DE102007031671A1 - Hip joint prosthesis for patient, has shaft or shaft neck and acetabulum coupled with one another using elastic elements e.g. elastic straps, where elastic elements develop pre-stressing in prosthesis - Google Patents

Abstract

The prosthesis has a ball head fastened to a shaft neck (7), where the ball head is supported in a calotte of a lug insert (3) in a rotatable manner. The lug insert is inserted into an acetabulum (4). A shaft (1) is implantable in a thigh bone (20), and the acetabulum is implantable in a pelvic bone (21). The shaft or the shaft neck and the acetabulum are coupled with one another using elastic elements e.g. elastic straps (6), where the elastic elements develop a pre-stressing in the prosthesis.

Description

The The invention relates to a hip joint prosthesis with a shaft, attached to the shaft neck of a ball head is, in turn, rotatable in the calotte of a pan insert is stored, and the socket insert is inserted into a hip socket, wherein the shaft in the femur and the acetabulum in the pelvic bone are implantable.

The market has a variety of prosthetic systems for the replacement of the natural hip joint. These usually consist of a shaft 1 coupled with a ball head 2 and a hip socket 4 coupled with a pan insert 3 , shaft 1 and acetabulum 4 are connected to the body by ingrowth in the femoral or pelvic bones and are carriers for the ball head 1 or pan insert 3 , The ball head 2 is in the dome of the pan insert 3 rotatably mounted - degree of freedom: 1 (please refer 1 ).

The the ball head in the correct position in the cup of the socket insert remains due to adequate tension of the hip joint surrounding bands realized by the patient. The sufficient tape tension is added Intra-operative set and checked by the doctor.

Now It may happen due to various indications that the Belt tension over time decreases or the set Tape tension proves to be insufficient. Then it is possible that while running, while the swinging of the leg, due to the inertia of the leg of the ball head is briefly lifted from the calotte of the socket insert. Emotional then the ball head due to decreasing inertial forces and the present tape tension back into the calotte of the socket insert into it, it comes mostly to the impulsive impact of the ball head on the Pfan neneinsatz. This can occur when hitting the side Range - almost tangential impact force - too microscopic material removal (so-called "stripe-wear") of the socket insert. at Impact in the Kalottengrund - almost vertical impact force - is even a macroscopic destruction the pan insert conceivable.

Of the Invention is based on the object, a hip joint prosthesis according to the preamble of claim 1 to improve so that always a sufficient bias in artificial Joint prevails.

According to the invention this Task solved by that the shaft or the shank neck and the acetabulum via elastic elements with each other coupled, wherein the elastic elements a bias voltage in the hip joint prosthesis build up. By coupling the shaft and hip socket by means of elastic Elements, the bias of the artificial joint is increased, without that the tape tension of the natural bands elevated must become. Furthermore can additionally an adaptation of the stress-strain curve of the elastic Elements can be made to the specific needs of each patient.

In an embodiment of the invention are the elastic elements have rubber-elastic bands, which at one end with the hip pan and connected to the shaft or the shank neck at the other end are. Preferably, the rubber elastic bands are silicone elastomers.

By rubbery elastic bands - e.g. Silicone elastomer, additional fabric reinforcement conceivable - which at one end with the Hüfpfanne and connected to the shaft at the other end, becomes a bias voltage on the artificial Joint applied. By cut the bands, e.g. double folding and sewing, as it is possible intraoperatively is, can be another increase the bias can be achieved.

In another embodiment the invention, the rubber elastic bands at both ends with the Hüfpfanne are connected and run in their middle area over one Point of support on the shaft or shaft neck. Through this rubber-elastic Ribbons - e.g. Silicone elastomers, additional tissue reinforcement conceivable - which at both ends with the Hüfpfanne are connected and in their central region via a support point on the shaft or Sheep neck run, a bias on the artificial Joint applied. The height the bias is dependent from the angle between the shanks of the neck and the acetabulum. Is the shank neck approximately perpendicular to the acetabular cup is the bias largest. ever further tipped the shaft neck starting from this middle position becomes, the more the bias decreases. Again, by shortening the bands e.g. double folding and sewing, as it is possible intraoperatively is, another increase the bias can be achieved.

In another inventive embodiment, the elastic members are a rubber-elastic cuff which encloses / encapsulates the artificial joint and is connected at one end to the Hüfpfanne and at the other end to the shaft or the shank neck. By a rubber-elastic cuff - for example, made of a silicone elastomer, additional tissue reinforcement conceivable - which encloses the artificial joint / encapsulates and at one end with the Hüfpfanne and the other Ren end is connected to the shaft, a bias is applied to the artificial joint. An increase in the bias by manipulating the cuff is difficult. However, a change in the bias can be achieved by changing the crosspoint on the shaft or stock neck.

As already mentioned, is by cut the bands or the cuff, e.g. by double folding and stitching, the Preload adjustable.

to Attachment of the elastic elements are preferred on the face of the Acetabulum and / or Fasteners are arranged on the shaft or the shaft neck.

These Fastening devices are for example hooks, fittings, Pins or projections.

following The prior art and the invention are based on figures explained in more detail.

1 shows the state of the art. A hip prosthesis usually consists of a shaft 1 coupled with a ball head 2 and a hip socket 4 coupled with a pan insert 3 , shaft 1 and acetabulum 4 are with the body of the patient by ingrowth in the thigh 20 or pelvic bone 21 connected and are carriers for the ball head 2 or pan insert 3 , The ball head 2 is in the dome of the pan insert 3 rotatably mounted.

2 shows a hip joint prosthesis according to the invention, in which unlike the hip joint prosthesis according to 1 elastic elements 5 build a preload in the hip joint prosthesis. The elastic elements 5 are for this purpose with one end on the shaft 1 and with her other end on the acetabulum 4 attached. The elastic elements 5 are designed so that they the shaft 1 or sheep neck 7 in the direction of the acetabulum 4 kraftbeaufschlagen. The number of elastic elements 5 should be selected according to requirements. There should be at least two elastic elements 5 be. In a preferred embodiment, there are three.

Same Reference numerals in the figures also refer to like objects.

3 shows a hip joint prosthesis with rubber elastic bands 6 with one end on the shaft 1 and with the other end on the acetabulum 4 are attached. Rubber elastic in this context means that the bands 6 exert a tensile force, ie the shaft 1 to the acetabulum 4 pull it out and do it permanently. The bands 6 should maintain their traction over the entire period of use of the hip joint prosthesis and show no fatigue during this period. These rubber-elastic bands are made of silicone elastomers and are thus harmless to the human body.

4 shows a hip joint prosthesis according to the invention, in which a rubber-elastic band 6 with both ends on the acetabulum 4 is attached and in its middle area over a support point 9 at the Schafthals 7 running. As a result, the shank neck 7 to the acetabulum 4 pulled out and thereby achieved the bias.

5 shows a hip joint prosthesis according to the invention, in which the elastic elements of a rubber-elastic cuff 10 which encloses or encapsulates the artificial joint and at one end with the Hüfpfanne 4 and at the other end with the shank neck 7 with a screw connection 12 is anchored.

In all the above embodiments is by shortening the bands 6 or the cuff 10 , eg by double folding and stitching, the preload adjustable.

For fastening the bands 6 or the cuff 10 are on the face 11 the acetabulum 4 and on the shaft 1 or the shank neck 7 Fasteners arranged. These attachment devices are, for example, support points 9 (please refer 4 ), Hooks, screw connections 12 (please refer 5 ), Pins or projections.

Claims (8)

Hip joint prosthesis with a shaft ( 1 ), on whose shank neck ( 7 ) a ball head ( 2 ), in turn, in the calotte of a socket insert ( 3 ) is rotatably mounted, and the socket insert ( 3 ) in a hip socket ( 4 ) is inserted, wherein the shaft ( 1 ) in the femurs ( 20 ) and the acetabulum ( 4 ) in the pelvic bones ( 21 ) are implantable, characterized in that the shaft ( 1 ) or the sheep neck ( 7 ) and the acetabulum ( 4 ) via elastic elements ( 5 ) are coupled together, wherein the elastic elements ( 5 ) build a preload in the acetabular prosthesis. Hip prosthesis according to claim 1, characterized in that the elastic elements ( 5 ) rubber elastic bands ( 6 ), which at one end with the Hüfpfanne ( 4 ) and at the other end with the shaft ( 1 ) or the sheep neck ( 7 ) are connected. Hip joint prosthesis according to claim 2, characterized in that the rubber-elastic bands ( 7 ) are made of silicone elastomer. Hip joint prosthesis according to claim 2 or 3, characterized in that the rubber-elastic bands ( 7 ) at both ends with the Hüfpfanne ( 4 ) and in its central region via a support point ( 9 ) on the shaft ( 1 ) or sheep neck ( 7 ) to run. Hip prosthesis according to claim 1, characterized in that the elastic elements ( 5 ) a rubber-elastic cuff ( 10 ), which encloses / encapsulates the artificial joint and at one end with the Hüfpfanne ( 4 ) and at the other end with the shaft ( 1 ) or the sheep neck ( 7 ) connected is. Hip joint prosthesis according to one of claims 2 to 5, characterized in that by shortening the bands ( 6 ) or the cuff ( 10 ), eg by double folding and sewing, the bias is adjustable. Hip joint prosthesis according to one of claims 1 to 6, characterized in that on the end face ( 11 ) of the acetabulum ( 4 ) and / or on the shaft ( 1 ) or the sheep neck ( 7 ) Fastening devices are arranged. Hip joint prosthesis according to claim 7, characterized in that the fastening devices support points ( 9 ), Hooks, fittings, pins or projections are.