FR2639822A1 - Ring screwed into the osseous cotyles - Google Patents

Abstract

The method is distinguished by the fact that limited cut-outs 1a are formed in different areas of the threaded outer surface of the ring 1, these limited cut-outs 1a forming elastically deformable tongues 1c which, after the ring has been screwed in, are pushed back in order to ensure penetration of all the tongues, or of only some of them, into the osseous cotyle, beyond the outer profile of the ring.

Description

 Ring screwed into the bony acetabulum.

 The object of the invention relates to the technical field of means for replacing or repairing the joints of the human body.

 Many types of rings are known to be screwed and anchored with or without cement in the bony acetabulum. In particular, the present invention relates to the rings which were the subject of the Patent Application No. 87.01887 of which the applicant is also the holder.

 According to this previous application, it had sought to improve the anchoring in the bone acetabulum, in particular by a plurality of small projections and depressions executed over all or part of the development of the traditional threading thus multilining the surfaces in contact.

 It is also important to improve the anchorage but selectively, i.e. only at the required locations of the bone acetabulum, depending on the texture of the bone.

 For this, and according to a first characteristic, it is carried out according to different zones of the threaded outer surface of the ring, limited cuts constituting elastically deformable tongues that are pushed back, after screwing the ring to ensure penetration of the ring. set of tongues or some only in the bony acetabulum, beyond the outer profile of the ring.

 According to another feature, the deformable tongues of the screwed ring are made by any means such as electro-erosion, laser beam ..., after execution of the peripheral thread, and they are positioned regularly or not on the peripheral surface of the ring.

 Another characteristic lies in the fact that the deformable tongues are retracted inside the ring before it is screwed into the bony acetabulum, and then they are pushed back by inaction after screwing the ring.

 According to another characteristic, the penetration of the deformable tongues in the bone acetabulum is obtained by placing the nucleus arranged for this purpose in the ring previously screwed into the bone acetabulum.

 These and other features will become apparent from the following description.

To fix the object of the invention, without however limiting it, in the appended drawing
Figure 1 is an external view illustrating a screwed ring arranged with deformable tongues.

 Figure 2 is a partial sectional view showing a deformable tab retracted inside the ring.

 Figure 3 is a partial sectional view illustrating the penetration of a deformable tongue into the bony acetabulum by a fixed arrangement of the core.

 Figure 4 is a partial sectional view showing the penetration of a deformable tongue in the bony acetabulum by a removable arrangement of the core.

 In order to make more concrete the object of the invention, it is now described in a non-limiting manner with reference to the embodiments of the figures of the drawings.

 The aim sought, as stated in the preamble, is to improve the anchoring of the rings screwed into the bone acetabulum, in particular as a function of the texture of the bone. More particularly, it has been desired to obtain reinforcement of the anchoring along limited zones of the bony acetabulum, independently of the weaving of the ring in said acetabulum.

 For this, it has been planned to carry out by any means such as laser beam, electro-erosion or other, limited cuts (la) on the threaded periphery (lb) of the ring (1), to form tabs (lc ) elastically deformable.

These cuts can be made in any number (three, four or more) and evenly or irregularly on the peripheral surface. On the other hand, their dimensions are established according to the dimensions of the ring itself, in particular its thickness, in order to allow a correct deformation in their entirety but not punctually, under the thrust exerted on them during the impaction .

 The tongues thus produced, it is to make them fulfill their role of reinforcing the anchoring after screwing the ring into the bony acetabulum.

 For this purpose, more solutions are envisaged.

For example and as illustrated in Figure 2, the tongues (lc) are retracted within the ring in the limit of the elastic deformation. The ring thus prepared is screwed into the bony acetabulum, then with the aid of a suitable impaction tool, all or only some of the tongues are pushed back so that the threads they carry penetrate more deeply into the bone. bone acetabulum than the general threading of the ring.

 We can also push all the tabs to the establishment of the connecting core with the femoral head (Figure 3) by arranging it with fixed organispousseurs such as ramps (2a> or bosses which allow for the introduction into the ring to push the tabs beyond its periphery.

 To carry out the selective pushing of the tongues according to the texture of the bone, provision is also made to equip the core (2) with removable pushing elements (FIG. 4), for example in the form of profiled lugs or fingers (3). ), housed in cavities (2b) of the core. These elements can be of different lengths in order to achieve a depression of variable depth of the tongues in the bony acetabulum.

 The advantages are apparent from the description, it highlights in particular: the combination between the screwed ring and the impacted ring obtained by the deformable tongues acting after establishment of the ring ~ the possibility of choosing the tongues to deform according to the texture of the bone or other parameter; strengthening the anchorage of the ring in the bony acetabulum.

Claims (6)

-1- Ring screwed into the bony acetabulum, characterized in that its threaded outer surface has, according to different zones, limited cutouts (1a) constituting tongues (1c) elastically deformable so as to be pushed back after screwing the ring into the bony acetabulum, beyond its outer profile, by reported means adapted to cooperate with at least one tongue (the) selected. -2- ring according to claim 1, characterized in that the deformable tongues (lc) are made by any means such as electro-erosion, laser beam .. after execution of the peripheral thread, and they are positioned regularly or not on the peripheral surface of the ring.  Ring according to i-evendlcatlon 1, caractoriso in cp that the means comprise a core (2) of connection with the femoral head ~ said core having for this purpose at least one pusher element tongues (lc).  -4- Ring according to claim 3, characterized in that the core (2) is equipped with fixed pushing elements (2a) such as ramps, bosses, intended to push the deformable tongues (lc) beyond the outer profile of the ring when the core is set up in the ring. -5- Ring according to claim 3, characterized in that the core <2) is equipped with removable pushing elements (3> such as profiled lugs, fingers, intended to push the deformable tongues (lc) beyond the profile outside the ring when the core is set up in the ring.  -6- Ring according to claim 5, characterized in that the removable pushing elements (3) are of different lengths to achieve a depression of varying depth of the tongues in the bony acetabulum.