DE10007615A1 - Implant for femur bone segments fractured due to osteoporosis, comprises a thin walled hollow reinforcement member made of a mesh formed into a tube. - Google Patents

Abstract

A prophylactic implant against fractures from the osteoporotic bone segment of the femur (2) is described. DOLLAR A It has a thin-walled hollow reinforcing body (1) made of a tube network formed into a tube with a curved course and of such a length that it passes through a medial opening (3) in the femur (2) below the trochanter minor (4) a bone canal (6) can be guided into the femoral neck (5) and can be fixed along the bone canal (6).

Description

The present invention relates to a prophylactic implant against fractures Osteoporotically affected bone segments of the femur.

A prophylaxis implant is known which is not only for use in Femur is provided from DE-C-196 52 608. It contains an implant described with an essentially cylindrical reinforcement body, which milled into the osteoporotic bone segment is set. The implant is hollow and its outer wall is one such condition that bone material enters the interior of the Reinforcing body can grow, but then free from the lack of osteoporotic bone material. This will structure and restores the stability of the affected bone.

In the case of use in the femur, especially in the femoral neck area, from laterally a bone canal was milled into the neck of the femur and then the implant introduced from the lateral. This already ensures permanent secondary fixation mentioned ingrowth of bone material inside the Reinforcement body.

With the known implant, it has now proven to be problematic Cut out the neck of the femur from the side since the bone canal is cut out in the femoral neck inevitably has the consequence that trapezoids in the lateral Area of the femur may be damaged, which may result in fatigue of the greater trochanter.  

Against this background, it is the object of the present invention Prophylaxis implant of the type mentioned, in which one lateral destruction of trapezoids in the femur during implantation is not takes place.

This task is solved by an implant with the characteristics of Claim 1 and alternatively of claim 3.

According to the first proposed solution, prophylaxis Implant a thin-walled hollow reinforcement body from one to one Pipe shaped lattice network with a curved course of such Length that it is from a medial opening in the femur below the Trochanter minors can be inserted into the femoral neck through a bone canal and is fixable along the bone canal.

The implant therefore has a strong curvature, similar to how a Round nail known for 35 years. However, a round nail is half open, so that organizing bone material is not possible. This stands however, the focus of the therapeutic mode of action of the implant according to the invention, which according to that of the known implant is similar to the above-mentioned document. However, the shape in the present case a completely different one than in the known case.

Because of the curvature, it is possible that the implant from medial is pushed into the bone canal to be prepared without the Trapezoids in the area of the greater trochanter would be impaired.

Operatively, the procedure is now such that below the trochanter minor of the cortex of the femur is opened medially and the bone canal opens is cleared to the femoral neck using a milling cutter. Then the Push the reinforcement body into the channel until its head part touches the  End of the bone channel in the femoral neck or inside the joint head strikes. Then, the medial openings of the corticostomy of the femur closed natural bone material.

It is particularly advantageous if the reinforcement body is made of body-compatible metal and sections of open mesh has three-dimensional spatial network structure on its surface. The the latter space network structure is known to serve to ensure that the surrounding bone material can grow through the structure and so an inhibitory effect against migration of the implant from the cutout exercises in the relevant bone segment of the femur.

The latter property resides in the implant according to the second Proposed solution from the outset: it has a hollow tube as Reinforcing body, the outer wall of which is formed from a open-mesh, three-dimensional spatial network structure and has one curved course on and is of such length that it is from a medial Opening in the femur below the trochanter minor through a bone canal can be guided into the femoral neck and can be fixed along the bone canal. This spatial network structure can - as already mentioned - bone material grow into the inside of the sleeve from the outside.

The implants of both proposed solutions can thereby be advantageous be further developed that the reinforcing body consists of a sleeve which is closed proximally with a tapered head part. This The head section is not particularly spherical, as is the case with the implant is the case according to the prior art. Rather, the rejuvenation of the Head part of the easy insertion of the implant into the bone canal.

In particular, the implant according to the first proposed solution is on one Immigration prevented from the milling by a closure body, which the  The reinforcement body is closed distally by opening it in its open distal End is set, with the closure body on its outer edge with a resilient fan ring with a compared to the diameter of the Reinforcing body is provided with a larger diameter that during implantation of the reinforcement body is partially compressed and at one Movement tendency of the reinforcement body in the opposite direction the direction of insertion during implantation and thus the Counteracts movement tendency. Through the spreading fan wreath the reinforcement body in the bone canal is sufficient fixed. This type of definition can also be used advantageously in the case of the implant according to the second proposed solution, as long as namely, no bone material has grown into the reinforcement body is.

The ingrowth of bone material can be done by coating the Outer wall of the reinforcement body with one that is absorbable by the body Funds are accelerated. Hydroxyapatite, for example, comes as an agent or an alpha tricalcium phosphate ceramic.

The reinforcing body as a whole can, moreover, with hydroxyapatite, one alpha-tricalcium phosphate ceramic or a mixture thereof with the one before milled cancellous bone serve to close the sleeve. This too the process of organizing bone material into the interior of the Reinforcement body clearly stimulated.

The invention is based on an embodiment according to the Drawing figure explained in more detail. The only drawing figure shows schematically a section through a femur with inserted in a bone canal Prophylaxis implant.  

The prophylaxis implant is generally provided with the reference number 1 . This is strongly curved in the manner of a round nail, so that it can be guided from a medial opening 3 in the femur 2 below the trochanter minor 4 to the femoral neck 5 . In this exemplary embodiment, the reinforcement body 1 consists of a grid network shaped into a tube, such as a metal network. Proximally, the reinforcement body 1 is closed with a conically tapering head part 7 . The latter is shaped in such a way that the implant can be guided into the femur 2 as easily as possible.

The reinforcement body 1 has a closure body 8 distally. This has a resilient fan ring 9 in its outer edge. This is slightly compressed during implantation, but expands out of the bone channel 6 when the reinforcing body 1 tends to move and counteracts the movement tendency.

In the present case, the opening 3 in the cortex of the femur 2 is closed with bone material 10 which has previously been cleared from the bone canal.

The operation required for the implantation is very simple and largely unencumbering for the patient. Total surgery times approx. 15 minutes can be reached. This is another major advantage compared to known implants.

Claims (8)

1. Prophylaxis implant against fractures of osteoporotically affected bone segments of the femur ( 2 ), comprising a thin-walled, hollow reinforcement body ( 1 ) made of a tube network shaped into a tube with a curved course and of such length that it extends from a medial opening ( 3 ) in the Femur ( 2 ) below the trochanter minor ( 4 ) can be guided through a bone canal ( 6 ) into the femoral neck ( 5 ) and can be fixed along the bone canal ( 6 ). 2. Prophylaxis implant according to claim 1, wherein the reinforcing body ( 1 ) consists of body-compatible metal and in sections has an open-mesh, three-dimensional network structure on its surface. 3. Prophylaxis implant against fractures of osteoporotically affected bone segments of the femur ( 2 ), having a hollow tube as a reinforcing body ( 1 ), the outer wall of which is formed from an open-mesh, three-dimensional network structure, with a curved course and of such length that it is medial Opening ( 3 ) in the femur ( 2 ) below the tranchanter minor ( 4 ) through a bone channel ( 6 ) in the femoral neck ( 5 ) and can be fixed along the bone channel ( 6 ). 4. Prophylaxis implant according to one of claims 1 to 3, wherein the reinforcing body ( 1 ) consists of a sleeve which is closed proximally with a tapered head part ( 7 ). 5. Prophylactic implant according to claim 4, wherein the reinforcing body (1) is distal, closed by a closure body (8) which can be placed in the open distal end of the sheath (1), said closure body (8) externally applied to its Edge is provided with a resilient fan collar ( 9 ) with a larger diameter than the diameter of the reinforcement body ( 8 ), which is partially compressed when the reinforcement body is implanted and which, when the reinforcement body ( 1 ) tends to move, in the opposite direction to the insertion direction during implantation spreads out and thus counteracts the tendency to move. 6. Prophylaxis implant according to one of claims 1 to 5, in which the Outer wall coated with a body-resorbable agent is. 7. The prophylaxis implant according to claim 6, wherein the agent is hydroxyl is apatite. 8. The prophylaxis implant according to claim 6, wherein the agent consists of a Alpha tricalcium phosphate ceramic exists.