passes through it, in which the spring 48 and balls 47 are installed with the possibility of partial exit from the rolled edges of the hole 46. When installing the handle in the cutout 50, the bottom platform 42 is inserted with the deployed side having a shorter length until the thickening 45 stops into the back wall of the inlet 38 into the cavity and the bottom platform 42 stops against the wall of the internal cavity 39. Then the handle 40 is rotated 90 °, while the balls 47 fit into the support grooves 49 on the lateral cylindrical surface of the cavity 39 of Fig. 11, Fig 14. That is, quick and simple movements are performed to insert the lower platform into the cutout of the handle and turn.

The tool is ready to go.

The proposed implant for metaphyseal fixation of the tibial component of the knee endoprosthesis and the holder for its installation is used as follows.

In the preoperative period, by means of radiographs and/or CT images, the state of bone structures is assessed, selecting the type and position in space of the endoprosthesis planned for installation with optimal dimensions.

In revision arthroplasty, surgical access is performed, in particular, medial parapatellar access. The endoprosthesis components are removed using thin chisels and oscillating saw blades. Perform debridement of the joint. Existing defects of the femur and tibia are assessed and the need for an implant for metaphyseal fixation is determined. In case of a type 2 tibial defect according to the AORI (Anderson Orthopedics Research Institute) classification, an implant for metaphyseal fixation is not required; in types 2 and 3, its use is mandatory, according to the concept of zonal fixation of a revision endoprosthesis. Produce the removal of remnants of bone cement and fibrous tissue in the metaphysis of the tibia. The medullary canal is opened with an awl. Next, the canal is processed with sweeps to the planned depth, which depends on the length of the stem of the tibial component of the endoprosthesis. When cortical contact is reached, the treatment is stopped.

Using a reamer as a guide, the metaphyseal bone is processed with a conical cutter. Upon reaching immersion and full contact of the conical cutter with the surrounding bone, the processing is stopped.

Further, with the help of a trial tibial component, a trial landing is made and the obstacles available for this are determined. If obstacles are found, the conical cutter or other tool is reused for a more thorough cleaning.

Before installing the implant, it is tried on with the shaft and the plateau of the tibial component Fig. 17. Depending on the type and manufacturer of the endoprosthesis, if necessary, perform intraoperative modeling using wire cutters. FIG. 18, changing the width and shape of the side cutouts depending on the number of protrusions on the plateau, their location and shape.

Then the prepared implant is installed on the conical element of the working part of the holder until the balls with the internal recesses of the implant are fixed and installed in the bone bed by cementless fixation using coaxial blows of a movable hammer until the circular limiter stops against the bone.

After installation, the holder is removed. The protruding surfaces of the side walls and cutouts of the implant, if necessary, are additionally modeled with an oscillator saw and/or bone nippers for a tight fit of the tibial component. 19.

Next, the femur is processed and a fitting femoral component of the endoprosthesis is installed.

When installing fitting components, the stability of the ligamentous apparatus and the range of motion in the joint, as well as the sliding trajectory of the patella, are assessed. If necessary, perform radiographs to assess the spatial orientation of the components. The joint cavity and bone canals are washed with antiseptic solutions, all surfaces are dried with vacuum suction. The technique for placing the tibial component can be either fully cemented or hybrid. With cement technique, the bone marrow canal is washed and dried using a pulsating lavage system, bone cement is kneaded in a mixer and injected into the bone canal to the entire depth of the rod immersion using a syringe-injector, applied to the inner surface of the implant for metaphyseal fixation and sawdust of the tibia with such calculation that the entire cavity of the bone canal and metaphysis should be filled with cement. Next, the tibial component assembly with the nail is impacted to the planned depth with the selected rotation. The bone cement is pressed with constant pressure on the tibial component during the entire process of cement polymerization. The hybrid technique uses an uncemented intramedullary nail for the tibial component. In this technique, the cement is kneaded in a mixer and applied to the tibial component, to the surface facing the bone bed, and to the keel of the component liberally to achieve contact with the surface of the metaphyseal fixation implant. The tibial component of the endoprosthesis is implanted using the pin pressfit technique, which creates a hybrid fixation: a cement mantle at the implant interface for metaphyseal fixation/endoprosthesis and cementless fixation at the rod/bone interface. Indications for choosing the type of fixation are determined based on the quality of the bone. In severe osteoporosis, an all-cement technique is preferred.

The installation of all components of the endoprosthesis is completed by the standard method. The wound is sutured in layers.

When installing or revising the tibial components of endoprostheses with three and four stiffeners, implants and holders with three and four side holes and protrusions, respectively, are used. Depending on the anthropometric parameters of the patient, implants and instruments with different angles of inclination are selected.

The presented implant for metaphyseal fixation of the tibial component of the knee endoprosthesis is suitable for all the most famous manufacturers of knee endoprostheses: Stryker, DePuy, Zimmer, which have similar plateau protrusions and diameters of the tibial component rods, differing only in shape and location.

Clinical example

Patient L., aged 64, applied to the Department of Traumatology and Orthopedics with complaints of pain in the area of the left knee joint, limitation of movements and lameness. A history of knee arthroplasty 9 years ago, 1 year ago, a complication developed in the form of a periprosthetic infection, in connection with which the first stage of surgical treatment was performed - removal of the endoprosthesis with the installation of an articulating cement spacer impregnated with antibacterial drugs. An examination was carried out, including a general clinical blood test, determination of the level of C-reactive protein. Performed a puncture of the joint with the study of the contents of the cellular composition and seeding for sterility. According to the examination, there are no signs of an infectious process in the knee joint. For the purpose of preoperative planning, a teleroentgenogram was performed, and a massive tibial defect type 2a according to the AORI classification was diagnosed, formed as a result of an extensive microbial osteolytic lesion. Due to the size of the defect, it was decided to use an implant for metaphyseal fixation of the tibial component of the knee joint endoprosthesis made of porous titanium nickelide with the following characteristics: height - 40 mm, wall inclination angle - 11°, diameter of the lower internal hole -16 mm, with two cutouts for side walls.

Revision arthroplasty of the left knee joint was performed under spinal anesthesia with the RHK revision system manufactured by Zimmer using an implant for metaphyseal fixation of the tibial component of the endoprosthesis. The postoperative period was uneventful, the patient was activated and adapted to walking on crutches. On the third day after the operation, a control radiography of the left knee joint was performed in two projections. 20, FIG. 21: in the area of the tibia and the tibial component of the endoprosthesis, an implant for metaphyseal fixation is determined. In the postoperative period, physiotherapy exercises were performed to restore the range of motion in the knee joint. The patient was discharged with recommendations: observation by a trauma surgeon at the place of residence, walking with crutches for 3 months, anticoagulants and antibiotics in prophylactic doses up to 28 days after surgery. A control radiography was recommended 1, 3, 6 and 12 months after the operation, consultation of the operating surgeon. On control radiographs 1 month after surgical treatment: the components of the endoprosthesis are stable, the relationship between the device of the individual form and the components of the endoprosthesis is correct, there are no signs of migration. In the area of the implant for metaphyseal fixation and other components of the revision endoprosthesis, osteolysis zones are not determined. The patient does not complain of pain, walks without additional support.

The results of applying the method of replacing massive bone defects and the device of an individual form indicate an increase in the quality of orthopedic care and the quality of life of the patient. The results of treatment show and prove the industrial feasibility and usefulness of the claimed invention, the achievability of its stated goals.

As a result of the use of the proposed implant and holder, the technique of surgery for revision knee arthroplasty, with massive bone defects of types 2 and 3 according to the AORI classification, was simplified, which reduced the operation time by an average of 20 minutes and made it possible to use the entire range of revision knee arthroplasty, depending on required degree of connectivity. The above results provide an individual approach in each clinical case, reduce the risk of complications and improve long-term results of surgical treatment in patients undergoing revision knee arthroplasty.

Claims (8)

1. Implant for metaphyseal fixation of the tibial component of the knee endoprosthesis in the form of a hollow truncated cone, having an upper edge of a larger diameter than the lower edge of a smaller diameter, with a central hole for the rod of the tibial component of the endoprosthesis, with a porous metal wall, from the upper edge of the hollow truncated cone cuts go down to interact with the protrusion of the plateau of the tibial component, the inner surface of the hollow truncated cone has protrusions, characterized in that the implant wall is made of porous titanium nickelide (NiTi), on the inner side surface of the hollow truncated cone along one diametral line passing through the central axis at an equal distance between the cutouts, at the level of the lower edge of the cutouts there are recesses for interaction with the balls of the working part of the holder, on the inner side surface of the hollow truncated cone has sections with stepped protrusions: the upper sections start from the upper edge larger diameter of a hollow truncated cone, the stepped protrusions of the upper sections have a length equal to the distance between the cutouts and end above the edge of the recesses at a distance of 1/10 of the implant height, the lower section is located below the edge of the recesses at a distance of 1/10 of the implant height and reaches the lower edge of the smaller diameter of a hollow truncated cone, has circular stepped protrusions, the diameter of the circular stepped protrusions gradually decreases in the direction from the upper edge of the larger diameter of the hollow truncated cone to the lower edge of the smaller diameter, the edges of the edges of the hollow truncated cone are rounded. 2. The implant according to claim. 1, characterized in that the hollow truncated cone can be round or elliptical. 3. The implant according to claim. 1, characterized in that it has from two to four side cutouts for interaction with the protrusions of the tibial component. 4. The implant according to claim 1, characterized in that the total number of stepped protrusions on the inner surface of the hollow truncated cone in the upper and lower sections is from 2 to 10 with a protrusion height of 4 to 10 mm. 5. The implant according to claim. 1, characterized in that the side walls of the hollow truncated cone can be directed at an angle of up to 20° to the central axis of the implant. 6. The holder for implant installation according to claim 1, including a handle and a lower working part, characterized in that the working part has the shape of a truncated cone, immersed in the implant in the form of a hollow truncated cone, from the side of the larger base of the truncated cone of the holder there is a circular limiter with a diameter , exceeding the diameter of the larger base of the truncated cone, and the rod, through the truncated cone, the circular limiter and the rod passes the central cylindrical hole, between the central cylindrical hole and the side wall of the truncated cone there are blind channels with rolled outlet holes on the outer side surface of the wall of the truncated cone, blind channels located perpendicular to the longitudinal axis of the holder, opposite along one diametral line located between the protrusions on the outer side surface of the truncated cone, the protrusions on the outer side surface of the truncated cone are located under the circular limiter, correspond in shape, the size and location of the implant cutouts, fixation elements in the form of springs are installed in the blind channels, acting on the balls with the possibility of their partial exit from the rolled holes of the blind channels to interact with the recesses on the inner side surface of the implant, corrugation is made in the central part of the rod on the outer side surface, at the opposite end of the rod there is a rectangular through hole, which reaches the central cylindrical hole, a circular groove for the clutch balls is made, followed by a square tetrahedral end of the rod interacting with the clutch; the coupling has an outer cylinder with circular ribs on the surface, a thrust ring on the side of the working end of the holder and an inner two-stage cylinder, between which a return spring is installed, the outer cylinder is mounted with the possibility of movement along the inner cylinder, which at the first stage from the side of the working end of the holder has a larger outer diameter than on the second stage, which forms a cavity for the return spring with the outer cylinder, a through hole passes in the inner cylinder, having a section with a section in the form of a square at the working end, corresponding in shape to the square tetrahedral end of the rod, on two opposite walls of which opposite each other cylindrical holes are made with an internal annular protrusion for the balls, interacting with the circular groove of the rod, when it is installed in the coupling, the section of the through hole with a cross section in the form of a square passes into a cylindrical section, the second stage of the internal two-stage cylinder the clutch comes out of the outer cylinder of the clutch and has an external thread in this area from the side of the transverse handle, for interaction with it; the transverse handle on the working side has a cylindrical hole with a thread in the lower part in the center for connection with the section of the second stage of the two-stage clutch cylinder with an external thread coming out of the clutch, in the upper part in the center of the transverse handle there is the first round impact pad with an inlet hole in the cylindrical inner a cavity for installing a handle in the form of a rod with an upper and lower platform, a movable hammer in the form of a dumbbell is placed on the handle rod, a cylindrical thickening is made in front of the lower platform on the handle rod, the lower platform has the shape of a rectangular parallelepiped with a length different from the width, with rounded ends, with a central through cylindrical hole connecting the rounded ends of the parallelepiped, on the edges of the central through hole there are balls protruding from the rolled holes, between which a spring is installed with the possibility of partial stroke, the rounded ends of the parallelepiped of the lower platform of the handle have t width equal to the diameter of the cylindrical thickening of the handle, the balls from the rolled holes interact with the support grooves on the side surface of the cylindrical inner cavity of the transverse handle, the cylindrical inner cavity has a diameter equal to the length of the parallelepiped at the level of the central through hole, the height is equal to the height of the parallelepiped, the cylindrical inner cavity has on the inner side surface located along one diametral line in the direction of the central longitudinal axis of the transverse handle, two support grooves for interacting with balls placed in rolled holes on the rounded ends of the parallelepiped of the lower platform of the handle when it is rotated by 90°, an inlet to the cylindrical inner cavity and the inner cavity is connected to the side surface of the transverse handle by a cutout having a width equal to the diameter of the cylindrical thickening of the handle and a height equal to the total height of the cylindrical thickening of the handle and the height of qi cylindrical internal cavity, the surface of the transverse handle, except for the first round shock platform, is covered with heat-resistant rubber. 7. The holder according to claim 6, characterized in that the working part in the form of a truncated cone may have a round or elliptical shape of the bases and side walls directed at an angle of up to 20°. 8. The holder according to claim 6, characterized in that it has from one to four protrusions on the outer side surface of the truncated cone of the working part.

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