DE19704577B4 - Handling instrument of joint components with joint surfaces - Google Patents

Abstract

handling instrument for joint components with joint surfaces with a grip part and a suction element arranged at the end, which is a self-contained, to the articular surface of the Joint component sealing applied and with this articular surface thereby a sealed suction chamber forming sealing element and a Having the pressure in the suction chamber lowering device, characterized characterized in that Suction chamber (8) with a piston-cylinder unit (9, 11) is, in which a cylinder (9) sealed displaceable piston (11) a suction chamber (14) divides, whose volume according to the position of the piston (11) in the cylinder (9) is variable, and that the piston-cylinder unit (9, 11) in the handle part (5) is arranged.

Description

The The invention relates to a handling instrument for joint components with joint surfaces a gripping part and a suction element arranged at the end, which is a self-contained, to the articular surface of the Joint component sealing applied and with this articular surface thereby a sealed suction chamber forming sealing element and a Having the pressure in the suction chamber lowering device.

At the Insertion of artificial Joints, for example of hip joints, have to with a generally spherical joint surface provided joint inserts in joint sockets are used, which in turn are anchored in the bone. The Insertion takes place, inter alia, in an interference fit, and for this it is necessary that the joint operations be accurately oriented when inserted relative to the sockets, to prevent tilting.

It is known at the joint inserts Provide devices to which such handling instruments can attack for example, by positive engagement or by a frictional engagement. So can such handling instruments screwed into threaded recesses become.

Indeed is necessary with all these known handling instruments, the joint inserts with appropriate attack devices for the handling instruments equip. This complicates the construction of the joint inserts and in some cases also leads to spatial Difficulties as a place for such attack devices is not always available.

These Problems arise not only when inserting joint inserts, but Generally when handling joint components with articular surfaces. there it can also be spherical Rod ends act, which must be plugged for example on Steckkonen. Also handling them is difficult, there is a risk that the very precisely machined joint surface Handling damaged becomes.

In the US 3,859,992 a handling instrument for joint components is described, in which a provided with an O-ring suction head is suckling against the inside of a joint component can be applied. This results in a gentle treatment of the joint component, however, in the known device complicated pipe connections for connection to a suction source are necessary, which complicate the handling.

It Object of the invention, a generic handling instrument so to design it with the desired Accuracy is manageable, especially without obstruction by complicated Suction connections.

These Task is in a handling instrument of the type described above Type according to the invention thereby solved, that the Suction chamber is connected to a piston-cylinder unit, in a piston which is displaceable in the cylinder and which can be displaced in a suction space divides, whose volume according to the position of the piston in Cylinder changeable is, and that that Piston-cylinder unit in Handle is arranged.

By This embodiment is a completely independent handling device created in which can be dispensed with complicated additional devices who can, because the vacuum pump to generate the negative pressure in the handle itself is arranged. The training as a piston-cylinder unit is here particularly advantageous because such a configuration is a very simple has constructive design and requires little space.

The Sealing element can be designed in different ways, it This may, for example, be an elastomeric ring or around a cylindrical pipe section made of elastically deformable material. It is particularly advantageous if the sealing element has a sealing edge in the form of a self-contained, outward has protruding, flexible sealing lip. Like a suction cup This sealing lip attaches to the joint surface and ensures a secure closure of Suction chamber.

It can be provided that the Suction chamber over a lockable Ventilation opening with the Environment communicates. This makes it possible to control the pressure in the suction chamber deliberately to increase and thereby the connection between the handling instrument and the joint component to solve.

It is advantageous if the piston by a spring in an end position is displaceable, in which the volume of the suction chamber is maximum, this corresponds to the holding position, as in this position the Pressure in the suction chamber is minimal.

It is advantageous if the piston carries a projecting out of the cylinder actuating handle, so that the pressure change in the suction chamber by an operator by displacement of this operating handle can be accepted. In particular, the piston-cylinder Ag be arranged in the handle part.

The following description of preferred embodiments of the invention used in conjunction with the drawings for further explanation. Show it:

1 a longitudinal sectional view through a joint socket and held on a manipulating instrument hinge insert in a simplified handling instrument with suction cup;

2 a longitudinal sectional view through a joint socket, a joint insert and a handling instrument with piston-cylinder unit before attaching the handling instrument to the hinge insert;

3 a longitudinal sectional view of the piston-cylinder unit of 2 when attaching to a joint insert;

4 : a view similar 3 with sucked handling instrument;

5 : a view similar 4 in a handling instrument with a pipe-shaped sealing element and

6 : a view similar 4 with an O-ring-shaped sealing element.

The Invention will be explained below using the example of a joint insert, the can be inserted into a socket. It goes without saying, that the Invention also used to handle other joint components which can be a joint surface have, for example, spherical prosthesis heads.

The handling instrument shown in the drawing serves to handle a joint insert 1 , which may for example consist of low density polyethylene and a hemispherical joint surface 2 having. Such a hinge insert 1 becomes when implanting an artificial joint in a hemispherical socket 3 used, which in turn is anchored in the bone. The insertion can be done by screwing, but in many cases by a self-locking Konuspassung, in which the slightly tapered outside hinge insert 1 in a complementary recess of the socket 3 is pressed.

Before inserting the hinge insert, it is also often necessary to insert trial pivot inserts into the socket 3 to check their location. These articulated inserts must then each be removed from the socket again, and also for insertion and removal of these trial joint inserts such a handling instrument is needed.

In 1 is to explain the function of a handling instrument 4 a simplified embodiment of a handling instrument 4 which, however, does not produce the vacuum necessary for the function in the same way as a handling instrument according to the invention. This embodiment is therefore merely an explanation of the principle of operation.

The handling instrument 4 according to 1 comprises a cylindrical handle part 5 , on one end of which is a suction cup 6 is arranged made of flexible material, for example made of silicone. This sucker 6 has an obliquely outwardly projecting, self-contained sealing lip 7 on, which is a downwardly open suction chamber 8th encloses. For establishing a connection between the handling instrument 4 and the hinge insert 1 becomes the sealing lip 7 to the articular surface 2 of the joint insert 1 created so that the suction chamber 8th is sealed to the outside. By further approach of the handling instrument 4 to the articular surface 2 will continue under deformation of the sealing lip 7 the volume of the suction chamber 8th initially reduced, but then this approach is canceled, so that the volume of the suction chamber 8th increased by the inherent elasticity of the suction cup material again. This enlargement of the Saugkammervolumens 8th leads to a reduction of the pressure in the suction chamber 8th and thus to a tight eye of the suction cup 6 at the articular surface 2 , This is a secure connection between handling instrument 4 and joint insert 1 In this condition, the joint insert can be made 1 by means of the handling instrument 4 transported and into the joint socket 3 be used.

To release this connection, it is sufficient to overcome the suction forces mechanically, that is, when vigorously removing the handling instrument 4 from the joint insert 1 this connection will be released again.

While in the simplified embodiment according to 1 the lowering of the pressure in the suction chamber by a deformation of the suction cup 6 takes place, is for this pressure change in the embodiment of 2 to 4 a special pressure reducing device is provided.

The handling instrument 4 according to 2 to 4 comprises a likewise cylindrical handle part 5 with a cylindrical interior 9 , in by means of an O-ring 10 sealed a piston 11 is mounted longitudinally displaceable. One on the piston 11 attacking grip 12 protrudes from the handle part 5 out, so that the piston 11 by means of this handle 12 in the interior 9 can be moved. On the piston 11 supports a coil spring 13 starting in the interior 9 is arranged and the the piston 11 moved to the extended position, where the handle 12 farthest from the handle part 5 protrudes.

The piston 11 separates from the interior 9 one through the O-ring 10 sealed suction chamber 14 with variable volume starting from a flow channel 15 at the end of the grip part 5 with the suction cup 6 surrounded suction chamber 8th communicates.

To this handling instrument 4 with the hinge insert 1 to connect, is first in the same way as in the embodiment of 1 the sealing lip 7 of the suction cup 6 to the articular surface 2 of the joint insert 1 sealing applied, so that the suction chamber 8th is closed. Subsequently, in the in 3 illustrated manner the piston 11 against the coil spring 13 shifted, so that the volume of the suction chamber 14 is minimized. If you leave the handle 12 then go, the piston will 11 through the coil spring 13 again from the interior 9 pushed out, so that the volume of the suction chamber 14 increases, and this leads to a lowering of the pressure in the with the suction chamber 14 over the flow channel 15 connected suction chamber 8th , The connection between handling instrument 4 and joint insert 1 is made by it.

You can simply be solved by the fact that the piston 11 over the handle 12 against the action of the coil spring 13 in the handle part 5 is inserted.

In the embodiment of the 2 to 4 becomes the suction chamber 8th from a suction cup-shaped sealing element with an outwardly projecting sealing lip 7 educated.

In principle, it would also be possible to carry out this sealing element in a different way, for example in the form of a short piece of pipe 16 made of flexible material ( 5 ) or as an O-ring 17 made of elastomeric material ( 6 ). It is only essential that the suction chamber by conditioning the handling instrument 4 at the articular surface 2 is sealed to the outside. The handling instruments according to the 5 and 6 are the rest otherwise the same structure as the handling instrument of 3 and 4 ,

In the handling instrument of 3 to 6 the lowering of the pressure takes place in the suction chamber 8th by displacement of the piston 11 ,

Claims (7)

Handling instrument for joint components with joint surfaces with a handle portion and a suction element arranged thereon end, which has a self-contained, sealingly applied to the articular surface of the joint component and this joint surface thereby forming a sealed suction sealing element as well as a pressure in the suction chamber lowering device by characterized in that the suction chamber ( 8th ) with a piston-cylinder unit ( 9 . 11 ), in which an in cylinder ( 9 ) sealed displaceable piston ( 11 ) a suction space ( 14 ) whose volume corresponds to the position of the piston ( 11 ) in the cylinder ( 9 ) is variable, and that the piston-cylinder unit ( 9 . 11 ) in the handle part ( 5 ) is arranged. Handling instrument according to claim 1, characterized in that the sealing element is an elastomeric ring ( 17 ). Handling instrument according to claim 1, characterized in that the sealing element is a cylindrical tube piece ( 16 ) is made of elastically deformable material. Handling instrument according to claim 1, characterized in that the sealing element ( 6 ) a sealing edge in the form of a self-contained, outwardly projecting, flexible sealing lip ( 7 ) having. Handling instrument according to one of the preceding claims, characterized in that the suction chamber ( 8th ) communicates with the environment via a closable ventilation opening. Handling instrument according to one of the preceding claims, characterized in that the piston ( 11 ) by a spring ( 13 ) is displaceable in an end position in which the volume of the suction chamber ( 14 ) is maximum. Handling instrument according to one of the preceding claims, characterized in that the piston ( 11 ) one out of the cylinder ( 9 ) protruding confirmation handle ( 12 ) wearing.