Joint for a knee-joint brace.

(42) Date of commencement of the patent: 15. 5.1991 (45) Date of issue: 25.11.1991

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>DE-PS 354651 DE-PS 365907 DE-PS 397483 EP-Al-92314 EP-B2-59472</td><td>BANDAGIST HEINDL SOCIETY MBH A-4040 LINZ, UPPER AUSTRIA (AT).</td>

<td></td><td>(72) Inventor:</td>

<td></td><td>REISINGER KARL OTTENSHEIM, UPPER AUSTRIA (AT).</td>

(54) JOINT FOR A KNEE JOINT SUPPORT (57) In the case of a joint for a knee joint support with two rails (1, 2) associated with the thigh and the lower leg, which are interconnected via two in a bearing recess (5) of the other rail (2) engaging pivot pins (3, 4) are hingedly connected, it is proposed to provide the bearing recess (5) for the pivot pins (3, 4) in a on the associated rail (2) removably mounted articulated insert (6).

CQ

AT 393 620

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AT393 620B

The invention relates to a joint for a knee joint support with two on the one hand the thigh and on the other hand the lower leg associated rails, which are connected to each other via in a bearing recess, preferably in a guide slot, the other rail engaging hinge pin.

A knee joint support generally has the task, in particular after a ligament injury, of allowing movement of the knee joint, at least in a predetermined frame, without having to fear overloading of the ligaments in order not only to prevent muscular atrophy but also to allow muscle to build up. For this purpose, the knee joint supports on both sides of the knee on two with the aid of bandages on the upper and lower leg attached to each other articulated rails, which form a positive guidance for the physiological knee joint due to the joint formed by them. To adapt the support joint movement to the rotational and sliding movement of the physiological knee joint, it is known to provide the thighs associated with two pivot pins, which engage in a guide slot of the lower leg associated rails so that first of a pivot pin and then after reaching a Stop the other pivot pin forms the respective axis of rotation for the support joint. Although such a support joint with two successive coming to rotation axes can not accurately simulate the rotational sliding movement of the physiological knee joint, but can be achieved by the associated departure from a precise physiological knee joint guidance increasing protection of the cruciate ligament in the extended position near, if the Stützgelenkskondyl smaller as the physiological condyle is chosen. A disadvantage of these known knee joint supports, however, that an individual adjustment of the support joints to the respective requirements with respect to the movement possibilities to be granted can hardly be achieved and limited to the limitation of the respective permitted pivot angle, which is determined by external, displaceable attacks on the rails, which again the risk of unwanted or abusive adjustment. Added to this is that the movement of the pivot pin leads in the guide slots to wear, which can make the leadership task of the knee joint support in question and significantly determines the life of the knee joint support.

The invention is therefore an object of the invention to improve a joint for a knee joint support of the type described with simple means so that a wide adaptation to different tasks of the knee guide can be ensured. In addition, the unavoidable wear of the support joints should not determine the life of the entire knee joint support.

The invention solves the problem set by the fact that the bearing recess is provided for the pivot pin or the pivot pin on an interchangeable attached to the associated rail hinge insert or are.

Because of this measure, for example, different guide slots for the pivot pin can be used, the joint can also be adapted to different tasks of motion control of a knee joint. For this purpose, only the attachment of a corresponding hinge insert is required. The interchangeability of the joint inserts also makes the life of the entire knee joint support independent of the wear of the joint, because the wear-prone joint parts are interchangeably attached as hinge inserts on the associated rails and therefore can be renewed if necessary, without having to disassemble the knee joint support as a whole.

The interchangeable attachment of the joint inserts also offers the advantageous opportunity to relocate given by the joint end positions, without having to influence the movement, because yes the joint insert must be attached to this purpose on the associated rail only in different rotational positions, which is a additional adjustment of the knee joint support opened. Although this mounting option can be achieved in different rotational positions on different structural ways, particularly simple construction conditions result in that the hinge insert is formed as a circular disk with a peripheral toothing and that the associated rail has a recess provided with a corresponding internal toothing for receiving the hinge insert. To a Drehversetzung of the hinge insert, it is only necessary in this case, remove the hinge insert from the receiving recess of the rail in the axial direction of the circular disk to use it again after a corresponding rotation about the circular disk axis in the toothed receiving recess. The toothing is not only a necessary for the joint function rotational security, but also allows a rotational adjustment in relatively small increments.

The interchangeable hinge inserts also offer the advantage that the provided in the joint insert guide slot can form the mutual angle of rotation of the rails limiting stops for at least one pivot pin, so that no external, displaceable attacks are necessary. A change in the rotation angle to be admitted is ensured by the replacement of the joint insert, eliminating all the disadvantages associated with the conventional displaceable external stops.

In order to obtain a simple, space-saving and especially the lateral stability of the knee joint support securing construction, despite the interchangeable attachment of the joint inserts, finally, the rail carrying the joint insert with the hinge insert between fork-like leg of the other rail grab. The joint insert used in a receiving recess in this case requires no separate axial position assurance, because yes, the fork-like, the hinge insert encompassing legs of the other rail this axial securing

Take -2AT393 620B.

In the drawing, the subject invention is for example shown

1 shows an inventive joint for a knee joint support in a schematic, according to the section line (II) of FIG. 2 torn side view,

Fig. 2 shows this joint in section along the line (Π-Π) of Fig. 1 and the

3 and 4 show two different embodiments of a knee joint according to the invention in a representation corresponding to FIG. 1 on a larger scale.

The joints shown consist essentially of two mutually articulated rails (1) and (2), which are installed together with the rails of a same joint for the opposite side of the knee in a knee joint support and fixed by means of the knee joint support on the leg so that the rails (1) with the thigh and the rails (2) are connected to the lower leg. The articulated connection itself is achieved by means of two pivot pins (3) and (4), which engage in a bearing recess (5) of the respective other rail. In contrast to conventional support joints of this type, the bearing recesses (5) are not provided in the respective rails themselves, but in a joint insert (6) which is removably attached to the associated rail (2). For this purpose, the hinge insert (6) form a circular disc with a peripheral toothing (7) and the rail (2) has a recess (8) with an internal toothing for receiving the hinge insert (6). Since the hinge insert (6) receiving the head part (9) of the rail (2) is held between two this head part on both sides embracing, fork-like legs (10) of the other rail (1), a separate axial securing of the hinge insert (6) in the Receiving recess (8) of the rail (2) not required. The pivot pins (3) and (4) are held in the legs (10) of the rail (1) and pass through the hinge insert (6) in the bearing recess (5), so that for replacement of the hinge insert (6) only the pivot pins (3 ) and (4) must be solved before the rail head (9) between the fork legs (10) of the rail (1) can be pulled out. For easy release of one end of a head (11) forming the pivot pin (3) and (4) have this in the region of its other end a snap ring (12) for the axial position assurance, as shown in FIG. 2 can be removed. After removing the snap rings (12) thus the pivot pins (3), (4), which enforce a rolling sleeve (13) to reduce friction and thus to reduce wear, are pulled out of the fork legs (10). To insert a new hinge insert (6) this is to be inserted into the toothed recess (8) and inserted into the joint fork formed by the legs (10), so that the pivot pins (3) and (4) can be used.

The hinge insert (6) according to FIGS. 1 and 2 has a common bearing recess (5) for both pivot pins (3), (4), wherein the bearing recess forming a guide slot (5) gives the mutual rotational movement of the two rails (1) and (2) limiting stops. In the in Fig. 1 drawn in the extended position of the joint, the rail (1) about the pivot pin (4) can be pivoted as a rotation axis until the pivot pin (3) reaches the gate stop (14). The further rotational movement of the joint then takes place about the pivot pin (3), wherein this rotational movement is in turn limited by the slotted guide when the pivot pin (4) abuts the sliding link, the leadership of the pivot pin (3) to the pivot pin (4) Rotary axis determined.

According to the Fig. 3, a hinge insert (6) is used, which allows only a rotational movement about the pivot pin (4) as a rotation axis, because this pivot pin (4) in the associated bearing recess (5) is held displaceable. The second bearing recess (5) for the pivot pin (3) results in this case, only a limitation of the permitted rotation angle.

Another design variant is shown in FIG. 4 represented, in which the hinge insert (6) each forms a circular arc slotted guide for the two pivot pins (3) and (4). The arrangement is made such that the two pivot pins (3) and (4) each represent in its one end position the axis for the circular arc-like link guide for the other pin. The arc length of the slotted guide is in turn the respective angle of rotation, whereby the replacement of the different joint inserts (6), the respective desired adjustment of the support joint to the respective movement requirements can be easily ensured. In addition, the angle position of the end positions can be changed by a rotational adjustment of the joint inserts (6) about their axis, without changing the angle of rotation. This rotational adjustment also allows consideration of different angular positions of the pivot pin (3), (4), so that the hinge inserts according to FIGS. 3 and 4 at a joint according to FIGS. 1 and 2 and vice versa can be used.

In order to minimize sliding friction between the end faces, a sliding coating (15) can be provided between the fork-like legs (10) of the rail (1) and the joint head (9) of the rail (2), as shown in FIG. 2 This slide coating (15) can be assigned to both the joint head (9) and the legs (10). If it is also to be effective in the region of the joint insert (6), then it is advisable to coat the inside of the legs (10).

The invention is of course not limited to the illustrated embodiment. For example, the pivot pins (3) and (4) could be provided in a replaceable hinge insert to

To achieve an approximation to a particular condylar shape, which depends on the mutual distance of the pivot pin. It probably does not need to be mentioned that in this case, the slotted guide must also be changed accordingly. But it could also be used more than two pivot pin, if it is z. As applies to limit the pivot range over the pivot pin or ensure a more extensive movement adjustment to the physiological knee joint.