Medullary cavity reamer

Abstract

The present invention belongs to the field of medical devices, and discloses a medullary cavity reamer. The medullary cavity reamer according to the present invention comprises an operating rod, an anchoring ball head and a reamer head which are coaxially connected in sequence, wherein the ratio of the outer diameter of the anchoring ball head to the length of the reamer head is greater than 1 and less than 2. The medullary cavity reamer of the present invention can realize effective medullary expansion adaptively according to the shape of the medullary cavity, thereby ensuring a good implantation position of a subsequently implanted prosthesis in the medullary cavity.

Description

Technical Field

[0001] The invention belongs to the field of medical instruments, and in particular relates to a medullary cavity reamer. Background Art

[0002] The intramedullary reamer is an important surgical tool for reaming and expanding the femoral medullary cavity during hip replacement surgery. The expansion method of the intramedullary reamer is similar to that of ordinary machined reamer, and its main object of resection is cancellous bone.

[0003] The existing intramedullary reamer technology is very mature and can meet the needs of most conventional hip joint surgeries. However, with the increasing demand for hip replacement, hip revision surgeries are also increasing. In hip revision surgeries, it is often necessary to implant an extended femoral stem. Due to the existence of the anterior femoral arch, the extended femoral stem must match it, which puts forward certain requirements for the expansion of the medullary cavity. In the prior art, soft intramedullary reamer is usually used for medullary expansion. Although this soft intramedullary reamer can complete the expansion of the medullary cavity to a certain extent and avoid the problem of the reamer itself penetrating the cortical bone, it is still impossible to fully achieve effective expansion of the medullary cavity deeper at the end of the anterior femoral arch, which can easily lead to the poor position of the implanted femoral stem prosthesis, thereby causing the problem of easy fracture of the femur. In addition, the existing soft intramedullary reamer is helpless against the sclerosis and occlusion of the medullary cavity and the sclerosis of bone cement filling in revision surgery.

[0004] In view of the shortcomings of the prior art, technicians in this field hope to seek a medullary cavity reamer that can adapt to the shape of the medullary cavity and effectively expand the medullary cavity to ensure that the subsequently implanted prosthesis is well implanted in the medullary cavity. Summary of the invention

[0005] In order to solve all or part of the above problems, the present invention aims to provide a medullary cavity reamer that can realize effective medullary expansion adaptively according to the shape of the medullary cavity, so as to ensure a good implantation position of the subsequently implanted prosthesis in the medullary cavity.

[0006] The intramedullary reamer of the present invention comprises an operating rod, an anchoring ball head and a reamer head which are coaxially connected in sequence, wherein the ratio of the outer diameter of the anchoring ball head to the length of the reamer head is greater than 1 and less than 2.

[0007] Furthermore, at least one cutting channel extending from the end of the reamer head toward the anchoring ball head is formed on the reamer head, and a through hole communicating with the cutting channel is formed on the anchoring ball head.

[0008] Furthermore, the reamer head is formed with a plurality of cutting channels extending from the end of the reamer head toward the anchoring ball head, and the anchoring ball head is formed with a plurality of through holes respectively connected to the corresponding cutting channels, and the through holes are connected to each other.

[0009] Further, the cutting channel has a tapered width in a direction toward the through hole.

[0010] Furthermore, the reamer head comprises a plurality of coaxially connected cutting columns, and the outer diameter of each cutting column gradually decreases in a direction from the anchoring ball head toward the reamer head.

[0011] Further, the end of the cutting column of the reamer head which is away from the anchoring ball head is configured as a tip.

[0012] Furthermore, the outer diameter of the anchoring ball head is smaller than the inner diameter of the human medullary cavity and larger than 4 / 5 of the inner diameter of the human medullary cavity.

[0013] Furthermore, the ratio of the outer diameter of the operating rod to the outer diameter of the anchoring ball head is greater than 1:5.

[0014] Further, the outer diameter of the operating rod is smaller than the outer diameter of the cutting column of the reamer head close to the anchoring ball head.

[0015] Furthermore, the operating rod, the anchoring ball head and the reamer head are integrally formed.

[0016] The real medullary cavity reamer of the present invention solves the problems of medullary cavity reamer easily penetrating cortical bone and failing to effectively expand the medullary cavity according to the shape of the medullary cavity in the human medullary cavity with its simple and exquisite design. The medullary cavity reamer of the present invention can effectively anchor the nail at the medullary opening point, realize the medullary opening and then expand the medullary cavity, and its direction is easy to control and its passability is strong. It not only saves labor but also effectively reduces the number of fluoroscopy times, and has extremely high clinical use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a medullary cavity reamer according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A cross-sectional view of the intramedullary reamer is shown;

[0019] Figure 3 Schematic diagram of the working state of the intramedullary reamer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0021] Figure 1 and Figure 2 The structure of the intramedullary reamer 100 according to an embodiment of the present invention is shown. Figure 1 and Figure 2As shown, the intramedullary reamer 100 comprises an operating rod 1, an anchoring ball head 2 and a reamer head 3 which are coaxially connected in sequence. The ratio of the outer diameter of the anchoring ball head 2 to the length of the reamer head 3 is greater than 1 and less than 2.

[0022] Figure 3 The schematic diagram shows that the intramedullary reamer 100 of the embodiment of the present invention is placed in the intramedullary cavity 200 of the femur for medullary expansion in hip joint revision surgery. When the intramedullary reamer 100 of the embodiment of the present invention is in use, the intramedullary reamer 100 can enter the intramedullary cavity 200 of the femur to remove cancellous bone 201. The design of the anchoring ball head 2 and the reamer head 3 can ensure that the intramedullary reamer 100 is always in the center of the patient's medullary cavity. Figure 3 The design can provide the operator with a more effective anchoring point for opening the medullary cavity 200, reduce the number of fluoroscopy times, and thus greatly simplify the surgical procedure. At the same time, due to the proportional design of the outer diameter of the anchor ball head 2 and the length of the reamer head 3 of the medullary cavity reamer 100 of the embodiment of the present invention, the problem of the reamer head 3 penetrating the cortical bone 202 can be effectively avoided. In addition, the operating rod 1 of the medullary cavity reamer 100 of the embodiment of the present invention can be a hard rod, which provides direct force transmission between the anchor ball head 2 and the reamer head 3, which is superior to the several force components provided by the existing soft medullary cavity reamer, and can effectively remove the hardened material and the bone cement filled in the medullary cavity during the revision surgery, while reducing the doctor's force and increasing the controllability of the direction of the medullary cavity reamer 100.

[0023] The intramedullary reamer 100 of the embodiment of the present invention has a simple and exquisite design, which solves the problem that the intramedullary reamer 100 is easy to penetrate the cortical bone during medullary expansion, especially in joint revision surgery, and cannot effectively expand the medullary cavity according to the shape of the medullary cavity in the human body, and has extremely high clinical use value.

[0024] In such Figure 1 and Figure 2 In the illustrated embodiment, the reamer head 3 may be formed with at least one cutting channel 31 extending from the end of the reamer head 3 toward the anchoring ball head 2, and the anchoring ball head 2 is formed with a through hole 21 connected to the cutting channel 31. The cutting channel 31 is used to cut the cancellous bone in the medullary cavity 200 and provide a conveying channel for the reamed cancellous bone to be discharged through the through hole 21.

[0025] Preferably, the reamer head 3 may be formed with a plurality of cutting channels 31 extending from the end of the reamer head 3 toward the anchoring ball head 2, and the anchoring ball head 2 may be formed with a plurality of through holes 21 respectively connected to the corresponding cutting channels 31, and the through holes 21 are interconnected. The plurality of cutting channels 31 may improve the cutting efficiency of the reamer head 3, and the interconnected through holes 21 may enable the cancellous bone to be discharged quickly, and may also effectively prevent the cancellous bone removed from the reamer from being blocked in any through hole 21.

[0026] Further preferably, in order to further improve the discharge efficiency of the reamed cancellous bone through the through hole 21 , the cutting channel 31 may have a gradually decreasing width in the direction toward the through hole 21 .

[0027] In such Figure 1 In the illustrated embodiment, the reamer head 3 may include a plurality of coaxially connected cutting columns 32, and the outer diameter of each cutting column 32 gradually decreases in the direction from the anchoring ball head 2 toward the reamer head 3. Such a design helps to improve the cutting performance of the reamer head 3, thereby helping to improve the efficiency of the reamer head 3 in expanding the medullary cavity.

[0028] Preferably, the end of the cutting column 32 of the reamer head 3 away from the anchoring ball head 2 is configured as a pointed end, so that the reamer head 3 can be easily inserted into cancellous bone or hard solidified materials such as bone cement in the medullary cavity.

[0029] According to the intramedullary reamer 100 of the embodiment of the present invention, the anchoring ball head 2 can be spherical or oblate. When the anchoring ball head 2 is spherical, the outer diameter of the anchoring ball head 2 mentioned below should be understood as the diameter of the anchoring ball head 2; when the anchoring ball head 2 is oblate, the outer diameter of the anchoring ball head 2 mentioned below should be understood as the width of the anchoring ball head 2 (such as Figure 1 The maximum outer diameter dimension in the up and down direction shown.

[0030] In a preferred embodiment, the outer diameter of the anchoring ball head 2 can be smaller than the inner diameter of the human medullary cavity 200 and larger than 4 / 5 of the inner diameter of the human medullary cavity 200. This arrangement allows the medullary cavity reamer 100 to have sufficient redundant space in the medullary cavity, and the operating rod 1 can drive the anchoring ball head 2 to swing at a certain angle inside the medullary cavity, thereby facilitating the medullary cavity reamer 100 to expand the medullary cavity at a variable angle or advance, so that the medullary cavity reamer 100 can adapt to the change in the shape of the medullary cavity to expand the medullary cavity, for example, it can adapt to the shape of the anterior arch of the femur to expand the medullary cavity.

[0031] Furthermore, the ratio of the outer diameter of the operating rod 1 to the outer diameter of the anchoring ball head 2 may be greater than 1:5. This arrangement makes the diameter of the operating rod 1 smaller, which helps to increase the redundant space of the intramedullary reamer 100 in the intramedullary cavity 200, thereby making it easier for the intramedullary reamer 100 to expand the medullary cavity or advance at a variable angle, so that the intramedullary reamer 100 can expand the medullary cavity to adapt to changes in the shape of the intramedullary cavity 200. In addition, without affecting the hardness of the operating rod 1 required for expanding the medullary cavity, the design of the longer operating rod 1 allows it to be slightly bent to facilitate the expansion or advancement of the reamer head 3.

[0032] Furthermore, the outer diameter of the operating rod 1 may be smaller than the outer diameter of the cutting column 32 of the reamer head 3 near the anchoring ball head 2. This arrangement makes the outer diameter of the operating rod 1 smaller than the maximum outer diameter of the cutting column 32. This arrangement not only allows the operating rod 1 to be slightly bent when the length is long (without affecting the hardness of the operating rod 1 required for medullary expansion) to facilitate medullary expansion or advancement of the reamer head, but also ensures the overall structural strength of the reamer head 3 to ensure the medullary expansion effect of the reamer head 3.

[0033] According to the intramedullary reamer 100 of the embodiment of the present invention, the operating rod 1, the anchoring ball head 2 and the reamer head 3 can be integrally formed, which helps to improve the overall structural strength of the intramedullary reamer 100. Preferably, the intramedullary reamer 100 can be made of materials such as stainless steel, titanium alloy, tungsten steel or ceramics. It is further preferably made of titanium alloy.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A medullary cavity reamer, characterized in that: The invention comprises an operating rod, an anchoring ball head and a reamer head which are coaxially connected in sequence, wherein the ratio of the outer diameter of the anchoring ball head to the length of the reamer head is greater than 1 and less than 2; wherein the reamer head is provided with at least one cutting channel extending from the end of the reamer head toward the anchoring ball head, and the anchoring ball head is provided with a through hole connected with the cutting channel; the reamer head is provided with a plurality of cutting channels extending from the end of the reamer head toward the anchoring ball head, and the anchoring ball head is provided with a plurality of through holes respectively connected with the corresponding cutting channels, and each of the through holes is connected with each other; the cutting channel has a gradually decreasing width in the direction toward the through hole; the reamer head comprises a plurality of coaxially connected cutting columns, and the outer diameter of each cutting column gradually decreases in the direction from the anchoring ball head toward the reamer head; the end of the cutting column of the reamer head away from the anchoring ball head is configured as a tip; the outer diameter of the anchoring ball head is smaller than the inner diameter of the human medullary cavity and larger than 4 / 5 of the inner diameter of the human medullary cavity.

2. The intramedullary reamer according to claim 1, characterized in that: The ratio of the outer diameter of the operating rod to the outer diameter of the anchoring ball head is greater than 1:

5.

3. The intramedullary reamer according to claim 2, characterized in that: The outer diameter of the operating rod is smaller than the outer diameter of the cutting column of the reamer head close to the anchoring ball head.

4. The intramedullary reamer according to claim 1, characterized in that: The operating rod, the anchoring ball head and the reamer head are integrally formed.

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