DE10320124B3 - Osteosynthesis plate, especially an angle-stable radius plate, for the surgical treatment of bone fractures - Google Patents

Abstract

The invention relates to an osteosynthesis plate, in particular an angle-stable radius plate, for the operative treatment of bone fractures, comprising bores for receiving bone screws, at least some of the bores being provided with an internal thread. At least two bores are partially interlocking and overlapping and each have a conical internal thread, the interlocking bores being arranged in the longitudinal and / or transverse direction of the plate or on a predetermined radius.

Description

The invention relates to an osteosynthesis plate, in particular an angle-stable radius plate, for operative care of bone fractures, including holes for receiving bone screws, at least some of the bores are provided with an internal thread are.

According to the implant to stabilize a fracture DE 197 50 493 A1 a plate is provided which has guides for preferably two screws, which hold the screws stably at an angle to the plate. The above-mentioned guides should allow the screws to be held at a fixed angle to the plate even if they loosen in the bone or the distance between the plate and the bone changes.

When using two screws whose Head a conical male thread should not only have an angle-stable fixation of head and shaft fragment of the bone to each other, but beyond another one rotational stability which loosen these screws, e.g. prevented during pendulum exercises.

The angle specified by the guides corresponds accordingly DE 197 50 493 A1 approximately the physiological angle of the head and lies in the range between 35 ° and 40 °, measured to the longitudinal axis of the shaft. In its lower part, the plate also has three holes on a continuous line, of which a middle hole is designed as an elongated hole. These holes are used to hold common cortex screws. The contact surface of the plate itself is concave, which means that the plate should come to rest better on the surface of the bone. The middle hole as an elongated hole makes it possible to find a favorable position for a corresponding cortex screw in relation to the bone substance. This would in itself be desirable for the further bores, but then the disadvantage of undesired material weakening described above also arises, which is further reinforced by the fact that the plate has lateral constrictions when viewed from above.

From the DE 43 41 980 A1 An osteosynthetic bone plate is known which has a plurality of round and / or elongated holes arranged in the longitudinal direction for receiving bone screws.

The arranged in the bone plate holes have a conical thread, the screw head of the bone screws also a conical, but external thread has. By designing the holes in the bone plate and of the screw head of the bone screw with a conical thread is achieved that the screw head is jammed in the bone plate when tightening and the bone screws in this way firmly with the bone plate stay in contact. As an advantage it is pointed out that the safe Connection of the bone fragments not by pressing the bone plate onto the bone surface, but. only achieved by the seat of the bone screws in the bone fragments is so that the Periosteum is not additionally affected and in this way the healing process is accelerated.

At least one hole from the DE 43 41 980 A1 known plate has an elongated shape running parallel to the longitudinal axis of the plate, the end radii having different dimensions.

The radius facing away from the bone fracture is made smaller than the radius facing towards the bone fracture. The elongated hole is conical and has a circumferential internal thread. The conicity of this hole corresponds to that of the screw head of a corresponding bone screw. When the bone screw is tightened, there is a movement along the bone plate and thus a compression of the bone fragments. A tight fitting of a piece of bone with several screws, possibly also of smaller diameter, is according to the DE 43 41 980 A1 not possible. If several of the holes having a longitudinal shape were adjacent, stability problems would result from weakening the plate material. This could in turn only be compensated for by a greater thickness, so that the overall structure is undesirably increased by the greater plate thickness.

With the osteosynthesis plate after EP 0 468 192 A2 there are several bores connecting the top and bottom of the plate for receiving bone screws.

According to the solution shown there as the preferred embodiment, the plate holes are conical and preferably provided with an internal thread. The screws used to fix the plate have a conically tapering head, preferably with a conical external thread. The screws are screwed into the bone through the plate holes in a manner known per se. When the screw is fully screwed in, the conical screw head tensions in the conical plate bore, this effect being supported by the preferably introduced threads. This aforementioned tensioning is essential when the screw is to be used only in a unicortal manner and the plate is not resting on the bone surface. The conical screw connection is advantageous in that the threads wedge into each other when tightened firmly. Reduce this wedging reduces the risk of unintentional loosening of the plates / screw connection with corresponding recurring loads.

It is from the foregoing, therefore Object of the invention, a further developed osteosynthesis plate, in particular an angle-stable radius plate, for operative care of bone fractures, which enables much greater degrees of freedom when occupying the bone and taking the risk of Bone tears largely reduced when driving in the bone screws is.

The solution to the problem of the invention is carried out with an osteosynthesis plate, in particular an angle-stable one Radius plate, according to the features of the claim 1, the subclaims at least expedient configurations and training.

Accordingly, according to the invention in the Osteosynthesis plate next to or in addition to drilling after the State of the art at least two holes partially in each other gripping and overlapping executed these bores each have a conical internal thread. The interlocking bores can be in longitudinal plate and / or transverse direction, but in particular also on a predetermined radius to be ordered.

The bore diameter can refer to conventional bores can be reduced according to the prior art, because of the possible redundant setting several bone screws in the respective hole groups for the necessary Overall stability Care is taken. On the other hand, there is the possibility based on the Location of a fracture select one of the holes without the danger there is that in Area or nearby a fracture occurs in the fracture.

In one embodiment of the invention the bore angles, i.e. the longitudinal axes of the holes, not at right angles to the longitudinal plate or panel cross-section, but in a dimension deviating from the right angle, so that defined inclinations the bone screws can be reached when driving them in.

The respective bore angle is preferably related on the longitudinal axis of the plate in the range of essentially 45 ° to 135 °. there can Adjacent holes of the interlocking hole groups different angles with different inclinations have screwed in bone screws. This measure will as mentioned above the risk of undesirable bone tears or an expansion of the fracture when attaching the osteosynthesis plate reduced.

The overlaps of the one another according to the invention cross holes are in the range of 10% to 35% of the average Hole diameter of a single hole.

In another embodiment it is assumed that the Different diameters of the interlocking, overlapping holes Assumes values.

Based on this basic idea the invention provides for between two spaced bores larger diameter to form a intersecting hole of smaller diameter. With such a sequence of a larger diameter hole, a smaller hole Diameter and again a larger diameter hole is one undesirable Reduction of stability the plate over their relevant cross-sectional or longitudinal sectional area effective countered.

In one embodiment of the invention the plate cross-section a sickle shape. The convex shows Part of the sickle upwards, with the concave part of the sickle facing the bone surface is. According to the convex part of the sickle executed with a larger radius than this is the case in the concave lower part of the plate.

The bone screws to be used preferably have a conical complementary to the threaded bores Thread on so that the effect known from the prior art of jamming with the As a result of a secure, angularly stable hold of the screws.

The screw heads have a design Ball head thread form. In this case, the threaded holes have at least in its upper section, a spherical head shape complementary to the screw heads.

With the angularly stable radius plate it is envisaged that the Plate has a wider plate head, being in the plate head between two spaced bores the at least two interlocking Bores with a conical internal thread are arranged.

It can be the spaced holes as well the interlocking holes according to the invention on one common radius. additional it is possible, to provide at least one additional elongated hole in the head area, which is in transition between head and plate longitudinal area located.

At least one other elongated hole can be parallel to the longitudinal axis extend the plate.

The plate head can optionally have a curvature. An offset is formed between the plate head and the longitudinal plate area, so that an anatomically matched implant is created. The implant has a continuously increasing width in the transition between the longitudinal plate area and the plate head. The plate head itself can have an asymmetrical shape, with this shape as a circumscriber on the outside forms an equilateral triangle.

The free end of the plate longitudinal area faces in a preferred embodiment, a radius of curvature. The Bores for receiving the bone screws are recessed, which means when the bone screws are screwed in, an essentially flush surface results.

The invention is based on the following of an embodiment as well as explained with the help of figures.

Here show:

1 Side view and plan views of a radius plate according to the first embodiment of the invention and a sectional view of the detail of the interlocking, overlapping bores;

2 a further embodiment of an angularly stable radius plate, left, with an elongated hole in the head area and comprising detailed representations and a section along the line AA;

3 an embodiment of a radius plate, also in an angle-stable design, right, with additional holes in the transition area of the head part as well as detailed representations and a section along the line AA, and

4 an embodiment of an angularly stable radius plate, left, analogous to the illustration 3 , also comprising detailed pictures and a section along the line AA.

The osteosynthesis plate according to the figures goes from a plate longitudinal area 1 , a cranked transition area 2 and a plate head 3 out.

In the longitudinal area of the plate there are bores running essentially on the longitudinal axis 4 , which are designed to accommodate at least a part of a screw head (not shown).

Depending on the length of the plate, e.g. In the range of 51 mm to 93 mm, the number of holes varies between three and eight.

In the embodiment of the plate after 1 , Middle, are two spaced, perpendicular to each other elongated holes 5 formed in the cranked transition area.

Between two head holes 6 there is a section with several interlocking holes 7 ,

These interlocking holes 7 have a conical thread and can be at an angle to each other.

In the embodiment according to 1 , lower illustration, is instead of the transverse elongated hole 5 the formation of two further head bores 8th intended.

The transition between the longitudinal plate area 1 and plate head 3 is steadily increasing on the broad side.

The plate is particularly in the area of the head 3 anatomically shaped.

In the embodiments according to the figures, a triple bore pair in the plate head 3 assumed, however, double pairs of holes or pairs of holes with a number greater than three, depending on use and plate size, are also conceivable.

With the representations after 1 are the interlocking holes 7 on an imaginary straight line; however with the 2 to 4 on a radius on which also the outer head bores 6 can be located.

It should be noted at this point that all Elements and details recognizable in the figures are essential to the invention are to be understood as disclosed.

The multitude of interlocking Drilling allows for advantageous tighter occupancy, which in turn has the consequence that bone screws smaller diameter can be used. On the other hand, however the surgeon also drill one of the relevant holes that the fracture away, use it so that corrective measure do not have to be carried out on the implant.

The advantage of elongated holes 5 lies in the fact that when driving in a bone screw in the area of the elongated hole, an angle adjustment or adjustment of the implant is still possible. Bone substance can also be introduced into the fracture area through the respective elongated hole.

The respective hole angle of the interlocking holes can be related to the longitudinal or plate but the transverse plate axis vary and preferably run essentially between 45 ° and 135 °. Here again, it is advantageous to determine the hole angle of adjacent holes deviating from one another, in particular starting from an imaginary one Perpendicular, at an angle of e.g. + 35 ° for one hole and -35 ° for the adjacent one Drilling.

The area of overlap of the interlocking Drilling is around 10% to 35% of the average hole diameter, So that the inherent stability received per hole when inserting an associated bone screw remains.

From the figures it is also clear that the plate head 3 taking into account the anatomical conditions is archable.

The shape of the plate head can also be asymmetrical chosen be, being outside as Describing the shape of the plate head that of an uneven one Triangle comes close.

The free end of the longitudinal plate area 1 has a radius of curvature 9 on.

All in all, the osteosynthesis plate presented, in particular an angle-stable radius plate, represents an anatomically adapted implant, for example for the distal spoke on the palm side thereof, whereby no corrective measures need to be taken on the implant during the actual operation and for its execution. The interlocking bores allow great flexibility in the use of the implant without the stability properties of the plate being influenced in a sustainable manner.

In contrast to otherwise usual exclusive Elongated holes are in interlocking, overlapping Bores with the corresponding thread, several screws exactly or optionally positioned and stable in angle, with the other Advantage of the different angular orientation the hole and the bone screw following the course of the hole.

1

Plate longitudinal region

2

cranked area

3

disk head

4

drilling

5

Long hole

6

head bore

7

in one another gripping holes

8th

Further head bore

9

rounding radius

Claims (23)

Osteosynthesis plate, in particular an angle-stable radius plate, for the surgical treatment of bone fractures, comprising bores for receiving bone screws, at least some of the bores being provided with an internal thread, characterized in that at least two bores ( 7 ) are partially interlocking and overlapping and each have a conical internal thread, the interlocking bores ( 7 ) are arranged in the longitudinal and / or transverse direction of the plate or on a predetermined radius. Osteosynthesis plate according to claim 1, characterized in that the respective hole angle related to the longitudinal axis of the plate in the range of essentially 45 ° to 135 °. Osteosynthesis plate according to claim 1, characterized in that the respective hole angle in relation to the transverse axis of the plate in the range of essentially 45 ° to 135 °. Osteosynthesis plate according to one of the preceding claims, characterized in that each of the interlocking bores ( 7 ) has a different hole angle. Osteosynthesis plate according to one of the preceding claims, characterized in that the overlapping of the interlocking bores ( 7 ) is in the range between 10% and 35% of the average bore diameter. Osteosynthesis plate according to one of the preceding claims, characterized in that the diameter of the interlocking, overlapping bores ( 7 ) takes different values. Osteosynthesis plate according to claim 6, characterized in that between two spaced holes of larger diameter a smaller diameter intersecting hole is provided is. Osteosynthesis plate according to one of the preceding Expectations, characterized in that the Plate cross-section has a sickle shape. Osteosynthesis plate according to one of the preceding Expectations, characterized in that the to be inserted a conical complementary to the threaded holes Own thread. Osteosynthesis plate according to one of the preceding Expectations, characterized in that the screw heads have a spherical thread shape. Osteosynthesis plate according to claim 10, characterized in that the Threaded bores at least in their upper section have a spherical head shape that is complementary to the screw heads have. Osteosynthesis plate according to one of the preceding claims, characterized in that the plate has a wider plate head ( 3 ), whereby in the plate head ( 3 ) between two spaced bores, the at least two interlocking bores ( 7 ) are arranged with a conical internal thread. Osteosynthesis plate according to claim 12, characterized in that the spaced bores and the intermeshing bores ( 7 ) lie on a common radius. Osteosynthesis plate according to claim 12 or 13, characterized in that at least one elongated hole ( 5 ) is provided, which is in the transition between the head ( 3 ) and longitudinal plate area ( 1 ) is located. Osteosynthesis plate according to claim 14, characterized in that at least one elongated hole extends parallel to the longitudinal axis of the plate. Osteosynthesis plate according to claim 14, characterized in that at least one elongated hole ( 5 ) extends perpendicular to the longitudinal axis of the plate. Osteosynthesis plate according to one of claims 12 to 16, characterized in that the plate head ( 3 ) is arched. Osteosynthesis plate according to one of claims 12 to 17, characterized in that between the plate head ( 3 ) and longitudinal plate area ( 1 ) a crank is formed. Osteosynthesis plate according to one of claims 12 to 18, characterized in that this in the transition between the longitudinal plate area ( 1 ) and plate head ( 3 ) has a continuously increasing width. Osteosynthesis plate according to one of claims 12 to 19, characterized by an asymmetrical plate head ( 3 ). Osteosynthesis plate according to claim 20, characterized in that the plate head ( 3 ) on the outside as a circumscriber has the shape of an uneven triangle. Osteosynthesis plate according to one of the preceding claims, characterized in that the free end of the longitudinal plate region ( 1 ) a radius of curvature ( 9 ) having. Osteosynthesis plate according to one of the preceding Expectations, characterized in that all Bores for receiving bone screws are recessed are.