DE10056698A1 - Method and appliance consist of adapter with markings, conical shaft, or endoprosthesis - Google Patents

Abstract

A unit consisting of an adapter (5) with markings (7) and insertion ball is placed on the conical shaft (3) of the inserted endoprosthesis. The end position of the unit is obtained by turning the adapter. The required position of the unit, obtained by setting the CCD angle, is transferred as a mark (8) on the shaft (2) of the endoprosthesis.

Description

The invention relates to a method and device for determining the End positions when implanting endoprostheses, in particular also when replacing parts of a hip endoprosthesis system Hip revisions, including a trial adapter with an eccentric inner cone and the extent of the existing degree scale on the taper shank of the used Endoprosthesis is brought, an appropriate on the trial adapter Test ball is placed, the ball is engaged with the pan that Surgeon adjusting the end position by turning the trial adapter CCD angle and neck length compensation determines this position of the Trial adapter by transferring a mark from the degree scale to the Shaft of the endoprosthesis, trial adapter with trial ball removed Ball and adapter with the same scale on the Scope so that a certain mark matches of the adapter with the marking on the shaft.

In the case of hip joint revisions, the replacement of the is particularly available First aid necessary, the plug head or ball from the metal cone of an implanted shaft of an endoprosthesis and removed subsequent reconstruction with a simultaneous correction setting of the CCD angle and neck length compensation must be done. In doing so, a Adapter with an eccentric inner cone on the metal cone of the shaft of the remaining endoprosthesis and placed on the outer cone of the adapter becomes a new plug head, usually a ceramic ball, with the same inner cone how the outer cone of the adapter is set. Under no circumstances may the Adapter with the ball already has a fixed cone connection with the shaft of the Enter the endoprosthesis. The surgeon determines the by rotating the adapter required and desired correction setting of the CCD angle. Often, by inserting the ball into the pan, one becomes already very intensive but undesirable connection between the cones found so that only with much effort and effort the surgeon Can twist and determine the best CCD angle.

An endoprosthesis system is known in which the upper edge of the shaft the endoprosthesis has a toothing, via which an adapter with which Articulated ball, can be brought with an internal toothing. If the adapter is now rotated, there is a certain locked position of  Adapter and ball head attached to it. The disadvantage here is that the Surgeon only against the resistance and the tooth height of the adapter can twist so that it has to work in the direction of the neck length compensation. Also an identification of the position of the adapter to the shaft of the Endoprosthesis is not available here.

EP 0423 303 is a modular hip joint prosthesis with an adjustable one Articulated head is known, with the final cementing of the articular head the femoral shaft is first attached, this is a first conical receptacle has, into which a pin with a marking can be inserted, which serves the to determine the subsequent position of the joint head temporarily, using a sectoral scale on the neck support of the joint head. So that too at the same time the position of the milling cutter is determined, which the medullary cavity for receiving which clears out under the enlarged joint head. A stepless determination of the CCD angle and an eccentric adapter to accommodate the joint balls are not shown or are included here.

Accordingly, the object of the invention is a method and corresponding means for simply determining the position of the ball heads on the CCD angle during hip surgery to indicate the To help the surgeon, with the help of known swivel sleeves or eccentric adapter the right valgus / varus or antetorsion / retro to find torsion.

To achieve this object, a method and an apparatus for Determining the end positions of ball heads when implanting Endoprostheses proposed, using a trial adapter with eccentric Inner cone and on the circumference of the existing degree scale on the cone shaft of the inserted endoprosthesis is placed on the trial adapter appropriate test ball is placed, the ball engages with the pan the surgeon is brought to the end position by turning the trial adapter determines the setting of the CCD angle and neck length compensation, this position of the sample adapter by transferring a mark from the Degree scale on the shaft of the endoprosthesis, trial adapter with Test ball removed, the ball and adapter intended to remain with uses the same degree scale on the circumference in such a way that a match of a specific marking of the adapter with the marking on the shaft given is.

For this purpose, the operator is provided with inexpensive test adapters during manufacture given the appropriate size and test heads, the Trial adapter a scale engraved with numbers in the lower area of the circumference Has letters or other representations, so that the surgeon after the Determination of the final position of the ball head at will Marks the adapter on the shaft of the endoprosthesis.  

Then the test adapter and test ball are removed and through the to permanent whereabouts of certain parts are replaced.

This procedure is now very simple, especially for revisions to use advantageously.

Further advantages result from the following description of a Embodiment and are explained in more detail with reference to the drawing.

It shows:

Fig. 1 a shaft of an endoprosthesis with a perspective view of a mock sample adapter and ball head,

Fig. 2 shows the final eccentric adapter with the indicated ball head.

Fig. 1 shows first the proximal part of a possible wise implanted endoprosthesis 1, which need not be shown in detail. The receiving cone 3 sits on the shaft 2 , ready for receiving a spherical head, a straight adapter or an eccentric adapter. A test adapter 5 with an eccentric inner cone 6 is also shown . While the inner cone 6 runs along the axis 10 , ie in the direction of the CCD angle, the actual central axis 11 of the sample adapter 5 is shown in the maximum position valgus. On the lower edge of the sample adapter 5 there is a scale 7 engraved with numbers or applied in some other way. Letters or other different symbols can also be used.

A test ball head 20 is indicated by dash-dotted lines on the test adapter 5 .

During a revision of an existing hip joint endoprosthesis, for example, the surgeon removed the previous ball head and found that he had to make both the position of the ball head at a CCD angle and a greater distance, that is to say neck length compensation. He determines an adapter with an eccentric inner cone and a certain length for neck length compensation. In order to determine the final position of the ball head, he takes the corresponding test adapter 5 with test ball head 20 for the selected adapter of a certain size and identifier and places it on the cone 3 . After connecting to the pan, the surgeon can turn the trial adapter until he determines the desired and required position of the ball head. In this position, a marking 8 is made on the shaft 2 for a specific number, for example the number 12 on the trial adapter, if the endoprosthesis 1 used does not yet have a fixed marking. In any case, it is within the scope of this invention that two opposing markings 8 are present on an endoprosthesis below the cone 3 . These can be attached or attached directly to the neck during the manufacture of the endoprostheses by etching or applying paint.

Subsequently, the sample adapter 5 and ball head 20 are removed and the final adapter 14 , as shown in FIG. 2, is placed on the cone 3 together with the ball head 30 to be implanted, the number "12" now being identical with the scale of the sample adapter on the scale 15 of the adapter 14 with the mark 8 on the shaft 2 is made to coincide.

So the two inner cones 6 of the trial adapter 5 and the adapter 14 to be implanted match the respective scales 7 and 15 .

In the case of the adapter 14 to be implanted, usually made of an implant material such as titanium, the scale 15 is attached to the front side around the entrance of the inner cone 6 in order to be able to hit the set mark 8 more precisely.

The scales 7 and 15 are preferably provided with numbers from 1 to 12 like a clock, with a finer subdivision also possible. The test adapter 5 and the test ball head 20 are preferably made of a clinically safe material, for example plastic, and are held in a warning color, for example red. In addition, on the circumference of the test adapter 5 and on the test ball head 20 there are warnings 9 several times on the circumference, e.g. B. "NO IMPLANT" available.

Claims (10)

1. A method for determining the end positions when implanting or revising endoprostheses, characterized in that a trial unit ( 40 ) consisting of trial adapter ( 5 ) with existing markings ( 7 ) and trial plug-in ball ( 20 ) on the conical shaft ( 3 ) of the inserted endoprosthesis ( 1 ) is brought, the operator determines the end position of the sample unit ( 40 ) by rotating the sample adapter ( 5 ), the required position of the sample unit ( 40 ) for setting the CCD angle, this position of the sample unit ( 40 ) by transferring one of the markings of the Degree scale ( 7 ) as a mark ( 8 ) on the shaft ( 2 ) of the endoprosthesis ( 1 ), the sample unit ( 40 ) removed, the plug-in ball ( 30 ) and adapter ( 14 ) with the same degree scale ( 15 ) on the circumference intended to remain so that there is a match with the previously determined marking on the adapter ( 7 ) with the marking ( 8 ) on the shaft ( 2 ). 2. Device for determining the end positions when implanting or revising endoprostheses, characterized in that adapters ( 14 ), trial adapter ( 5 ) and the endoprosthesis ( 1 ) carry markings ( 7 , 8 , 15 ). 3. Device according to claim 2, characterized in that the adapter ( 14 ) and the sample adapter ( 5 ) carry identical markings ( 7 , 15 ), the markings ( 7 , 15 ) always having a specific position for the position of the inner cone ( 6 ) take in. 4. The device according to claim 2, characterized in that the markings ( 7 , 15 ) on the adapter ( 14 ) and trial adapter ( 5 ) are scales with lines and numbers. 5. The device according to claim 2, characterized in that the scales ( 7 , 15 ) consist of lines with letters or other symbols. 6. The device according to claim 2, characterized in that the adapter ( 14 ) carries a scale ( 15 ) on its front or underside. 7. The device according to claim 2, characterized in that the sample adapter ( 5 ) carries a scale ( 7 ) on the circumference of the outer cone. 8. The device according to claim 2, characterized in that the sample unit ( 40 ) consisting of sample adapter ( 5 ) and test plug ball ( 20 ) are made of plastic in a warning color. 9. The device according to claim 2, characterized in that on the sample adapter ( 5 ) and test plug ball ( 20 ) warning notices ( 9 ) are attached. 10. The device according to claim 2, characterized in that the endoprosthesis ( 1 ) carries at least two opposite markings ( 8 ).