SHOULDER PROSTHESIS WITH MODULAR EPIPHYSEAL PART

Abstract

The invention relates to a shoulder prosthesis comprising a diaphyseal part extending along a diaphyseal axis and on which an epiphyseal part is mounted, the epiphyseal part having an upper face which is inclined along a front plane with respect to the diaphyseal axis, and a lower central face bearing against a complementary upper face of the diaphyseal part. According to the invention, the epiphyseal part is reversible by rotation through 180° about an axis normal to the lower central face bearing against the epiphyseal part to modify the inclination of the upper face of the epiphyseal part.

Claims

1. A shoulder prosthesis comprising a diaphyseal part extending along a diaphyseal axis, surmounted by an epiphyseal part , the epiphyseal part having an upper surface inclined along a front plane with respect to the diaphyseal axis , and a lower central face bearing against an upper complementary surface of the diaphyseal part, wherein the epiphyseal part is reversible by rotation through 180° about an axis normal to the lower central face of the epiphyseal part to modify the inclination of the upper surface of the epiphyseal part.

2. The shoulder prosthesis according to claim 1, wherein the epiphyseal part is adapted to adopt a first position in which an axis normal to its upper face is inclined by an angle of 135° along the front plane with respect to the diaphyseal axis, and a second position pivoted by 180° about the axis normal to its lower central face , in which the axis normal to its upper face is inclined by an angle of 145° along the front plane with respect to the diaphyseal axis.

3. The shoulder prosthesis according to claim 1, wherein the lower central face of the epiphyseal part and the complementary upper face of the diaphyseal part are inclined by an angle a along the front plane with respect to the upper face, so as to make it possible to modify the inclination between the upper face of the epiphyseal part and the diaphyseal axis by an angle equal to +/−2α.

4. The shoulder prosthesis according to claim 3, wherein the angle a is equal to 5°.

5. The shoulder prosthesis according to claim 2, wherein the lower central face of the epiphyseal part and the complementary upper face of the diaphyseal part are inclined by an angle a along the front plane with respect to the upper face, so as to make it possible to modify the inclination between the upper face of the epiphyseal part and the diaphyseal axis by an angle equal to +/−2α.

6. The shoulder prosthesis according to claim 5, wherein the angle a is equal to 5°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other characteristics and advantages of the invention will become apparent from the following description, which is given by way of non-limiting indication and made with reference to the appended figures, in which:

[0027] FIG. 1 is a schematic representation illustrating, at a front plane, a shoulder prosthesis according to the invention, the epiphyseal and diaphyseal parts being represented before assembly and to form an anatomical prosthesis;

[0028] FIG. 2 is a schematic representation similar to that of FIG. 1, illustrating the assembled epiphyseal and diaphyseal parts;

[0029] FIG. 3 is a schematic representation similar to that of FIG. 1, before assembly, to form an inverted shoulder prosthesis;

[0030] FIG. 4 is a schematic representation similar to that of FIG. 3, illustrating the assembled epiphyseal and diaphyseal parts.

DETAILED DESCRIPTION OF THE INVENTION

[0031] In reference to FIGS. 1 to 4, the invention relates to a modular shoulder prosthesis (1), i.e. that it comprises a diaphyseal part (2), and an epiphyseal part (3), which are distinct and can be interchanged.

[0032] In a known manner, the diaphyseal part (2) extends along a diaphyseal axis (4), and is surmounted by the epiphyseal part (3). The assembly between the diaphyseal and epiphyseal parts is well known to a person skilled in the art, such that it will not be described in detail.

[0033] Still in a known manner, the epiphyseal part (3) has an upper face (5) inclined along a front plane with respect to the diaphyseal axis (4), and a lower central face (6) bearing against a complementary upper face (7) of the diaphyseal part (2).

[0034] The inclination of the upper face (5) of the epiphyseal part (3) depends on the type of shoulder prosthesis.

[0035] For example, for a shoulder prosthesis of the anatomical type, the upper face (5) of the epiphyseal part (3) must be more inclined than for a prosthesis of the inverted type in which the upper face (5) of the epiphyseal part (3) is close to the horizontal.

[0036] In practice, the angle of inclination of the upper face (5) of the epiphyseal part (3) is defined by the angle formed by an axis (8) normal to said upper face (5) with respect to the diaphyseal axis (4).

[0037] The shoulder prosthesis (1) according to the invention makes it possible, with only one and same epiphyseal part (3), to design two shoulder prostheses (1), the upper faces (5) of the epiphyseal parts (3) of which have different angles of inclination.

[0038] To this end, and according to the invention, the epiphyseal part (3) is reversible by rotation through 180° about an axis (9) normal to the lower central bearing face (6) of the epiphyseal part (3) in order to modify the inclination of the upper face (5) of the epiphyseal part (3).

[0039] In other words, the epiphyseal part (3) is capable of adopting a first position (see FIGS. 1 and 2) in which the axis (8) normal to its upper face (5) is inclined by a first angle, for example 135°, along the front plane with respect to the diaphyseal axis (4), and a second position (see FIGS. 3 and 4) pivoted by 180° about the axis normal (9) to its lower central bearing face (6), in which the axis normal (8) to its upper face (5) is inclined by a second angle, for example 145°, along the front plane with respect to the diaphyseal axis (4).

[0040] In this way, by simple rotation of the epiphyseal part (3), it is possible to produce two different types of shoulder prostheses (1), for example a prosthesis (1) of the anatomical type, see FIGS. 1 and 2, and a prosthesis (1) of the inverted type, see FIGS. 3 and 4.

[0041] To do this, and according to a particular embodiment, the lower central face (6) of the epiphyseal part (3) and the complementary upper face (7) of the diaphyseal part (2) are inclined by an angle a along the front plane with respect to the upper face (5), so as to make it possible, during the pivoting of the epiphyseal part (3) by 180°, to vary the inclination between the upper face (5) of the epiphyseal part (3) and the diaphyseal axis (4) by an angle equal to +/−2α.

[0042] For example, in reference to the appended figures, the lower central face (6) of the epiphyseal part (3) and the complementary upper face (7) of the diaphyseal part (2) are inclined at an angle of 5° along the front plane and with respect to the upper face (5).

[0043] Thus, in the example of the figures, the axis (9) normal to the lower central face (6) of the epiphyseal part (3) is inclined along the front plane with respect to the diaphyseal axis (4) by an angle of 140°. In this way, the upper face (5) of the epiphyseal part (3) is capable of adopting a first position, see FIGS. 1 and 2, in which the axis (8) normal to said upper face (5) is inclined along the front plane and with respect to the diaphyseal axis (4) by an angle of 135° , and a second position, see FIGS. 3 and 4, in which the axis (8) normal to the upper face (5) of the epiphyseal part (3) is inclined along the front plane and with respect to the diaphyseal axis (4) by an angle of 145°.

[0044] From the above, if two possible angle values are considered, as mentioned above, namely 135° and 14°, 4 epiphyseal sizes and 4 diaphyseal diameters, it is then necessary to make available 4 parts for the epiphyseal parts (3) and 4 parts for the diaphyseal parts (2) to respond to all the possible implantation configurations, i.e. a total of 8 parts.

[0045] From the above, the present invention makes it possible to decrease the number of parts necessary for the design of different shoulder prostheses (1).

[0046] Of course, the values of the angles of inclination described above are not limiting. It can absolutely be considered to change the value of the angle a and/or the angle of inclination of the lower central face (6) of the epiphyseal part (3) and of the complementary upper face (7) of the diaphyseal part (2) to provide other types of prostheses (1) having other inclination, with, for example, pairs of angle values of 130°/140° or 140°/150°.