FR2710829A1 - Artificial prosthetic cuff - Google Patents

Abstract

The invention relates to an artificial prosthetic cuff intended to replace the substance lost at the level of the rotator cuff of the shoulder. This prosthetic cuff consists principally of a flat portion of trapezoidal shape (10), the small base (11) of which is connected by way of a semi-rigid portion (20) to tie rod wires (3, 4) which are flexible and can be cut. Application: surgery.

Description

The invention relates to an artificial prosthetic cap intended to replace the losses of substances at the level of the rotator cuff of the shoulder.

Previously, these ruptured caps were not treated surgically and progressed to osteoarthritis between the acromion and the humeral head.

Different surgical treatments have been proposed - Extensive resections of the cuff, first of all, which worsened the lesions.

- The advancement of tendons, such as the thorny sus, or the realization of neighboring muscle flaps, aimed at closing the cavity that appeared in the rotator cuff, but, this, by sacrificing muscles located in the vicinity.

This is how certain prosthetic caps were developed but which pose the problem of their reinsertion at the level of the external part of the humerus.

The invention is intended to remedy these drawbacks.

The invention aims to create a biocompatible and well tolerated prosthetic cap, having a large thickness making it possible to lower the humeral head and move it away from the acromial conflict, in a form adaptable to the losses of substances from the rotator cuff , which are often wider inside than outside, easy to insert, and having a porosity favorable to the penetration and diffusion of blood and fibrous materials.

The artificial prosthetic cap according to the invention is mainly characterized in that it consists, essentially, of a flat, flexible, breakable and porous part, of trapezoidal shape whose small base is connected to wires of tie rods flexible and breakable, via a semi-rigid part.

The width (L) of the large base and the width (I) of the small base of the trapezoidal part represent, according to a preferred embodiment, respectively three-quarters and half the height of said trapezoidal part.

The height (h) of the semi-rigid part, connecting the small base of the trapezoidal part to the tie rods, represents approximately one-eighth of the height of said trapezoidal part.

The tie rods are flat and have a width representing approximately one-eighth of the height (H) of the trapezoidal part and a length representing approximately six times the width (L) of the large base of said trapezoidal part.

The thickness of the trapezoidal part can reach 4 mm, while the thickness of the tie rods is approximately 1 mm.

The tie rods, two in number, are connected to each of the outer corners of the semi-rigid intermediate part.

The prosthetic cap, as a whole, is symmetrical with respect to an axis (XX) perpendicular to the base of the trapezoidal part passing through the middle of the latter.

Said cap is made of polyester made bio-compatible by a treatment comprising three cycles of de-enzymation.

The advantages obtained, thanks to the invention, consist essentially in that the trapezoidal shape of the cap adapts well to the shape of the cavities resulting from a loss of substances from the natural cap of the rotators, which are often wider. inside and outside, that said prosthetic cap is easy to insert using the tie rods, that it is perfectly breakable without the risk of fraying, and that it allows a better distribution of the forces on the cap by pulling on the links. It should be added to this that the fitting of this artificial headdress does not cause any muscle weakening and that the lowering of the humeral head which it allows avoids conflict and osteoarthritis between the humeral head and the lower edge of the acromion , and, this, without any particular operational difficulty.

Other characteristics and advantages will appear in the following description of an embodiment of the artificial prosthetic cap according to the invention, given by way of nonlimiting example, with regard to the appended drawings, in which - Figure 1 shows a top view of the cap before mounting, - Figure 2 shows a top view of a humeral head with a ruptured cap, - Figure 3 shows a top view of the humeral head according to Figure 2, after assembly of the prosthetic cap, - Figure 4 shows a side view of the humeral head according to Figure 2, during presentation of the prosthetic cap.

Figures 1 to 4 show an artificial prosthetic cap consisting of a trapezoidal part 10 whose small base 11 is connected to the son of tie rods 3, 4 via a semi-rigid part 20; this prosthetic cap being symmetrical with respect to an axis (XX) perpendicular to the base 1 2 of the trapezoidal part 1 O; the tie rods 3, 4 being connected to each of the external corners 21, 22 of the intermediate part, said prosthetic cap being intended to compensate for a rupture 52 of the natural cap 51 of the humeral head 50 with collarbone 53 and to be inserted between said humeral head 50 and acromion 60.

By examining in more detail FIG. 1, it is noted that the trapezoidal part 10 can be reduced in height at will, by shearing along a line (W) perpendicular to the axis of symmetry (XX) of the cap, in order to adapt the height of this trapezoidal part 10 to the width of the break 52 of the natural cap; The tie rods can also be reduced in length at will.

By comparing FIGS. 2 to 4 with one another, it is noted that, after adapting the trapezoidal portion 1 O of the artificial cap to the dimensions and to the shape of the break 52 of the natural cap 51, it suffices to pass the wires of tie rods 3, 4 between the humeral head 50 and the acromion 60 and thus effect a transosseous insertion of said trapezoidal part 10, in said rupture 52, by exerting traction on the wires of tie rods 3, 4, then suturing the sides of the trapezoidal part 10 of the prosthetic cap with the edges of the break 52. The tie rods 3, 4 can then be cut on demand.

This prosthetic cap can therefore be used in ruptures of the rotator cuff of the shoulder that cannot be sutured, making it possible to respect the neighboring muscle and tendon capital, while lowering the humeral head relative to the acromion.

This cap can also be used in other losses of tendon substances, where the need for sufficient thickness will be retained. It can be used in all transosseous muscle reinsertions as a support for muscle rehabitation and reinsertion in a bony trench.

Finally, the composition of this porous cap allows the free circulation of liquids and perhaps the application of a tissue of granulations in contact with it. By a route initially resecting the acromion clavicular joint, it is entirely possible to put this cap prosthesis in place without particular operating difficulty. The breakable nature of this prosthesis is of course very important, because it makes it possible to adapt the size of the prosthesis to all the circumstances of cuff rupture encountered.

Claims (9)

Claims  l. Artificial prosthetic cap intended to replace the losses of substances at the level of the rotator cuff of the shoulder, characterized in that it consists mainly of a flat, flexible, breakable and porous part of trapezoidal shape (10), the small base (11) is connected to flexible and breakable tie rods (3, 4) via a semi-rigid part (20). 2. Prosthetic coping according to claim 1 characterized in that the width (L) of the large base and the width (I) of the small base of the trapezoidal part (10) represent respectively three-quarters and half the height (H) of said trapezoidal part (1 0). 3. Prosthetic coping according to claim 1 characterized in that the height (h) of the semi-rigid part (20), connecting the small base (11) of the trapezoidal part (10) to the tie rods (3, 4), represents the eighth of the height (H) of said trapezoidal part (l 0). 4. Prosthetic cap according to claim l, characterized in that the tie rods (3, 4) are flat and have a width representing approximately one-eighth of the height (H) of the trapezoidal part (10) and a length representing approximately six times the width (L) of the large base (12) of said trapezoidal part (10). 5. Prosthetic cap according to claim l, characterized in that the thickness of the trapezoidal part (10) can reach 4 mm. 6. Prosthetic cap according to claim 1 characterized in that the thickness of the tie rods (3, 4) is about 1 mm. 7. Prosthetic cap according to claim 1 characterized in that the tie rods (3, 4), two in number, are connected to each of the corners (21, 22) of the semi-rigid intermediate part (20). 8. Prosthetic cap according to claim 1, characterized in that it is symmetrical with respect to an axis (XX) perpendicular to the base (12) of the trapezoidal part (l O) passing through the middle of the latter. 9. Prosthetic cap according to claim l, characterized in that it is made of polyester.  l O. Prosthetic cap according to claim l, characterized in that it undergoes, after manufacture, a biocompatibility treatment consisting of three cycles of de-enzymation.