RU2254833C1 - Artificial knee joint having a positioning unit - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has femur part having supporting member for fastening and controllably rotating prosthesis bucket and fixing members; crural part having supporting member for fastening crus mounted on rotation axle. The prosthesis bucket supporting member is mounted in a way allowing rotation about symmetry axis and has cylindrical tail part having ring-shaped groove. The fixing means are manufactured as two pairs of threaded boss-bushing type arranged in parallel when passing through openings in the femoral part on both sides of the ring-shaped cylindrical tail part groove. They have rims pressed with screws to ring-shaped groove surface. The bosses have sharp edges and are positioned on the same side with one lateral casing surface and the bushings having rounded edges are arranged on the opposite side. Compression spring is mounted between each threaded boss and bushing.

EFFECT: improved rotation conditions with any type of supporting members without taking off the prosthesis bucket.

6 cl, 4 dwg

Description

The invention relates to medical equipment, namely to artificial knee joints, and can be used when prosthetics of the lower extremities.

The process of constructing a prosthesis scheme includes finding the optimal one, taking into account the diversity of individual characteristics of the disabled person, the relative positions of the modular nodes. In the general case, for constructing and adjusting (adjusting) an individual prosthesis scheme, adjusting and connecting devices (DCS) must provide adjustable movements of the modules relative to each other. This is a linear movement, a change in the angle (between the longitudinal axes of the modules), and also rotation around the longitudinal axis. In addition to the listed functions, the DCS, as a rule, provides a modular connection of the prosthesis nodes and consists of two detachable parts built into the connected modules. There is also a large number of DCS of various designs in the form of independent products.

Firms Otto Bock, PKK “ENERGY” and others use DCS, one part of which is a pyramid, and the response part is a sleeve with four screws integrated into the IRS and the receiving sleeve to connect the thigh receiving sleeve to the ICS. This DCS allows you to change the angle, but does not provide rotation of the connected modules.

In the invention according to the patent US 5759206, 02/02/1998 for the rotation of the connected modules around the axis of the pyramid, the latter has a threaded hole for connecting the receiving sleeve of the lower leg with a washer and screw mounted on the inside of the receiving sleeve. The main disadvantage is the need to remove the prosthesis from the stump to perform alignment.

In the invention according to US Pat. Adjustment is also accompanied by removal of the prosthesis from the stump.

In the combined adjustment device of the lower limb prosthesis (RU 2142758 C1, 12.20.1999) linear, angular and rotary movements are independent of each other due to the use of a connection with an adjustable clearance by means of bolts and nuts. However, this invention does not show the means of connecting with the ICS, which does not allow us to evaluate the feasibility of the device in a hip prosthesis on a long stump.

In US Pat. , eleven). The pyramid is connected by means of a conical fit to the element of the supporting surface. Fixation is carried out due to friction in a conical fit during tightening, therefore, fixation from unauthorized rotation is not guaranteed. This technical solution does not entail an increase in the dimensions of the ICS, however, it cannot be implemented for supports of other types that do not use pyramids (for example, supports with the “sleeve with four screws” type). In addition, for locking after turning and for attaching the sleeve to the ICS, the same locking mechanism is used (four screws resting against the pyramid), which, when the screws are loosened, creates an angular play between the support and the sleeve.

An object of the present invention is to provide an IKS with a built-in alignment device that allows the IKS to rotate relative to the receiving sleeve of the thigh with any type of support without removing the receiving sleeve.

The technical result is a reduction in the complexity of adjusting an individual prosthesis construction scheme, as well as the absence of angular play. An additional technical result consists in the possibility of manufacturing a hip prosthesis on a long stump, since the overall dimensions of the ICS from the introduction of the adjusting device do not increase.

The technical result is achieved by the fact that the artificial knee joint contains a femoral part with a support for attaching and adjustable rotation of the receiving sleeve of the thigh with fixation means and an ankle part with a support for attaching the lower leg mounted on the axis of rotation. The support for mounting and adjustable rotation of the thigh receiving sleeve has a cylindrical shank with an annular groove and is installed in the opening of the femoral part with the possibility of rotation around its own axis of symmetry. The fixing means are made in the form of two pairs of threaded boss - sleeve, located in parallel through holes in the femoral part on both sides of the annular groove of the cylindrical shank and installed with the possibility of tightening the screws of their edges to the surface of the annular groove. Moreover, the bosses made with sharp edges are located on the side of one side surface of the housing, and the bushings having rounded edges are opposite, while a compression spring is installed between each threaded boss and the sleeve.

The joint may be characterized in that the fixation means comprise covers attached to both side surfaces of the housing opposite each other, while elastic elements made of hard rubber or polyurethane are placed between one of the covers and the bosses, and the other cover has openings opposite the screw key sockets .

The joint can be characterized by the fact that the support for attaching the lower leg and / or the receiving sleeve of the thigh includes elements for modular fastening, made in the form of a tetrahedral pyramid and a supporting surface.

The joint can also be characterized in that the support for fastening the receiving sleeve of the thigh includes elements for modular fastening, made in the form of a sleeve with a supporting surface and four screws.

The joint can also be characterized by the fact that the support for fastening the lower leg includes a modular fastening of the type sleeve - clamp.

The joint can also be characterized by the fact that it contains a locking mechanism, including a spring-loaded latch and a socket located on the femoral and lower legs, while the compression spring with the guide cup is installed in a cylindrical shank.

Patented technical solution that provides adjustable rotation during the construction and adjustment of the prosthesis scheme can be implemented both in mono- and polycentric IKS.

The invention is illustrated in the drawings, where

figure 1 presents the design of the ICS in the context;

figure 2 is the same as in figure 1, a section along aa;

figure 3 is the same as in figure 1, side view;

figure 4 - design of ICS with options for modular connecting elements.

In figures 1-3, the design of the adjusting device for the example of a single-axis IKS with a locking mechanism is disclosed.

IKS contains two components - the femoral 10 and the ankle 12, mounted on the axis 14. The femoral part 10 includes a housing 16 and a support 18. The locking mechanism 19 includes a latch 20 located on the additional axis 22 of the housing 16. The latch 20 has a pin 26 for attaching the cable 30 remote controls. The reciprocal part of the locking mechanism 19 - socket 32 is made in a separate part 34, attached to the lower part 12.

The support 18 includes elements for modular fastening of the thigh receiving sleeve: a support platform 36 and a pyramid 38, as well as a cylindrical shank 40 installed in the opening of the housing 16. A compression spring 42 is placed in the opening of the shank 40, acting on the latch 20 through the guide cup 44.

The lower part 12 consists of a body part 46, in the groove of which is secured by a bolt 48 part 34 with a socket 32 of the locking mechanism. The supporting platform 50 of the modular fastening of the lower leg is made in the body part 46, and the pyramid 52 is an independent part with a thread for the bolt 48.

The latch 20 has a shank 58, designed to limit the rotation of the latch when reinstalling the pin 26 under the right or left leg. An elastic element 62 is mounted on the housing 16 in the contact zone with the abutment surface 60 of the ankle portion 12.

The support 18 with the elements 36, 38 of the modular fastening of the receiving sleeve of the thigh is mounted with the possibility of rotation around its axis with subsequent fixation. The fixation is carried out by pressing the threaded bosses 63 and the bushings 64 by means of a screw 66 to the annular groove 72 made on the cylindrical shank 40. The bosses 63 and the bushings 64 are placed in the housing 16 in two parallel holes 73.

Between the threaded bosses 63 and the bushings 64 are placed compression coil springs 74. The holes 73 are closed on both sides by covers 76, 78 attached by screws 80 to the housing 16. The cover 78 has two openings 82 opposite the “keyed” sockets of screws 66. Between the bosses 63 and cover 76 accommodates elastic elements 84 made, for example, of hard rubber or polyurethane.

The functioning of the patented IKS with the adjusting device does not change when using other modular elements. So, instead of a support 18 with elements 36 and 38 for modular fastening of the thigh receiving sleeve, a support 90 with elements for modular fastening — a sleeve 91 with a spherical surface 92 and four screws 93 can be used. The same applies to elements 50, 52, which can be replaced by a modular “sleeve-clamp” type fastener consisting of a sleeve 94 with a slot and a screw 96. In this case, the sleeve 94 is made in a body part 95, to which a part 34 is attached with a bolt 97 and a nut 98.

The functioning of the ICS as a prosthesis unit is known and does not change from the introduction of an adjusting device of rotation into its design, therefore, it is not given in this description.

The rotation of the ICS relative to the receiving sleeve of the thigh, performed when adjusting the construction scheme of the prosthesis, is carried out as follows. The screws 66 are loosened, while the screw heads 66 abut against the cover 78, the springs 74 press the bushings 64 away from the surface of the annular groove 72. When the screws 66 are further loosened, the threaded bosses 63, compressing the elastic elements 84, also depart from the surface of the annular groove 72. When turning the sleeve together with the support will move without angular play, which is an important advantage of ICS. After turning the support 18 with the receiving sleeve of the thigh fixed to it to the desired angle, the support 18 is fixed by tightening the screws 66. In this case, the screws 66 will be screwed into the boss 63, and the elastic elements 84, pressing the boss 63 in the axial direction, will not allow the latter to rotate together with screws.

The fixation is ensured by pressing the threaded bosses 63 and bushings 64 against the annular groove 72 on the cylindrical shaft 40. The bosses 63 are made with sharp edges 86, and the edges 88 of the bushings 64 are rounded. When tightening the screws 66, one of the sharp edges 86, crashing into the body of the cylindrical shank 40, prevents the support 18 from turning in one direction, and the other in the opposite direction. The edges 88 of the bushings 64 in contact with the cylindrical shank 40 are rounded, so they do not cut into the body of the shank 40 when tightening the screws 66 and are easily removed by the springs 74 from the shank when they are unscrewed.

Thus, the proposed design of the ICS allows you to accurately rotate the ICS at a predetermined angle relative to the receiving sleeve when constructing and adjusting the hip prosthesis scheme without removing the prosthesis from the stump.

Claims (6)

1. An artificial knee joint containing a femoral part with a support for mounting and adjustable rotation of the thigh receiving sleeve with fixing means and a tibial part with a support for mounting the lower leg mounted on the axis of rotation, characterized in that the support for mounting and adjustable rotation of the thigh receiving sleeve has a cylindrical shank with an annular groove and is installed in the opening of the femoral body with the possibility of rotation around its own axis of symmetry, and the fixing means are made in the form of two pairs of threaded b knuckle - a sleeve placed in parallel through holes in the femoral part on both sides of the annular groove of the cylindrical shank and installed with the possibility of screwing their edges to the surface of the annular groove, and the bosses made with sharp edges are located on the side of one side surface of the housing, and bushings having rounded edges, with the opposite, while a compression spring is installed between each threaded boss and the sleeve. 2. The joint according to claim 1, characterized in that the means of fixation contain covers attached to both side surfaces of the housing opposite each other, while elastic elements made of hard rubber or polyurethane are placed between one of the covers and bosses, and the other cover has holes in front of the screwdriver sockets. 3. The joint according to claim 1, characterized in that the support for attaching the lower leg and / or the receiving sleeve of the thigh includes elements for modular fastening made in the form of a tetrahedral pyramid and a supporting surface. 4. The joint according to claim 1, characterized in that the support for attaching the receiving sleeve of the thigh includes elements for modular fastening, made in the form of a sleeve with a supporting surface and four screws. 5. The joint according to claim 1, characterized in that the support for mounting the lower leg includes a modular mount type sleeve - clamp. 6. The joint according to any one of claims 1 to 5, characterized in that it comprises a locking mechanism, comprising a spring-loaded latch and a socket located on the femoral and lower leg parts, the compression spring with a guide cup mounted in a cylindrical shank.

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