CN116172758A

CN116172758A - Device for reinforcing fixation of acetabular prosthesis

Info

Publication number: CN116172758A
Application number: CN202310311828.8A
Authority: CN
Inventors: 黄勇; 周一新; 杨德金; 张纪
Original assignee: Beijing Jishuitan Hospital
Current assignee: Beijing Jishuitan Hospital
Priority date: 2023-03-28
Filing date: 2023-03-28
Publication date: 2023-05-30

Abstract

The invention relates to a device for enhancing the fixation of an acetabular prosthesis, said device being a screw, comprising: the screw tail cap is used for locking with a nail hole of the acetabular prosthesis; the screw rod comprises a head bone ingrowth section, a front pushing thread section, a middle bone ingrowth screw rod section and a rear pushing thread section which are connected in sequence from head to tail; the head bone ingrowth section and the intermediate bone ingrowth screw section are provided with a porous coating for promoting bone tissue ingrowth therein. According to the invention, the head bone ingrowth section and the middle bone ingrowth screw rod section are arranged into the porous coating structure, when the screw is implanted into a human body, bone tissues can grow into the porous coating, the risk of loosening the screw is reduced, and the fixation strength of the acetabular prosthesis in the pelvis is further increased.

Description

Device for reinforcing fixation of acetabular prosthesis

Technical Field

The invention relates to a device for enhancing fixation of an acetabular prosthesis, and belongs to the technical field of medical appliances.

Background

As the life expectancy of patients receiving artificial total hip replacements and patients increases for more and more years, the number of hip revision operations increases year by year. The bone dissolution, infection around the prosthesis, accidental or unavoidable damage to the bone bed of the host during revision, insufficient bone grafting in the previous operation and the like are all causes of bone defects in hip revision, developmental hip dysplasia, acetabular invagination, fracture fragments absorbed after acetabular fracture, old infection of the hip joint and the like are all causes of acetabular bone defects in primary total hip replacement. The reconstruction of severe acetabular bone defects, whether it be primary total hip replacement or hip revision, is a challenge that has to be faced.

The small and inclusive bone defect can adopt a non-bone cement mortar cup with a porous coating, and whether bone is planted or not can be determined according to the requirement. However, large, non-inclusive bone defects are quite difficult to treat, and methods currently employed are: the ultra-large hemispherical mortar cup is placed at a higher position, a double-leaf type elliptic mortar cup, a cancellous bone transplanting and anti-protruding cage, a structural bone grafting and reconstruction ball cage, a granular bone pressing bone grafting combined bone cement mortar cup and the like. The disadvantages of these methods include the non-true biological fixation, lack of integration of the bone graft, and the technical difficulty of closely matching the host bone when using a dual-leaf cup or prosthesis.

In addition to the traditional methods, in recent years, the use of tantalum metal cups in combination with tantalum metal bone trabecular reinforcing blocks to treat severe acetabular bone defects has become increasingly popular, and follow-up reports of clinical efficacy with the combined use of TM cups and tantalum metal reinforcing blocks are currently satisfactory. However, for the acetabular bone defect which is more serious like the PaproskyIIIB type and even incorporates the pelvic discontinuity, the prosthesis is required to be reconstructed, because the bone defect is serious, a plurality of screws with chemical design are required to enhance the stability of the prosthesis, and because the traditional screw surface is free from bone ingrowth design, the screw with the traditional mechanical fixation is only mechanically fixed, and under the condition of insufficient stability of the prosthesis, the screw with the traditional mechanical fixation is loosened, withdrawn and even broken under the action of long-term repeated stress, so that the risk of failure caused by the loosening of the acetabular prosthesis is increased.

Disclosure of Invention

In view of the above technical problems, the present invention provides a device for enhancing fixation of an acetabular prosthesis, and in particular, a device for enhancing fixation of an acetabular prosthesis in an artificial hip joint revision, wherein a head bone ingrowth section and an intermediate bone ingrowth screw section are provided in a porous structure, and when a screw is implanted into a human body, bone can grow in a small hole, thereby further enhancing fixation strength of the acetabular prosthesis in pelvis.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a device for enhancing fixation of an acetabular prosthesis, the device being a screw, comprising:

the screw tail cap is used for locking with a nail hole of the acetabular prosthesis;

the screw rod comprises a head bone ingrowth section, a front pushing thread section, a middle bone ingrowth screw rod section and a rear pushing thread section which are connected in sequence from head to tail;

the head bone ingrowth section and the middle bone ingrowth screw section are provided with porous coatings for promoting bone tissue ingrowth.

In the device for enhancing fixation of the acetabular prosthesis, preferably, the screw tail cap is a cylinder or a truncated cone, and the side surface of the cylinder or the truncated cone is a smooth side surface, a side surface provided with threads or a side surface provided with small holes.

The device for enhancing fixation of an acetabular prosthesis preferably wherein the anterior push thread section is disposed at a distance of 0.5cm to 2cm from the cephalad bone ingrowth section.

In the device for enhancing the fixation of the acetabular prosthesis, preferably, the pitch of the screw threads of the front pushing screw thread section is 0.5-3mm, and the height of the screw threads is 0.5-4mm.

The device for enhancing the fixation of the acetabular prosthesis preferably has the length of the rear pushing thread section of 0.5-1.5cm, the thread spacing of 0.5-3mm and the thread height of 0.5-4mm.

The device for enhancing fixation of an acetabular prosthesis preferably has a porous coating thickness of 50um-2mm for the head bone ingrowth section and the intermediate bone ingrowth screw section.

The device for enhancing fixation of an acetabular prosthesis preferably has a coating length of 1-6cm for the intermediate bone ingrowth screw segment.

The means for enhancing fixation of an acetabular prosthesis preferably the cross-sectional shape of the screw shaft comprises a cylindrical, conical or polygonal shape.

The length of the screw rod of the device for enhancing the fixation of the acetabular prosthesis is preferably 2-14cm, and the diameter of the screw rod is 3-8mm.

The means for enhancing fixation of the acetabular prosthesis preferably has the plurality of holes in the head bone ingrowth section and the intermediate bone ingrowth screw section in a discrete or uniform distribution.

Due to the adoption of the technical scheme, the invention has the following advantages:

1. in the first technical scheme of the invention, the small holes are arranged at the tail cap of the screw to form a porous structure, so that the screw hole part of the acetabular prosthesis can be locked and fixed with the nail hole part of the acetabular prosthesis by means of bone cement, and the fixing strength of the acetabular prosthesis is improved; in the second technical scheme, screw threads are arranged on the tail cap of the screw, so that screw thread locking can be formed with the nail hole part of the acetabular prosthesis; in the third technical scheme, the screw tail cap is designed into a conical structure, and can form taper locking with the conical nail hole part of the acetabular prosthesis.

2. According to the invention, the head bone ingrowth section and the middle bone ingrowth screw section are arranged into a porous structure, when the screw is implanted into a human body, bone tissues can grow in the porous structure, the risk of loosening the screw is reduced, and the fixation strength of the acetabular prosthesis in the pelvis is further increased.

Drawings

FIG. 1 is a schematic illustration of an bone in-growth screw for securing an acetabular prosthesis to a pelvis according to one embodiment of the invention;

FIG. 2 is a schematic view of a bone in-growth screw according to the present invention;

FIG. 3 is a schematic view of a bone in-growth screw according to a second embodiment of the present invention;

FIG. 4 is a schematic view of a bone in-growth screw according to a third embodiment of the present invention;

the figures are marked as follows:

1-a screw tail cap;

2-a screw rod;

201-head bone ingrowth section; 202-advancing the thread segments; 203-ingrowth of intermediate bone into the screw section; 204-post-drive screw section.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the present invention will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are intended to be within the scope of the present disclosure.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The terms "first," "second," "third," "fourth," and the like as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

The screw fixing device aims at the problem that the existing traditional screw surface bone-free ingrowth design only depends on mechanical fixing, and under the condition that the stability of the prosthesis is insufficient, the screw of the traditional mechanical fixing can be loosened, withdrawn or even broken under the action of long-term repeated stress, so that the risk problem that the acetabular prosthesis is loosened and fails is increased. The invention provides a device for enhancing the fixation of an acetabular prosthesis, which is characterized in that a head bone ingrowth section and an intermediate bone ingrowth screw section are arranged into a porous structure, when a screw is implanted into a human body, bones can grow in small holes, and the fixation strength of the acetabular prosthesis in pelvis is further enhanced.

The technical scheme of the invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1, which is a schematic view of fixing an acetabular prosthesis in a pelvis by using the bone in-growth screw provided by the present invention, it is seen from the figure that bone in-growth screw designs of different lengths, different directions, and different diameters can be performed according to the bone condition of a patient.

In a preferred embodiment of the present invention, as shown in fig. 2, the bone in-growth screw comprises a screw tail cap 1 and a screw rod 2, wherein the screw tail cap 1 is a cylinder or a truncated cone, and the side surface of the screw tail cap 1 is provided with threads matched with the nail hole of the acetabular prosthesis, so that the threads on the screw tail cap 1 and the nail hole of the acetabular prosthesis form a thread locking; the screw shaft 2 comprises a head bone ingrowth section 201, a front advancing screw section 202, an intermediate bone ingrowth section 203 and a rear advancing screw section 204 connected in sequence from head to tail. More preferably, the head bone ingrowth section 201 and the middle bone ingrowth screw section 203 are provided with a porous coating (the porous coating is a grid-like structure in fig. 2) for promoting bone tissue ingrowth into the porous coating, further increasing the fixation of the acetabular prosthesis in the pelvis, avoiding the bone-free ingrowth design of the traditional screw surface, relying solely on mechanical fixation, and in case of insufficient stability of the prosthesis itself, the screw of the traditional mechanical fixation will have the risk of loosening, backing out and even breaking under the action of long-term repeated stress.

As shown in FIG. 2, the whole length of the screw is 3cm to 15cm, the cross section of the screw rod 2 can be cylindrical, conical or polygonal, the material is titanium alloy or other high-strength alloy, the length is 2cm to 14cm, and the diameter of the screw rod is 3mm to 8mm.

Further, the length of the front advancing thread segments 202 is 0.5cm to 3cm, the pitch of the threads of the front advancing thread segments 202 is 0.5-3mm, and the height of the threads is 0.5-4mm.

Further, the length of the rear push thread segment 204 is 0.5-1.5cm, the pitch of the threads is 0.5-3mm, and the height of the threads is 0.5-4mm.

Further, the middle bone in-growth screw section 203 is coated with a coating, the thickness of the coating is 50 μm-2mm, the middle bone in-growth screw section 203 is of a porous coating structure, can be a 3D printing titanium alloy porous coating, can be a titanium slurry plasma coating and is covered with a hydroxyapatite coating or a porous tantalum metal coating, and the coating part is 1 cm-6 cm long.

Further, the head bone ingrowth section 201 has a porous coating section of 0.5cm to 2cm, the thickness of the coating is 50um to 2mm, and the coating can be a 3D printing titanium alloy porous coating, a titanium slurry plasma coating, a surface covering hydroxyapatite coating or a porous tantalum metal coating.

In a preferred embodiment of the invention, as shown in fig. 3, the bone in-growth screw comprises two parts, a screw tail cap 1 and a screw shaft 2, wherein the screw tail cap 1 is tapered to form a taper lock with the tapered nail hole portion of the acetabular prosthesis. The screw shaft 2 comprises a head bone ingrowth section 201, a front advancing screw section 202, an intermediate bone ingrowth section 203 and a rear advancing screw section 204 connected in sequence from head to tail. More preferably, the head bone ingrowth section 201 and the middle bone ingrowth screw section 203 are provided with a porous coating for promoting bone tissue ingrowth into the porous coating, further increasing the fixation of the acetabular prosthesis in the pelvis, avoiding the bone ingrowth-free design of the traditional screw surface, relying solely on mechanical fixation, and under the condition of insufficient stability of the prosthesis itself, the screw of the traditional mechanical fixation will have the risk of loosening, withdrawing and even breaking under the long-term repeated stress.

As shown in FIG. 3, the whole length of the screw is 3cm to 15cm, the cross section of the screw rod 2 can be cylindrical, conical or polygonal, the material is titanium alloy or other high-strength alloy, the length is 2cm to 14cm, and the diameter of the screw rod is 3mm to 8mm.

Further, the length of the front advancing thread section 202 is 0.5cm to 3cm, the thread pitch of the front advancing thread section 202 is 0.5-3mm, and the thread height is 0.5-4mm; the length of the rear push thread segment 204 is 0.5-1.5cm, the pitch of the threads is 0.5-3mm, and the height of the threads is 0.5-4mm.

In a preferred embodiment of the present invention, as shown in fig. 4, the bone ingrowth screw comprises two parts of a screw tail cap 1 and a screw rod 2, wherein the screw tail cap 1 is a cylinder or a truncated cone, a porous coating is arranged on the side surface of the screw tail cap, and the small hole and the nail hole part of the acetabular prosthesis are locked and fixed by bone cement, so that the fixation strength of the acetabular prosthesis in the pelvis is improved. The screw shaft 2 comprises a head bone ingrowth section 201, a front advancing screw section 202, an intermediate bone ingrowth section 203 and a rear advancing screw section 204 connected in sequence from head to tail. More preferably, the head bone ingrowth section 201 and the middle bone ingrowth screw section 203 are provided with a porous coating for promoting bone tissue ingrowth into the porous coating, further increasing the fixation of the acetabular prosthesis in the pelvis, avoiding the bone ingrowth-free design of the traditional screw surface, relying solely on mechanical fixation, and under the condition of insufficient stability of the prosthesis itself, the screw of the traditional mechanical fixation will have the risk of loosening, withdrawing and even breaking under the long-term repeated stress.

As shown in FIG. 4, the whole length of the screw is 3cm to 15cm, the cross section of the screw rod 2 can be cylindrical, conical or polygonal, the material is titanium alloy or other high-strength alloy, the length is 2cm to 14cm, and the diameter of the screw rod is 3mm to 8mm.

In some more preferred embodiments of the invention, the small holes of the head bone in-growth section 201 and the intermediate bone in-growth screw section 203 are discretely or uniformly distributed.

According to the invention, the head bone ingrowth section and the middle bone ingrowth screw rod section are arranged to be of a porous structure, and when the screw is implanted into a human body, bone tissue grows into the porous structure, so that the fixation strength of the acetabular prosthesis in a pelvis is further increased, the bone ingrowth-free design of the surface of the traditional screw is avoided, and the screw which is fixed by the traditional machine can be loosened, withdrawn or even broken under the long-term repeated stress under the condition of insufficient stability of the prosthesis.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for enhancing fixation of an acetabular prosthesis, said device being a screw, comprising:

a screw tail cap (1) for locking with a nail hole of an acetabular prosthesis;

a screw shaft (2), the screw shaft (2) comprising a head bone in-growth section (201), a front advancing screw section (202), an intermediate bone in-growth screw section (203) and a rear advancing screw section (204) connected in sequence from head to tail;

the head bone ingrowth section (201) and the intermediate bone ingrowth screw section (203) are provided with a porous coating for promoting bone tissue ingrowth.

2. Device for enhancing the fixation of an acetabular prosthesis according to claim 1, characterized in that the screw tail cap (1) is a cylinder or a truncated cone, the sides of which are smooth sides, sides provided with threads or sides provided with small holes.

3. The device for enhancing the fixation of an acetabular prosthesis according to claim 1, characterized in that the anterior pushing thread section (202) is arranged at a distance of 0.5cm to 2cm from the head bone ingrowth section (201).

4. A device for enhancing the fixation of an acetabular prosthesis according to claim 3, characterized in that the thread pitch of the front advancing thread segments (202) is 0.5-3mm and the thread height is 0.5-4mm.

5. The device for enhancing the fixation of an acetabular prosthesis according to claim 1, characterized in that the length of the posterior pushing thread section (204) is 0.5-1.5cm, the pitch of the threads is 0.5-3mm, and the height of the threads is 0.5-4mm.

6. The device for enhancing fixation of an acetabular prosthesis according to claim 1, characterized in that the porous coating thickness of the head bone in-growth section (201) and the intermediate bone in-growth screw section (203) is 50um-2mm.

7. The device for enhancing fixation of an acetabular prosthesis according to claim 6, characterized in that the coating length of the intermediate bone ingrowth screw segment (203) is 1-6cm.

8. Device for enhancing the fixation of an acetabular prosthesis according to claim 1, characterized in that the cross-sectional shape of the screw shaft (2) comprises a cylindrical, conical or polygonal shape.

9. Device for enhancing the fixation of an acetabular prosthesis according to claim 1, characterized in that the screw shaft (2) has a length of 2-14cm and a screw diameter of 3-8mm.

10. The device for enhancing fixation of an acetabular prosthesis according to claim 1, characterized in that the multiple holes on the head bone in-growth section (201) and the intermediate bone in-growth screw section (203) are discretely or uniformly distributed.