A medullary cavity bone cement removal device

Abstract

The present invention relates to medical equipment, and more specifically, to a medullary cavity bone cement extraction device, comprising a housing and a drill bit whose rear end is mounted on the housing and can rotate, the drill bit is hollow, and its inner cavity is provided with a push-pull rod that can move axially along the inner cavity, one end of the push-pull rod extends out of the housing and is connected to a handle, and the other end is provided with a driving mechanism, and a grasping mechanism is provided at the front end of the drill bit, and the push-pull rod is pushed and pulled by the handle, and the push-pull rod drives the driving mechanism to drive the grasping mechanism to radially open or close. The present invention is provided with a grasping mechanism, and when the front end of the drill bit passes through the middle of the bone cement and its tip penetrates the bone cement, the grasping mechanism is controlled by the handle to change from a closed state to an open state, so that the bone cement can be quickly pulled out. At the same time, the present invention is also provided with a guide, and by controlling the direction of the guide, it can be ensured that the tunnel through which the inner ring of the guide ring through which the drill bit passes will not damage the bone cortex.

Description

Technical Field

[0001] The invention relates to medical equipment, in particular to a medullary cavity bone cement removal device. Background Art

[0002] With the arrival of an aging society in China and the development of joint surgery, the number of patients who need hip revision surgery is increasing year by year. Revision surgery is difficult. If the femoral stem prosthesis used in the previous surgery is a cemented prosthesis, cleaning and removing the original bone cement in the femoral medullary cavity during the revision surgery is a major challenge. During the revision surgery, the bone cement remaining in the femoral medullary cavity must be thoroughly cleaned. The existing bone cement removal instruments include medullary cavity ball drills, medullary cavity straight drills, scrapers, medullary cavity bone knives, medullary cavity probes, splitting knives, nucleus pulposus forceps, etc. However, the existing devices cannot quickly remove the bone cement after destroying the medullary cavity bone cement, and during the removal process, part of the bone cement is hard and firmly embedded in the femoral cortex, which can easily cause damage to the femoral cortex, perforation, and even femoral shaft fractures, increasing the patient's pain. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a removal device which can quickly and safely remove bone cement from the medullary cavity.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a medullary cavity bone cement removal device, comprising a shell and a drill bit whose rear end is mounted on the shell and can rotate, the drill bit is hollow, and its inner cavity is provided with a push-pull rod that can move axially along the inner cavity, one end of the push-pull rod extends out of the shell and is connected to a handle, and the other end is provided with a driving mechanism, and a grasping mechanism is provided at the front end of the drill bit. The push-pull rod is pushed and pulled by the handle, and the push-pull rod drives the driving mechanism to drive the grasping mechanism to radially open or close.

[0005] Preferably, the driving mechanism comprises a guide block fixedly connected to the other end of the push-pull rod and a driving rod driven to move by the guide block, and the driving rod drives the grasping mechanism to move.

[0006] Preferably, the gripping mechanism includes a plurality of barbs arranged on the outer wall of the drill bit and distributed circumferentially along the drill bit and a plurality of positioning pins fixedly arranged on the outer wall of the drill bit, each of the barbs being connected to a driving rod, and each driving rod driving the corresponding barb to rotate around the corresponding positioning pin.

[0007] Preferably, one end of each barb is a free end and the other end is a driving end, the driving end is mounted on the corresponding positioning pin, and one end of each driving rod extends out of the inner cavity and is fixedly connected to the corresponding driving end.

[0008] Preferably, a guide column is formed at the other end of each driving rod, and a guide groove is radially provided on the guide block. The guide column is inserted into the guide groove. When the guide block moves axially with the push-pull rod and drives the other end of the driving rod to move axially, the guide column moves radially along the guide groove.

[0009] Preferably, the inner cavity is fixedly provided with a plurality of connecting rods, and one end of each connecting rod extends out of the inner cavity and is fixedly connected to a positioning pin.

[0010] Preferably, the outer wall of the drill bit is formed with a plurality of receiving grooves, and each barb can be folded into a corresponding receiving groove.

[0011] Preferably, each of the barbs is arc-shaped.

[0012] Preferably, a guide is provided at the front end of the drill bit.

[0013] Preferably, the guide includes a guide ring and a guide rod, the inner ring of the guide ring can accommodate the front end of the drill bit, the outer ring of the guide ring is fixedly connected to one end of the guide rod, and the other end of the guide rod extends to the rear end of the drill bit and is connected to a handle.

[0014] As can be seen from the above technical solutions, the present invention is provided with a grasping mechanism. When the front end of the drill bit passes through the middle of the bone cement and its tip penetrates the bone cement, the grasping mechanism is controlled by the handle from a closed state to an open state, so that the bone cement can be quickly pulled out. At the same time, the present invention is also provided with a guide. By controlling the direction of the guide, it can be ensured that the tunnel passed by the inner ring of the guide ring through which the drill bit passes will not damage the bone cortex. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0016] Combine the following Figure 1 The present invention is described in detail. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0017] The present invention provides a medullary cavity bone cement extraction device, comprising a housing 1 and a drill bit 2 whose rear end is mounted on the housing and can rotate, the drill bit is driven to rotate by a motor, and the rotating drill bit can rotate and cut the medullary cavity bone cement to extract the bone cement. The drill bit is hollow, and its inner cavity is provided with a push-pull rod 3 that can move axially along the inner cavity, one end of the push-pull rod extends out of the housing and is connected to a handle 4, and the other end is provided with a driving mechanism 5, and a grasping mechanism 6 is provided at the front end of the drill bit; during the implementation process, the handle pushes and pulls the push-pull rod, and the push-pull rod drives the driving mechanism to drive the grasping mechanism to radially open or close. When the extraction device of the present invention is not working, the grasping mechanism is in a closed state; when the extraction device of the present invention is used to cut bone cement, the grasping mechanism is in a closed state, and after the drill bit penetrates the bone cement, the push-pull rod is pushed by the handle, and the push-pull rod drives the driving mechanism to drive the grasping mechanism to open, and then the drill bit is pulled back, at which time the grasping mechanism grabs the bone cement, and the bone cement can be quickly extracted. After the work is completed, the push-pull rod is pulled by the handle, and the grabbing mechanism is retracted and returned to the initial state.

[0018] The driving mechanism 5 of the present invention includes a guide block 51 fixedly connected to the other end of the push-pull rod and a driving rod 52 driven by the guide block to move, and the driving rod drives the gripping mechanism to move, thereby realizing the opening and closing of the gripping mechanism. Specifically, the gripping mechanism 6 includes a plurality of barbs 61 arranged on the outer wall of the drill bit and distributed along the circumference of the drill bit, and a plurality of positioning pins 62 fixedly arranged on the outer wall of the drill bit, each of the barbs is connected to a driving rod, and each driving rod drives the corresponding barb to rotate around the corresponding positioning pin, thereby realizing the radial opening or closing of the barb through the forward or reverse rotation of the barb.

[0019] During the implementation process, one end of each barb is a free end, and the other end is a driving end, which is mounted on the corresponding positioning pin, one end of each driving rod extends out of the inner cavity and is fixedly connected to the corresponding driving end, and a guide column 53 is formed at the other end of each driving rod, and a guide groove 54 is radially provided on the guide block, and the guide column is snapped into the guide groove. When the guide block moves axially with the push-pull rod and drives the other end of the driving rod to move axially, the guide column moves radially along the guide groove. Specifically, when the push-pull rod is pushed and pulled, the guide block moves axially, and the other end of the driving rod moves along with it. At this time, since one end of the driving rod is constrained by the positioning pin and the driving end, when the other end of the driving rod moves axially, one end rotates around the positioning pin, and the other end of the driving rod must move radially. The matching design of the guide column and the guide groove of the present invention can meet its radial movement. The matching mode of the guide groove and the guide column adopts a snap connection to prevent the two from being separated when moving. If the guide groove adopts a dovetail groove, the guide column can move radially along the dovetail groove, but will not move axially relative to the dovetail groove, that is, the two will not be separated.

[0020] In order to facilitate the installation and fixing of the positioning pin, the inner cavity is fixedly provided with several connecting rods 7, and one end of each connecting rod extends out of the inner cavity and is fixedly connected to a positioning pin. Preferably, the outer wall of the drill bit is formed with several receiving grooves 8, and each barb can be folded into the corresponding receiving groove to prevent the barb from interfering when the drill bit is working, and can also reduce the volume. Each of the barbs is arc-shaped, which can ensure that the barb is umbrella-shaped after opening, which is conducive to grabbing bone cement.

[0021] The front end of the drill bit of the present invention is provided with a guide 9 to guide the drill bit and prevent the drill bit from damaging the bone cortex. Specifically, the guide includes a guide ring 91 and a guide rod 92. The inner ring of the guide ring is slightly larger than the outer diameter of the drill bit. When the drill bit is working, it cuts within the range of the inner ring of the guide ring to avoid damaging the radial bone cortex. During implementation, the difference between the outer diameter and the inner diameter of the guide ring is about 3mm, which is more convenient for guiding. The outer ring of the guide ring is fixedly connected to one end of the guide rod, and the other end of the guide rod extends to the rear end of the drill bit and is connected to a handle 93. Thus, the direction of the guide can be controlled by the handle to guide the drill bit to cut within a specified range, thereby ensuring that the tunnel through which the drill bit passes will not damage the bone cortex, improving the surgical effect, and reducing the patient's pain.

Claims

1. A medullary cavity bone cement removal device, comprising a housing and a drill bit whose rear end is rotatably mounted on the housing, characterized in that: The drill bit is hollow, and its inner cavity is provided with a push-pull rod that can move axially along the inner cavity. One end of the push-pull rod extends out of the shell and is connected to a handle, and the other end is provided with a driving mechanism. A grabbing mechanism is provided at the front end of the drill bit. The push-pull rod is pushed and pulled by the handle, and the push-pull rod drives the driving mechanism to drive the grabbing mechanism to open or close radially; the driving mechanism includes a guide block fixedly connected to the other end of the push-pull rod and a driving rod driven by the guide block, and the driving rod drives the grabbing mechanism to move; the grabbing mechanism includes a plurality of barbs arranged on the outer wall of the drill bit and distributed circumferentially along the drill bit, and a plurality of positioning pins fixedly arranged on the outer wall of the drill bit, each of the barbs is connected to a driving rod, and each driving rod drives the corresponding barb to rotate around the corresponding positioning pin.

2. The medullary cavity bone cement removal device according to claim 1, characterized in that: One end of each barb is a free end, and the other end is a driving end, which is mounted on the corresponding positioning pin, and one end of each driving rod extends out of the inner cavity and is fixedly connected to the corresponding driving end.

3. The medullary cavity bone cement removal device according to claim 2, characterized in that: A guide column is formed at the other end of each driving rod, and a guide groove is radially provided on the guide block. The guide column is inserted into the guide groove. When the guide block moves axially with the push-pull rod and drives the other end of the driving rod to move axially, the guide column moves radially along the guide groove.

4. The medullary cavity bone cement removal device according to claim 1, characterized in that: The inner cavity is fixedly provided with a plurality of connecting rods, and one end of each connecting rod extends out of the inner cavity and is fixedly connected with a positioning pin.

5. The medullary cavity bone cement removal device according to claim 1, characterized in that: The outer wall of the drill bit is formed with a plurality of receiving grooves, and each barb can be folded into a corresponding receiving groove.

6. The medullary cavity bone cement removal device according to claim 1, characterized in that: Each of the barbs is arc-shaped.

7. The medullary cavity bone cement removal device according to any one of claims 1 to 6, characterized in that: A guide is arranged at the front end of the drill bit.

8. The medullary cavity bone cement removal device according to claim 7, characterized in that: The guide comprises a guide ring and a guide rod, the inner ring of the guide ring can accommodate the front end of the drill bit, the outer ring of the guide ring is fixedly connected to one end of the guide rod, and the other end of the guide rod extends to the rear end of the drill bit and is connected to a handle.

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