IT202000002134A1 - HYBRID SUB-ISCHIATIC POTTING AND PROCESS OF CONSTRUCTION - Google Patents

Description

INVASATION FOR TRANSFEMORAL PROSTHESIS AND ITS PROCEDURE

OF REALIZATION

DESCRIPTION

Technical field of the invention

The present invention refers to a socket for transfemoral prosthesis and to a related manufacturing process.

Background

Lower limb prostheses are devices aimed at the anatomical restoration of the absent portion of the limb and at restoring the deficient function. Prostheses can be classified according to the anatomical level affected by the amputation or congenital pathology and according to the construction technique. According to the construction technique? possible to distinguish? traditional prostheses?, also called? exoskeletal? and? modular prostheses? also called? endoskeletal ?.

Traditional prostheses are prostheses characterized by having rigid external walls with a load-bearing function that determine their external cosmetic shape. They are made with materials such as wood, synthetic lamination resins and polyurethane foam, which make them resistant, reliable and safe. This type of prosthesis are now in disuse due to the poor adjustment potential to the advantage of the pi? modern? modular prostheses ?.

The? Modular prostheses? they were introduced in the 1960s and only from the 1980s were light alloys such as aluminum, titanium and carbon fibers used for them. In particular this last material has contributed, thanks to its properties? mechanics and workability, to improve the characteristics of the prostheses. Modular prostheses are usually more? light than traditional ones: the weight of a prosthesis plays a fundamental role in portability? of the prosthesis itself and on the energy expenditure resulting from its daily use. The modularity? of the components allows to adjust the reciprocal position of the prosthetic components and to update it in virtue of of the evolution of the patient's needs. In technical jargon, these adjustments are aimed at obtaining an adequate static (standing posture) and dynamic (while walking) alignment.

The prostheses to which the present invention refers are those reserved for transfemoral amputations. The aforementioned prostheses are usually made up of components of industrial production, such as the articular elements (knee), prosthetic feet, tubular structure, connection joints, and of tailor-made components such as the socket and the cosmetic coating, suitably assembled and configured.

The condition of the stump, the state of the residual musculature, the consistency of the subcutaneous tissue, the possible presence of scars, adhesions or edematous deposits, as well as? the physical and psychological conditions of the patient determine the choice of the prosthetic components pi? adequate to obtain a satisfactory recovery of the capacity? ambulatory.

The potting? the part that requires the highest degree of customization as? the connecting element between the patient, or user, and the artificial limb. It allows control and transfers the loads to the abutment during walking. The internal morphology of the potting can? present contact areas specifically dedicated to body weight support and areas that need to be 'discharged'. Its effectiveness, appropriateness and tolerability? they are closely linked to materials, design and cutting lines (ie the limits of the upper perimeter of the socket).

The socket of a modular prosthesis for transfemoral amputation is usually carried out according to two different methods:

? rigid walls (in wood, lamination resin or thermoplastic); ? with flexible walls with two large windows in the frame, one front and one rear;

In both cases, the potting can? have different designs. There are four types of socket for transfemoral prostheses adopted:

? ? quadrilateral?

? potting? CAT-CAM (with ischial containment) ?;

? potting? (Marlo Anatomical Socket) ?;

? ? sub-ischial? potting.

The first three types of sockets, albeit in a different way, physically interact with the patient's ischium while the fourth is the best solution. recent whose upper margins are more? lows of the ischium which is therefore not involved.

Socket? Quadrilateral?

The? Quadrilateral? it has a horizontal plane of support of the ischium, four distinct walls of interface with the abutment, with specific functions both of stabilization of the same and of containment of the musculature. The high front cutting lines give consistency to the position of the ischium on the plane. The stability antero-posterior of the abutment and the stable positioning of the ischium on the plane are obtained by creating the typical shape of the quadrilateral socket, with the width in the antero-posterior direction smaller than that in the medio-lateral direction and with the anterior wall of greater height than the rear one.

Without these geometric constraints there would be the risk of both excessive anteversion of the pelvis and loss of balance by the amputee during the walk due to a sliding of the ischium out of the support plane.

Potting? With ischial containment?

The? Ischiatic containment? Potting ?, born in 1985, compared to the quadrangular potting, provides a design that contains the branch and the tuberosity? ischial thanks to cutting lines pi? high that generate an oblique gripping force from top to bottom. The cutting lines more? proximal ones favor the maintenance of the alignment of the femur and the stabilization of the pelvis.

This solution improves safety during the journey and provides more? volume for the muscles allowing you to use the hip flexors more. The load ? more distributed on the soft tissues and the stress on the tuberosity is reduced? ischial.

Pot? M.A.S.?

The? M.A.S.? born in 1999,? a development of the ischiatic containment potting, and it too contains the branch and the tuberositis. ischial. It provides for front and rear cutting lines more? low and ischial fin pi? high. The result is a greater articular excursion in flexion of the hip, better adhesion with the abutment, better aesthetics and comfort in the gluteal area. Greater muscle recruitment. Unlike the ischial containment, the containment of the ischial branch complex with the MAS leaves the gluteus maximus muscle free from the load of the weight force, thus allowing it to contract freely during flexion-extension of the hip joint.

Potting? Sub-ischial?

Recently conducted studies have shown that the prosthetic sockets described above limit the functionality? joint of the hip, offer reduced comfort and can lead to the onset of painful pathologies (cysts or calluses due to areas of hyperpressure) reducing the time of daily use of the prosthesis itself.

These studies have encouraged the development of new socket solutions with sub-ischial cutting lines made applicable thanks to the introduction of new suspension systems (anchoring mechanisms between the socket and the abutment) which provide active pumps capable of establishing a sub-ischial pressure. atmospheric. L? Ischio not? contained inside the socket. The stability ? obtained through soft tissue compression and vacuum assisted suspension systems.

The currently existing sub-ischial sockets are therefore necessarily combined with the use of suspension systems with assisted vacuum. There are three types of solutions:

1. invaded a wall with apical depression chamber obtained thanks to the presence of a membrane interposed between cuff and socket;

2. reservoir on a wall with a vacuum chamber between the socket and cap obtained with the cap turned up over the edges of the reservoir and sealed with a toggle adhering to the reservoir;

3. double-walled cradle (internal flexible and external rigid) anchored together, with a vacuum chamber obtained with the cap turned up over the edges of the cradle and sealed with a toggle adherent to the cradle.

These types of potting are made starting from the negative plaster cast performed with the patient in a sitting position (unloaded). The internal morphology of the pot? determined therefore by the modeling process, or? stylization ?, of the positive plaster cast with plaster removal in predetermined areas based on the characteristics of the abutment.

These solutions, while presenting benefits in terms of articularity? of hip and comfort, have the following limitations in different ways:

? there is a constraint to use vacuum assisted suspension systems; ? there? a high compression of the abutment tissues also obtained through the use of prefabricated silicone caps of a size smaller than the standard;

? the dimensions and weight of the components are considerable;

? they are difficult to apply to abutments proximal to the joint.

Summary of the invention

The technical problem posed and solved by the present invention? therefore that of providing a socket for transfemoral prosthesis which allows to overcome the drawbacks mentioned above with reference to the known art.

This problem is solved by a socket for transfemoral prosthesis according to claim 1.

The present invention also provides a process for making a socket for transfemoral prosthesis according to claim 10.

The present invention also provides a transfemoral prosthesis according to claim 9.

Preferred features of the present invention are the subject of the dependent claims.

The present invention provides some relevant advantages. The main advantage lies in the fact that the contrived socket has improved conditions of use.

The contrived socket is configured as a? Hybrid? Sub-ischial socket, able to reduce the limitations mentioned above.

L? contrived potting allows you to:

- remove the limitations to the hip joint;

- improve comfort;

- improve device control;

- reduce the overall dimensions and improve the aesthetics;

- reduce the number and weight of components;

- stimulate action and muscle tone;

- removing the constraint, which the known sub-ischial solutions present, of the vacuum assisted suspension system;

- make an essential, light and effective anchoring system adoptable.

Furthermore, the contrived socket allows anchoring to the abutment through a? Passive? Hypobaric suspension system, that is? not bound to the use of mechanical or electromechanical active pumps for air suction. This entails numerous advantages linked to the lower overall weight of the prosthetic system, the lower manufacturing costs, the simplicity? constructive.

Other benefits, features and methods? of use of the present invention will become evident from the following detailed description of some embodiments, presented by way of non-limiting example.

Brief description of the figures

Will come reference is made to the figures of the attached drawings, in which:

? Figures 1 and 2 show axonometric views of a first embodiment of a socket according to the invention;

? Figures 3 and 4 show an axonometric view of a second embodiment of a socket according to the invention;

? Figure 5 shows a simplified illustrative view of the loading conditions acting on the abutment of a user of an embodiment of the socket according to the invention;

? Figure 6 shows a simplified axonometric view of a positioning frame which can be used in a method of manufacturing an embodiment of a socket according to the invention.

? Figure 7 illustrates a schematic and simplified view of a method for making an embodiment of the socket according to the invention.

The thicknesses and curvatures shown in the figures introduced above are intended as purely illustrative, they are generally magnified and not necessarily shown in proportion.

Detailed description of preferred embodiments

Various embodiments and variants of the invention will be described below, with reference to the figures introduced above.

Similar components are denoted in the various figures with the same numerical reference.

In the detailed description that follows, further embodiments and variants with respect to embodiments and variants already mentioned. treated in the same description will be illustrated limited to the differences with what already? exposed.

Furthermore, the different embodiments and variants described below are capable of being used in combination, where compatible.

With reference initially to Figure 1, according to an embodiment of the invention? generally denoted by 1 a socket 1 for transfemoral prosthesis.

The socket 1 comprises a substantially flexible casing 2 configured to fit an abutment 4 of a user. In particular, the casing 2? configured to fit the abutment in adherence 4.

The casing 2? provided with an upper edge 6, otherwise called? cutting lines ?, which can be positioned below the perineum and trochanter of the user. Preferably, the casing 2 has an apical closure 5 substantially opposite the upper edge 6. The configuration of the casing 2? such that the upper edge 6 defines an opening through which the stump 4 can? be shod. The apical closure 5? a bottom portion of the casing 2.

Furthermore, the casing 2 has an internal surface 7 whose configuration? described below.

The configuration? such that the resultant of the forces acting on the stump 4 is s? that the socket 1 remains integral with the abutment 4 during use.

In particular, the internal surface 7 of the casing 2 has a conformation which includes:

- a first insertion portion 8 intended to come into contact with the hamstrings of a user and exerting a first thrust S1 on the stump 4 reacting to the weight of the user. Such a push? a passive thrust with components of medio-lateral and cranio-caudal force;

- a second insertion portion (9) intended to come into contact with the sub-trochanteric area of a user and exerting on said abutment (4) a second thrust S2 reacting to the weight of said user. Such a push? a passive thrust with components of medio-lateral force, as opposed to the S1 thrust, and cranio-caudal;

- a third insertion portion (10) intended to come into contact with the apical-medial area of said abutment (4) and exerting a third support thrust S3 on said abutment (4). Such a push? an active apical-medial thrust with components of medio-lateral force, in opposition to the S4 and cranio-caudal thrust;

- a fourth insertion portion (11) intended to come into contact with the lateral femoral diaphyseal area of said abutment (4) and exerting a fourth supporting thrust S4 on said abutment (4). Such a push? an active thrust with components of medio-lateral force, as opposed to the thrust S3, and cranio-caudal;

The configuration? such that the resultant of the first thrust, second thrust, third thrust and fourth thrust includes an average lateral grip force and an upward thrust force on the abutment 4. In particular, the forces resulting from the two pairs of thrusts translate into a medium-lateral grip and an upward thrust from which a? floating? effect derives. hydrostatic of the abutment 4 inside the socket 2. The configuration of the socket 2, in particular its internal surface 7? such as to allow total contact between the abutment 4 and the internal surface 7 and at the same time a physiological orientation of the abutment in the frontal plane.

Preferably, the casing 2 can? comprise silicone polymers.

Usefully, the casing 2 can? be made of biomedical silicone. In particular, the silicone can? be customized in the composition and in the sizing to obtain the properties? appropriate mechanical-elastic and dependent on the anatomical-morphological-weight and functional characteristics of the user. The casing 2 can have a uniform thickness of about 3 mm.

The mechanical characteristics of the silicone of flexibility, deformability, isotropy and homogeneity? give the pot 1 the capacity? from:

- accommodate muscle contractions during walking, improving proprioception and avoiding vacuum losses

- follow the anatomy of the abutment during the sitting position, avoiding the introduction of air or the rotation of the socket;

- absorb shocks while protecting skeletal structures.

The socket 1 also comprises a substantially rigid containment frame 3 provided with at least one side wall 12 and a medial wall 13 coupled to the casing 2 and intended to be positioned respectively in a lateral position and in a medial position of the abutment 4.

The lateral 12 and medial 13 walls are arranged facing each other to define spacings, or windows in which the user's muscles can? deform.

Preferably, the lateral wall 12 and the medial wall 13 can be separated from the upper edge 6 for a minimum length of between 5 mm and 10 mm.

Conveniently, as illustrated in Figure 2, the lateral 12 and medial 13 walls can be connected by a band 20 of substantially rigid synthetic fabric. The 20 band can? have a height of about 5 cm. In the remaining figures, the 20 band does not? illustrated for simplicity.

Preferably, the lateral wall 12 and the medial wall 13 can be joined to define a U-shaped conformation having an apical portion 14 in the vicinity. of which ? inserted the apical closure 5 of the envelope 2. The apical closure 5 of the envelope 2 can? be adjacent and integral with the apical portion 14 of the frame 3.

In particular, the potting can? comprise at least one one-way valve 16 associated with the apical closure 5. Conveniently, the one-way valve 16 can? be configured to expel air from a chamber 15 defined between the apical closure 5 and the abutment 4 at the time of insertion of the abutment itself in the socket 1. The chamber 15 represents the variable volume contained between the inside of the envelope 2 and the outside of a silicone cap 30 fitted on the abutment. Such a room? proximally delimited by a sealing membrane placed directly on the aforementioned cap 30. The volume of the aforementioned chamber 15 is progressively reduced during the fitting of the socket 1 due to the expulsion of air from the aforementioned one-way valve 16 until it is canceled and the anchor sub-atmospheric pressure.

Preferably, the potting? capable of anchoring to the abutment 4 through a passive hypobaric suspension system not bound to the use of active mechanical or electromechanical pumps for air suction.

The frame 3 can? comprise at least one transverse element 17 coupled to the casing 2 and which connects the lateral wall 12 and the medial wall 13, as illustrated in Figure 1. Conveniently, the transverse element can? be positioned anteriorly with respect to the abutment 4, preferably at a distance of about 20 mm from the upper edge 6. The height of the transversal element 17 can? be about 5cm.

Advantageously, the frame 3 can? include carbon fiber composite material. Particularly, the chassis 3 can? be made of carbon, that is? can comprising layered carbon fibers pre-impregnated in a resin matrix, for example epoxy resin.

The carbon frame gives adequate stiffness and stability? in the lateral medial plane and the windows, the spaces identified between the lateral 12 and medial 13 walls, allow to accommodate the muscular contractions of the stump and the consequent volumetric variations during walking and to increase comfort in a sitting position.

In a second embodiment, illustrated in Figures 3 and 4, the socket 1 can? comprise a second casing 2a covering the casing 2 and the frame 3. In this case, the frame 3 can? be interposed between the casing 2 and the second casing 2a. In this second variant, the socket 1 provides a double layer of silicone 2, 2a in which? interposed the frame 3 which, in this case, can? have a medial wall 13 and a lateral wall 12 not connected anteriorly. This second embodiment? useful in the presence of particularly toned and voluminous 4 abutments.

The socket 1, both in the first embodiment described, and in the second embodiment described,? configured to be connected to the remaining parts that generally make up a prosthesis (joint components, prosthetic feet, tubular rods). A transfemoral prosthesis, therefore, can? comprise a socket 1 as previously described.

A procedure for making a? Socket 1 for transfemoral prosthesis? described below, with reference to Figure 7, which shows, in a simplified form, some manufacturing steps.

The procedure can? comprise a step A, B of making a negative cast 33 of a stump 4 of a user in which the stump 4 is coated with hardening material while? subjected to predetermined load conditions. The predetermined load conditions are set up:

- initially placing the abutment 4 under the effect of the weight force of the user, or otherwise called the patient, inducing a first push S1 on the hamstring of the user to obtain a first portion of insertion 8 on the negative cast 33, and a second thrust S2 on the sub-trochanteric area of the user to obtain a second insertion portion 9 on the negative cast 33;

- subsequently placing the abutment 4 under the effect of traction forces inducing a third push S3 on the apical-medial area of the user to obtain a third insertion portion 10 on the negative cast 33, and a fourth push S4 on the diaphyseal area -femoral of the user to obtain a fourth insertion portion 11 on the negative cast 33.

In particular, step A, B of making a negative cast 33 involves the following steps, which provide for an initial metric survey A of the abutment 4 and a subsequent obtaining B of a plaster cast as a negative cast 33.

The user, or patient, is made to wear a silicone cap 30 on the abutment 4, preferably a cap for a suspension system of the hypobaric type.

The circumferences of the abutment 4 are measured every 5 cm starting from the apex and continuing proximally.

The points of relief of the measurements and the position of the trochanter are reported on the cuff 30. These will be transferred first on the internal surface of the negative cast 33 and then on a positive cast 34 and will allow a control in a subsequent modeling or "stylization" phase.

The patient, in an upright position, with the aid of suitable support means 31, comprising a positioning frame 31a provided with a gypsum easel and a connecting frame, houses the abutment 4 inside the support means 31, in particular inside the positioning frame 31a.

The positioning frame 31a is adjusted on the basis of the size and orientation of the abutment 4, the position of the trochanter and the ischial branch, calibrating the height and diameter of the housing, orienting the abutment in space both in the sagittal plane (flexed -extension) that frontal (abadduction) and defining the localization and depth? of both subischiatic and subtrochanteric support.

The top edge of the? Positioning frame? must not exceed the trochanter, the lower edge of the same must be about 5 cm from the apex of the abutment 4. The sub-ischial support device is adjusted in the direction of depth. and must be placed below the tuberosity? ischial almost to simulate a cranio-caudal thrust (? insertion area of the hamstring?). A thickness should be applied to the sub-trochanteric area. Referring to Figure 6, a positioning frame 31a comprises an adjustable structure. In particular, the positioning frame 31a comprises five modules 40, 41 associated with each other to define a containing structure in which it can? the abutment 4 of a user be inserted.

The positioning frame 31a comprises longitudinal adjustable sliders 45, and radial adjustable sliders 43 thanks to which the containing structure can be adjusted to accommodate abutments of different sides, lengths and volumes.

Advantageously, the positioning frame 31a can? comprise an adjustable sub-ischial support device 42. In particular, the sub-ischial support device 42? adjustable in the sense of depth? in order to define the intensity? of the first thrust S1 in the insertion portion 8 and of the second thrust S2 in the insertion portion 9.

Usefully, the positioning frame 31a can? comprising a spherical joint 44 configured to connect the positioning frame 31a to a gypsum stand for aligning the abutment in the frontal plane (abadduction) and in the sagittal plane (flexion-extension).

The configuration of the positioning frame 31a? such as to provide:

- a volume in a distal area for the passage and positioning of elastic bands 32 for the realization of the third thrust S3 in the insertion portion 10 and of the fourth thrust S4 in the insertion portion 11; - a volume in an apical area for the connection of the air suction device to an elastic sealing tube to generate the vacuum and compact the plaster casts on the abutment 4.

Subsequently, two elastic bands 32 are applied which surround the abutment respectively in the medial apical area and in the lateral femoral diaphyseal area. Traction forces are applied by means of the elastic bands 32 stretched along opposite directions and inclined with respect to the femoral axis of said abutment 4. The two elastic bands 32 are simultaneously stretched in opposite directions with an angular opening of about 45? with respect to the femoral axis. The two traction forces are balanced so as not to misalign the abutment 4 in the frontal plane and the intensity? ? such as to support the entire weight of the patient who is asked to lift the contralateral limb from the ground.

The calibration of the thrusts and the adjustment of the positioning frame 31a are carried out in such a way as to simultaneously satisfy the technical requirements mentioned above and the sensation of comfort of the patient who must not experience painful pressure points.

Once all the adjustments have been made, the abutment 4, with the cap on, is uniformly covered with hardening material, in particular with plaster bandages. Following these adjustments, the insertion portions 8, 9, 10, 11 are defined on the abutment 4 and, therefore, on the hardening material.

Usefully, the patient is made to wear two tubular knitted stockings and an elastic tubular seal connected to a suction pump. The patient is made to reposition in an upright position on the support means 31 with the abutment housed in the previously adjusted positioning frame 31a. The sub-ischial support device is tightened, the sub-trochanteric thickness is applied and the two elastic bands 32 are applied as previously defined. Then the patient is asked to shift his weight entirely on the abutment 4; the suction pump is activated, able to remove the air and compact the plaster bandages to the abutment 4, allowing the accurate modeling of a plaster cast.

The gypsum catalyzes with the shaping thus conferred by the two tractionated elastic bands 32 (active thrusts), by the sub-ischial support device and by the sub-trochanteric thickness (passive thrusts).

A negative cast 33 is thus obtained, preferably finished and outlined. The negative cast 33, then,? obtained by means of an air suction device, or suction pump, connected to the elastic sealing tube that covers the plaster casts. The air suction device? operated while the abutment 4? subjected to the load conditions, that is? during the application of the S1, S2, S3, S4 thrust system.

The process involves a subsequent step C of making a positive cast 34 of the abutment 4, preloaded, starting from the negative cast 33.

The negative cast 33 can? be filled with a plaster cast generating the positive cast 34 on which the heights at which the circumferences were measured are reported. The rough positive cast can? be modeled, or stylized. The plaster is rasped in order to smooth and homogeneous the curves of the thrusts both? Active? which? passive ?. The imperfections are removed from the surface so that it is smooth and free of discontinuity points. Circumferences are rechecked so that they are consistent with the measurements previously taken.

In a preferred embodiment, the positive cast 34 is not derived directly from the negative cast 33. The step C of making a positive cast 34 can be obtained. foresee:

- a sub-phase of making a positive test cast by filling the negative cast 33 with hardening material, preferably gypsum;

- a subsequent sub-phase of making a wearable cast, or otherwise called? potting test? by coating the positive test cast with polymeric material.

Phase C then provides for a further sub-phase of obtaining the positive cast by filling the wearable cast with hardening material, preferably gypsum.

In this preferred embodiment, the negative cast 33 is used to create a test positive, or provisional, cast for simplicity. not illustrated, from which a test pot is obtained, or a? test pot ?.

The test socket is put on the patient and adjusted if necessary. Once the right conformation has been found, the test socket is used as a negative cast to make the positive cast 34.

In particular, the temporary plaster cast is modeled, or? Stylized ?, and positioned on a support and connected to an air suction pump to perform a thermoforming phase aimed at creating the potting-test. Preferably, the test socket can? be made of glycol-polyethylene terephthalate (PETG) with a thickness ranging from 12 to 15 mm (depending on the weight characteristics of the patient). Such material? used both for its properties? mechanical and for its transparency that allows visual inspection during the test.

The socket-test, to which a vacuum generation valve is applied, is used to verify both with static and dynamic tests (during the walk):

a) the correctness of the upper edge 6 (? cutting lines? below the trochanter laterally, under the ischium in a postero-medial position);

b) that in the articular excursion of the hip there is no interference of the upper margins of the reservoir;

c) that the entire surface of the abutment is in contact with the walls of the reservoir (visual check);

d) that the patient does not feel pain;

e) that the patient does not feel a localized pressure in some specific area (the sensation perceived must be of total contact);

f) that the thrust system creates the desired orientation in the sagittal and frontal plane;

g) alignment of the socket with the remaining prosthetic components.

Having obtained what is desired, possibly following some adjustment, the potting-test is filled with a plaster cast and the positive cast 34 is recreated.

The process then comprises a subsequent step D of coating the positive cast 34 with substantially flexible material, preferably biomedical silicone, to obtain a casing 2 whose shape follows the preloaded abutment 4.

In particular, after having recovered the alignment, the positive plaster cast is smoothed, and when? completely devoid of humidity? it is connected to an air suction pump.

A template is placed on the plaster which replicates the morphology of the unidirectional valve 16 which will have to? be housed in socket 1 for the hypobaric anchoring system;

In relation to the volume of the cast, a mixture of about 500 grams of silicone is created. Such a mixture? the result of the combination of two types of silicone of different hardness (Shore A / B 65/80). The hardness and proportion of the components? modulated in virtue? of the properties necessary mechanical elastic, largely dependent on the weight characteristics and muscle tone of the patient. To such a mixture can? a coloring pigment be added;

Are? Mats? of silicone with a thickness of about 3 mm which are placed on the positive cast 34 until it is completely covered. Everything is sealed with a nylon film, connected to the vacuum cleaner and left under vacuum for about 2 hours.

The silicone is then contoured and placed in the oven for about 8-10 hours at a progressively increasing temperature from 50 ° C to 100 ° C until vulcanization.

Subsequently, the process involves step E of manufacturing a containment frame 3 in which composite material, preferably carbon fiber composite material, is applied to the casing 2 to define a frame to be heat treated. The frame to be treated has at least one medial portion 13 and at least one side portion 12, and is subsequently subjected to heat treatment so as to obtain the frame 3.

In particular, the silicone-coated positive cast 34 is coated with transparent film. Then the perimeter of the frame 3 is drawn on the film, which is usefully perforated in some points to facilitate the escape of air in a subsequent suction phase.

Carbon fiber fabrics pre-impregnated with epoxy resin are cut out. In particular, four fabrics with unidirectional fibers and another four fabrics with bidirectional fibers. Of the latter, two are cut at an angle of 90? and two more at a 45 ° angle.

A nylon stocking is fitted over the coated positive cast 34 to allow the passage of air during an aspiration phase. Subsequently, a polyvinyl acetate (PVA) bag is applied to the product. Subsequently a pump is connected to the suction valve and activated for the suction of the air.

Inside the drawn profile, with cranio-caudal direction from the proximal edge of the frame (level 0) to the apex of the frame, 3 equidistant levels are identified (hereinafter referred to as level 1, level 2 and level 3). inside the profile drawn, the eight carbon fiber fabrics previously cut in the following order:

I.? Bi-directional fibers? cut to 45? with respect to the longitudinal axis from the apex to? level 0?

II. Bidirectional fibers with a 90 axis? with respect to the longitudinal axis from the apex to? level 0 ?;

III. Unidirectional fibers parallel to the longitudinal axis from the apex to the? level 0 ?;

IV. Unidirectional fibers parallel to the longitudinal axis from the apex to the? level 1 ?;

V.? Unidirectional fibers? parallel to the longitudinal axis from the apex to the? level 2 ?;

YOU. Unidirectional fibers parallel to the longitudinal axis from the apex to the? level 3 ?;

VII. Bidirectional fibers with a 90 axis? with respect to the longitudinal axis from the apex to? level 0 ?;

VIII. Bidirectional fibers cut to 45? with respect to the longitudinal axis from the apex up to? level 0 ?.

An insulation fabric is then applied to facilitate subsequent detachment and another bag of PVA is applied.

With the air suction pump activated, the cast 34 covered with the applied fabrics is placed in an oven which is gradually brought from 0 ° C to 100 ° C.

After an hour the superimposed carbon layers are worked manually to favor mutual adhesion and to remove the interposed air.

The product is left in the oven for 9 hours until completely catalyzed. After having extracted the product from the kiln and after having allowed it to cool, the cutting lines, or the upper edge 6, of the carbon frame 3 are finished.

Usefully, the procedure can? provide for a further finishing phase. In this finishing phase, once the alignment has been recovered, the carbon frame is filled with plaster.

Subsequently, the traditional lamination is carried out with a methacrylate matrix and carbon and glass fiber reinforcement and any coloring pigment. This phase ? useful to give further mechanical resistance and to anchor the attachment for the prosthetic components in the apical area of the frame; Then the one-way valve 16 is glued for the expulsion of the air, in particular in the seat that had been reserved for it.

The connection of the lateral wall 12 and the medial 13 in the posterior position can? be made with a synthetic reinforcement fabric with a height of about 5 cm.

In order to be able to carry out the second embodiment described above, the process can? provide for a further step of making a second layer 2a of the casing 2.

In this case, the product resulting from the previous steps (first silicone layer 2 and frame 3 with finishing lamination) is repositioned on the positive cast 34. The preparation of the second silicone layer 2a and its deposition on the product until vulcanization are performed with the same modality? of the first layer.

The present invention? It has been described heretofore with reference to preferred embodiments. ? it is to be understood that each of the technical characteristics implemented in the preferred embodiments, described herein purely by way of example, can? advantageously be combined, in a different way from what has been described, also with other characteristics, to give shape to further embodiments which also pertain to the same inventive core. ? it is therefore to be understood that other embodiments may exist which pertain to the same inventive nucleus, as defined by the scope of protection of the claims set forth below.

Claims (15)

CLAIMS 1. socket (1) for transfemoral prosthesis comprising: - a substantially flexible casing (2) configured to fit an abutment (4) of a user, and provided with an upper edge (6) which can be positioned below the perineum and trochanter of said user; - a substantially rigid containment frame (3) provided with a medial wall (13) and a side wall (12) coupled to said casing (2) and intended to be positioned respectively at a medial position and a lateral position of said stump (4); wherein said casing (2) has an internal surface (7) whose conformation comprises: - a first insertion portion (8) intended to come into contact with the hamstrings of a user and exerting a first thrust (S1) on said abutment (4) reacting to the weight of said user; - a second insertion portion (9) intended to come into contact with the sub-trochanteric area of a user and exerting a second thrust (S2) on said abutment (4) reacting to the weight of said user; - a third insertion portion (10) intended to come into contact with the apical-medial area of said abutment (4) and exerting a third support thrust (S3) on said abutment (4); - a fourth insertion portion (11) intended to come into contact with the lateral femoral diaphyseal area of said abutment (4) and exerting a fourth support thrust (S4) on said abutment (4); the configuration being such that the resultant of said first thrust (S1), second thrust (S2), third thrust (S3) and fourth thrust (S4) comprises a medium lateral grip force and an upward thrust force on said abutment (4). The socket (1) according to claim 1, wherein said medial wall (13) and said side wall (12) are distant from said upper edge (6) for a minimum length comprised between 5 mm and 10 mm. 3. Socket (1) according to one or more? of the preceding claims, in which said medial wall (13) and said lateral wall (12) are joined to define a U-shaped conformation having an apical portion (14) in the vicinity of of which ? inserted an apical closure (5) of said envelope (2). Pot (1) according to the preceding claim, comprising at least one one-way valve (16) associated with said apical closure (5) and configured to expel air. 5. Socket (1) according to one or more? of the preceding claims, wherein said frame (3) comprises at least one transverse element (17) which connects said medial wall (13) and said side wall (12), preferably positioned at a distance of about 20 mm from said upper edge (6 ). 6. Socket (1) according to one or more? of the preceding claims, comprising a second casing (2a) covering said casing (2) and said frame (3), said frame (3) being interposed between said casing (2) and said second casing (2a). 7. Socket (1) according to one or more? of the preceding claims, wherein said envelope (2) comprises biomedical silicone. 8. Socket (1) according to one or more? of the preceding claims, wherein said frame (3) comprises composite material in carbon fiber. 9. Transfemoral prosthesis comprising a socket (1) according to one or more? of the previous claims. 10. Procedure for making a socket (1) for transfemoral prosthesis comprising: - a step (A, B) of making a negative cast (33) of a stump (4) of a user in which said stump (4) is coated with hardening material while? subjected to predetermined load conditions, said predetermined load conditions being arranged: initially placing said abutment (4) under the effect of the weight force of said user, inducing a first thrust (S1) on the hamstrings of said user to obtain a first insertion portion (8) on said negative cast (33), and a second thrust (S2) on the sub-trochanteric area of said user to obtain a second insertion portion (9) on said negative cast (33); subsequently placing said abutment (4) under the effect of traction forces inducing a third thrust (S3) on the apical-medial area of the user to obtain a third insertion portion (10) on said negative cast (33), and a fourth thrust (S4) on the diaphyseal-femoral area of the user to obtain a fourth insertion portion (11) on said negative cast (33); - a subsequent step (C) of making a positive cast (34) of said abutment (4) preloaded starting from said negative cast (33); - a subsequent step (D) of coating said positive cast (34) with substantially flexible material to obtain a casing (2) whose shape follows said preloaded abutment (4); - a subsequent step (E) of making a containment frame (3) in which composite material is applied to said casing (2) to define a frame to be heat treated having at least a medial portion (13) and at least a lateral portion ( 12), said frame to be treated being subsequently subjected to heat treatment to obtain said frame (3). 11) Process according to claim 10, in which said traction forces are applied by means of elastic bands (32) elongated in mutually opposite directions and inclined with respect to the femoral axis of said abutment (4). 12. Process according to claim 10 or 11, wherein said traction forces have intensity, direction and direction such as to support the entire weight of said user. 13) Procedure according to one or more? of claims 10 to 12, wherein said step (A, B) of making a negative cast (33) comprises positioning said abutment (4) in an adjustable positioning frame (31a), said positioning frame (31a ) comprising at least one adjustable sub-ischial support device (42). 14) Procedure according to one or more? of claims 10 to 13, wherein said negative cast (33)? obtained by means of an air suction device operated while said abutment (4)? subjected to said load conditions. 15) Procedure according to one or more? of claims 10 to 14, wherein said step of making a positive cast (34) provides: - a sub-phase of making a positive test cast by filling said negative cast (33) with hardening material; - a subsequent sub-phase of making a wearable cast by means of a coating of said positive test cast; - a further step of obtaining said positive cast (34) by means of a filling of said wearable cast with hardening material.