Acetabular rasp

Abstract

The present invention provides an acetabular rasp, comprising a hemispherical shell, wherein the outer spherical surface of the shell is provided with a plurality of first cutting teeth, and the shell is characterized in that four second cutting teeth are provided at the top of the shell, wherein the second cutting teeth are through-hole type cutting teeth, and the through-hole type cutting teeth include through holes and tooth edges; the four through-hole type cutting teeth are respectively a first through-hole type cutting tooth, a second through-hole type cutting tooth, a third through-hole type cutting tooth and a fourth through-hole type cutting tooth; the top vertex of the shell is located within the through-hole range of the first through-hole type cutting tooth; the distances from the center of the through-holes of the four through-hole type cutting teeth to the vertical axis passing through the top vertex of the shell are increased in equal intervals in sequence, and the intervals are equal to the distances from the center of the through-holes of the first through-hole type cutting teeth to the vertical axis passing through the top vertex of the shell. The top of the acetabular rasp of the present invention adopts four evenly arranged through-hole type cutting teeth, and after cutting the acetabular cartilage, the top of the obtained cutting surface has high smoothness.

Description

Technical Field

[0001] The present invention particularly relates to an acetabular rasp. Background Art

[0002] The acetabular rasp is an essential surgical tool for processing the acetabular socket during hip replacement surgery. The main cutting objects are the acetabular cartilage and a small amount of subchondral bone. During the operation, the cutting teeth on the surface of the acetabular rasp move at a low speed under certain pressure conditions to remove the necrotic tissue at the patient's hip joint. The top tooth blades will cut two different tissues, the acetabular cartilage and the subchondral bone, at the same time. By selecting blades of different sizes to grind the acetabulum progressively, the blade will eventually be completely seated in the acetabulum, so that the patient's acetabulum can be cut into a size close to the outer dimensions of the prosthesis. The cutting surface of existing acetabular rasps for cutting cartilage is often not smooth enough, especially at the top of the cutting sphere, where there is often a more obvious annular protrusion, which increases the subsequent processing steps and also brings hidden dangers to the subsequent acetabular reconstruction. Summary of the invention

[0003] The object of the present invention is to provide an acetabular rasp, which solves the problem in the prior art that an obvious annular protrusion exists on the top of the cutting surface of the acetabular rasp, resulting in low smoothness.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] An acetabular rasp comprises a hemispherical shell, wherein the outer spherical surface of the shell is provided with a plurality of first cutting teeth, and is characterized in that four second cutting teeth are provided on the top of the shell, wherein the second cutting teeth are through-hole type cutting teeth, and the through-hole type cutting teeth comprise through holes and tooth edges; the four through-hole type cutting teeth are respectively a first through-hole type cutting tooth, a second through-hole type cutting tooth, a third through-hole type cutting tooth and a fourth through-hole type cutting tooth; the top vertex of the shell is located within the through-hole range of the first through-hole type cutting tooth; the distances from the centers of the through-holes of the four through-hole type cutting teeth to the vertical axis passing through the top vertex of the shell are increased in sequence at equal intervals, and the intervals are equal to the distances from the centers of the through-holes of the first through-hole type cutting teeth to the vertical axis passing through the top vertex of the shell.

[0006] The present invention may be improved as follows: the minimum distance from the top vertex of the shell to the edge of the circular hole of the first through-hole type cutting tooth is less than 1.0 mm.

[0007] In the present invention, the distances from the centers of the through holes of the first through hole type cutting teeth, the second through hole type cutting teeth, the third through hole type cutting teeth and the fourth through hole type cutting teeth to the vertical axis passing through the top vertex of the shell are equidistantly spaced at 1.5-2.5 mm.

[0008] The present invention can be further improved, wherein the projections of the centers of the three through holes of the first through hole type cutting tooth, the second through hole type cutting tooth and the fourth through hole type cutting tooth on the plane where the bottom of the shell is located are on a straight line, recorded as the first straight line; the straight line where the projections of the centers of the through holes of the third through hole type cutting tooth and the centers of the through holes of the first through hole type cutting tooth on the plane where the bottom of the shell is located are located is recorded as the second straight line; the second straight line is perpendicular to the first straight line.

[0009] The present invention may be improved as follows: the straight line where the projections of the two end points of the longest diameter of the first through-hole type cutting tooth on the plane where the bottom of the shell is located are located is at 45 degrees to the first straight line.

[0010] Furthermore, the straight line where the projections of the two ends of the longest diameter of the second through-hole cutting tooth on the plane where the bottom of the shell is located are parallel to the straight line where the projections of the two ends of the longest diameter of the first through-hole cutting tooth on the plane where the bottom of the shell is located; the cutting direction of the second through-hole cutting tooth is set in the opposite direction to the cutting direction of the first through-hole cutting tooth. The cutting direction of the through-hole cutting tooth refers to the direction from the tooth edge end to the through-hole end along the longest diameter of the through-hole cutting tooth.

[0011] The present invention can be improved as follows: the straight line where the projections of the two ends of the longest diameter of the second through-hole type cutting tooth on the plane where the bottom of the shell is located passes through the projection of the center of the through hole of the third through-hole type cutting tooth on the plane where the bottom of the shell is located.

[0012] Furthermore, the straight line where the projections of the two end points of the longest diameter of the third through-hole type cutting tooth on the plane where the bottom of the shell is located passes through the projection of the center of the through hole of the fourth through-hole type cutting tooth on the plane where the bottom of the shell is located.

[0013] The present invention can be further improved so that the first cutting teeth have the same structure as the second cutting teeth and are also through-hole type cutting teeth.

[0014] Furthermore, the centers of all the first cutting tooth through holes are arranged in a spiral line on the surface of the shell, and the rotation center of the spiral line is the top vertex of the shell.

[0015] The present invention may be improved as follows: the endpoint at one end of the tooth edge of the two end points of the longest diameter of each of the first cutting teeth is located on the spiral line where the center of the through hole is located.

[0016] Furthermore, the intervals between two adjacent first cutting teeth in the process of extending from the rotation center to the bottom edge of the shell on each spiral line are equal. The interval between two adjacent first cutting teeth refers to the distance between the end point at one end of the tooth edge of one of the two ends of the longest diameter of a first cutting tooth and the end point at one end of the through hole of the next first cutting tooth.

[0017] The present invention can be further improved in that the bottom of the acetabular rasp is fixedly connected with a cross-shaped bracket, and the cross-shaped bracket is used to be connected to the connecting rod.

[0018] The present invention has the following beneficial effects:

[0019] (1) The top of the acetabular rasp of the present invention adopts four evenly arranged through-hole cutting teeth, and after cutting the acetabular cartilage, the top of the obtained cutting surface has high smoothness.

[0020] (2) The acetabular rasp of the present invention optimizes the arrangement of the four through-hole cutting teeth. The first straight line is perpendicular to the second straight line, the first through-hole cutting tooth is at 45 degrees to the first straight line, the second through-hole cutting tooth is parallel to the first through-hole cutting tooth and is arranged in the opposite direction, and the arrangement direction of the second through-hole cutting tooth points to the center of the through hole of the third through-hole cutting tooth, thereby further improving the smoothness of the cutting surface.

[0021] (3) The acetabular rasp of the present invention can adopt a combination of through-hole cutting teeth and other tooth-shaped cutting teeth to meet the needs of using acetabular rasps of different sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 This is a schematic diagram of the overall structure of the acetabular rasp according to Example 1 of the present invention;

[0024] Figure 2 It is a front view of the acetabular rasp of Example 1 of the present invention;

[0025] Figure 3 is a top view of the acetabular rasp of Example 1 of the present invention;

[0026] Figure 4 This is a diagram showing the arrangement of the center of the through hole of the second cutting teeth of the acetabular rasp in Example 1 of the present invention;

[0027] Figure 5 This is a diagram showing the arrangement of the second cutting tooth edges of the acetabular rasp in Example 1 of the present invention;

[0028] Figure 6 This is a diagram showing the arrangement of the first cutting teeth of the acetabular rasp in Example 1 of the present invention;

[0029] Figure 7 This is a schematic diagram of the overall structure of the acetabular rasp according to Embodiment 2 of the present invention;

[0030] Figure 8 This is a diagram showing the arrangement of the first cutting teeth of the acetabular rasp in Example 2 of the present invention;

[0031] Fig. 9 This is a schematic diagram of the overall structure of the acetabular rasp according to Embodiment 3 of the present invention;

[0032] Fig.10 This is the test result of the axial force wear trend of the acetabular rasp in Example 1 of the present invention;

[0033] Fig.11 The test results of the rotational torque wear trend of the acetabular rasp in Example 1 of the present invention;

[0034] Fig.12 The axial force test results of different acetabular rasps of Example 1 of the present invention are as follows;

[0035] Fig.13 The test results of the rotational torque of different acetabular rasps of Example 1 of the present invention are as follows;

[0036] Fig.14 This is a rendering of the simulated cutting surface of the acetabular rasp of Example 1 of the present invention;

[0037] Fig.15 This is a rendering of the simulated cutting surface of the acetabular rasp of Example 2 of the present invention;

[0038] Fig.16 This is a simulation diagram of the cutting surface of the acetabular rasp according to Example 3 of the present invention;

[0039] The markings in the accompanying drawings are as follows: 1. Shell; 2. First cutting tooth; 3. Second cutting tooth; 4. First through-hole type cutting tooth; 5. Second through-hole type cutting tooth; 6. Third through-hole type cutting tooth; 7. Fourth through-hole type cutting tooth. DETAILED DESCRIPTION

[0040] Example 1

[0041] like Figure 1-6The acetabular rasp shown includes a hemispherical shell 1 with a radius of 30 mm and a thickness of 1 mm. A cross-shaped bracket for fixed connection with a connecting rod is provided at the bottom of the shell 1. A first cutting tooth 2 is provided on the outer spherical surface of the shell 1. The first cutting tooth 2 is a through-hole type cutting tooth. The through-hole type cutting tooth includes a circular through hole and a tooth blade (in the actual processing of the acetabular rasp, the circular through hole refers to a circular through hole milled along the radial direction of the shell 1. The diameter of the circular through hole is 4.5 mm. The point on the surface of the shell 1 is used as the center of the circle and the diameter is 4.5 mm. The edge of the circular through hole is then punched to punch out an arc-shaped tooth blade. The distance from the highest point of the tooth blade to the surface of the shell 1 is 1 mm, and the length of the tooth blade is 4 mm. The circular through hole here refers to the circular hole on the surface of the shell 1 before stamping. The actual hole shape after the tooth blade is punched out is not a completely circular hole). The centers of the through holes of all first cutting teeth 2 (through hole type cutting teeth) are arranged in three alternating spiral lines on the spherical surface of the shell 1, the rotation center of the spiral line is the top vertex of the shell 1, the pitch of the spiral line is equal, and the endpoints of the two ends of the longest diameter of each through hole type cutting tooth at one end of the tooth blade are located on the spiral line where the center of the through hole is located. The intervals between two adjacent through hole type cutting teeth on the spiral line extending from the rotation center of the top of the shell 1 to the bottom edge of the shell 1 are equal (the interval between two adjacent through hole type cutting teeth refers to the distance between the endpoints of the two ends of the longest diameter of a through hole type cutting tooth at one end of the tooth blade to the endpoints of the two ends of the longest diameter of the next through hole type cutting tooth at one end of the through hole).

[0042] Among them, four second cutting teeth 3 are provided on the top of the shell 1, and the second cutting teeth 3 are through-hole cutting teeth. The top vertex of the shell 1 is located within the through-hole range of the first through-hole cutting teeth 4. In this embodiment, the minimum distance from the top vertex of the shell 1 to the edge of the circular hole of the first through-hole cutting teeth 4 is less than 0.5mm. The centers of the four through-hole cutting teeth are evenly arranged in sequence from the top vertex of the shell 1 to the outer edge of the shell 1 at equal intervals, namely the first through-hole cutting teeth 4, the second through-hole cutting teeth 5, the third through-hole cutting teeth 6 and the fourth through-hole cutting teeth 7, and the distances from the centers of the through-holes of the first through-hole cutting teeth 4, the second through-hole cutting teeth 5, the third through-hole cutting teeth 6 and the fourth through-hole cutting teeth 7 to the vertical axis passing through the top vertex of the shell 1 are 2mm, 4mm, 6mm and 8mm respectively. The projections of the centers of the three through holes of the first through hole type cutting tooth 4, the second through hole type cutting tooth 5 and the fourth through hole type cutting tooth 7 on the plane where the bottom of the shell 1 is located are on a straight line, which is recorded as the first straight line; the straight line where the projections of the centers of the through holes of the third through hole type cutting tooth 6 and the centers of the through holes of the first through hole type cutting tooth 4 on the plane where the bottom of the shell 1 is located is recorded as the second straight line; the second straight line is perpendicular to the first straight line. The straight line where the projections of the two ends of the longest diameter of the first through hole type cutting tooth 4 on the plane where the bottom of the shell 1 is located is 45 degrees to the first straight line. The straight line where the projections of the two ends of the longest diameter of the second through hole type cutting tooth 5 on the plane where the bottom of the shell 1 is located is parallel to the straight line where the projections of the two ends of the longest diameter of the first through hole type cutting tooth 4 on the plane where the bottom of the shell 1 is located; the sharpening direction of the second through hole type cutting tooth 5 is set in the opposite direction to the sharpening direction of the first through hole type cutting tooth 4 (the sharpening direction of the cutting tooth refers to the direction from the tooth edge end to the through hole end along the longest diameter of the through hole type cutting tooth). The straight line where the two ends of the longest diameter of the third through-hole type cutting tooth 6 are projected on the plane where the bottom of the housing 1 is located passes through the projection of the center of the through hole of the fourth through-hole type cutting tooth 7 on the plane where the bottom of the housing 1 is located. The straight line where the two ends of the longest diameter of the fourth through-hole type cutting tooth 7 are projected on the plane where the bottom of the housing 1 is located passes through the projection of the center of the through hole of the first through-hole type cutting tooth on one of the spiral lines of the first cutting tooth 2 on the outer periphery on the plane where the bottom of the housing 1 is located.

[0043] Example 2

[0044] like Figure 7-8 The acetabular rasp shown in the figure is different from that of Example 1 in that the first cutting teeth 2 are through-hole type cutting teeth, and the centers of the through-holes of the first cutting teeth 2 are arranged in six alternating spiral lines on the spherical surface of the shell 1.

[0045] Example 3

[0046] like Fig. 9The acetabular rasp shown in the figure is different from that of Example 1 in that the first cutting tooth 2 is a through-hole type cutting tooth, the center of the through-hole of the first cutting tooth 2 is arranged in a spiral line on the spherical surface of the shell 1, and the distance between two adjacent through-hole type cutting teeth is evenly distributed on the surface of the shell in eight equal parts.

[0047] Performance Testing

[0048] The relevant cutting parameters of the acetabular rasp in Example 1 of the present invention are shown in Figure 10-13 It can be seen that the acetabular rasp has high sharpness and has no obvious wear trend after ten repeated tests. Figure 14-16 The acetabular rasp of the present invention has high smoothness on the top of the acetabulum cutting surface, has no obvious annular residue, and has a good cutting effect.

[0049] The above embodiments of the present invention are not intended to limit the protection scope of the present invention, and the implementation modes of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structures of the present invention based on the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, should fall within the protection scope of the present invention.

Claims

1. An acetabular rasp, characterized in that: The invention comprises a hemispherical shell (1), wherein the outer spherical surface of the shell (1) is provided with a plurality of first cutting teeth (2), and is characterized in that four second cutting teeth (3) are provided on the top of the shell (1), wherein the second cutting teeth (3) are through-hole type cutting teeth, and the through-hole type cutting teeth comprise through holes and tooth edges; the four through-hole type cutting teeth are respectively a first through-hole type cutting tooth (4), a second through-hole type cutting tooth (5), a third through-hole type cutting tooth (6) and a fourth through-hole type cutting tooth (7); the top vertex of the shell (1) is located within the through-hole range of the first through-hole type cutting tooth (4); the distances from the centers of the through-holes of the four through-hole type cutting teeth to the vertical axis passing through the top vertex of the shell (1) are increased in sequence at equal intervals, and the intervals are equal to the distances from the centers of the through-holes of the first through-hole type cutting tooth (4) to the vertical axis passing through the top vertex of the shell (1).

2. The acetabular reamer according to claim 1, characterized in that: The minimum distance from the top vertex of the housing (1) to the edge of the circular hole of the first through-hole cutting tooth (4) is less than 1.0 mm.

3. The acetabular rasp according to claim 2, characterized in that: The distances from the centers of the through holes of the first through hole type cutting teeth (4), the second through hole type cutting teeth (5), the third through hole type cutting teeth (6) and the fourth through hole type cutting teeth (7) to the vertical axis passing through the top vertex of the shell (1) are equidistantly spaced at 1.5-2.5 mm.

4. The acetabular rasp according to any one of claims 1 to 3, characterized in that: The projections of the centers of the three through holes of the first through hole type cutting tooth (4), the second through hole type cutting tooth (5) and the fourth through hole type cutting tooth (7) on the plane where the bottom of the shell (1) is located are on a straight line, which is recorded as the first straight line; the straight line where the projections of the centers of the through holes of the third through hole type cutting tooth (6) and the centers of the through holes of the first through hole type cutting tooth (4) on the plane where the bottom of the shell (1) is located are recorded as the second straight line; the second straight line is perpendicular to the first straight line.

5. The acetabular rasp according to claim 4, characterized in that: The straight line where the projections of the two end points of the longest diameter of the first through-hole cutting tooth (4) on the plane where the bottom of the housing (1) is located are located is 45 degrees to the first straight line.

6. The acetabular rasp according to claim 5, characterized in that: The straight line on which the projections of the two end points of the longest diameter of the second through-hole cutting tooth (5) on the plane on which the bottom of the shell (1) is located is parallel to the straight line on which the projections of the two end points of the longest diameter of the first through-hole cutting tooth (4) on the plane on which the bottom of the shell (1) is located; the sharpening direction of the second through-hole cutting tooth (5) is arranged in the opposite direction to the sharpening direction of the first through-hole cutting tooth (4).

7. The acetabular rasp according to claim 6, characterized in that: The straight line on which the projections of the two ends of the longest diameter of the second through-hole type cutting tooth (5) on the plane where the bottom of the shell (1) is located passes through the projection of the center of the through hole of the third through-hole type cutting tooth (6) on the plane where the bottom of the shell (1) is located.

8. The acetabular reamer according to claim 7, characterized in that: The straight line on which the two end points of the longest diameter of the third through-hole type cutting tooth (6) are projected on the plane on which the bottom of the shell (1) is located passes through the projection of the center of the through hole of the fourth through-hole type cutting tooth (7) on the plane on which the bottom of the shell (1) is located.

9. The acetabular reamer according to claim 8, characterized in that: The first cutting teeth (2) and the second cutting teeth (3) have the same structure and are also through-hole type cutting teeth; the centers of the through-holes of all the first cutting teeth (2) are arranged in a spiral line on the surface of the shell (1), and the rotation center of the spiral line is the top vertex of the shell (1).

10. The acetabular reamer according to claim 9, characterized in that: The endpoint at one end of the tooth edge of the two ends of the longest diameter of each of the first cutting teeth (2) is located on the spiral line where the center of the through hole is located.

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