DE4320086C2 - Modular shaft for a revision hip prosthesis system - Google Patents

Description

The invention relates to a shaft for an inspection hip prosthesis system comprising an insertable into the thigh bone Ren anchoring section, extend the anchoring section the section and an angled joint ball section for placement the joint ball, a continuous longitudinal bore being provided, into the one from the joint ball section up to the anchoring section Cut-reaching locking screw can be used, and the longitudinal bore at least in the area of the anchoring section as a thread bore is formed.

A comparable shaft is known from DE 32 05 577 C3. The before known shaft has elements which be as extension pieces be drawn and at one end a conical plug and have a conical socket at its other end, which in Corresponding socket sections or socket sections be neighboring elements can be used in such a way that a self-locking Ver bond arises.

By designing the connector as self-locking one easy assembly can be achieved. It is stated there that the self-locking cone connection against a sufficiently strong holding force produce a moving apart of the parts, which is also a considerable Torque can be transmitted. Furthermore, the cone connection in the event of a reoperation can be easily resolved.  

To achieve optimal longitudinal stability and for intraoperative Such a self-locking connection is not too easy to handle peaceful.

A modular shaft is also known from DE 89 11 046 U1, wherein to connect the individual elements on the one hand also Ko Nut sections on the elements to be connected and on one clamping slide-on holding sleeve are provided, the ones to be connected Elements also in the direction perpendicular to the longitudinal axis be positively pushed into one another. This connection technique is also very difficult to handle intraoperatively.

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

In the cone connection provided by DE 40 31 520 A1 there is a Cone designed as an expansion cone, which is axially from above inserted spreading screw is spread and thus fixable. The previously known solution, however, only allows a backup of one gene cone connection and not several such connections one completely modular shaft.

EP 0 368 488 A1 describes a cone connection which is used for axial connection on the cone section has a stud attachment, in a corresponding recess at the bottom of the cone recess snaps into place.

Another cone connection is known from EP 0 290 735, which is designed to prevent rotation by means of a nose.

A generic shaft is known from EP 0 243 298 A2. At this previously known shaft is an axially extending screw used to tighten an end wedge in the axial direction to thereby  To push expansion parts outwards and thus in the bone hole tense. With the screw there is a radial expansion of the Spread parts attached at the lower end accomplished.

The invention is based on this known prior art based on the task of designing a shaft of the type mentioned at the beginning shape that he from a practically arbitrary number of relatively small Ele elements can be put together, in particular a free, individual suitable setting of the anti-torsion angle should be possible.

This object is achieved in that the verb section at least partially by a plurality of cones cuts interlocking sleeve elements is formed, which also have a longitudinal bore, in the region of the joint ball section a countersunk ring shoulder as an axial contact for a head of the Siche is designed to by tightening the locking screw ver the sleeve elements after positioning them against each other tighten.

This configuration makes it possible to use a plurality of optimal sleeve length adjustment of the same sleeve elements To realize prosthesis shaft, the one before the operation individual elements to try out the optimal configuration are pluggable and the elements during the operation are then clearer Can be pre-assembled on the commonly used sieve.

The configuration according to the invention enables the operator to Revision prosthesis stem during surgery of the bone conditions can adjust, d. H. anchoring sections can be healed in different diameters can be provided. The prosthesis length can in coordination with the leg length with the help of different lengths of sleeve Senelemente be specified, without thereby the strength, such as e.g. B. in a self-locking cone connection is lost. At im Planned prosthesis socket, the surgeon has the option of Determine tetorsion afterwards. This is especially from Be interpretation, because otherwise excessive rotational forces can occur,  that put additional strain on the change situation. It is according to the invention easily possible, the antetorsion to the original conditions to fit.

In addition to a simple assembly of the prosthetic socket, the solution according to the invention also a simple disassembly, since the Lö the central locking screw all connections loosened at the same time and no self-locking clamp connections with the help of special tools must be solved. The Revi is accordingly sions prosthesis replacement possible without any additional Bone defects would arise. The prosthesis can be removed as a whole become or even partially, d. H. one sleeve or several sleeves, depending on Requirement. According to the invention, no separate lock nut for the Locking screw are provided and the axial bracing and Connect all sleeve elements including the joint ball side Section and the anchoring section can be threaded through this section on the one hand and the installation of the head of the locking screw on the other hand.

In summary, the solution according to the invention thus enables the To put the prosthesis together unfixed, so that it can be size as a trial implant for review can and, if the selected size turns out to be suitable, can then fix in situ so that the trial implant is the same the final implant is timely.

In a further embodiment of the invention it is provided that the sleeve Element is designed so that when plugging together an approximately zylin deriform surface results.

According to the invention, the uppermost sleeve element Ge Steering ball sections with different offset (CCD angle) put. This enables an optimal setting of the CCD angle. Wei terhin the joint ball section relative to the shaft after its Im plantation by twisting in an optimal way and the turned on provided anti-torsion angles can be fixed with the locking screw.  

The joint ball section can have a cone section on which Chen the joint ball can be placed with a corresponding conical hole is.

A further embodiment of the invention results from subclaim 5.

In the following the invention is illustrated by a preferred embodiment shown in connection with the drawing. Show:

Fig. 1 is a view of an inventive Revisionshüftprothesen sheep tes in the configuration according to a first size,

Tion Fig. 2 is a Fig. 1 of an configura larger,

Fig. 3 is a sectional view of the configuration of FIG. 1 in the pulled 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, wherein a sleeve element 5 is used in the embodiment of FIG. 3, while a sleeve element 5 and a sleeve element 5 in the embodiment of FIG. 1 '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 anchoring section 2 has a cone 6 and the joint ball section 3 has a cone recess 7 .

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

The sleeves 5 , 5 'and the joint ball section 3 have 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 on the annular shoulder 16 and the distal end engages in the threaded portion 10 b, so that the individual parts can be transferred into the clamped state by tightening this locking screw.

By selecting a suitable joint ball section 3 , the angle of the win can be optimally adapted to the specific circumstances, and it is also possible to twist the joint ball section 3 about the longitudinal axis 11 in the anchored anchoring section 2 and to adjust it.

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

In the exemplary embodiment, a titanium alloy is used as the material. If clinically necessary, a fine 15 can be plugged onto the joint ball section 3 , 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 trochanter major independently of the ante torsion angle. The Fine 15 is secured by a screw 17 ge.

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 th joint ball section ( 3 ) for fitting the joint ball, a continuous longitudinal bore ( 10 ) being provided in the from the joint ball section ( 3 ) forth into the anchoring section ( 2 ) reaching locking screw ( 12 ) can be inserted, and wherein the Längsboh tion ( 10 ) at least in the area of the anchoring section ( 2 ) is designed as a threaded bore, characterized in that the connec tion section is at least partially formed by a plurality of Konusab sections ( 6 and 7 ) nested sleeve elements ( 5 , 5 '), which also have a longitudinal bore ( 10 ), a recessed in the region of the joint ball section ( 3 ) Ring shoulder ( 16 ) as an axial contact for a head ( 13 ) of the safe is formed ungsschraube (12) to clamp by tightening the locking screw (12), the sleeve elements (5, 5 ') by positioning the same against each other. 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 articulated Kugelkugelab sections ( 3 ) can be placed with different offset. 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 ).