JPS61502308A - lumbar leg implant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention lumbar leg implant Technical field The present invention relates to a lumbar leg implant according to the preamble of claim 1.

Conventional technology with a surface pattern so that bone grows on the implant and settles within the surface pattern. and/or non-cemented implants with high or low levels of synthesis within the medullary canal of the bone. Luntable lumbar leg implants are known.

The surface profiles required to promote bone growth without connective tissue are diverse. regular honeycomb pattern or regular and/or irregular surface pattern. It has a pattern of turns, so-called mudrapolisks. Known lumbar and leg inbulans In this case, this surface pattern extends the entire length of the leg. However, the bone is It can only grow within the bony support of the bone.

In the case of known implants, the more or less rounded crural envelope of the femur Enlarged '111 cross-section to match internal cross-section for the strongest possible fit. Attempts are made to achieve this.

For this purpose, the prosthesis axis is primarily more or less round. And the round cross section is a leg pro. It spans the entire length of the tape axis.

f-lil! ! A round prosthesis cross-section located within a round cross-section of It has the disadvantage of dynamic instability. Therefore, 78 people 1986-502308 (2) Sitting on a stool The stool is used for frequent and Bone growth can be inhibited by a constant four-load state that repeats regularly. Therefore Te implant. Implants are removed quickly, and later the implant becomes loose.

Synthetic, i.e. mainly round cross-section, so the implant is extraosseous in the upper implant area. A large circumferential stress (hoop stress) is generated in the fluid, and experience shows that this circumferential stress The cover does not proliferate.

This often results in circumferential stress fractures of the bone during insertion of the prosthesis during surgery. Ru.

Most of the legs of the structure are not considered. Therefore, the fitability of the known legs is not achieved.゛Even if the legs of known implants are exceptionally curved, the medullary cavity Fitting may be achieved only by chance due to individual differences in the size of the bone and bone curvature. It is. Mainly, in all known legs, the cortical peduncle vX (section b in Figure 1) is strong under load; The flexible deformation prevents harmful relative movement between the bone and the implant. We are neglecting the fact that this will inevitably occur.

Purpose and outline The purpose of the invention is to ensure a strong composite so that it does not loosen later, and also to ensure that it is not loaded immediately. To devise a non-cementable lumbar leg implant that enables That is.

This object is achieved according to the invention by the features of claim 1.

The lumbar crural implant is a two-part composite leg implant. The patterned surface The head side of the legs has an elongated cross section with no roundness. This cross section is perpendicular to each other It has two main shafts located at , and these have different lengths.

As a result, the cross section of the head side portion of the leg becomes elongated. This length of cross section The elongated shape provides previously unattainable rotational stability of the implant within the bone. will be accomplished. The shape of the cross section is optimally matched to the somewhat rounded cross section of the leg covering of the femur. has been completed. The cephalic part of the leg has a patterned surface and a long cross section. , long enough to penetrate only into areas of cancellous bone. This spongy substance The cross-section of the bone is anchored within the patterned surface of this cranial portion of the leg. allows bone growth.

Slip-fit parts that are at least partially elastically and/or plastically deformable are self-aligning. The core facilitates the penetration of this lumbar crural implant into the interior of the bone, and also facilitates integration. Ensure a tight fit. J” tight fit of this composite in the imbued state , the loads that create moments on the implant are absorbed. this moment Reliable prevention of movements that can occur due to the impact is extremely important. Table of slip-fit parts Bone growth will occur on the surface where the implanted slip-fit component will be located. Since there is no pattern, there is no pattern applied.

The rotational stability of the implant is mainly determined by the fact that the cross-section of the head side of the leg is oval or oval. Achieved by being a shape or rectangle.

A slip fit, on the other hand, places the composite in the lower cortical area of the implant where bone growth does not occur. arise. The round cross-section of the slip-fit component is ideally suited for the round cross-sectional shape of this section. It is Noh.

The abdominal part of the femur can deform extremely greatly during loading, so Due to the elastic and/or plastic deformability of the inserted slip-fit parts. , harmful relative movement between the bone and the implant is avoided. femoral part of the leg part of the cortex Bones are curved and therefore at least partially elastically and/or plastically deformable. The shape-synthesizing component allows for the synthesis of implants into the cortical osteocutaneous area of the medullary canal. do. This is not entirely possible with the implants known up to now.

The cross-sectional dimensions of the femur and the medullary cavity vary depending on body size, gender, etc. this is due to the at least partially elastic and/or plastic deformability of the slip-fit parts. and is optimally corrected. The main advantage is the material and/or design geometry of the slip-fit parts. is specially formed and/or selected 1q. Experts say that when applying pressure, When the pressure on the slip-fit parts increases, the stiffness of the slip-fit parts increases. Uniform formation and material selection can be performed. After this ensures a secure fit. The absorption of forces that create moments at is improved (q.

For extreme differences in section surfaces, implants of various dimensions are available. can do. The inner diameter of the femur varies, for example, between 8 and 18#. I can do it. Easily manage complete lumbar crural implants and quickly select them during surgery. The advantage is that the head side of the leg and the slip-fit parts can be manufactured separately so that you can choose between them. There is. Both sections can be connected to each other in a removable manner. Head side part of the leg For example, only two unit sizes are required. elasticity and/or Only slip-fit parts that can be deformed plastically or plastically are manufactured in different sizes and supported. It is held in the holding part.

The head part of the leg and the sliding fit part are screwed together to form one structural unit. It is best to assemble the This assembly of parts is used during surgery to insert the implant. This can be done before the transfer.

The head-side part of the leg with the surface pattern is made of steel in a conventional manner, e.g. It can be composed of metals. Slip-in parts can be made of metal or plastic.

8 To eliminate the risk of corrosion or stress fracture at the connection site with the metal part on the head side of the leg. Therefore, compared to metals and plastics, low-molecular-weight polyethylene, which has a particularly high pressure resistance, is more durable. It can be said that it is out of step.

If the slip fit part is made of metal, this slip fit should be at least partially It is a metal cylinder with elastically deformable walls. This at least partially The wall of the deformable metal cylinder is at least partially slit from the outer edge. ing. The number and width of the slits determine the elastic properties of this cylinder. For example, the formation Part of the cylinder wall consists of tongue-like segments spaced from each other in the circumferential direction. It is possible to make it happen.

The design and structural features of the leg/composite implant of the present invention are the combined effect of the combination. bring about. The neck collar puts your weight on the bone and prevents the prosthesis from soaking in. This is avoided by tilting the head and placing the bone in the femur away from the hip and neck. beneath At the same time, the sliding fit part ensures the absorption of moment loads and Due to the plastic and/or elastic deformability of the slip-fit parts in the Harmful relative movements between the bone and the bone which can be elastically deformed under load are avoided. results and This ensures that twisting of the implant is eliminated. Implants are difficult This may prevent bone growth into the implant or cause problems later on. There is no risk of it becoming stuck, and it can be loaded immediately after being inserted into the bone.

Embodiments of the invention are described in detail below in connection with the figure numbers of the drawings.

Brief description of the drawing FIG. 1: Cross-sectional view of an embodiment of a lumbar crural implant inserted into the femur.

FIG. 2: A sectional view taken along the line It-It in FIG. 1.

Detailed description of examples In Figure 1, the non-deformable cancellous bone region is a, and it can be elastically deformed under load. The cortical bone area is shown in b.

Lumbar crural implants can be constructed of metal or ceramic materials, depending on your needs. It has a head 1 that can be fitted. The head side part 4 made of metal with legs 4°5 is A neck part 2 having a collar 3 is drawn. The head side part 4 of the legs 4 and 5 is a general one. The surface pattern is applied by the method. This head-side part 4 of the leg 4.5 has the In the case of the embodiment shown in FIG. and/or a plastically deformable slip-fit part 5 is screwed in. start illustrating The solid-fit part is a cylindrical component.

The slip-fitting part is located in the round region of the cortex (part b) of the cortex. place This slip-fit part 5 has a round cross section.

In order to realize the elastic deformability of at least a part of the slip-fit part 5, the illustrated In the embodiment shown, a sleeve l-9 extending from the free end is provided inside the jacket. child An elastically deformable tongue is located between the slits 9.

As shown in Figure 2, the head side portions 4 of the legs 4, 5 are elongated cross sections, has a rectangular south face. What this shows is that these cross sections are located at right angles to each other. It is to move the main axes of different lengths to the right. This a formation reliably eliminates twisting. There is.

international search report I1.1^1 Engineer, Team PCT/DE85100202

Claims (10)

[Claims] (1) The legs 4 and 5 are composite legs, and have a pattern with the head side portion 4 of the composite legs. has two main cross-sectional axes of different lengths located at right angles to each other with the applied surface, and This part 4 is at least partially elastic with a round cross section and an unpatterned surface. and/or coupled to a plastically deformable sliding fit part 5. and consists of legs having a patterned surface, a neck part having a collar, and a head part. Lumbar crural implant for performing non-cemented implants. (2) The cross section of the head side portion 4 of the legs 4, 5 is oval, oval, or rectangular. The lumbar leg implant according to claim 1, characterized in that: (3) The head side portion 4 and the sliding fit part 5 are removably connected to each other. The hip leg according to claim 1 or 2, characterized in that: Department Imbrandt. (4) The head side portion 4 and the sliding fit portion 5 are screwed together. The lumbar leg implant according to any one of claims 1 to 3. (5) The design shape and/or is characterized in that the material of the slip-fit part 5 is formed and/or selected. The lumbar leg implant according to claim 1. (6) Plastics, mainly polyethylene such as low molecular weight polyethylene with high pressure resistance. Claims 1 to 5, characterized in that the sliding fit part 5 is configured. A lumbar leg implant as described in any of the above. (7) The slip-fit part 5 is at least partially an elastically deformable metal component. The waist leg insulator according to any one of claims 1 to 5, characterized in that: Runt. (8) The sliding fit part 5 is a metal structure having at least partially elastically deformable walls. According to either claim 6 or 7, which is Linda. lumbar leg implant. (9) The wall of the metal cylinder is at least partially provided with slits. The lumbar leg implant according to claim 8, characterized by: (10) A tongue is formed in the wall of the sliding fit part 5. The lumbar leg implant according to scope 9.