DE4320086C3 - Modular shaft for a revision hip prosthesis system - Google Patents

Description

The invention is directed to a shaft for a revision hip prosthesis system comprising a ver anchoring section, a lengthening the anchoring section cut and an angled joint ball section for attaching the Articulated ball, with a continuous longitudinal bore being provided in the one from the joint ball section into the anchorage section Cut-reaching locking screw can be used, the longitudinal boh tion at least in the area of the anchoring section as a threaded hole tion is formed, and wherein the connecting portion at least partially as can be plugged into one another by a plurality of cone sections Sleeve elements is formed, which also have a longitudinal bore.

A comparable shaft is from DE 32 05 577 C3 known. The previously known shaft has elements which are called extension pieces and at one end a conical plug and a conical socket at its other end have, which in corresponding receptacles cuts or spigot sections of neighboring ele elements can be used in such a way that a self-locking Connection arises.

By designing the connector as itself simple assembly is to be achieved in an inhibiting manner. It is stated there that the self-locking Ko nut connection against a sufficiently firm holding force produce a moving apart of the parts, whereby to which a considerable torque are transmitted could. Furthermore, the cone connection in the case a reoperation can be easily solved.

To achieve optimal longitudinal stability and for intraoperative handling is itself such inhibitory connection, however, is not satisfactory.

DE 89 11 046 U1 also has a modular structure ter shaft known, whereby to connect the individual Elements, on the one hand, also have a cone section te on the elements to be connected and on one clamping sleeve that can be slid on are provided, with the elements to be connected in addition but also in the direction perpendicular to the longitudinal axis be pushed into each other conclusively. This verb Manure technology is also very difficult intraoperatively manageable.

DE 33 36 004 C2 also describes a ver extendable shaft or an adapter, whereby cone parts held together by cylindrical sleeves and a screw connection perpendicular to the longitudinal axis of the elements to achieve an axially fixed connection are provided.

In the cone provided from DE 40 31 520 A1 connection, a cone is designed as an expansion cone, the with the help of an axially inserted from above spread screw is expandable and thus fixable. The before known solution, however, only allows a security a single cone connection and not more re such connections one completely modular assembled shaft.

EP 0 368 488 A1 describes a cone connection described for the axial connection to the cone section has a bolt approach that in a ent speaking recess on the bottom of the Konusausneh mung into place.

Another conical connection is known from EP 0 290 735 dung known, which by means of a nose as Verdrehsi Security is designed.

A generic shaft is from the EP 0 243 298 A2 is known. With this previously known To do this, an axially extending screw is used turns to tighten an end wedge in the axial direction, to thereby push expansion parts outwards and to brace it in the bone hole. It will with the screw a radial expansion of the lower end attached spreading parts accomplished.

Based on this known prior art the invention has for its object a shaft of the type mentioned in such a way that he from a practically arbitrary number of relatively small el elements can be assembled, in particular one free, individually adjusted setting of the Antetor sions angle should be possible.

This object is achieved in that in the area of Joint ball section a recessed ring shoulder as an axial system for a head of the locking screw is designed to by tightening the Locking screw the sleeve elements after positioning them to brace against each other, being in the joint ball section and threaded bore sections are provided in the sleeves.

This configuration makes it possible to use Form a plurality of mutually identical hull optimal length adjustment of the Pro to realize the thesis, even before the Operation the individual elements to try the optimal configuration can be plugged together and the elements during the operation are then clearly arranged pre-assembled on the usual way the sieve can lie.

The configuration according to the invention enables that the surgeon chose the revision prosthesis socket Adjust the bone conditions during the operation can d. H. it can anchor sections to Healing provided in different diameters become. The prosthesis length can be adjusted to the leg length with the help of sleeves of different lengths elements are specified without this Strength such as B. with a self-locking cone connection, is lost. With implanted prothe The surgeon has the option of ante Determine torsion afterwards. This is especially the case half meaning because it would otherwise be inflated Rotational forces can come that change burden the situation additionally. It is according to the invention easily possible, the anti-torsion the original adapt to certain conditions.

In addition to a simple assembly of the prothe senschaftes enables the solution according to the invention also a simple disassembly because by loosening the central locking screw at the same time all conn solutions and not self-locking Clamp connections using separate tools have to be solved. Accordingly, the Revision prosthesis can be changed easily without that above all additional bone defects arise would. The prosthesis can be removed as a whole or also partially, d. H. one sleeve or several sleeves sen, as required. According to the invention, no need to be separate second lock nut for the locking screw be provided and the axial bracing and Ver bind all sleeve elements including the joint spherical section and the anchoring section can cut through this thread section hand and the attachment of the head of the locking screw on the other hand.  

In summary, the invention So solution, the prosthesis first unfixed together plugged in so that they are the required size integrated as a kind of trial implant for review can and if the selected size fits proves send, fixation can then take place in situ, so that the trial implant also the final implant.

In a further embodiment of the invention, it is provided hen that the sleeve element is permitted so that when plugged together an approximately cylindrical Lateral surface results.

According to the invention, the top one can be used Sleeve element joint ball sections with difference Put on the bend (CCD angle). So that is optimal adjustment of the CCD angle possible. Furthermore, the joint ball section can be relative to Shaft after its implantation by twisting in optimally set and the set ante torsion angle fixed with the locking screw the.

The joint ball section can have a cone have cut on which the joint ball with egg ner corresponding conical hole can be placed.

Another embodiment of the invention results from subclaim 5.

The invention is based on a before drafted embodiment in connection with the Drawing shown. Show:

Fig. 1 is a view of a Revi invention sionshüftprothesen-shaft in the configuration accordingly a first size,

Fig. 2 is a Fig. 1 representation corresponding to a larger configuration,

Fig. 3 is a sectional view of the configuration of FIG. 1 in the exploded state and

Fig. 4 shows a section along the line IV-IV in Fig. 3.

A shown in the drawing revision hip prosthesis shaft 1 comprises an anchoring section 2 and a cranked joint ball section 3 and an extension section 4 of the anchoring section 2 which is composed of two sleeve elements 5 and 5 '. These sleeve elements 5 and 5 'differ by a different axial length, a sleeve element 5 being used in the embodiment according to FIG. 3, while in the embodiment according to FIG. 1, a sleeve element 5 and a sleeve element 5 'are combined.

The individual elements of the modular prosthesis are connected via cone sections, ie cone extensions 6 and cone recesses 7 .

In the exemplary embodiment, the Varankerungsab section 2 has a cone pin 6 and the joint ball section 3 has a cone recess 7 .

Each sleeve element 5 or 5 'also has a cone recess 7 and a cone section 6 which is tapered relative to the outer surface 8 to form an annular shoulder 9 such that in the assembled state (see FIGS . 1 and 3) the Mantelflä surface 8 is substantially cylindrical.

The sleeves 5 , 5 'and the joint ball section 3 white sen a longitudinal bore 10 with a longitudinal axis 11 . The anchoring section 2 is provided with a threaded bore 10 b. In the sleeve elements 5 , 5 'longitudinal bore sections 10 c are provided with an internal thread. A corresponding threaded bore section 10 d is also formed in the joint ball section 3 . At the extreme end of this section 10 d, an annular shoulder 16 is provided, to which a section 10 e connects.

In the section 10 e, a locking screw 12 can be inserted, the head 13 comes to rest against the ring shoulder 16 and the distal end engages in the threaded section 10 b, so that the individual parts are transferred into the clamped state by tightening this locking screw can.

By selecting a suitable joint ball section 3 , the angle can be optimally adapted to the specific circumstances, it being possible to cut and adjust the joint ball section 3 around the longitudinal axis 11 when the anchoring section 2 is implanted.

The anchoring section 2 has on its outer side longitudinal ribs 14 which extend radially outwards, as can be seen in particular in Fig. 4 and which serve to achieve a most anchoring.

In the exemplary embodiment, a titanium alloy is used as the material. On the joint ball section 3 , a fine 15 can be plugged in if necessary, which can be kept in stock in different sizes. This fine 15 can be rotated about the longitudinal axis 11 and thus approach the split greater trochanter regardless of the antetorsion angle. The Fine 15 is secured by a screw 17 .

Claims (5)

1. Shaft for a revision hip prosthesis system comprising an anchoring section ( 2 ) which can be driven into the thigh bone, a section which extends the anchoring section ( 2 ) and an angled joint ball section ( 3 ) for fitting the joint ball, a continuous longitudinal bore ( 10 ) being provided in the from the joint ball section ( 3 ) a locking screw ( 12 ) extending into the anchoring section ( 2 ) can be inserted, the longitudinal bore ( 10 ) at least in the area of the anchoring section ( 2 ) being designed as a threaded bore, and the connecting section at least is partly formed by a plurality of conical sections ( 6 or 7 ) of interlocking sleeve elements ( 5 , 5 '), which also have a longitudinal bore ( 10 ), characterized in that in the region of the joint ball section ( 3 ) a recessed annular shoulder ( 16 ) as an axial system for a head ( 13 ) of the fuse gsScrew ( 12 ) is designed to tighten the sleeve elements ( 5 , 5 ') after positioning the same against each other by tightening the securing screw ( 12 ), wherein in the joint ball section ( 3 ) and in the sleeves ( 5 , 5 ' ) Threaded bore sections ( 10 d or 10 c) are provided. 2. Shank according to claim 1, characterized in that each sleeve element ( 5 , 5 ') is designed so that there is an approximately cylindrical outer surface ( 8 ) when assembling. 3. Shank according to claim 1, characterized in that joint ball sections ( 3 ) can be placed with different cranking. 4. Shank according to claim 1, characterized in that the joint ball section ( 3 ) has a cone section for fitting the conical bore of the joint ball. 5. Shank according to claim 1, characterized in that a fine ( 15 ) on the joint ball section ( 3 ) can be plugged in and fixed by a screw ( 17 ).