Patent Application
20220387087
The invention relates to a fracture fixation plate according to the preamble of claim 1.
From EP-B 2 675 378, a fracture plate is already known, which, however, has a special geometry which is rather disadvantageous for the intended purpose. In particular, in this known plate, the bone contact surface is designed such that it is concave in the region of the ulna head section and flat in the region of the radius head section. In order to achieve the best possible bone contact between the bone contact surfaces of the head sections of the fracture plate and the surfaces of the underlying bones or bone fragments, the radius head section and preferably also the ulna head section are therefore matched to the anatomy with regard a) to the separation between the head sections, b) the elevation angle of the head sections, and c) the rotation angle about the longitudinal axes of the head sections. Therefore, a disadvantage of this known fracture plate is the complicated matching of the bone contact surfaces of the head sections, in order to establish satisfactory bone contact.
The invention seeks to provide a remedy here. The underlying aim of the invention is to create a fracture fixation plate which enables an optimal bone contact between the bone contact surfaces of the head sections and the surfaces of the underlying bones or bone fragments.
The invention achieves the stated aim with a fracture fixation plate which has the features of claim 1.
The advantages achieved by the invention should essentially be considered to be that, by means of the fracture fixation plate according to the invention:
In a particular embodiment, the bone contact surface is designed such that it is spherically convex in the region of the ulna head section.
In an additional embodiment, the bone contact surface, in the region of the radius head section (6), is designed such that it is convex, preferably cylindrically curved.
The bone contact surface, in the region of the ulna head section, can be substantially trapezoidal, wherein the longer base of the trapezoid comes to lie distally. The bone contact surface, in the region of the radius head section, can be substantially rectangular, wherein one of the two shorter sides of the corner of the rectangle comes to lie distally.
In a particular embodiment, the notch formed between the two head sections and their neck sections is dimensioned/formed in such a manner that the flexor pollicis longus (FPL) tendon can be accommodated therein. For this purpose, the notch can be designed such that it is V-shaped and continuously widens in the distal direction.
Measured in the plane of the plate, the notch has the area FE which can be at most 10%, preferably at most 6%, of the total area FTOT of the fracture fixation plate, including the notch and any possible plate holes. The area FE is preferably at least 10 mm2, preferably at least 20 mm2. The area FE is preferably at most 60 mm2, preferably at most 45 mm2.
In an additional embodiment, the body section (2) has at least one threaded hole with a non-rotatable, positive-locking threaded hole insert made of a softer material than the material of the bone fixation plate.
The ulna head section and preferably the radius head section can each have at least one threaded hole with a non-rotatable, positive-locking threaded hole insert made of a softer material than the material of the bone fixation plate.
The ulna head section can have three threaded holes, preferably with a non-rotatable, positive-locking threaded hole insert made of a softer material than the material of the bone fixation plate.
The radius head section can have two or three threaded holes, preferably with a non-rotatable, positive-locking threaded hole insert made of a softer material than the material of the bone fixation plate.
Preferably, the convexly curved bone contact surface, in the region of the radius head section, has a curvature which extends from the distal end of the elongated body section to a distal end of the radius head section.
The invention and developments of the invention are explained in further detail below using partially diagrammatic representations of an embodiment example.
The embodiment of the fracture fixation plate 1 according to the invention shown in
The ulna head section 5 and the radius head section 6 diverge distally from one another. In addition, the ulna head section and the radius head section 5; 6 are each connected independently of one another to the distal end 4 of the body section 2 via a corresponding neck section 51; 61.
The body section 2, the ulna head section 5 and the radius head section 5; 6 are each provided with a number of threaded holes 7 for receiving bone securing elements 8, wherein the body section 2 in addition has an elongate compression hole 9.
The fracture fixation plate 1 has a bone contact surface 10 and an opposing surface 11, wherein the bone contact surface 10 is designed such that it is spherically convex in the region of the ulna head section 5 and the bone contact surface 10 is designed such that it is convexly cylindrically curved in the region of the radius head section 6.
By the convex design of the bone contact surface 10 in the region of the ulna head section and the radius head section 5; 6, both bone contact surfaces 10 have a bulging form, wherein the bone contact surface 10 is designed such that it is spherically convex in the region of the ulna head section 5 and cylindrically curved in the region of the radius head section 6. Here, the convexly curved bone contact surface 10, in the region of the radius head section 6, has a curvature which extends from the distal end 4 of the elongated body section 2 to a distal end of the radius head section 6.
The bone contact surface 10, in the region of the ulna head section 5, is substantially trapezoidal, wherein the longer base of the trapezoid comes to lie distally. The bone contact surface 10, in the region of the radius head section 6, is substantially rectangular, wherein one of the two shorter sides of the rectangle comes to lie distally.
Between the ulna head section 5 and the radius head section 6 and the associated neck sections 51; 61, a notch 12 is formed, which is dimensioned/formed in such a manner that the flexor pollicis lungus (FPL) tendon can be accommodated therein.
This notch 12 is designed such that it is V-shaped and continuously widens in the distal direction. Measured in the plane of the plate, the notch 12 has an area FE of 30 mm2. The total area FTOT of the fracture fixation plate 1, including the notch 12 and the threaded holes 7, is 630 mm2.
In a broader design of the fracture fixation plate, the total area FTOT is 686 mm2 and the area FE of the notch is 35 mm2.
Furthermore, the threaded holes 7 arranged in the body section 2 each comprise a non-rotatable, positive-locking threaded hole insert 13 which is made of a softer material than the material of the bone fixation plate 1. Analogously, the threaded holes 7 arranged in the ulna head section 5 and in the radius head section 6 also each comprise a non-rotatable, positive-locking threaded hole insert 13 made of a softer material then the material of the bone fixation plate 1.
Although there are various embodiments of the present invention as described above, they should be understood in such a way that the different features can be used both individually and also in any combination.
The invention is therefore not simply limited to the aforementioned, particularly preferred embodiments.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CH2019/000034 | 11/7/2019 | WO |
