DE19933382A1 - Filling implant for cartilage and bone defects in one joint - Google Patents

Abstract

The invention concerns an implant (1) designed to make up for cartilage and bone defects (10) in joints. Said implant has a body frame (2) comprising at least an anchoring plug (3) to be driven into the bone and a front plate (4) coupled to said plug. The front plate (4) is incorporated in a sliding head (5) made of a biocompatible and abrasion-resistant material. The surface of the sliding head (5) opposite the anchoring plug (3) is designed as a sliding surface (6). In another embodiment, the implant has a base element comprising at least an anchoring plug to be driven into the bone and also a sliding head produced in a biocompatible and abrasion-resistant material.

Description

The present invention is concerned with an implant for filling of cartilage and bone defects in a joint, such as in Knee joint.

Cartilage and bone damage in a joint can occur always met with the implantation of a total replacement implant become. Because of the massive nature of such an intervention one is endeavors to leave as much natural material in the joint as possible possible. Of course, this does not apply to all indications. That's the way it is For example, in the case of a tumor, the implantation is often not possible avoid a total endoprosthesis. But there are often defects, one of them gentler treatment are quite accessible. For example possible with arthroscopic surgery cartilage and bone defects Treat outpatient by removing the patient's cartilage from one less stressed joint area is transplanted into the cartilage defect area. Such cartilage defects are the result of, for example, osteoarthritis, which is associated with excessive and premature cartilage abrasion, causing the Rubber that covers the ends of the bones, becomes thinner and thinner comes to bone defects. Another surgical technique that deals with This topic is, for example, cartilage cell transplantation in which tried after genetically engineered cell cultivation of the body's own cartilage cells is, by injection of these cultured cells in the area of the cartilage and Bone defects to rebuild the cartilage. Aim of all of these efforts  is the natural function of the joint using the body's own material or to restore material obtained from it.

However, it is considered disadvantageous that in the method described the cartilage transplantation cartilage material from a healthy joint area is removed to be used in the area of cartilage and bone defects and heal there. When removing the cartilage material from the healthy area thus becomes consciously a weakening of itself healthy cartilage material to accept the cartilage defect remedy.

With this in mind, the object of the present invention is here To remedy this, i.e. a filling implant for cartilage and bone defects to indicate, in which no additional weakening of the healthy Cartilage material of the patient is made. The implant should arthroscopic surgery.

This task is solved by the filling implant with the characteristics of Claim 1 or alternatively of claim 8. Advantageous further developments are specified in the respective subclaims.

Accordingly, the filling implant according to the invention has the first Alternatively, a reinforcement body with at least one in the bones Anchor pin to be driven and a head plate connected to it. This is embedded in a sliding head made of a biocompatible abrasion-resistant material, the one facing away from the anchoring pin Surface is designed as a sliding surface.

The implant according to the invention therefore takes the place of cartilage material, in previous arthroscopic surgery, this was initially done by one healthy area has been removed and to fill up the cartilage and  Bone defect served. The implant has a nail-like structure. So the implant with its anchoring pin, which is particularly preferred has a tapered end, by several blows by means of a Percussion instrument on the head or sliding head in the bones on the floor of the cartilage and bone defect. On the at least one Anchoring pin sits the top plate of the possibly metallic Reinforcement body. This is embedded or cast into one biocompatible, abrasion-resistant material, which is the sliding partner for the forms natural sliding surfaces of the other joint part. After this Wrapping the filling implant into the defect granulated in any Space between the gliding head and the natural cartilage cartilaginous connective tissue. This also applies when using several Filling implants according to the invention for filling a larger cartilage and Bone defect. The gaps between multiple implants granulate after a certain time with cartilaginous connective tissue. The Surface or sliding surface of the with one or more implants Filled cartilage and bone defects then take on the function of natural cartilage true.

When filling a defect with several filling implants, the Distances of the anchoring pins should be determined so that the Touch sliding heads in the peripheral area, but do not overlap as they would otherwise form a graded surface that does not function as a Could perceive sliding surface. This is achieved in that arthroscopic intervention placers are used, the same Have dimensions like the filling implants that are then used. The surgeon first places a placer with his anchor pin of the filling implant to the bottom of the to be filled Cartilage and bone defects and marked by a light blow on the Headplate the place where the anchor pin will later be in the bone is driven. Then a second placer is placed so that its  The head plate just touched that of the first placer and the spot on which the anchor pin of the second implant should be driven, is also marked by a light tap on the headstock. These steps the surgeon continues until he has enough and Use of different sizes of the filling implant Cartilage and bone defects practically completely modeled with the Placers filled out. Then he removes the placers and then drives them corresponding filling implants with their anchoring pins to the respective marked areas in the bone.

A particularly strong hold of the sliding head on the reinforcement body can can be achieved if the top plate is provided with openings which reaches through the material of the sliding head. A particularly intimate one Connection between head plate and sliding head is achieved if the Sliding head is shed with the head plate.

The biocompatible material of the sliding head can, for example, be polyurethane his. The selection of the biocompatible material of the Sliding head as bioceramic. This can advantageously be a glass ceramic, an aluminum oxide ceramic or a zirconium oxide ceramic. It can with A composite material can also be used, for example in EP-B-0502082 in connection with a composite pan is described.

Alternatively, it is proposed that the filling implant according to the invention have a Base body with at least one to be driven into the bone Anchoring pin and an associated sliding head. At least the sliding head consists of a biocompatible, abrasion-resistant material, the the surface facing away from the anchoring pin is designed as a sliding surface. There is therefore no comparison with the first proposal  Reinforcement body more available. This simplifies the manufacture of the Filling implant and therefore lowers costs. According to one advantageous development of the second proposed solution of the basic body and the sliding head are made of the same material. Is particularly preferred in this embodiment, that the base body and sliding head in one piece are trained.

The material for the biocompatible material is again polyurethane, Bioceramics (glass ceramics, aluminum oxide ceramics, zirconium oxide ceramics) in Consideration as well as the composite material mentioned above.

A completely metallic filling implant made of, for example, titanium is also conceivable.

In both alternative solutions, it is particularly preferred if the The height of the sliding head is between 2 and 6 mm. At several filling implants used may well, depending on the shape of the Cartilage and bone defect filling implants with different Construction heights can be used. The goal is to be as smooth as possible Sliding surface of the cartilage following the cartilage and bone defect to create a snug surface. In addition, the construction height of the gliding head lead to stability of the joint ligaments.

It is preferably provided that the sliding head is circular with a Diameter range from 6 to 16 mm is formed. To fill up a Cartilage and bone defects can be filled implants with different Diameters are used so as to avoid the existing defect to be able to fill in optimally and completely.

The invention will now be described with reference to two exemplary embodiments explained. Here shows:  

Fig. 1 is a schematic view of the Füllimplantates invention according to the first proposal,

Fig. 2 is a view on the head plate of the sheath body of the implant of FIG. 1 from below,

Fig. 3 is a schematic view of the Füllimplantates according to the second proposed solution

Fig. 4 shows schematically the filling of a cartilage and bone defect in a condyle of the knee joint, and

Fig. 5 is a schematic side view of the condyle of a knee joint with filled cartilage and bone defect.

The same parts are designated with the same reference symbols in the following.

The filling implant 1 is shown schematically in FIG. 1. It has a reinforcing body 2 , which in the present case is equipped with only one anchoring pin 3 . The head plate 4 is attached to the anchoring pin 3 . The reinforcing body 2 is preferably made of metal, for example titanium.

The head plate 4 is embedded in a sliding head 5 , the material of which has the said properties with regard to biocompatibility and abrasion resistance. The anchor pin 3 to the remote surface of the slider 5 is formed as a sliding surface 6, as in this case indicates the rounding in FIG. 1. The sliding surface 6 works together with the natural cartilage of the other joint part.

The sliding head 5 has a height H and a diameter D. With different diameters D and different height H, different filling implants can be represented, which are suitable for forming a sliding surface that is essentially continuous towards the outside following the still existing natural cartilage, as will be explained further below with reference to FIG. 5.

FIG. 2 shows the view of the armoring body 2 of the implant according to FIG. 1 from below. The anchoring pin 3 is attached to the head plate 4 and is surrounded by openings 7 . The openings 7 ensure an intimate bond between the reinforcing body 2 and the material of the sliding head S. For this purpose, the sliding head 5 can have appropriately designed lugs (not shown) which can lock into the openings 7 , ie produce a positive fit. However, it is preferred to cast the mass of the sliding head 5 through the openings 7 .

Fig. 3 shows schematically the side view of the Füllimplantates 1 '. In contrast to the proposal according to FIG. 1, the sliding head 5 'is formed in one piece with the anchoring pin 3 ' of the base body 2 '. Here, too, which is the anchor pin 3 'facing away from the surface of the slider 5' is formed as a sliding surface 6 '. The filling implant 1 'can consist of ceramic or metal. With regard to the structural height H and the diameter D of the sliding head 5 ', the same applies as explained above for the first embodiment.

Can be Fig. 4 shows schematically how a cartilage and bone defect 10 filled in a condyle of the femur 9. 8 A whole number of filling implants 1 of different sizes, ie with different diameters of the sliding heads and possibly different structural heights H of the sliding heads, enable an individual overall implant for the greatest possible filling of the cartilage and bone defect 10 .

Remaining gaps 12 between the individual implants 1 are granulated over time by cartilaginous connective tissue.

Fig. 5 is schematically indicated how a cartilage and bone defect 10 is filled in the natural cartilage layer 11 on the condyles of a knee joint. Several individual implants 1 are arranged and hammered into the bone in such a way that the smoothest possible sliding surface adjoins the natural cartilage layer 11 .

With the filling implant, it is possible to fix them relatively easily Treat cartilage and bone defects in a targeted manner without serious Interventions become necessary. Rather, the implant can be in the way of implant arthroscopic surgery. The patient is spared a total resection of the To undergo joint. Over a period of several years, one can use the Complete implant produced according to the invention ensure that that the patient can move his joint free of symptoms for several years.

Furthermore, it is noted that the different structural heights of the filling implants, such as those arranged, for example, according to FIG. 4, also serve to lead to stability of the side bands after the defect has been filled. The side band in question slackens in the area of a defect. After filling the cartilage and bone defect with the filling implant, it regains its natural tension, which is conducive to the overall stability of the joint.

Claims (18)

1. Füllimplantat (1) for cartilage and bone defects (10) in a joint, comprising an outer pouch (2) with at least one driven into the bone anchoring pin (3) and an associated cover plate (4) which is embedded in a slider ( 5 ) made of a biocompatible, abrasion-resistant material whose surface facing away from the anchoring pin ( 3 ) is designed as a sliding surface ( 6 ). 2. Filling implant according to claim 1, wherein the head plate ( 4 ) is provided with openings ( 7 ). 3. Filling implant according to claim 1 or 2, wherein the biocompatible material of the sliding head ( 5 ) is polyurethane. 4. Filling implant according to claim 1 or 2, wherein the biocompatible material of the sliding head ( 5 ) is a bioceramic. 5. Filling implant according to claim 4, wherein the bioceramic Is glass ceramic. 6. filling implant according to claim 4, wherein the bioceramic one Alumina ceramic is. 7. filling implant according to claim 4, in the bioceramic one Zirconia ceramic is. 8. Filling implant ( 1 ') for cartilage and bone defects ( 10 ) in a joint, comprising a base body ( 2 ') with at least one anchoring pin ( 3 ') to be driven into the bone and an associated sliding head ( 5 ') made of a biocompatible , abrasion-resistant material whose surface facing away from the anchoring pin ( 3 ') is designed as a sliding surface ( 6 '). 9. Filling implant according to claim 8, wherein the base body ( 2 ') and the sliding head ( 5 ') consist of the same material. 10. Filling implant according to claim 9, wherein the base body ( 2 ') and sliding head ( 5 ') are integrally formed. 11. Filling implant according to one of claims 8 to 10, in which the biocompatible material is polyurethane. 12. Filling implant according to one of claims 8 to 10, in which the biocompatible material is a bioceramic. 13. Filling implant according to claim 12, wherein the bioceramic one Is glass ceramic. 14. Filling implant according to claim 12, wherein the bioceramic one Alumina ceramic is. 15. Filling implant according to claim 12, wherein the bioceramic one Zirconia ceramic is. 16. Filling implant according to claim 10, wherein the base body ( 2 ') and the sliding head ( 5 ') consists of body-compatible metal. 17. Filling implant according to one of claims 1 to 15, in which the structural height (H) of the sliding head ( 5 ) is in the range between 2 and 6 mm. 18. Filling implant according to one of claims 1 or 16, in which the sliding head ( 5 ) is circular with a diameter (D) in the range of 6-16 mm.