RU2583578C1 - Device for treatment of cotyloid cavity for hip replacement - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to surgical orthopaedics, and can be used for total hip replacement by endoparasites of cement-free fixation. Device for treatment of cotyloid cavity for hip replacement comprises housing, electric motor with rotation transfer shaft, motor switch, circular saw, pin with thread on one end, adapter sleeve for cotyloid component cement-free fixation, limiting tube to be arranged on said pin, lever, lever retainer and multistage transmission. Lever is connected with lower part of housing by means of hinge, and with housing upper part is through spring. Retainer lever is connected to upper part of housing by means of hinge. Housing has parallel longitudinal channel for shaft rotation and tube for said pin, rigidly connected to housing, and outer fixed unit rigidly connected with housing lower part located inside internal movable unit. Lever is simultaneously connected with inner moving unit by means of hinges and pusher to move movable unit relative to fixed perpendicular to axis of pin. Adapter sleeve for cotyloid component cement-free fixation is made with thread in axial hole for screwing pin and with outer thread for screwing acetabular component into threaded hole. Multistage transmission is arranged in housing, in external fixed block and internal movable block, and has shaft rotation transmission from electric motor and output shaft, on one end of which circular saw perpendicular to shaft is fixed, and latter is located parallel to channel of housing. Invention ensures uniform removal of ossificates surrounding cotyloid cavity, formation of flat surface at same (specified) distance from edge of acetabular component, reduced time of surgical intervention due to mechanized cotyloid cavity treatment, minimised damage of surrounding soft tissues.

EFFECT: total hip joint replacement with cement-free fixation endoparasites.

1 cl, 10 dwg

Description

The invention relates to medicine, namely to operative orthopedics, and can be used to remove ossificates surrounding the acetabulum or the acetabular component of the endoprosthesis during operations of primary or revision hip joint endoprosthetics with cementless fixation endoprostheses.

Currently, during primary or revision arthroplasty operations, if it is necessary to remove the ossificates surrounding the acetabulum (acetabular component of the endoprosthesis), or if it is necessary to create a flat surface of one of the walls of the cavity during augmentation, the following devices are known.

Osteotome and similar bits (flat, grooved) described in Ostroverkhov G.E., Bomash Yu.M., Lubotsky D.N. Operative surgery and topographic anatomy. - M: AOZT Litera. - 1996, p. 208, consist of a pen and a work surface. The disadvantage of the osteotome (and similar bits) is the inability to uniformly remove ossificates around the circumference of the acetabulum (acetabular component of the endoprosthesis), in addition, since bone is removed by hammering the osteotome (bit), there is a risk of removing excess bone tissue and “splitting” »The walls of the acetabulum. The quality of the treatment of the acetabulum in this case depends on the qualification of the doctor, his physical, psychological, emotional state during the operation. The use of the above devices is very difficult when using minimally invasive approaches in connection with a sufficiently large depth of the wound and a small value of the angle of surgical action.

Known medical drills for filing ossificates surrounding the acetabulum. For example, a surgical drill (Russia, patent for the invention No. 2294164, A61B 17/16) containing a housing and a drive connected to the housing, which is kinematically connected to the output shaft. The output shaft has a tool channel and a removable chuck at the working end. Also known are a surgical drill (Russia, patent for invention No. 2007136, A61B 17/16), comprising a housing with a handle, a drive, a cover and a clamping mechanism, a surgical drill (USSR, copyright certificate No. 957880, A61B 17/16), comprising a housing, inside of which there is an electric motor with a gearbox, an electric motor switch.

When using these tools, it is impossible to ensure uniform removal of ossificates around the entire circumference of the acetabulum (acetabular component of the endoprosthesis), because when working with these tools, there is no rigid “support point” in the depth of the wound, and the accuracy of cutting directly depends on the “hardness” of the surgeon's hands. Obviously, in the absence of a fulcrum, holding the drill “on weight”, it is impossible “by eye” to provide absolutely accurate manipulations of the hands to form the required circle line and surface plane of the “saw”, close to potentially achievable, which is important for creating tight contact between the bone and metal structures (if necessary, installation of additional augments), to prevent the impediment of soft tissues during movements in the joint.

Due to the natural "trembling" of the surgeon's hands, the disc may deviate to the sides of the axis of its rotation and damage the surrounding soft tissues, especially taking into account the high speed of the disc and the small absolute value of the permissible sawing error (units of millimeters) during this operation.

The closest known device for the treatment of the acetabulum during hip arthroplasty to the claimed is a device for the treatment of the acetabulum during hip arthroplasty according to the application US 2006079906 A1 (BENOIST GIRARD SAS), 04/13/2006, [0040] - [0043], containing the case , an electric motor with a shaft for transmitting rotation, an electric motor switch, a milling cutter.

The disadvantages of this device is the following.

1. Since the size of the cutter is larger than the size of the acetabular component of the endoprosthesis, and the processing (sawing) of the ossificates surrounding the acetabulum is performed from above (that is, towards the bottom of the acetabulum), it is difficult to visualize the surface being processed during processing. Due to the fact that the direction of the device’s body and, accordingly, the saw plane is determined using a mechanical guide (i.e. visually), with insufficient visualization, excessive removal of bone tissue around the acetabular component of the endoprosthesis is possible (due to the incorrect position of the axis of the body). Accordingly, when using the so-called minimally invasive approaches, the use of this device is difficult due to the possible excessive removal of both bone tissue around the acetabular component of the endoprosthesis and possible damage to the surrounding soft tissues.

2. Structurally, the device is designed in such a way that the cutter files off the ossificates along the entire perimeter of the bone surrounding the acetabular component of the endoprosthesis. Since ossicates can be located not around the entire perimeter, but, for example, in the area of the upper or posterior edge of the acetabulum, when the device is in operation, ossification will be removed in these areas, and additional damage to soft tissues (surrounding edges of the acetabulum).

3. If it is necessary to install augments on a limited area of the edge of the acetabulum, this device does not allow to form a uniform flat surface at a given distance from the edge of the acetabular component of the endoprosthesis, since during its operation the entire surface of the bone surrounding the acetabular component of the endoprosthesis is processed.

4. The inability to control the area of cutting excess bone tissue around the acetabular component of the endoprosthesis, since the diameter of the cutter and, accordingly, the area of the filed surface do not change during operation of the device. Thus, in the presence of pronounced ossificates from one edge of the acetabulum and their absence (or fewer) from the other edge, this device does not allow the removal of pronounced ossificates without damaging soft tissues from the opposite side.

5. The use of this device is also difficult when used in patients with a sufficiently large depth of the wound and a small value of the angle of surgical action.

The objective of the invention is to enable:

- uniform removal of ossificates surrounding the acetabulum;

- the formation of a flat surface at the same (predetermined) distance from the edge of the acetabular component of the endoprosthesis during hip joint replacement using cementless endoprostheses;

- reducing the time of surgical intervention due to the mechanization of the process of processing the acetabulum, minimizing damage to the surrounding soft tissues.

To solve the problem, a circular saw, a spoke with a thread on one end, an adapter sleeve for the acetabular component of the cementless fixation, a restriction tube for placement on the said spoke, a lever connected to the lower part of the body by means of a hinge, and with the upper part of the body through a spring, fix a lever arm connected to the upper part of the housing by means of a hinge, a multi-stage transmission, the housing has parallel longitudinal channels for the shaft of rotation and a tube for the spoke, fixedly connected to the housing, fixedly connected to the lower part of the housing, an external fixed unit, an internal movable unit located inside it , the lever is simultaneously connected to the internal movable block by means of hinges and a pusher with the possibility of moving the movable block relative to the stationary perpendicular to the axis of the spoke , the adapter sleeve for the acetabular component of the cementless fixation is made with a thread in the axial hole for screwing the spokes and with an external thread for screwing into the hole with the thread of the acetabular component, the multi-stage transmission is placed in the housing, in the external fixed unit and in the internal moving block, and has a transmission shaft rotation from the electric motor and the output shaft, at one end of which a circular saw is fixed perpendicular to the shaft, and the latter is parallel to the channel of the housing.

In the study of other well-known structural and technical solutions in this field of medicine, the specified set of features that distinguishes the invention from the prototype was not identified.

In FIG. 1 is a structural diagram of an apparatus for treating the acetabulum fixed in the acetabular component of the hip joint with cementless fixation in real scale 1: 1, FIG. 2 - construction of an external fixed unit and housing (fragment), scale 2: 1, in FIG. 3 - construction of an internal movable block, scale 2: 1, in FIG. 4 is a schematic illustration of the arrangement of elements of a multi-stage transmission, scale 5: 1, in FIG. 5 is a schematic illustration of a multi-stage transmission, scale 5: 1, in FIG. 6 - construction of the adapter sleeve, scale 9: 1, in FIG. 7 is a design of a threaded knitting needle, scale 8: 1, in FIG. 8 is a diagram of the fixation of the device in the acetabular component of the endoprosthesis of cementless fixation, scale 1: 1, in FIG. 9 is a diagram of a device fixation in the acetabular component of a cement fixation endoprosthesis, scale 1: 1, in FIG. 10 - the initial and final position of the moving block, scale 1: 1.

In FIG. 1 adopted the following notation:

1 - lever

2 - gear lock

3 - case

4 - electric motor

5 - conductive wire

6 - hollow tube

7 - hinge of gear lock

8 - spring

9 - the first hinge of the lever

10 - hinge of the internal movable block

11 - external fixed block

12 - internal movable unit

13 - pusher

14 - second lever joint

15 - circular saw

16 - output shaft.

In addition to the elements of the inventive device in FIG. 1 shows a fragment of the acetabulum and the acetabular component of cementless fixation:

17 - threaded needle

18 - ossification of the acetabulum

19 - restriction tube

20 - acetabular component of the endoprosthesis

21 - saw line

22 - threaded hole of the acetabular component of the endoprosthesis

23 - the wall of the acetabulum.

In FIG. 2 adopted the following notation:

3 - case

9 - the first hinge of the lever

11 - external fixed block

24 - housing channel

25 - the upper hole of the hollow tube

26 - groove of the external fixed unit

27 - the bottom hole of the hollow tube.

In FIG. 3 adopted the following notation:

28 - top cover

29 - bottom cover

30 - hole rear wall of the inner movable unit

31 - hole in the front wall of the inner movable unit

32 - channel of the output shaft.

In FIG. 4, 5 the following notation is accepted:

16 - output shaft

33 - shaft transmission of rotation from the electric motor

34 - the first gear bevel gear

35 - shaft of the external fixed unit

36 - gear wheel of the external fixed block

37 - shaft of the internal movable block

38 - gear wheel of the internal movable block

39 - second bevel gear

40 - thrust washer

41 - thread of the output shaft

42 is a cross-section of the gears of an external fixed unit and an internal mobile unit.

In FIG. 6 the following notation is accepted:

43 - threaded adapter sleeve

44 - internal thread adapter sleeve

45 - external thread adapter sleeve

46 - grooves for a screwdriver.

In FIG. 7 the following notation is accepted:

17 - a needle with a thread.

In FIG. 8 the following notation is accepted:

17 - threaded needle

19 - restriction tube

20 - acetabular component of the endoprosthesis of the hip joint of cementless fixation

43 - adapter sleeve with thread.

In FIG. 9, 10 the following notation:

A - the initial position of the lever and the inner movable unit

In - the final position of the lever and the internal movable unit

1 - lever

2 - gear lock

3 - case

8 - spring

9 - the first hinge of the lever

10 - hinge of the internal movable block

11 - external fixed block

12 - internal movable unit

13 - pusher

14 - second lever joint

47 - screw.

The inventive device for the treatment of the acetabulum during hip arthroplasty includes a housing 3, inside of which is an electric motor 4, the shaft of which is connected to a rotation transmission shaft 33 from an electric motor 4 located in the channel 24 of the housing 3. A conductive wire 5 is connected to the electric motor 4. Turning on and off electric motor 4 is carried out using a "foot" switch. An external fixed unit 11 is fixedly connected perpendicularly to the lower part of the casing 3, inside which the internal movable block 12 is located. Parallel to the casing 3, there is a hollow tube 6 fixedly connected directly to the casing 3 so that the upper hole 25 of the hollow tube 6 is at the same level with the upper end of the housing 3, and the lower hole 27 of the hollow tube 6 is located at the level of the lower wall of the external fixed unit 11. In the hollow tube 6 is a spoke with thread 17, which, in turn, screw connected to the adapter sleeve with a thread 43 using the internal thread of the adapter sleeve 44. A lever 1 is connected to the lower part of the housing 3 using the first hinge 9. The lever 1 is connected to the upper part of the housing 3 through a spring 8. The spring 8 is connected to the housing 3 and lever 1 by means of screws 47. The lever 1 is simultaneously connected to the inner movable block 12 by means of a hinge 10 of the inner movable block 12, the second hinge 14 of the lever 1 and the pusher 13 located between them with the possibility of longitudinal movement of the movable block 12 relative to the stationary Lok 11. From the upper part of the housing 3 is connected to a gear retainer 2 by a hinge 7 toothed retainer 2. External fixing unit 11 has a parallelepiped shape. On its outer wall there is a groove 26 along which the hinge 10 of the inner movable block 12 is moved together with the inner movable block 12. The inner movable block 12 contains a top cover 28 and a bottom cover 29, designed to protect the transmission mechanisms located inside it from bone sawdust. In the walls of the inner movable block 12, there is an opening 30 of the rear wall of the inner movable block 12 and a hole 31 of the front wall of the inner movable block 12, in which the shaft 37 of the inner movable block 12 is fixed. In the inner movable block 12 is the channel 32 of the output shaft 16, in which output shaft 16. The inner movable block 12 on the front side is made in the form of a rectangular protrusion in which the channel 32 of the output shaft 16 is located. The protrusion is designed to increase the working stroke of the circular saws 15 and, accordingly, increase the area saw cut.

The multi-stage transmission is located in the housing 3, in the external fixed unit 11 and in the internal mobile unit 12, is a gears series-connected to each other and consists of a rotation transmission shaft 33 from an electric motor 4 located in the channel 24 of the housing 3, connected to the gears of the first gear bevel gear 34. One of the gears of the first gear bevel gear 34 is located on the transmission shaft of rotation 33 from the electric motor 4, the other on the shaft 35 of the external fixed unit 11. On the shaft 35 of the outer the fixed block 11 also has a gear 36 of the external fixed block 11. The shaft 35 of the external fixed block 11 is fixed in the holes in the front and rear walls of the external fixed block 11 and is parallel to the shaft 37 of the internal movable block 12. The above components are fixed using keys, located between the shaft and the components. The gear 36 of the outer fixed block 11 is connected to the gear 38 of the inner movable block 12 located on the shaft 37 of the inner movable block 12. The shaft 37 of the inner movable block 12 is fixed in the hole 30 of the rear wall of the inner movable block 12 and the hole 31 of the front wall of the inner movable block 12. Also on the shaft 37 is a second bevel gear 39. One of the gears of this transmission is located on the shaft 37 of the internal movable unit 12, the other on the output shaft 16, on which the perpendi ulyarno device body 3 is fixed circular saw 15, fixed between the thrust washer 40 and a nut disposed on the thread 41 of the output shaft 16. The fixation components gears carried splines.

Due to the fact that the diameter of the acetabular component of the hip joint endoprosthesis, which is established by a patient in practical orthopedics, is from 44 to 66 mm, and the diameter of the ossificates surrounding the hollow does not exceed 5-7 mm, the claimed device must have 3 versions of the same to remove ossifications designs differing only in the length of the external unit and the diameter of the circular saw.

1. Acetabular component with a diameter of 44 to 50 mm: the diameter of the circular saw is 20 mm, the length of the external unit is 26 mm.

2. Acetabular component with a diameter of 52 to 60 mm: the diameter of the circular saw is 24 mm, the length of the external unit is 34 mm.

3. Acetabular component with a diameter of 62 to 66 mm: the diameter of the circular saw is 28 mm, the length of the external unit is 38 mm.

Another embodiment of the device is the presence of 3 removable external fixed and internal mobile blocks of different lengths.

The principle of operation of the claimed device is as follows.

During the operation, after removal of the femoral head, the acetabulum is treated with standard scans. The acetabular component of the endoprosthesis of cementless fixation is installed. It is also possible to install the so-called trial or fitting component.

The adapter sleeve with thread 43 is screwed into the threaded hole of the acetabular component of the endoprosthesis 22 using the external thread of the adapter sleeve 45.

On the spoke with a thread 17 between the acetabular component of the endoprosthesis 20 and the hollow tube 6, a restriction tube 19 of the required length is installed. Similarly, the device is installed in the trial (fitting room component of the endoprosthesis).

The rotation of the device is carried out by the hands of the surgeon around the axis of the threaded needle 17. Initially, the device is installed in the initial position A. When the motor 4 is turned on, rotation is transmitted from it to the circular saw 15 through a multi-stage transmission. When the lever 1 is pressed, the “internal” block 12 is “extended” together with the rotary circular saw 15. The lever 1 is fixed in the necessary position by means of the toothed lock 2. The ossificates of the acetabulum are cut off 18. When the device is rotated around the axis of the threaded needle 17, the circular saw 15 describes a circle with a diameter greater than the diameter of the acetabular component of the endoprosthesis, which allows uniformly cutting off excess bone tissue surrounding the acetabular component of the endoprosthesis. Thus, a uniform, even surface is formed. Depending on the height of the restriction tube 19, it is possible to perform a cut at the required (predetermined) distance from the acetabular component of the endoprosthesis 20 to the saw line 21.

The components of the inventive device for the treatment of the acetabulum during hip replacement can be implemented as follows.

The housing 3 and the lever 1 together represent a standard handle that is used in many surgical instruments. The length of the body is determined by the depth of the wound and can be 25 ... 30 cm.

The housing 3 can be made in the form of a parallelepiped or cylinder, the width (diameter) of the housing is determined by the dimensions of the electric motor 4 installed in the housing 3. Currently used electric motors have small dimensions (2 cm in diameter), for example, AnspacheMax 2 Plus electric drill manufactured by the company Synthes described by http://www.synthes.com/MediaBin/US%20DATA/Product%20Support%20Materials/Catalogs/10412A%202012%20PowerTools%20Catalog.pdf. (date of treatment October 13, 2014).

The dimensions of the housing 3 and the lever 1 must be such that a hand grip of the housing 3 with the lever 1 is ensured.

The spring 8 is a flat curved spring, which can be made in the form of a spring band.

The external fixed unit 11 is made of metal plates with a thickness of the order of 1 mm.

The internal movable block 12 is also made of metal plates with a thickness of the order of 1 mm.

The first hinge of the lever 9 is a metal rod fixed in the housing 3, can be made in the form of a bolt screwed into the housing 3.

The hinge of the inner movable block 10 is similar to the first hinge of the lever 9. Screwed or welded to the inner movable block 12.

The second hinge 14 of the lever 1 and the hinge 7 of the gear lock 2 are made in the form of a metal rod.

The pusher 13 is a plate with two holes at the ends.

The circular saw 15 is a standard (serrated) circular saw blade.

A threaded spoke 17 can be implemented as a Kirchner spoke with a threaded end.

The restriction tube 19, depending on the required length, may be implemented as one or more washers or as a hollow tube.

The first and second bevel gears 34 and 39 are bevel gears connected at right angles with a straight tooth and a gear ratio of 1: 1.

The gear 36 of the outer fixed block 11 and the gear 38 of the inner movable block 12 are a spur gear.

The gears 36 and 38 form a spur gear with a gear ratio of 1: 1.

The adapter sleeve with thread 43 can be made in the form of a metal rod with a thread on the outside and inside. For installation, a screwdriver with two pins installed in the grooves for the screwdriver 46 is used.

Bronze bearings can be used to rotate the mechanisms.

Thus, the implementation of the inventive device is not in doubt, since for its manufacture typical electromechanical units and parts are used.

The technical result of the invention is:

- uniform removal of ossificates surrounding the acetabulum;

- the formation of a flat surface at the same (given) distance from the edge of the acetabular component of the endoprosthesis;

- reducing the time of surgical intervention due to the mechanization of the process of processing the acetabulum, minimizing damage to the surrounding soft tissues.

Claims (1)

A device for treating the acetabulum during hip replacement, comprising a housing, an electric motor with a rotational transmission shaft, an electric motor switch, characterized in that a circular saw, a spoke with a thread at one end, an adapter sleeve for the acetabular component of the cementless fixation, a restriction tube are additionally inserted into it for placement on said spoke, a lever connected to the lower part of the body by means of a hinge, and with the upper part of the body through a spring, lever lock, connected internal with the upper part of the housing by means of a hinge, a multi-stage transmission, the housing having a parallel longitudinal channel for the shaft of rotation and a tube for the spoke, fixedly connected to the housing, motionless connected to the lower part of the housing, an external fixed block, an internal movable block located inside it, a lever simultaneously connected to the internal movable unit by means of hinges and a pusher with the possibility of moving the movable unit relative to the stationary perpendicular to the axis of the spoke, the bottom sleeve for the acetabular component of cementless fixation is made with a thread in the axial hole for screwing the spokes and with an external thread for screwing into the hole with the thread of the acetabular component, the multi-stage transmission is placed in the housing, in the external fixed unit and in the internal moving block, and has a rotation transmission shaft from the electric motor and the output shaft, at one end of which a circular saw is fixed perpendicular to the shaft, and the latter is parallel to the channel of the housing.

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