A reamer

Abstract

The present invention relates to a medical device, in particular to a reamer for medullary cavity expansion, comprising a cutter body, a first chipping edge and a second chipping edge, wherein the first chipping edge comprises a plurality of cutting edges arranged on the side of the cutter body and distributed in parallel along the length direction of the cutter body, and the second cutting edge is arranged at the front end of the cutter body, and the cutter body is a hollow structure. The hollow structure can remove large pieces of cancellous bone and bone marrow in the femoral medullary cavity and collect them as a whole, and has a better debris collection effect than using the reamer to expand the medullary cavity multiple times, and can realize the integration of drilling and expanding, and realize the medullary expansion function at one time.

Description

Technical Field

[0001] The invention relates to a medical device, in particular to a reamer for expanding a medullary cavity. Background Art

[0002] Intramedullary reamer is mainly used to expand the femoral intramedullary cavity, with specifications ranging from 9 to 16 mm. The existing reaming scheme mainly uses intramedullary reamer with specifications from small to large to gradually expand the intramedullary cavity. The gradual reaming process will bring some problems, such as the inconsistent rotation axis of the reamer during multiple uses, resulting in the prosthesis installation cavity being too large, the wrong size, and the wrong position; multiple operations increase the operation time and increase the risk of surgical errors.

[0003] In addition, the first medullary expansion of the existing medullary cavity reamer is generally performed by using a medullary burr or directly expanding the medullary cavity, which will produce a large intramedullary pressure on the medullary cavity, thereby causing a series of postoperative problems, such as venous thrombosis, etc. At the same time, after multiple medullary expansions, the cuttings produced by the medullary cavity reamer are small and difficult to clean and easy to leave residues. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a reamer, which can complete the medullary cavity expansion in one time, reduce the intramedullary pressure and reduce the residual cuttings during the medullary expansion process.

[0005] The present invention adopts the following technical scheme: a reamer comprises a tool body, a first cutting edge and a second cutting edge, the first cutting edge comprises a plurality of cutting edges arranged on the side of the tool body and distributed in parallel along the length direction of the tool body, the second cutting edge is arranged at the front end of the tool body, and the tool body is a hollow structure.

[0006] Furthermore, the tool body further comprises a first chip accommodating portion and a chip removal groove, wherein the first chip accommodating portion is formed by a front cutting edge and an included angle of a secondary plane, and the first chip accommodating portion is in communication with the hollow structure of the tool body to form a chip removal groove.

[0007] Preferably, the vertical projection profile of the first cutting edge is conical, and the taper is 1°-5°.

[0008] Preferably, the number of the first cutting edges is 3-7, an even number is recommended, and they are symmetrically distributed.

[0009] Preferably, the first cutting edge is a straight edge, and the rake angle is a negative rake angle.

[0010] Preferably, the second cutting edge is a continuous annular cutting edge or a serrated cutting edge.

[0011] Preferably, the number of the chip grooves is equal to the number of the first cutting edges.

[0012] Preferably, a connection end for connecting to a motor is provided at the rear end of the blade body.

[0013] Preferably, the connecting end is a hollow structure and is connected to the hollow structure of the blade body.

[0014] The beneficial effects of the present invention are as follows: in this solution, the cutter body is set as a hollow structure, which does not produce a squeezing effect on the cancellous bone and bone marrow. During the rotation process, the inner wall of the hollow structure can also play a role in rotational positioning and stabilization. At the same time, the reamer with a hollow structure only cuts the femoral medullary cavity in a small area of ​​the side and end cutting edges. The total cutting amount is small, the cutting force is small, and no excessive cutting heat is generated. When cutting with a hollow reamer, the cutting force required is relatively small and does not affect the overall cutting force. In addition, the cuttings after cutting by the end cutting edge are completely collected in the hollow structure, so the debris collection effect is better than the prior art. The medullary cavity expansion can be completed in one time, which can reduce the intramedullary pressure and less chip residue during the medullary expansion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings further illustrate the present invention, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention.

[0016] Figure 1 This is the reamer structure diagram;

[0017] Figure 2 It is the top view of the reamer;

[0018] In the figure: a cutter body 1, a first cutting edge 2, a second cutting edge 3, a connecting end 4, a front cutting surface 11, a secondary plane 12, a first chip receiving portion 13, and a chip removal groove 14. DETAILED DESCRIPTION

[0019] Example 1

[0020] like Figure 1 and Figure 2 As shown in , a reamer provided by one embodiment of the present invention includes a cutter body 1, a first cutting edge 2, and a second cutting edge 3. The first cutting edge 2 includes a plurality of cutting edges arranged on the side of the cutter body 1 and distributed in parallel along the length direction of the cutter body 1. The second cutting edge 3 is arranged at the front end of the cutter body 1. The second cutting edge 3 is now commonly used as a continuous annular cutting edge or a serrated cutting edge. The cutter body 1 is a hollow structure. The cutter body 1 also includes a first chip holding portion 13 and a chip removal groove 14. The first chip holding portion 13 is formed by the angle between the front cutting face 11 and the secondary plane 12. The first chip holding portion 13 is connected to the hollow structure of the cutter body 1 to form a chip removal groove 14.

[0021] Flowing along the front cutting edge 11, the rotating sub-plane 12 of the first cutting edge 2 and the front cutting edge 11 constitute the first chip holding portion, and excess chips enter the hollow structure of the tool body 1 along the chip groove 14 of the front cutting edge 11, which is the second chip holding portion. The cutting edge at the front end of the tool body 1 removes the cancellous bone and bone marrow in front of the tool body 1 as a whole, and the removed cancellous bone and bone marrow are collected in the hollow structure of the tool body 1.

[0022] Example 2

[0023] On the basis of the above-mentioned embodiment 1, the taper of the first cutting edge 2 is set to 5°, which has a better cutting effect and maximizes the cutting amount.

[0024] Example 3

[0025] Based on the above-mentioned embodiment 1, the taper of the first cutting edge 2 is set to 1°, which has the fastest cutting speed.

[0026] Example 4

[0027] On the basis of the above-mentioned embodiment 1, the number of the first cutting edges 2 is 4 and they are symmetrically distributed on the side of the cutter body, which greatly improves the cutting rate.

[0028] Example 5

[0029] On the basis of the above-mentioned embodiment 1, the first cutting edge 2 is selected as a straight edge, and the rake angle is set to a negative rake angle, which is beneficial to the cutting efficiency.

[0030] Example 6

[0031] On the basis of the aforementioned embodiment 1, the number of the chip removal grooves 14 is set to be the same as the number of the first cutting edges 2, which is conducive to the removal of chips and concentrates the chips in the hollow structure, which plays a key role in achieving the medullary expansion function in one go.

[0032] Example 7

[0033] On the basis of the above-mentioned embodiment 1, the rear end of the blade body 1 is provided with a connection end 4 for connecting to a motor, and the connection end 4 is provided as a hollow structure and is connected to the blade body, which plays an important role in realizing automation.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A reamer, characterized in that: The tool comprises a tool body, a first cutting edge and a second cutting edge, wherein the first cutting edge comprises a plurality of cutting edges arranged on the side of the tool body and distributed in parallel along the length direction of the tool body, and the second cutting edge is arranged at the front end of the tool body, and the tool body is a hollow structure; the tool body further comprises a first chip holding portion and a chip removal groove, the first chip holding portion is composed of a front cutting edge and an included angle of a secondary plane, and the first chip holding portion is connected with the hollow structure of the tool body to form a chip removal groove; the hollow structure is the second chip holding portion, and excess chips enter the second chip holding portion along the chip removal groove of the front cutting edge; the tool body The cutting edge at the front end removes the cancellous bone and bone marrow in front of the blade as a whole, and the removed cancellous bone and bone marrow are collected in the hollow structure of the blade; the vertical projection profile of the first cutting edge is conical, and the taper is 1°-5°; the number of the first cutting edges is 3-7; the rake angle of the first cutting edge is a negative rake angle; the second cutting edge is a continuous annular cutting edge or a serrated cutting edge; the number of the chip grooves is equal to the number of the first cutting edges; the rear end of the blade is provided with a connecting end for connecting the motor; the connecting end is a hollow structure and is connected to the blade.

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