WO1992008425A1 - Amputated limb prosthesis - Google Patents

Abstract

An amputated limb prosthesis comprising a rigid socket (1) covering part of the amputated limb and connected (6) to the artificial foot (or hand), and an inflatable flexible cover (20) for covering the outside (25) of the stump (30) while being pressed against the inside (21) of said socket (1). Said flexible cover (20) is extensile and both its main surfaces (21, 25) are impermeable. When it is in place on the stump (30) it is filled with a compressible flexible material (27) to form a sleeve.

Description

 AMPUTE MEMBER PROSTHESIS.

The invention relates to an amputated limb prosthesis.

If in the following description, the invention will be more particularly described in its preferred application of tifaial prosthesis, on the other hand, it can receive other applications, such as in particular prosthesis forearm, arm or thigh.

The pius generally, to date, when one wishes to carry out a tibial prosthesis, one begins by taking an impression of the stump, then of this impression one realizes a positive, on which one makes a flexible sleeve and finally, one covers the sleeve a rigid socket.

Although widely used, this technique has significant drawbacks, however. First of all, it is expensive because, on the one hand, it requires the use of highly specialized labor, and on the other hand, sometimes results in several days of hospitalization. In addition, if in the long run, the stump varies, or if a bad adaptation of the prosthesis appears, these operations must be repeated. Finally, as we know, in the long run, the flexible sleeves pack and get dirty, so they must be changed. In short, this technique called "by socket and sleeve", although satisfactory on the technical side of the prosthesis itself, is costly, in particular as a result of the hospitalization it requires or as a result of the manufacturing and delivery times. imposed by classical techniques. In document FR-A-2 095 097, it has been proposed to inject foam between the socket and the stump in place. This injection, which can only be done in the bottom of the socket, only serves to wedge the stump in place. In addition, the fitting of the stump is restrictive, painful for the patient and traumatic for the skin tissue. Furthermore, this system is fixed, therefore uncomfortable. Finally, this system cannot be used when the stump has undercuts.

In document US-A-4,923,475, the stump is covered with an inflatable flexible envelope, the assembly is placed in the socket and air is blown into the envelope. The air being by nature very compressible, it follows that once in place, the stump is badly held in space. In this way, the prosthesis is unstable, poorly centered, in particular by lack of alignment in space. In addition, during the support phase, the stresses transmitted by the stump to the envelope refer to the connection points on the socket or at the bottom of the envelope, which causes an irregular distribution of the pressures on the stump. . In short, this prosthesis is not comfortable, is medically unsatisfactory and does not allow the entire stump to be molded, in particular the lower end of the femur.

The invention overcomes these drawbacks. It is aimed at a socket and sleeve prosthesis, which is easier to implement, much less expensive and considerably reduces hospitalization and delivery times.

The invention relates to a prosthesis of the type with above inflatable casing which is stable, centered and conforms perfectly to the shape of the stump and in which, during the supports, the stresses are regularly distributed, which contributes to improving the comfort thereof, therefore Security. This amputated limb prosthesis comprising:

. a rigid socket covering part of the amputated limb, connected to the artificial foot (or hand); . and a flexible inflatable hollow envelope, intended to come to cover the external face of the stump and to be pressed against the internal face of the socket, is characterized in that the flexible envelope is extensible and waterproof on its two main faces, and, once in place on the stump, is filled with a flexible compressible material to form a sleeve. 0

In other words, the invention consists in using a standard sleeve forming an envelope, which adapts, by forming a comfort mattress to the measurements of the stump, when one subsequently injects inside said envelope, at the time of the adaptation on the patient, 2 a flexible filling material, such as a polyurethane foam, a gel and / or a silicone foam. The extensibility of the two faces of the envelope allows it to press homogeneously against the inner wall of the socket respectively and against the outer skin surface of the stump, centered beforehand _{Q in} particular under the effect of the thrust filling material which expands in situ.

Advantageously, in practice:

the socket and the sleeve before injection are of standardized size 5, which makes it possible to further reduce the cost of this system;

- the rigid socket is made of thermoplastic material obtained either by injection, or by blowing, or by rotational molding, or by the process called R.I.M. ;

- the external part of the sleeve is made of flexible plastic material _Q foam with closed cells and is associated with a flexible sheet impermeable to the injected materials to retain them, but permeable to gases, in particular to those which could be released during the foam formation in situ or during filling with flexible material; REPLACEMENT SHEET - The flexible sheet forming the internal part of the sleeve-envelope is constituted by a fabric, such as in particular a knitted fabric, laminated with a layer of flexible cellular foam;

- the envelope is made of an elastic elastic material, so, during filling, to simultaneously allow the adaptation of the internal face to the morphology of the stump and of the external face of the envelope to the internal face of the 'socket;

- In a preferred version, the envelope is made from a flexible, waterproof, extensible sheet, made by welding to constitute ies two sides of the envelope; it can advantageously be a film of linear polyurethane, or even of silicone, of thickness between 50 and 200 microns; the hollow envelope has vents and supply orifices for the reactive products intended to form the foam and to control the densities thereof; if more generally, one can use a single envelope, it can also be formed of a plurality of pockets;

- The filling material of the envelope is a flexible foam expandable in situ, in particular of polyurethane or silicone;

- the filling material of the envelope is a silicone gel; - the filling material adheres or not to the envelope;

- in an improved version, part of the envelope can be filled with a first material, and the rest with a different material; for example, the bottom may be filled with a silicone gel and the side flanks with a polyurethane or silicone foam; it can also be foams of different densities;

- the envelope has a variable number of tubes, distributed symmetrically with respect to the vertical axis of the stump, for example at the rate of half in the upper part and half in the lower part, some serving as a material feed ^injection, other vents, allowing self-centering the stump during injection; in practice, there are two tubes in the upper part and two tubes in the lower part of the sleeve. To facilitate centering of the stump during installation in the socket, one or more horizontal rings of compressible material are placed on the stump, which can be removed after filling, for example by cutting them.

The invention also covers all prostheses produced in this way, in particular tibial prostheses for amputation of the leg below the knee.

The manner in which the invention can be implemented and the advantages which ensue therefrom will emerge more clearly from the embodiment which follows, with the support of the appended figures.

Figure 1 is a schematic front view in summary perspective, of a tibial prosthesis implemented according to the invention.

Figure 2 shows a sectional view of how to inject the foam into the characteristic envelope.

FIG. 3 is a diagrammatic representation in section along the axis m-Hr of FIG. 1.

Figure 4 is a schematic perspective representation of the sleeve.

Figure 5 is a schematic perspective representation of the socket. Figure ό is a schematic representation in summary section of an assembly according to the invention. The tibia prosthesis according to the invention first of all comprises a rigid socket designated by the general reference (1), made of thermopiastic material, for example rotomapped, having on the front top a bulge (2) corresponding to the knee, on the rear top a notch (3) for the folding of the leg, and the bottom (4) of which is secured to a base (5) on which the rod (6) which carries the artificial foot, not shown, is fixed. This rigid socket (1) has an external face (7) and an internal face (8 ⁾ . As already said, the assembly is made of injected, blown or better, rotational molded thermoplastic material. In a variant, the rear of the socket can be slightly cut on a generator, so as to allow adjustment over time. According to a characteristic of the invention, the rigid socket is produced in a series of standardized sizes ^, adapted to the main conformations of individuals.

The lower part ⁽ 4) of the rigid socket (1) has a through hole (10), through which passes a conduit (11). The upper part, in particular at knee height ⁽ 2), has a second through orifice ⁽ 12 ⁾ through which passes a conduit (13). The interior of the rigid socket receives an inflatable envelope in the general shape of a bowl. designated by the general reference ⁽ 20 ⁾ , the outer membrane (21) closely follows the inner face (8) of the socket. This flexible sleeve-cover (20 ₎ is advantageously made of an elastic material. According to a characteristic of the invention, this envelope (20) intended to cover the stump and to adapt in the socket (1), is also produced in several standardized sizes to correspond to the different morphologies of the members of the individuals.

As already stated, ^the envelope is made of an elastic material, stretchable and sealed to allow, when remphssage, adapting to both the inner face of the sleeve to the morphology of the _stump, and ^adaptation of the face external of the sleeve to the internal face of the socket.

FE If more generally, the sleeve can be closed to form a single piece in the form of a bowl which is fitted on the stump, it can also be a flat piece, bordered by sealing means (zipper .. ), which allows it to be adapted to the stump without constraint, and which increases comfort.

According to a first embodiment of the invention, the outer membrane (21) of the envelope is associated with a sheet (25), flexible, impermeable to injection materials (liquids or pastes), so as to define a envelope that will be filled with a flexible material (27) during the adaptation to the stump designated by the general reference (30). In other words, the filling material (27) makes it possible to adapt the internal shape of the sleeve to the exact configuration of the stump (30). The characteristic flexible sheet (25) is impermeable, in particular to filling liquids, permeable to gases caused either during penetration of the filling material (27), or in-situ expansion of this material.

The manner of filling the envelope is shown in FIG. 2. The reagents (polyol and isocyanate), intended to form the polyurethane foam, are introduced in a known manner into an ampoule (40) provided with a suitable neck (41). , intended to be inserted in the conduit (11) connecting the envelope. In this way, the reactants reacting to each other by expanding, cause the foam (27) to penetrate into the envelope (26). The high opening (12) associated with its tube (13), forms a vent to allow the gases formed during the reaction and the excess of product, to escape.

In a preferred embodiment, the sleeve envelope (26) is made from a flexible, waterproof and extensible sheet 100 microns thick in linear polyurethane. This envelope has, as before, inlet and outlet orifices (vents).

The implantation of the prosthesis characteristic of the invention is carried out as follows.

REPLACEMENT SHEET Depending on the patient's stump, the technician chooses an appropriate standardized socket (1) and sleeve (20). It sets up the sleeve (20) in the socket (1) so that the external face (21) of the sleeve coincides perfectly with the internal face (8) of the socket and so that the orifices (10 , 12) coincide. The prosthetist then positions the empty prosthesis on the patient's stump, so that the flexible sheet (25) is directed towards the stump. He then injects through the orifice (11) an expandable foam and / or a silicone gel, or even a silicone elastomer, which avoids an exothermic reaction which can sometimes be painful. The filling material (27) fills all the available volume by adapting to the exact morphology of the stump, the filling material (27) solidifies while remaining adapted to the shape of the stump. In this way, the patient can immediately use this prosthesis.

In a variant, the filled sleeve can be put in place by turning over the stump.

FIG. 6 briefly illustrates a preferred embodiment of the invention. In this embodiment, the bowl-shaped sleeve designated by the general reference (50) is in the form of a single envelope previously put on the stump.

(30), formed of a linear polyurethane film 100 microns thick, so that the outer face (51) is pressed against the inner face of the socket (1) and the inner face (52) against the outer skin surface (31) of the stump (30). This empty envelope (50) is fitted on the stump (30). There is a ring near the bottom of the stump

(55) in a compressible material, for example very light foam, as well as a second similar ring (56) arranged on the top We put the stump (30) coated with the empty envelope (50) but inflatable, in the socket (1). The stump is then perfectly centered thanks to the compressible rings (55,56). The bottom (60) of the envelope (50) is then filled with a silicone gel, for example with a density close to 1, until the first compressible ring (55) is flush. Then filling the upper part (61) located between the two compressible rings (55,56) and intended to form the lateral sides of a silicone foam of density close to 0.2. Once the gel and the foam have solidified, the two rings (55) and (56) are removed, for example by cutting them.

Thanks to this arrangement, the stump (30) is perfectly centered, in particular during the supports, which does not make it possible to obtain the prior art, in particular the technique described in document US-A-4,923,475 cited in the preamble. In addition, a regular distribution of stresses is obtained, which contributes to improved comfort for the patient and better security.

If by chance over time, the stump varies in volume, simply remove the prosthesis, remove the sleeve, and replace it with a new, more appropriate standard sleeve and repeat the operation.

The prosthesis according to the invention is easy to place. easy to remove, does not require special hospitalization, and is therefore significantly improved in cost. This prosthesis differs from those described in the preamble by the fact that the sleeve can be fitted outside of the socket by turning, by simpie fitting or by dressing. When wearing, this prosthesis is comfortable because it distributes the pressures evenly over the entire surface of the stump. Furthermore, the stability of this prosthesis is excellent. In addition, it allows to equip stumps with undercuts.

Furthermore, the possible use (see Figure 6) of materials of different density and consistency improves comfort.

Finally, during installation, it is possible to ensure good centering of the stump in the socket, thanks to the compressible rings.

It could not have been foreseen that by bringing together the lessons learned from the two documents cited in the preamble FR-A-2 095 097 and US-A-4 923 475, one could successfully solve problems which have been acute for a long time , namely the uniform distribution of pressures and stresses over the entire surface of the stump, especially during the supports. In addition, the entire surface of the socket can be covered with the characteristic interposition sleeve, which improves the stability of the assembly and the comfort, since it is possible to cover the lower end of the femur, at least in the shin realization.

It can be used for any limb amputation prosthesis, in particular as a tibia prosthesis.

Claims

1 / Amputated limb prosthesis, comprising: . a rigid socket (1) covering part of the amputated limb, connected (6) to the artificial foot (or hand); . and a flexible inflatable hollow casing (20) intended to cover the external face (25) of the stump (30) and to be pressed against the internal face (21) of the socket (1), characterized in that the flexible envelope (20) is extensible and waterproof on its two main faces (21,25) and, once in place on the stump (30), is filled with a flexible compressible material (27) to form a sleeve. 2 / Prosthesis according to claim 1, characterized in that the socket (1) and the sleeve (20) are of standardized size and in that the rigid socket (1) is made of injected blown or rotational molded thermoplastic material. 3 / Prosthesis according to claim 2, characterized in that the envelope is constituted on its external face (21) by a fabric laminated with a layer of flexible cellular foam with closed cells, and on its internal face (25) with a sheet flexible (25) impermeable to liquids, but permeable to gases. 4 / A prosthesis according to claim 1, characterized in that the envelope (20) is made from a flexible extensible waterproof sheet made by welding to form the two faces (21,25) of the envelope (20). 5 / A prosthesis according to claim 4, characterized in that the flexible waterproof extensible sheet constituting the inflatable envelope (20) is made of a linear polyurethane film or silicone of thickness between 50 and 200 microns. 6 / Prosthesis according to one of claims 1 to 5, characterized in that 6 / Prosthesis according to one of claims 1 to 5, characterized in that the filling material (27) of the envelope (20) is chosen from the group comprising polyurethane foams, silicone or elastomer foams expandable in-situ and silicone gels. 7 / A prosthesis according to claim 6, characterized in that the bottom (51) of the envelope (50) is filled with a silicone gel while the lateral sides of this envelope (50) are filled with a foam of polyurethane. 8 / Prosthesis according to one of claims 1 to 6, characterized in that the bottom (51) of the envelope (50) is filled with a first foam, while the lateral flanks of the envelope (50) are filled with a second foam having a density different from the first. 9 / Prosthesis according to one of claims 1 to 8, characterized in that the envelope (20) has a number of tubes (11,13) distributed symmetrically relative to the vertical axis of the stump (30) and this, at the rate of half in the upper part (13) and half in the lower part (11), some serving as filling material for filling (27), others as vents. 10 / Prosthesis according to one of claims 1 to 9, characterized in that during installation, it also comprises at least one horizontal ring of compressible material surrounding the stump (30) and the casing (20), for center the assembly before expansion.