FR3065873A1 - HUMERAL PROTHETIC EMBASE FOR SHOULDER PROSTHESIS HAVING FIXING ARRANGEMENTS AT THE LEVEL OF HUMERAL EPIPHYSIS - Google Patents

Abstract

The lower part of the humeral prosthetic base, able to bear with a resected portion of a humeral head, is shaped to constitute a plate (1b) having holes (1c) for the passage of son of tuberter fixation sutures .

Description

Holder (s):

ASTON MEDICAL Limited company.

O Extension request (s):

® Agent (s): LAWRENCE AND CHARRAS CABINET.

FR 3 065 873 - A1 ® HUMERAL PROSTHETIC BASE FOR SHOULDER PROSTHESIS HAVING FIXING ARRANGEMENTS AT THE HUMER EPIPHYSIS LEVEL.

@) The lower part of the humeral prosthetic base, capable of bearing with a resected part of a humeral head, is shaped to constitute a plate (Ib) 1 having holes (1c) for the passage of suture threads, ί for fixing the tuberosities.

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The invention relates to the technical sector of orthopedic implants, in particular shoulder prostheses.

It is perfectly known to a person skilled in the art, with a view to reconstructing the shoulder joint, following different types of fractures, or pathologies, to use prostheses which essentially comprise a humeral implant and a gleoid implant, or sometimes just a humeral implant, in the case of a simple fracture.

From this basic concept, depending on the pathological cases to be treated, the surgeon can use either an anatomical prosthesis or a so-called inverted prosthesis.

In the case of an anatomical prosthesis, the humeral implant is fixed in the medullary canal of the humerus, being able to cooperate, either directly with the anatomical glenoid or with a glenoid element fixed at the level of the glenoid of the scapula. The humeral prosthetic head is therefore generally fixed by means of a rod, at the level of the humeral shaft.

In the case of an inverted shoulder prosthesis, in particular to have perfect congruence between the humerus and the glenoid, the spherical prosthetic head of the humeral joint is fixed at the level of the glenoid, by means of a base, to cooperate with a concave cup of complementary shape, which has the humeral element.

A solution of this type emerges, for example, from the teaching of patent FR 2 795 304, in which the center of rotation of the articulation head fixed at the level of the anatomic glenoid is offset downward relative to the plane median and at the center of said anatomical glenoid to lower, in a corresponding manner, said prosthetic articulation head.

In certain pathological cases, it is, moreover, necessary to fix fragments of tuberosities at the level of the metaphysis of the humerus, in relation for example, with a humeral rod fixed in the diaphysis, and consequently, with the aim of reconstruction of the tuberosities around the stem.

Solutions are also known in order to reconstruct and consolidate the tuberosities around an inverted prosthesis, especially in the case of complex fractures of the upper extremity of the humerus, and more particularly in geronto-tiaumatology.

For example, a collar can be added between the neck of a humeral rod and a humeral prosthetic base, intended to receive an insert capable of cooperating with a prosthetic articulation head fixed at the level of the glenoid cavity. This collar has holes for the passage of sutures, for the fixation of the tuberosities. This solution is not entirely satisfactory, because the addition of this flange for the passage of sutures tends to raise the prosthetic implant by the thickness of said flange, consequently generating a modification of the center of rotation of the shoulder and causing tension on the deltoid.

The purpose of the invention is to remedy these drawbacks in a simple, safe, efficient and rational manner.

The problem which the invention proposes to solve is to be able to fix the tuberosities in relation to a humeral base, at the level of the diaphysis, in particular in the case of an inverted prosthesis, while perfectly respecting the anatomy.

To solve such a problem, a humeral prosthetic base for shoulder prosthesis has been designed, having fixing arrangements at the level of the humeral epiphysis, the lower part of said base capable of bearing with a resected part of a humeral head, being shaped to form a plate having holes for the passage of suture threads for fixing the tuberosities

It follows from these characteristics that the plate, for the passage of the sutures, forms an integral part of the humeral base, which remains produced at a thickness corresponding to the thicknesses commonly used, in order to respect the anatomy without exerting tensions on the deltoid, since the center of rotation of the shoulder is not changed.

The humeral prosthetic base, according to the characteristics of the invention also has the following characteristics, considered separately, or in combination, namely:

• the plate constitutes the base of the humeral base.

• the humeral base and the plate are generally circular geometric shapes.

• the plate is connected to the periphery of the base by a groove.

• the plate holes are arranged over its entire circumference.

• the holes of the plate are arranged on a part of its circumference.

The invention, as claimed, advantageously applies in the case of an inverted prosthesis, but can also be applied in the case of a conventional anatomical prosthesis.

In the case of an inverted prosthesis, the humeral base has arrangements for receiving an insert delimiting a concave support and sliding surface, capable of cooperating with a joint head of a glenoid implant, in the form of a convex hemispherical cup.

In the case of a conventional anatomical prosthesis, the humeral prosthetic base has arrangements for receiving an insert in the form of a hemispherical cup constituting a humeral head capable of cooperating with a glenoid implant, in the form of an insert delimiting a surface. concave support and sliding.

The invention is set out below in more detail with the aid of the figures of the appended drawings in which:

FIG. 1 is a perspective view of the humeral base, according to the invention, seen from above,

FIG. 2 is a perspective view of the humeral base, considered seen from below,

FIG. 3 is a perspective view showing the coupling of the humeral base to a humeral rod,

- Figure 4 shows the establishment of the humeral base, at the level of a bone resection of a humeral head showing an example of passage of the suture threads for the fixation of the tubulations, in relation to said plate, that presents said base.

The humeral base, designated as a whole by (1), has all types of arrangements, to be fixed at the level of the humeral epiphysis, and more particularly, at the level of the resected part of the humeral head.

For example, the humeral base (1) can be coupled to a humeral rod (2), engaged in the medullary canal of the humerus. This coupling is carried out by any known and appropriate means, for example, by means of a cone (lf) formed in overflow from the underside of the base (1), and engaged in a corresponding hole formed at the level of the humeral stem head (2).

According to a characteristic underlying the invention, the lower part of the humeral base (1) is shaped to constitute a support plate (lb), with the resected part of the humeral head.

This plate (lb) has several holes (le), for the passage of suture threads (S) for the fixation of the tuberosities (Figure 4).

For example, the holes (le) are arranged over the entire circumference of the plate, or else over only part of said circumference.

As shown in the figures of the drawings, the plate (lb) is formed directly at the base of the body of the base (1), by being connected to the periphery (la) of said base by a groove (ld), for example of "V" cross section. The plate therefore results directly from the formation of the groove.

In the illustrated embodiment, the humeral base (1) and the plate (lb) have a generally circular geometric shape. The plate (lb) does not extend beyond the periphery of the base (1), the holes (le) are formed on the lower inclined part of the connection groove (ld) of said plate with the circular periphery of the body of the base (1).

The invention finds a particularly advantageous application in the case of an inverted shoulder joint prosthesis. For this purpose, the humeral base (1) has an internal cavity (le) for, in known manner, the fixing of an insert not presented, delimiting a concave bearing and sliding surface, able to cooperate with a head prosthetic joint of a glenoid implant, generally in the form of a convex hemispherical cup.

We refer, for example, to the teaching of the aforementioned patent FR 2 795 304.

Without departing from the scope of the invention, the humeral prosthetic base, according to the characteristics of the invention, can also be applied in the case of an anatomical prosthesis. In this case, the internal cavity (the) receives an insert in the form of a hemispherical cup constituting a humeral head, able to cooperate with a glenoid implant, in the form of an insert delimiting a support surface and concave sliding.

Reference is made to FIG. 4, which shows an example of fixing the tuberosities, by means of the suture threads (S) engaged through certain selected holes (le) of the plate (lb) surrounding said tuberosities.

The advantages are clear from the description, in particular it is emphasized:

• respect for the anatomy, without increasing the thickness of the humeral plate and, consequently, without modifying the center of rotation of the shoulder, • improving the rigidity of the prosthetic assembly, • the ease of placement of sutures, • the possibility of angularly orienting the humeral base with the plate, depending on the fractures, • after reduction of the joint, the possibility of carrying out tests, after placement of the humeral base and its humeral test insert.

Claims (8)

-1- Humeral prosthetic base (1) for shoulder prosthesis, having fixing arrangements at the level of the humeral hepiphysis, characterized in that the lower part of said base capable of bearing with a resected part of a head humeral, is shaped to form a plate (lb) having holes (le) for the passage of suture threads for fixing the tuberosities. -2- Base according to claim 1, characterized in that the plate (lb) constitutes the base of the humeral base (1). -3- Base according to claim 2, characterized in that the humeral base (1) and the plate (lb) are of generally circular geometric shapes. -4- Base according to any one of claims 1-3, characterized in that the plate (lb) is connected to the periphery of the base (1) by a groove (ld). -5- Base according to any one of claims 1-4, characterized in that the holes (le) of the plate (lb) are arranged over its entire circumference. -6- Base according to any one of claims 1-4, characterized in that the holes (le) of the plate (1) are arranged on a part of its circumference. -7- Base according to claim 1, characterized in that it has arrangements (the) for receiving an insert delimiting a support surface and concave sliding, capable of cooperating with a joint head of a glenoid implant , in the form of a convex hemispherical cup. -8- Base according to claim 1, characterized in that it has arrangements for receiving an insert in the form of a hemispherical cup constituting a humeral head capable of cooperating with a glenoid implant, in the form of an insert delimiting a surface support and sliding 10 concave.