CN211131549U

CN211131549U - Femoral implant

Info

Publication number: CN211131549U
Application number: CN201921259904.0U
Authority: CN
Inventors: 王彩梅
Original assignee: Beijing AK Medical Co Ltd
Current assignee: Beijing AK Medical Co Ltd
Priority date: 2019-08-05
Filing date: 2019-08-05
Publication date: 2020-07-31
Anticipated expiration: 2029-08-05

Abstract

The utility model provides a femoral implant, include: a pin capable of being inserted into the femoral neck; a crown portion provided at a first end of the pin, the crown portion being capable of wrapping an end of the femoral neck; a fluke disposed at the second end of the pin, the fluke having a retrieval position and a locking position, the fluke being movable from the retrieval position to the locking position under predetermined conditions, the fluke being capable of securing the pin to the femur when the fluke is in the locking position. The technical scheme of the utility model patient's later stage has been solved effectively among the prior art and has need cut off the femoral head and implement hip joint replacement art, influences great problem to the patient.

Description

Femoral implant

Technical Field

The utility model relates to an artificial joint prosthesis field particularly, relates to a femoral implant.

Background

Articular cartilage damage is a common disease in orthopedics. In the field of orthopedic surgery, arthritis caused by traumatic and degenerative cartilage tissue injury due to diseases, wounds and the like is a problem in the medical field all over the world, and the cartilage tissue has no blood supply, and nutrition comes from moistening of peripheral joint synovial fluid, so that regeneration is difficult after injury. Traditional methods for treating cartilage damage include joint grinding, drilling, microfracture, and arthroscopic lavage, which fail to restore damaged cartilage and subchondral bone to their original normal tissue structures. The autologous tissue transplantation has better curative effect but limited material supply; foreign materials are relatively abundant in origin, but may cause immune rejection and risk of disease transmission. Currently, the development of tissue substitutes for damaged tissue using tissue engineering is currently in the laboratory research phase, and there is no more effective treatment available.

Thighbones are the most important bones of human bodies, the thighbones are more important, and the supporting function of the thighbones is relied on for the vertical walking, the movement and the labor of people. The femoral head is also the most vulnerable site. After the femoral head is diseased, sclerotin of a patient seriously breaks, trabecula disappears or most of the trabecula disappears, large-area saccular light transmission at multiple positions in the femoral head changes, multiple positions of sclerotic high-density sclerotin changes, the femoral head seriously collapses, deforms, is flat and large, and often causes hip joint pain, joint function limitation, walking lameness and other symptoms. If no effective treatment is performed in the early stage, the femoral head is finally cut off in the clinic and hip replacement surgery is performed in the late stage, so that early intervention plays an important role in retaining the femoral head and preventing rapid deterioration of the disease.

Long-term clinical practice has shown that Total Hip Arthroplasty (THA) is undoubtedly an effective and robust treatment for coxitis, especially in elderly patients, with a 10-year survival rate of the prosthesis exceeding 90%. However, for younger patients, especially male patients under 55 years old, total hip arthroplasty suffers from a more pronounced deficiency in long-term effects — a higher early revision rate with a 10-year prosthesis survival rate of 80% and 33% after 16 years.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a femoral implant to solve among the prior art patient's late stage and need cut off the femoral head and implement the total hip joint replacement art, influence great problem to the patient.

In order to achieve the above object, the present invention provides a femoral implant comprising: a pin capable of being inserted into the femoral neck; a crown portion provided at a first end of the pin, the crown portion being capable of wrapping an end of the femoral neck; a fluke disposed at the second end of the pin, the fluke having a retrieval position and a locking position, the fluke being movable from the retrieval position to the locking position under predetermined conditions, the fluke being capable of securing the pin to the femur when the fluke is in the locking position.

Furthermore, the material of fluke is memory alloy.

Further, the coronal portion includes a porous structural layer configured to contact an end of the femoral neck and a contact layer disposed on an outer surface of the porous structural layer and configured to contact the acetabulum or the acetabular prosthesis.

Further, the inner surface of the porous structure layer comprises a cylindrical surface and a first conical surface which are connected, the first conical surface is gradually enlarged from the first end to the second end of the pin, and the cylindrical surface is arranged on the side with the larger diameter of the first conical surface.

Furthermore, the porous structure layer is made of memory alloy, the inner surface of the porous structure layer further comprises a second conical surface, the second conical surface is arranged in a mode that the diameter of the second conical surface is gradually reduced from the first end to the second end of the pin, and the cylindrical surface is connected with one side, with the larger diameter, of the second conical surface.

Further, a latticed groove is arranged on the surface of one side, facing the acetabulum or the acetabular prosthesis, of the contact layer.

Furthermore, a plurality of overflowing holes are formed in the contact layer and communicated with the pores of the porous structure layer.

Further, a plurality of overflowing holes are provided in the grid of the grid-like grooves, or a plurality of overflowing holes are provided at the intersections of the grid-like grooves.

Further, the porous structure layer is made of a metal material through 3D printing, and the contact layer is made of a polymer.

Further, the contact layer is arranged to protrude towards the axis of the pin to form a flange, and the flange is arranged between the femoral neck and the porous structural layer.

Use the technical scheme of the utility model, the pin is worn to establish in the femoral neck, the first end at the pin is fixed to the coronal portion, the fluke is fixed at the second end of pin, the coronal portion is fixed on the femoral head and is replaced the impaired femoral head surface cartilage that perhaps pathological change of patient through pin and fluke, the stress environment of femoral head pathological change region has been improved effectively, it sinks to resist the quick stress that pathological change district leads to, make the femoral head rotate smoothly in the acetabulum, rebuild joint function, and then realize the shank action among the patient daily life. Meanwhile, the coronal part of the femoral implant of the embodiment only replaces the surface of the femoral head, so that the femoral structures of more patients are reserved, and the influence of the operation on the patients is reduced to a certain extent.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of an embodiment of a femoral implant according to the present invention;

fig. 2 shows an enlarged partial structural schematic view at E of the femoral implant of fig. 1;

FIG. 3 shows a cross-sectional structural schematic view of a coronal portion of the femoral implant of FIG. 1;

FIGS. 4A-4D are schematic diagrams illustrating an arrangement of four examples of grid-like grooves and overflow holes on the crown surface of FIG. 3; and

fig. 5-7 illustrate a schematic surgical flow diagram of the femoral implant of fig. 1.

Wherein the figures include the following reference numerals:

10. a pin; 11. a fixing hole; 20. a crown portion; 21. a porous structural layer; 211. a first conical surface; 212. a cylindrical surface; 213. a second tapered surface; 22. a contact layer; 23. flanging; 24. an overflowing hole; 25. a grid-shaped groove; 30. a fixed part; 80. a duct; 90. the femur; 91. a femoral shaft; 92. a femoral neck; 93. the femoral head.

Detailed Description

Aiming at the problem that total hip joint replacement in the prior art has higher early revision rate to younger patients, the hip joint surface replacement technology which is proposed as early as 50 years ago has the unique advantages of small wound, good postoperative mobility, capability of keeping more femoral side bone mass and the like, and is advocated again to treat some young and motor-active hip joint disease patients. Currently, some manufacturers have introduced individual hip implants. All of these systems have several features including: (1) the joint interface is made of high-carbon cobalt-chromium alloy; (2) fixing the acetabulum prosthesis by non-bone cement; (3) fixing the femoral side prosthesis by bone cement; (4) metal-metal hip resurfacing system. The outstanding problems with modern resurfacing prostheses are severe joint wear and high early failure rates, and remain with total hip replacement. The present application proposes improvements to the femoral side implants that address the above-mentioned problems.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

As shown in fig. 1, a femur 90 of a human body comprises a femoral shaft 91, a femoral neck 92 and a femoral head 93, wherein the femoral head 93 extends into an acetabulum of a hip joint to form a rotation friction pair with the acetabulum to realize leg swinging. The femoral implant of the embodiment is aimed at intervening the femoral head 93 in the early stage of hip arthropathy of a patient, partially replacing the femoral head 93, preventing rapid disease deterioration, and simultaneously keeping the femur of the patient as much as possible and reducing the injury to the patient. As shown in fig. 1, the femoral implant of the present embodiment comprises a pin 10, a crown 20 and a fluke 30, wherein the pin 10 is capable of being inserted into the femoral neck, the crown 20 is provided at a first end of the pin 10, and the crown 20 is capable of wrapping the end of the femoral neck. A fluke 30 is provided at the second end of the pin 10, the fluke having a retrieval position and a locking position, the fluke being movable from the retrieval position to the locking position under predetermined conditions, the fluke being capable of securing the pin to the femur when the fluke 30 is in the locking position.

By applying the technical scheme of the embodiment, the pin 10 is arranged in the femoral neck 92 in a penetrating manner, the crown part 20 is fixed at the first end of the pin 10, the anchor claw is fixed at the second end of the pin 10, the crown part 20 is fixed on the femoral head 93 through the pin 10 and the anchor claw 30 and replaces the damaged or diseased femoral head surface cartilage of a patient, the stress environment of a diseased region of the femoral head is effectively improved, rapid stress collapse caused by the diseased region is resisted, the femoral head 93 can smoothly rotate in the acetabulum, the joint function is reconstructed, and further the leg action in daily life of the patient is realized. Meanwhile, the coronal part 20 of the femoral implant of the embodiment only replaces the surface of the femoral head 93, so that more femoral structures of the patient are reserved, and the influence of the operation on the patient is reduced to a certain extent.

Moreover, the femoral implant of the present embodiment directly replaces the surface of the femoral head of the patient, and compared with total hip replacement, the technical scheme of the present embodiment does not require a lining structure in the acetabulum, so that the diameter of the femoral head after operation can be kept in the original size, thereby realizing the advantage that the large-diameter femoral head can avoid dislocation.

The pins 10 are arranged along the axis of the femoral neck 92 or at a small angle to the axis of the femoral neck 92 such that the pins 10 extend in substantially the same direction as the femoral neck 92, facilitating fixation of the crown 20.

In the femoral implant of the present embodiment, the pin 10 and the fluke 30 are integrally formed of a memory alloy at 37 ℃ in the left-right direction, and the fluke 30 is in an open state; closing the fluke in a low temperature environment (e.g. sub-zero temperature conditions) so that the pin 10 and fluke 30 are rod-shaped for implantation into the patient's femur 90; after implantation into the patient's femur, fluke 30 gradually returns to the open state with increasing temperature to adhere to the femoral surface for fixation.

Preferably, as shown in fig. 2, the crown portion 20 of the present embodiment includes a porous structural layer 21 and a contact layer 22, the porous structural layer 21 can be in contact with the end portion of the femoral neck, and the contact layer 22 is disposed on the outer surface of the porous structural layer 21 and can be in contact with the acetabulum or the acetabular prosthesis. The contact layer 22 has good wear resistance to replace the femoral head cartilage surface for smooth rotation in the acetabulum. The porous structure layer 21 can simulate a porous structure formed by human skeletal trabeculae, realizes similar supporting effect, and has excellent osseointegration function and physiological bone self-healing function. After the implant is implanted into a human body, bone of the femoral head can grow into the porous structure of the porous structure layer 21, so that the structural strength of the contact surface of the bone and the porous structure layer 21 is enhanced, and the crown part 20 is stably and firmly connected to the femoral head 93 of the patient.

In the femoral implant of the present embodiment, the porous structure layer 21 may be made of biomedical materials such as ceramic and titanium by a 3D printing technology, the pins 10 are dense solid structures, which can provide sufficient structural support for the crown portion 20, and the pins 10 are made of the same material as the porous structure layer 21 and can be integrally formed by the 3D printing technology. The contact layer 22 is made of polymer materials (such as polyurethane, polyvinyl alcohol gel, polylactic acid and the like) with excellent wear resistance and is formed on the surface of the porous structure layer 21 in a thermoplastic mode, an injection molding mode and the like, the contact layer 22 made of the polymer materials highly reproduces the structure of the cartilage on the surface of the femoral head of a human body, and the service life of the prosthesis is prolonged.

Specifically, as shown in fig. 3, the inner side surface of the porous structure layer 21 of the present embodiment includes a cylindrical surface 212 and a first tapered surface 211 connected to each other, the first tapered surface 211 is disposed to gradually expand from the first end to the second end of the pin 10, and the cylindrical surface 212 is disposed on the side where the diameter of the first tapered surface 211 is larger. The taper of the first conical surface 211 is about 3-5 degrees, the depth of the cylindrical surface 212 is about 5-10 mm to form a counter bore, the first conical surface 211 is beneficial to realizing the firm fixation of the porous structure layer 21 and femoral head bone, and the counter bore formed by the cylindrical surface 212 can prevent the porous structure layer 21 from being loosened due to the edge force.

Further, as shown in fig. 3, the material of the porous structure layer 21 of this embodiment is a memory alloy, the inner surface of the porous structure layer 21 further includes a second tapered surface 213, the second tapered surface 213 is gradually reduced from the first end to the second end of the pin 10, and the cylindrical surface 212 is connected to the side of the second tapered surface 213 with the larger diameter. Similar to the operation of the fluke 30, the porous structure layer 21 of the present embodiment is also integrally formed with the pin 10 at about 37 ℃, and at this time, the porous structure layer 21 shrinks to make the outer surface of the porous structure layer approximate to a spherical surface; then the porous structure layer 21 is opened in a low temperature environment (such as a subzero temperature condition), so that the femoral head 93 of the patient can pass through the opening of the porous structure layer 21; after the implant is implanted into the femur of the patient, the porous structure layer 21 gradually recovers to the contracted state along with the temperature rise to cover the surface of the femoral head 93, and the second taper surface 213 abuts against the femoral head 93 so that the crown portion 20 cannot be pulled out of the femoral head 93, thereby realizing the fixation of the crown portion 20.

Further, as shown in fig. 2 and 3, the contact layer 22 of the present embodiment is convexly disposed toward the axis of the pin 10 to form a flange 23, and the flange 23 is located between the femoral neck 92 and the porous structural layer 21 after the crown 20 is implanted, so that the contact layer 22 can be prevented from being separated from the porous structural layer 21 under a stress environment.

In order to allow smooth rotation of the coronal portion 20 in the acetabulum, as shown in fig. 4A, a latticed groove 25 is provided on a surface of the contact layer 22 on a side facing the acetabulum or acetabular prosthesis. The grid-shaped groove 25 is formed by interweaving a plurality of grooves to form a net shape, joint synovial fluid can be stored in the grid-shaped groove 25 and coated on a contact surface between the crown part 20 and the acetabulum along with the rotation of the crown part 20 relative to the acetabulum, and the lubrication effect is realized. The specific shape of the grid-shaped grooves 25 may be a square net shape as shown in fig. 4A, a hexagonal net shape as shown in fig. 4B or 4C, a diamond net shape as shown in fig. 4D, or the like.

Further, as shown in fig. 2 and 3, the contact layer 22 of the present embodiment is further provided with a plurality of overflow holes 24, and each overflow hole 24 is communicated with the pores of the porous structure layer 21. The overflowing hole 24 realizes the communication between the femoral head bone and the articular surface, so that the articular fluid generated in the bone can be supplemented to the articular surface, the dry friction is effectively avoided, the abrasion of the contact surface 22 is reduced, and the service life of the femoral implant is prolonged. Meanwhile, the femoral head bone is communicated with the joint surface, so that a closed dead space in the femoral head bone implant can be prevented, the breeding of bacteria is effectively reduced, and infection and inflammation are prevented.

Specifically, as shown in fig. 4, the plurality of overflowing holes 24 may be provided in a grid of the grid-like grooves 25 as shown in fig. 4B, or may be provided at intersections of the grid-like grooves 25 as shown in fig. 4A, 4C, or 4D. Preferably, the diameter of the overflowing hole 24 of the present embodiment is 1 mm.

As shown in fig. 5 to 7, the femoral implant of the present embodiment may be generally divided into three steps when surgically implanted:

first, drilling a tunnel 80 in a patient's femur 90;

secondly, performing modeling treatment on the femoral head 93 of the patient, and prefabricating the surface of the femoral head 93 to adapt to the inner side surface of the porous structure layer 21;

thirdly, the pin 10 is inserted into the hole 80, the crown 20 is sleeved on the molded femoral head 93, and the fixation of the pin 10 is completed.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects:

the pin is arranged in the femoral neck in a penetrating mode, the coronal part is fixed at the first end of the pin, the anchor claw is fixed at the second end of the pin, the coronal part is fixed on the femoral head through the pin and the anchor claw and replaces the damaged or diseased femoral head surface cartilage of a patient, the stress environment of a femoral head diseased region is effectively improved, rapid stress collapse caused by a diseased region is resisted, the femoral head can smoothly rotate in an acetabulum, the joint function is rebuilt, and then leg movement in daily life of the patient is achieved. Meanwhile, the coronal part of the femoral implant of the embodiment only replaces the surface of the femoral head, so that the femoral structures of more patients are reserved, and the influence of the operation on the patients is reduced to a certain extent.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A femoral implant, comprising:

a pin (10) capable of being inserted into the femoral neck;

a crown (20) provided at a first end of the pin (10), the crown (20) being able to wrap around the end of the femoral neck;

a fluke (30) provided at a second end of the pin (10), the fluke having a retrieval position and a locking position, the fluke being movable from the retrieval position to the locking position under predetermined conditions, the fluke being capable of securing the pin to the femur when the fluke (30) is in the locking position.

2. The femoral implant according to claim 1, wherein the fluke (30) is of a memory alloy.

3. The femoral implant according to claim 1, characterized in that said coronal portion (20) comprises a porous structural layer (21) and a contact layer (22), said porous structural layer (21) being contactable with an end portion of said femoral neck, said contact layer (22) being provided on an outer surface of said porous structural layer (21) and being contactable with an acetabulum or an acetabular prosthesis.

4. The femoral implant according to claim 3, wherein the inner surface of the porous structural layer (21) comprises a cylindrical surface (212) and a first tapered surface (211) connected, the first tapered surface (211) being arranged progressively larger from the first end to the second end of the pin (10), the cylindrical surface (212) being arranged on the side of the first tapered surface (211) having the larger diameter.

5. The femoral implant according to claim 4, wherein the porous structure layer (21) is made of a memory alloy, the inner surface of the porous structure layer (21) further comprises a second tapered surface (213), the second tapered surface (213) is arranged to be gradually reduced from the first end to the second end of the pin (10), and the cylindrical surface (212) is connected to the side of the second tapered surface (213) with the larger diameter.

6. The femoral implant according to claim 3, characterized in that a latticed groove (25) is provided on a side surface of the contact layer (22) facing the acetabulum or acetabular prosthesis.

7. The femoral implant according to claim 6, characterized in that a plurality of overflowing holes (24) are arranged on the contact layer (22), and the overflowing holes (24) are communicated with the pores of the porous structural layer (21).

8. The femoral implant according to claim 7, characterized in that a plurality of said overflowing holes (24) are provided in a grid of said grid-like grooves (25), or a plurality of said overflowing holes (24) are provided at the intersections of said grid-like grooves (25).

9. The femoral implant according to claim 3, characterized in that said porous structural layer (21) is made of a 3D printing of a metallic material and said contact layer (22) is made of a polymer.

10. The femoral implant according to claim 3, characterized in that said contact layer (22) is arranged projecting towards the axis of said pin (10) forming a cuff (23), said cuff (23) being arranged between said femoral neck and said porous structural layer (21).