DEVICE FOR GRIPPING A PROSTHETIC ELEMENT SUCH AS A CUP AND METHOD FOR USING A GRIPPING DEVICE AS AN EXPERIMENTAL SETUP

Description

FIELD OF APPLICATION OF THE INVENTION

[0001] The present invention relates to a device for gripping prosthetic elements such as cups and in particular to adaptations making it possible to ensure this gripping in the best conditions and to adapt this gripping in order to simplify the intraoperative testing phases. The closest prior art is document WO 2018 / 109371 A1, which defines the preamble of claim 1. DESCRIPTION OF THE PRIOR ART

[0002] Acetabular prostheses are well known in the orthopedic field. They consist of a metal cup with a more or less hemispherical external shape, sometimes extended by a truncated or full cylinder.

[0003] The cup has an external surface which may or may not extend beyond the equator, a continuous hemispherical or partially conical concave internal surface, with or without a threaded pole hole for connecting an instrument.

[0004] This cup can be a dual mobility cup with a smooth, polished, hemispherical internal surface, or a single mobility cup whose internal surface includes a wedging cone with a specific roughness, extended by more or less spherical caps. Thus, the interior of the cup can be of variable shape: hemispherical, hemispherical extended by a cylinder, partially conical.

[0005] This cup is intended to be implanted in the bony acetabulum of a patient. An insert is then assembled inside the cup, forming the joint in which a femoral prosthetic head is placed.

[0006] The internal surface conditions can vary: for a metal / polyethylene friction pair, it is polished, for a pair with a ceramic insert, the conical surface has a roughness suitable for assembly.

[0007] After preparing the bone site, dynamic intraoperative tests are performed to verify the adequacy of the cup sizes with the positions (lengths and diameters) of the heads associated with the femoral stems. These tests are performed with trial pieces made available in the ancillary. The tests provide information on the optimal configuration (limb length, joint stability, range of motion) of the components to be implanted. The final metal cups are oriented and installed in the patient's bony acetabulum. The polyethylene or ceramic insert is assembled in situ. The prosthetic femoral head of the appropriate length is mounted on the femoral stem, and the joint is then reduced.

[0008] To attach the cups to an instrument in order to transport them, position them and release them into the patient, there are currently several technical solutions,

[0009] For example, there are systems that screw into the bottom of the cups. This is not possible in some configurations and when possible, it is advisable to obstruct the threaded hole to avoid migration of wear particles, which is costly in terms of handling time. Indeed, the implementation of such a system requires the screwing and unscrewing of the instrument, the screwing of a stopper.

[0010] Another system described in document US10,245,161 consists of temporarily bonding to the cup. To this end, this document describes a device for gripping and fitting an acetabular cup comprising at least two snap-on rims. The device comprises a gripper which is a separate subassembly of the handle. This gripper comprises teeth capable of engaging with the rims of the acetabular cup. The gripper comprises a movable pusher, capable, during its movement, of exerting a thrust on the acetabular cup along the axis of revolution of said acetabular cup, so as to release the rims of the acetabular cup from their engagement with the teeth included by the gripper. The gripping device comprises an actuating device for actuating the movable pusher,

[0011] Such a device has several disadvantages described below.

[0012] Due to the different opposing surfaces, the quality of grip is limited. In addition, the transmission of forces applied to areas without adhesion of the cup is not effective during stresses and conflicts generated during installation of the implant.

[0013] Manipulation of this cup is made difficult by indirect surgical approaches which bypass soft and bony tissues, very short incisions,

[0014] In addition, with current gripping instruments, there is a risk of the cup becoming detached from the gripper when it is placed in and at the bottom of the bone site. Indeed, the adhesion depends on the number of teeth engaged with the snap-on edges. This can lead to inaccurate implantation, damage to the bone, and additional time to conduct the intervention.

[0015] The use of a sterile interface mounted previously in the laboratory on the cup exists (as also described in US10.245.161). It has the advantage of being able to be quickly connected to a gripping device without being contaminated by any external manipulation. The safety of the assembly in the laboratory is controlled. However, the intermediate part must be machined in a very rigorous and restrictive manner, which leads to very high costs. In addition, obtaining by molding is not possible because the material used must also meet biocompatibility requirements, which limits the choice or considerably increases the medical-technical argument to be developed.

[0016] Finally, for the solution described in US10,245,161, the various elements must be positioned precisely so as to be able to implement their function. Indeed, the teeth must be positioned on the snap-on parts. In addition, the gripper must be correctly oriented in the intermediate part.

[0017] Another disadvantage concerns the intraoperative testing phase described above. To perform limb length tests intraoperatively, it is necessary to have all versions in all sizes of trial inserts. In fact, all the components of the final prosthesis are reproduced by the trial pieces. All these trial pieces represent a very large volume in the dedicated ancillary boxes as well as a cost for reconditioning and / or sterilization after each use. With current limb length testing instruments, it is necessary to clean the bottom of the cup to install a trial insert, the type and size of which must be clearly identified, as well as the diameter of the trial head; there is a risk of unavailability and presentation error to the surgeon.

[0018] Another disadvantage is that the instruments proposed for rapid cup bonding are enclosed mechanisms that cannot be completely dismantled. They are therefore difficult to access for complete and effective cleaning. BRIEF DESCRIPTION OF THE INVENTION

[0019] What the applicants found was that they carried out research aimed at providing a reliable, rapid and simple connection of a prosthetic element such as a prosthetic cup to a gripping tool intended to transport it, position it and release it on the patient's bone site.

[0020] Such a device is intended for gripping sterile or non-sterile implants, prosthetic components, acetabular and glenoid components, trial pieces, trial cups, trial inserts.

[0021] This research led to the design and production of a gripping device for a prosthetic element such as a cup, the prosthetic element comprising an interior volume having an interior surface, the device comprising a gripping tool cooperating punctually with the prosthetic element for the purposes of manipulation and / or installation on the patient, said tool comprising a handle with at one end, a grip and at another end, a gripping module, said gripping module being controlled by the user's reaction on a lever blade associated with the handle to move from a retaining position to a rest position and vice versa.

[0022] This device is remarkable in that it comprises a mechanical interface inserted between the prosthetic element and the gripping module and which is fixed to the prosthetic element, said mechanical interface having a convex outer surface projecting partly into the interior volume of the prosthetic element and matching the interior surface of the prosthetic element, and a concave interior volume with which the gripping module cooperates, the mechanical interface consisting of a plurality of blades which, radiating around the same central part, adopt a profile with an internal surface and an external surface, said external surface forms said convex outer surface to match all or part of the profile of the interior surface of the prosthetic element, said mechanical interface being preformed and made of a material such that its elasticity allows it to be retained in the prosthetic element, so that the rest position of the gripping module controlled by the lever blade allows the latter to be introduced into the concave interior volume and to exit the latter, and that the retaining position allows the gripping moduleintroduced into the concave interior volume to grip the interface and retain the prosthetic element when the latter must be moved or to release the mechanical interface of the prosthetic element when the latter is in place and fixed to the patient's bone, the concave interior volume of the mechanical interface being preformed with peripheral bearing surfaces with which preformed peripheral retaining surfaces cooperate in the gripping module so that a movement controlled by the lever blade ensures the creation of a stress tending to extend the peripheral retaining surfaces so as to ensure the punctual fixing of the gripping module to the mechanical interface. said gripping module comprises a gripping crown equipped externally with said peripheral retaining surfaces and internally with inner peripheral inclined surfaces cooperating with outer peripheral inclined surfaces provided on the outer surface of aexpansion shaft movable in translation and one end of which is articulated to the lever blade so that the action on the lever blade causes a translational movement leading to the expansion of the peripheral retaining surfaces or their retraction to the rest position.

[0023] The mechanical interface can be: mounted / assembled then sterilized with the prosthetic element, available in the ancillary bowl on the operating table, disassembled and repositioned in situ.

[0024] The use of a mechanical interface introduced into the interior volume of a prosthetic element such as a cup is particularly advantageous in that it increases, by matching said interior volume, the adhesion surface for gripping purposes without making the resulting assembly more voluminous.

[0025] It also allows two parts to be separated: a part dedicated to the prosthetic element and its dimensions with the external surface of the interface and a part intended for cooperation with the gripping tool and its gripping module. This latter part can be identical whatever the dimensions of the prosthetic element so that the gripping module can be common for any dimension of prosthetic element,

[0026] The radiating lamella configuration provides the necessary elasticity to the interface to allow it to be held in position in the prosthetic element. The radiating lamella configuration provides the necessary elasticity to the interface to allow it to be held in position in the prosthetic element.

[0027] The configuration of the radiating lamellae integrates the stress sectors that transmit the force to several congruent contact surfaces in the internal equatorial zone of the prosthetic element. The division into angular portions promotes and allows the functional clearances necessary for the realization by molding of the mechanical interface. The number of lamellae contributes to containing the volumes of the elements of the expansion axis.

[0028] According to another particularly advantageous characteristic of the invention, the convex outer surface formed by the outer surface of said lamellae is preformed with a peripheral groove formed between a convex surface portion positioned at the bottom of the inner volume of the prosthetic element and a convex surface portion positioned at the edge of the prosthetic element. This groove constitutes a separation in the outer profile of the lamellae contributing to their elasticity,

[0029] According to another particularly advantageous characteristic of the invention, the internal surface of the profile of said slats is preformed with said peripheral support surfaces.

[0030] According to another particularly advantageous characteristic of the invention, said gripping module comprises a head of the gripping module which guides the translation of the expansion shaft, said head being split by a slot. This head is split by a slot so as to facilitate assembly and disassembly with the expansion shaft linked to the lever blade.

[0031] According to another particularly advantageous characteristic, said gripping crown comprises a slot opening the ring that it forms. This slot made in the gripping crown participates in the same function as the slot made in the head. Complete cleaning of the instrument and the changing of parts of suitable sizes and dimensions are therefore facilitated.

[0032] According to another particularly advantageous characteristic of the invention, the material of the mechanical interface is a rigid and biocompatible material,

[0033] According to another particularly advantageous characteristic of the invention, the material of the mechanical interface is polypropylene resin, a more specific one marketed under the trade name propilux. Polypropylene resin has the advantage of being rigid and biocompatible. It also allows for production by molding.

[0034] According to another particularly advantageous characteristic of the invention, the mechanical interface comprises teeth cooperating with preformed surfaces on the rim of the prosthetic element. These teeth are optional. They act as stops; when the prosthetic element is a cup, they oppose the rotational and torsional stresses of the cup / gripping module connection. These teeth ensure the hold between the cup and the gripper in the sterile packaging. In addition to their role as stops, they allow the mechanical interface to be positioned in relation to optional and complementary elements of the cup: internal holes, peripheral tabs.

[0035] According to another particularly advantageous characteristic of the invention, the concave volume of the mechanical interface is sized and preformed to present bearing surfaces corresponding to those of an insert intended to be received after placement of the prosthetic element to receive a trial or definitive head. Thus, the mechanical interface of the invention which facilitates the gripping of the prosthetic elements such as a cup with the advantages described above has the other function of also serving as a trial insert. To this end, the hemispherical concave surface located in place of the head and which allows the guidance and positioning of the gripping module, conditions the center of the trial head or the definitive head. The interface allows the tests to be carried out directly in situ without having to use other instruments.This secures the association of components, limits assembly errors and saves operating time. When packaged with the implant, the mechanical interface replaces trial inserts in instrument boxes, frees up space on the table and eliminates cleaning and repackaging.

[0036] Another object of the invention is therefore a method of using a gripping device for a prosthetic element such as a cup defined by all or part of the characteristics described above, remarkable in that it consists of using said mechanical interface as a trial insert.

[0037] The fundamental concepts of the invention having just been set out above in their most basic form, other details and characteristics will emerge more clearly on reading the description which follows and with reference to the appended drawings, giving by way of non-limiting example, embodiments of a cup gripping device in accordance with the invention. BRIEF DESCRIPTION OF THE TOPS

[0038] [ Fig. 1 ] is a schematic drawing of an exterior side view of an embodiment of a device according to the invention; [ Fig. 2 ] is a schematic drawing of an exploded perspective view of the gripping end of the device of the figure 1 ; [ Fig. 3 ] is a schematic drawing of a sectional view of the gripping end of the device of the figure 1 ; [ Fig. 4 ) And [ Fig. 5 ] are schematic drawings of the exterior perspective views of the reception of a test or final head: [ Fig. 6 ] is a schematic drawing of an exterior side view of a mechanical interface according to the invention; [ Fig. 7 ] is a schematic drawing of an exterior top view of the mechanical interface of the figure 6 : [ Fig. 8 ] is a schematic drawing of an external side view of a gripping crown according to the invention: [ Fig. 9 ] is a schematic drawing of an exterior top view of the gripping crown of the figure 8 ; [ Fig. 10 ] is a schematic drawing of an exterior side view of a movable expansion shaft according to the invention; [ Fig. 11 ] is a schematic drawing of an exterior top view of the expansion shaft of the figure 10 ; [ Fig. 12 ] is a schematic drawing of an exterior side view of the head of the handle of the gripping tool: [ Fig. 13 ] is a schematic drawing of an exterior top view of the sleeve head of the figure 12 . DESCRIPTION OF A PREFERRED EMBODIMENT

[0039] As illustrated by the figure 1 , the device referenced D as a whole ensures the gripping of a cup 100 by means of a gripping tool O for the purposes of manipulation and / or installation on the patient (not illustrated).

[0040] This tool O comprises a handle 200 with at one end a grip 210 and at another end called a gripping end a gripping module 220.

[0041] Said gripping module 220 is controlled by the action of the user (not shown) on a lever blade 211 associated with the handle 200 to move from a retaining position to a rest position and vice versa. The user actuates the lever blade 211 by moving the pivoting lever from the illustrated rest position to a working position (not shown) by pivoting according to the arrow F1.

[0042] As illustrated, the device D comprises a mechanical interface 300 fixed to the cup 100 before gripping by the tool O and with which the gripping module 220 cooperates.

[0043] As illustrated by the figures 2 , 3 , 8 And 7 . said mechanical interface 300 has a convex outer surface 310 matching the inner surface of the cup 100 and a concave inner volume 320 with which the gripping module 220 cooperates.

[0044] This mechanical interface 300 is composed of a plurality of blades 330 corresponding to angular portions which, radiating around the same central part 340, adopt a profile with an internal surface 331 and an external surface 332. Said external surface 332 forms said convex external surface 310 matching a part of the substantially circular profile of the internal surface 110 of the cup 100 (cf. figure 3 ),

[0045] This mechanical interface 300 has an elasticity resulting from its material but also from its design. Thus, the convex outer surface 310 formed by the outer surface 332 of said lamellae 330 is preformed with a peripheral groove 311 formed between a convex surface portion positioned at the bottom of the cup and a convex surface portion positioned at the rim 120 of the cup 100. This groove 311 adopts a semi-circular profile open to the outside. Another characteristic contributing to the elasticity of the mechanical interface 300 concerns the slots 350 separating the different lamellae 330. This elasticity allows the mechanical interface 300 to be retained in the cup 100.

[0046] The mechanical interface further comprises on the outer periphery of its upper edge teeth 360 cooperating with surfaces preformed for this purpose on the rim 120 of the cup.

[0047] The internal surface 331 of the slats 330 forms the concave internal volume 320 of the mechanical interface 300. It is preformed in the upper part of peripheral support surfaces 333 facing the central axis of the mechanical interface 300.

[0048] As illustrated by the figures 2 And 3 . when the gripping module 220 is introduced into the concave interior volume 320, said peripheral support surfaces 333 are opposite peripheral retaining surfaces 231 preformed in the gripping module 220.

[0049] As further illustrated by the figures 8 And 9, these peripheral retaining surfaces 231 are constituted by the outer surface of projections projecting downwards from a gripping ring 230, a constituent element of the gripping module 220. These projections are also preformed with inner peripheral incised surfaces 232 facing the central axis of the gripping ring 230. As illustrated, this gripping ring 230 has a certain elasticity due to its material but also due to its configuration. Thus, the projections are spaced apart and separated by slots 233. In addition, the ring formed by the ring 230 is itself split. This slot 234 has another function which will be described later.

[0050] As illustrated by the figures 2 And 3. these inner peripheral inclined surfaces 232 cooperate with outer peripheral inclined surfaces 241 arranged on the outer surface of a movable expansion shaft 240 in translation (according to the double arrow F2) and one end 242 of which is articulated to the lever blade 211 so that the movement of the lever blade 211 controlled by the rotation of the lever 212 causes the translational movement of the shaft 240, As illustrated in more detail by the figures 10 And 11 , the outer peripheral inclined surfaces 241 are preformed on the periphery of a bulge of said shaft. The lower part 243 of this bulge matches the surface of the concave volume. In addition, an axial projection 244 is introduced into an axial orifice 370 made in the bottom of the mechanical interface 300 for the purposes of positioning and guiding the translation according to the double arrow F2.

[0051] As illustrated by the figures 2 And 3. another constituent element of the gripping module is constituted by the head 250 of the gripping module 220 which guides the translation (double arrow F2) of the expansion shaft 240. As illustrated in more detail by the figures 12 And 13 , this head 250 is split by a slot 251 so as to facilitate assembly and disassembly with the expansion shaft 240 linked to the lever blade 211. The slot 234 made in the gripping crown 230 participates in the same function. Complete cleaning of the instrument and the change of parts of suitable sizes and dimensions are therefore facilitated.

[0052] The lower face of this head 250 is further preformed with a hexagonal projection 252 allowing the orientation and correct positioning of the gripping crown 230 preformed for this purpose.

[0053] There figure 2 shows the coaxiality of the different elements: cup 100, mechanical interface 300 and gripping module 220.

[0054] The gripping of the mechanical interface 300 associated with the cup 100 by the gripping module 220 is illustrated by the figure 3 This gripping can take place for the placement of the cup 100 or the release of the mechanical interface 300 relative to the cup 100 fixed to the patient's bone.

[0055] The user's action on the pivoting lever 212 according to the arrow F1 has the effect of causing the lever blade 211 to exert axial traction according to the arrow F3 on the expansion shaft 240 which moves in translation according to this arrow. The outer peripheral inclined surfaces 241 formed on the outer surface of said movable expansion shaft 240 then exert a radial stress according to the arrows F4. This stress according to the arrow F4 is reflected on the inner surfaces 232 and therefore outer surfaces 231 of the projections of the gripping ring 230 which reflects it on the blades 330 of the mechanical interface 300 ensuring the gripping of the gripping module 220 on the mechanical interface 300 and of the mechanical interface 300 on the cup 100.

[0056] The return to the rest position of the pivoting lever 212 allows the gripping module to no longer exert stress on the mechanical interface 300 and to release its internal concave volume 320.

[0057] Leaving the mechanical interface 300 in place in the cup 100 itself fixed to the patient's bone can allow the implementation of another function of the invention.

[0058] Indeed, as illustrated by the figures 4 And 5 , the mechanical interface 300 is designed to serve as a test insert for test or final heads 400.

[0059] To do this as illustrated by the figures 6 And 7. the concave volume 320 of the mechanical interface is sized and preformed to present support surfaces corresponding to those of the insert intended to be received after installation of the cup 100. The internal surface of the profile of said strips 300 has been preformed so as to form the receiving and retaining volume for the head,

[0060] It is understood that the device which has just been described and represented above has been done so with a view to disclosure rather than limitation. Of course, various arrangements, modifications and improvements may be made to the examples above, without departing from the scope of the invention.

[0061] Thus, although the cup, the mechanical interface and the head illustrated in this non-limiting embodiment adopt a so-called single mobility configuration, the invention also applies with shapes and dimensions adapted to a so-called double mobility configuration.

Claims

1. Gripping device (D) for a prosthetic element (100) such as a cup, the prosthetic element (100) comprising an inner volume having an inner surface, the device comprising a gripping tool (O) engaging occasionally with the prosthetic element (100) for the purpose of handling and / or fitting on the patient, said tool comprising a shaft (200) with, at one end, a handle (210) and, at another end, a grip module (220), said grip module (220) being controlled by the action of the user on a lever blade (211) associated with the shaft to switch from a retaining position to a resting position and vice versa, said device comprising a mechanical interface (300) interleaved between the prosthetic element (100) and the grip module (220) and fastened to the prosthetic element (100), said mechanical interface (300) having a convex outer surface (310) projecting partially into the inner volume of the prosthetic element (100) and moulding the inner surface of the prosthetic element (100), and a concave inner volume (320) with which the grip module (220) engages, the mechanical interface (300) consisting of a plurality of strips (330) which, radiating around one same central part, adopt a profile with an inner surface (320) and an outer surface (310), said outer surface (310) forms said convex outer surface to mould all or part of the profile of the inner surface (110) of the prosthetic element (100), said mechanical interface (300) being preformed and made of a material such that its elasticity enables it to be retained in the prosthetic element (100), such that - the rest position of the grip module (220) controlled by the lever blade (211) enables the latter to be introduced into the concave inner volume (320) and to exit the latter, and that - the retaining position enables the grip module (220) introduced into the concave inner volume (320) to grip the interface (300) and to retain the prosthetic element (100) when the latter must be moved or to release the mechanical interface (300) from the prosthetic element (100) when the latter is in place and fastened to the patient's bone, the concave inner volume (320) of the mechanical interface (300) being preformed with peripheral bearing surfaces (331) with which peripheral retaining surfaces preformed in the grip module (220) engage, such that a movement controlled by the lever blade (211) creates a stress tending to extend the peripheral retaining surfaces, so as to ensure the occasional fastening of the grip module (220) to the mechanical interface (300), CHARACTERISED IN THAT said grip module (220) comprises a grip crown (230) equipped externally with said peripheral retaining surfaces (231) and internally with inner peripheral inclined surfaces (232) engaging with outer peripheral inclined surfaces (241) provided on the outer surface of an expansion shaft (240) movable in translation and one end of which is articulated to the lever blade (211), such that the action on the lever blade (211) causes a translational movement leading to the expansion of the peripheral retaining surfaces (231) or their retraction into the rest position.

2. Device (D) according to claim 1, wherein the convex outer surface (310) formed by the outer surface of said strips (330), is preformed with a peripheral groove (311) provided between a convex surface part positioned at the bottom of the inner volume of the prosthetic element (100) and a convex surface part positioned at the rim of the prosthetic element (100).

3. Device (D) according to claim 1, wherein the internal surface of the profile of said strips (330) is preformed from said peripheral bearing surfaces (331).

4. Device (D) according to claim 1, wherein the mechanical interface (300) comprises teeth (360) engaging with surfaces preformed on the rim of the cup (100).

5. Device (D) according to claim 1, wherein the concave volume (320) of the mechanical interface (300) is sized and preformed to have bearing surfaces corresponding to those of an insert intended to be accommodated after placement of the prosthetic element for the purpose of accommodating a test or final head (400).

6. Device according to claims 1 and 5, wherein the internal surface of the profile of said strips is preformed so as to form the accommodating volume for the insert.

7. Device according to any one of the preceding claims, wherein the material of the mechanical interface (300) is polypropylene resin.

8. Device according to claim 1, wherein said grip module (220) comprises a head (250) of the grip module (220) which guides the translation of the expansion shaft (240), said head (250) being slit by a slot (251).

9. Device according to claim 8, wherein said grip crown (230) comprises a slot (234) opening the ring that it forms.

10. Method for using a gripping device for a prosthetic element such as a cup of the device according to any one of claims 1 to 9, CHARACTERISED IN THAT it consists of using said mechanical interface (300) as a test insert.