Orthosis to prevent lateral patellar dislocations

Abstract

An orthosis for preventing lateral dislocation of the patella comprises a rigid frame (1) which has at least one dimensionally stable upper rigid frame part (2), a dimensionally stable lower rigid frame part (3) and articulation means (4) which comprise at least one first and a second articulation part (4A, 4B), the first articulation part (4A) being rigidly connected to the dimensionally stable upper rigid frame part (2), the second articulation part (4B) being rigidly connected to the dimensionally stable lower rigid frame part (3), the articulation means (4) connecting the dimensionally stable upper and lower rigid frame parts (2, 3) to form a joint, an incompressible lateral stop (5) for laterally supporting a patella (10) and a rigid support (6) which retains the lateral stop (5).The rigid support (6) has a through opening (7) through which extends a retaining element for the lateral stop (5).

Description

Title of the invention: Orthosis to prevent lateral patellar dislocations Technical field

[0001] The present invention relates to an orthosis for preventing lateral patellar dislocations.

[0002] By orthosis is meant an object that can be held around the knee of a human being and serves to support the kneecap (patella). State of the art

[0003] There is a risk, especially following an injury, that the kneecap may come out of its socket if the load is unfavorable. This is called a luxating patella. "Lateral" indicates that this unwanted displacement of the kneecap occurs in a lateral direction away from the center of the body.

[0004] A conventional orthosis may be formed, for example, by an elastic tubular body which, during use, surrounds the knee and has a recess for the kneecap. Due to the flexibility of such an orthosis, however, the kneecap is only relatively weakly supported.

[0005] In principle, harder and less flexible components can be used. Depending on the flexion of the knee, however, there is a gap to the kneecap or too much pressure is exerted on the kneecap.

[0006] Reliable support of the patella is also not achieved with other known orthoses. Short version

[0007] It is an object of the invention to provide an orthosis which avoids dislocation of the patella as safely as possible for practically all movements of the leg.

[0008] This problem is solved with an orthosis according to the invention. Advantageous configurations are specified in the dependent claims and the following description.

[0009] According to the invention, an orthosis for preventing lateral dislocations of the patella comprises a rigid frame which comprises at least one non-deformable upper rigid frame part, a non-deformable lower rigid frame part and articulation means. The articulation means comprise at least two joints, which in each case connect the upper and lower dimensionally stable rigid frame part to each other in an articulated manner. In addition, the orthosis comprises a lateral stop for lateral support of a patella. The lateral stop is made of a non-compressible material, such as silicone.

[0010] The invention thus differs from a so-called flexible corset, which comprises a frame very flexible, primarily due to the hard frame. The dimensional stability of its hard frame parts indicates in particular that these are not flexible or at least less flexible compared to textiles or rubber materials. The shape of the rigid frame can be changed solely or essentially solely by the articulation means and in a predetermined manner. In this way, a secure contact of the lateral stop can advantageously be ensured even when constrained in a flexion-valgus-external rotation position.

[0011] During use, the lateral stop exerts lateral pressure on the kneecap. An essential idea of ​​the invention can be seen in the fact that the lateral stop must not give way in the event of an unwanted load on the leg. This requires the incompressible material of the lateral stop. In contrast to soft plastics with padding or bandages with a round ventral patellar opening, this largely prevents the lateral stop from being displaced too much and not fulfilling its supporting function when the kneecap presses against the lateral stop.

[0012] Silicone as a material for the side stop avoids pressure points, but is sufficiently hard or rigid. Other suitable materials can also be used.

[0013] The lateral stop preferably consists of a molded material whose shape is individually manufactured according to an individual mold of the knee of a respective patient. A lateral stop is therefore not simply selected from a group of predetermined lateral stops for a specific patient. Rather, information about the shape of the knee area is obtained by taking an impression, which is reflected in the lateral stop that is subsequently produced. For example, an optical impression can be taken in which a 3D model of the knee area is determined, for example, by camera recordings. The individual shape of the lateral stop provides particularly secure contact with the kneecap.

[0014] Inexpensive, precise and rapid manufacturing of the shape of the molding material is achieved when the molding material is brought into a deformable and deformed state on a patient's knee or a patient's knee replica. In this case, a patient's knee replica means an individual replica of the knee region of the respective patient.

[0015] When shaping the lateral stop, the entire spatial range of motion of the knee area should be taken into account. This can be achieved by a function impression. Thus, a shape of the molding material is produced by bringing it into a deformable state and deforming it on a patient's knee or the patient's knee replica while moving the patient's knee or the patient's knee replica over a physiologically possible range of motion. As a result, the orthosis does not restrict the freedom of movement or only restricts it invo- lunarly.

[0016] The lateral stop may be shaped to have contact areas with the patella and in particular with at least one of: the femur (i.e. the thigh bone), the fibula (i.e. the fibula) and the tibia (i.e. the tibia). In particular, one or more contact areas may exist for all of the aforementioned leg components. Thus, in the event of unwanted stress on the leg, stabilizing pressure is not only exerted on the patella, but also on the neighboring areas of the leg.

[0017] A rigid support is preferably provided which holds the side stop and is connected to the rigid frame. The support may therefore advantageously be located between the side stop and the rigid frame and may be made of a different material than the side stop.

[0018] Preferably, the rigid support is made of one or more materials less flexible than the material of the lateral stop. For example, the support may comprise or consist of carbon and / or polymer plastics.

[0019] It may be advantageous for the rigid support to be made of at least two materials which differ in their bending rigidity. In addition to carbon, for example, aromatic polyamides such as Kevlar may be used.

[0020] Depending on the location, greater rigidity or greater flexibility can be achieved by the different materials. This is particularly advantageous when there is a medial attachment means for connecting the rigid support to a medial portion of the rigid frame. Here, the rigid support material with the lowest bending stiffness can be located between the medial attachment means and the rigid support material with the highest bending stiffness. In particular, the material with the lowest bending stiffness can be arranged on a portion of the support that is proximal to the patella and on a distal portion that is spaced therefrom.

[0021] The lateral stop may be rigidly connected laterally to the hard frame and may be connected to the hard frame as a medial fixation means by a tension strap for pulling the lateral stop against the patella. A tension strap may be provided, for example, by one or more flexible straps. These are preferably of little or no elasticity, i.e. they have a predetermined, essentially invariable length.

[0022] "Medial" refers to the side pointing from the kneecap toward the opposite knee. "Lateral" indicates the opposite direction, i.e. pointing away from the other knee or the center of the body.

[0023] The articulation means may be designed to move the lateral stop away from the articulation means when the upper and lower dimensionally stable rigid frame parts are inclined. This explains the fact that the circumference of the knee increases as the knee bends. Conversely, in an extension, The knee position most at risk for patellar dislocation is where the lateral stop is brought closer to the rigid frame area to which it is attached. In this way, a free space between the stop and the patella is largely avoided.

[0024] Alternatively or additionally, the articulation means may be designed to move a fixing section of the rigid frame, to which the middle fixing means are connected, when the dimensionally stable upper and lower rigid frame parts are inclined such that the tension on the middle fixing means is reduced. This also takes into account the change in circumference of the knee during flexion. Brief description of the figures

[0025] Other effects and characteristics of the invention are described below with reference to the attached schematic figures:

[0026] [Fig. 1] is a schematic representation of an embodiment of the orthosis according to the invention. Description of particular embodiments

[0027] [Fig.l] schematically represents an exemplary embodiment of an orthosis according to the invention. The orthosis for preventing lateral patellar dislocations comprises a rigid frame 1 which has at least one upper rigid frame part 2 of stable shape, a lower rigid frame part 3 of stable shape and articulation means 4 which comprise at least a first and a second articulation part 4A, 4B. The first articulation part 4A is rigidly connected to the upper dimensionally stable rigid frame part 2. The second articulation part 4B is rigidly connected to the lower dimensionally stable rigid frame part 3. The articulation means 4 connect the upper and lower rigid frame parts 2, 3 which are non-deformable to each other in an articulated manner. An incompressible lateral stop 5 laterally supports a patella 10.A rigid support 6 holds the lateral stop 5, the rigid support 6 having a continuous opening 7 through which a holding element of the lateral stop 5 extends.

[0028] A secure hold of the patella can be achieved with the orthosis according to the invention. An undesirable deviation towards the patella can advantageously be avoided for most knee movements.

Claims

Claims

1. An orthosis for preventing lateral patellar dislocation, comprising a rigid frame (1) which has at least one dimensionally stable upper rigid frame part (2), a dimensionally stable lower rigid frame part (3) and joining means (4) which comprise at least a first and a second joining part (4A, 4B), the first joint part (4A) being rigidly connected to the dimensionally stable upper rigid frame part (2), the second joint part (4B) being rigidly connected to the dimensionally stable lower rigid frame part (3), the joint means (4) connecting the dimensionally stable upper and lower rigid frame parts (2,3) are articulated with each other and an incompressible lateral stop (5) for laterally supporting a patella (10) characterized in that the orthosis comprises a rigid support (6) configured to complete the rigid frame and which holds the lateral stop (5), the rigid support (6) having a continuous opening (7) through which extends an element for holding the lateral stop (5).,

2. Orthosis according to claim 1, characterized in that the lateral stop (5) is made of a molded material whose shape is individually manufactured according to an individual mold of the knee of a respective patient.

3. An orthosis according to claim 2, characterized in that a shape of the molding material is made by bringing it into a deformable state and deforming it on a patient's knee or a replica of a patient's knee.

4. Orthosis according to any one of claims 1 to 3, characterized in that the lateral stop (5) is shaped to have contact zones with the patella and in particular with at least one of: the femur, the fibula and the tibia.

5. Orthosis according to any one of claims 1 to 4, characterized in that the rigid support (6) is connected to the rigid frame (1).

6. Orthosis according to claim 5, characterized in that the rigid support (6) is made of one or more materials less flexible than the material of the lateral stop (5).

7. Orthosis according to claim 5 or 6, characterized in that the rigid support (6) is made of at least two materials which differ in their bending rigidity.

8. An orthosis according to claim 7, characterized in that a medial attachment means for connecting the rigid support (6) to a middle part of the rigid frame (1) and in that the material of the rigid support (6) with the lowest bending stiffness is located between the medial attachment means and the material of the rigid support (6) with the greatest bending stiffness.

9. An orthosis according to any one of claims 1 to 8, characterized in that the lateral stop (5) is rigidly connected laterally to the hard frame (1) and is connected to the hard frame (1) as a medial fixation means by a tension strap for pulling the lateral stop (5) against the patella.

10. An orthosis according to any one of claims 1 to 9, characterized in that the articulation means are designed to move the lateral stop (5) away from the articulation means when the upper and lower dimensionally stable rigid frame parts (2, 3) are inclined.

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