FR3125700A1 - Method and system for manufacturing an orthopedic splint and its orthopedic splint. - Google Patents

Abstract

The invention relates to a method of manufacturing an orthopedic splint, the splint consisting of two non-identical alveolar (8) plastic shells (3, 4), the two shells (3, 4) extending substantially longitudinally and being intended to envelop a limb (2) of a patient, the shells (3, 4) being interconnected by a plurality of fasteners, in which said method comprises a subsequent step of thermoforming the two shells (3, 4) during which the two shells (3, 4) are fitted around the limb (2) of the patient and at least a portion of at least one of the two shells (3, 4) is heated to a temperature between 50°C and 70 °C so as to modify the shape of said portion while remaining within the circumferential limits of the two shells (3, 4). Figure to be published with abstract: Fig. 7

Description

Method and system for manufacturing an orthopedic splint and its orthopedic splint.

Technical area.

The present invention relates to an orthopedic splint, its method of manufacture and the system for implementing the method of manufacture.

It concerns the technical field of splints, i.e. orthopedic devices intended to immobilize a limb or a joint. These splints are mainly used in cases of injury or suspicion of traumatic injury (direct or indirect trauma, sprain, dislocation, contusion, crushing, burns, etc.) but are also worn after the medical diagnosis has been made, particularly in cases of rheumatism to put the joint to rest, tendonitis, fracture, tendon sutures, flexum to gain greater range of motion. More particularly, the present invention applies to so-called "cuff" splints for the hand, "BABP" that is to say Brachio Anté-Brachio Palmar for joint immobilization of the wrist and elbow and "Botte" for the ankle and leg.

State of the art.

It is known to produce splints in conventional plaster, in polymerization resin, of the corset type and plexiglass splints or even thermoformed splints.

Plaster splints are inexpensive but have the main disadvantages of being heavy, unhygienic because they cause significant maceration after a few days and cause compression of the limb to be treated.

Resin splints are relatively light but just as unhygienic (significant maceration) and generate unwanted compression as well as harmful heat for the limb.

Plexiglas splints or bodices are light and robust but they are expensive, complex to install and do not solve the problem of limb hygiene due to still significant maceration.

thermoformable splints are classically light but still present a problem relating to hygiene due to persistent maceration and more limited immobilization because they are hemi-circumferential.

We also know the documents US10758396, US20180357348, US 20160074203 or US 20200100847 which present splints made up of two shells but all the splints presented in these documents surround the entire limb on at least one transverse section of the splint. Thus, at least locally, such splints induce hygiene/maceration problems and the impossibility of reaching the limb without removing the splint.

The classic splints being circular by closing mechanically on the limb, do not allow post-installation adjustment to overcome the problem of atrophy of the limb whose muscle mass melts after a few days after its immobilization.

The invention aims to remedy this state of affairs.

In particular, an object of the invention is to provide a method and a manufacturing system to provide an orthopedic splint fulfilling its primary therapeutic function while being suitable for prolonged contact with the skin, without maceration or hygiene problem. .

An essential objective is to offer a splint that scrupulously respects the orthopedic obligations and goals while leaving free all the joints not necessary for these obligations and goals, in particular allowing the maintenance of writing activity and avoiding ankylosis that is not orthopedically necessary.

A complementary objective is to offer a biodegradable splint.

Another objective consists in proposing an effective solution to the particular problem of therapeutic treatments, for example consisting of a change of dressing, or even essentially aesthetic treatments or management of burns (for example treatments of the epidermis).

A complementary objective is to offer an orthopedic splint produced quickly, light and inexpensive.

An additional objective is to overcome the problem of atrophy of the limb (muscle mass that melts after a few days) and to offer a fastening system that allows tension adjustment throughout the treatment.

Presentation of the invention.

It has thus been observed by the applicant, after various experiments and manipulations, that it is particularly interesting to produce a splint with two shells, which are not surrounding and which is perfectly adapted and adaptable to the patient's limb.

The solution proposed by the invention is a method of manufacturing an orthopedic splint, the splint consisting of two non-identical plastic alveolar shells, the two shells extending substantially longitudinally and being intended to partially envelop a limb of a patient, the shells being interconnected by a plurality of adjustable fasteners.

• une étape de numérisation du membre du patient, installé dans une position d’immobilisation orthopédique souhaitée, autour duquel l’attelle orthopédique est destinée à être mise en place ;
• une étape de définition de la forme (ou encore des contours) et des dimensions des deux coques de l’attelle sur la base de la numérisation du membre du patient ;
• une étape de construction additive simultanée des deux coques, par application successive de cordons d’au moins un polymère consistant en de l’acide polylactique (PLA), délivrés par une buse, les uns sur les autres à partir d’un premier cordon disposé sur une plaque chauffante de manière à former verticalement lesdites deux coques ;

dans lequel ledit procédé comprend une étape ultérieure de thermoformage des deux coques pendant laquelle, une fois les deux coques installée autour du membre du patient, on chauffe au moins une portion d’au moins une des deux coques à une température comprise entre 50°C et 70°C de manière à modifier la forme de ladite portion tout en conservant les limites circonférentielles des deux coques.The method is remarkable in that the method comprises the following successive steps:

• a step of scanning the patient's limb, installed in a desired orthopedic immobilization position, around which the orthopedic splint is intended to be put in place;
• a step of defining the shape (or even the contours) and the dimensions of the two shells of the splint on the basis of the digitization of the patient's limb;
• a step of simultaneous additive construction of the two shells, by successive application of beads of at least one polymer consisting of polylactic acid (PLA), delivered by a nozzle, on top of each other from a first bead arranged on a heating plate so as to vertically form said two shells;

wherein said method comprises a subsequent step of thermoforming the two shells during which, once the two shells are installed around the patient's limb, at least a portion of at least one of the two shells is heated to a temperature of between 50°C and 70°C so as to modify the shape of said portion while maintaining the circumferential limits of the two shells.

The expression “cellular shell” is understood to mean a shell that is perforated or hollowed out at a large number of locations so as to present a stretched mesh appearance, the mesh of which has heterogeneous dimensions. These cells or recesses mean that the surface defined by the circumferential limits of a shell is covered with polymer material on at most 60%, even on at most 50%, or even on at most 40% depending on the nature of the splint ("cuff", "babp", "boot" or others) depending on the orthopedic specifications and constraints.

Such a honeycomb mesh with variable geometry, inspired by bone fiber, allows the introduction of electrotherapy electrodes. Thus, physiotherapy can be started immediately, effectively reducing amyotrophy and shortening the duration of rehabilitation, sick leave and therefore the overall cost of treatment for the community.

The expression "desired orthopedic immobilization position" in connection with the scanning step means that the limb is placed and maintained in the appropriate position as defined by the rules for orthopedic surgery.

The expression "non-identical" is understood to mean in connection with the shells the fact that these shells do not have the same shapes and dimensions, on the one hand from the fact that each one adapts to a limb contour, conventionally non-symmetrical, and on the other hand from the fact that the cells or recesses present on each shell depend on the zones where access must be authorized as well as on the member locally (strength or on the contrary local fragility). Areas at risk of bedsores or areas of surgical incision are left free to avoid any post-operative scarring and infectious complications. Dressing care and scar monitoring are all the easier.

The expression “simultaneous additive construction” means in connection with the two shells the fact that the latter are manufactured vertically at the same time, side by side, on the heating plate. Each shell extending substantially longitudinally, the polymer cords are added on top of each other passing from one shell to the other, the two shells being placed facing each other on the heating plate.

Thanks to the particular characteristics of the manufacturing process according to the invention, the splint is adaptable and adjustable, within the circumferential limits defined during the initial manufacturing phase, throughout the duration of use of the splint, from on the one hand according to the orthopedic needs and on the other hand according to the evolutions of the member, in particular due to local amyotrophy.

According to a particularly interesting aspect of the invention, the orthopedic splint according to the invention is made of PLA, recyclable and biodegradable, perfectly suited for prolonged contact with the skin.

The orthopedic splint according to the invention is ventilated and makes it possible to ensure normal washing of the hands, which is crucial in an epidemic period.

The splint is breathable, prevents maceration and odor. It makes desquamation possible and allows the patient to take showers, bathe and begin rehabilitation more quickly with partial support in balneotherapy. Its resistance to water avoids the removal/re-making of plaster, thus reducing the risk of secondary displacement of fractures.

The improvement in terms of hygiene is important in the hot season, especially in regions with a temperate climate, but becomes essential during an epidemic period. By reducing pruritus, the incidence of complications related to the introduction of foreign bodies into the cast is reduced, particularly in paediatrics.

Other advantageous characteristics of the apparatus which is the subject of the invention are listed below. Each of these characteristics can be considered alone or in combination with the remarkable characteristics defined above. Each of these characteristics contributes, where appropriate, to the resolution of specific technical problems defined further on in the description and to which the remarkable characteristics defined above do not necessarily participate. The latter may be the subject, where appropriate, of one or more divisional patent applications:

Even once printed, the characteristics of the splint obtained by the manufacturing method according to the invention allow secondary correction in the event of discomfort or therapeutic need, simply by applying heat locally between 50°C and 70°C, either with a simple classic hair dryer, without changing the splint.

Advantageously, the heating of at least a portion of at least one of the two shells takes place at a temperature of between 55°C and 65°C.

Preferably, during the aforesaid subsequent thermoforming step, the heating of said portion lasts between 1 and 4 minutes, preferably between 2 and 3 minutes.

According to one embodiment, the aforesaid heating plate has, on its surface in contact with the aforesaid first cord, a temperature of between 60°C and 80°C.

Advantageously, the aforesaid polymer, when it leaves the nozzle, has a temperature of between 200°C and 235°C.

According to a particularly advantageous aspect of the invention, the polymer beads are delivered at a speed varying between 50 and 90 millimeters per second.

Advantageously, during the aforesaid digitization step, a plurality of three-dimensional sensors are applied to the patient's limb, said sensors determining, during the step of defining the shape and dimensions of the two shells, the circumferential limits of each of the two shells.

The present invention also relates to a system for manufacturing an orthopedic splint, the splint consisting of two non-identical plastic alveolar shells, the two shells extending substantially longitudinally and being intended to partially envelop a limb of a patient, the shells being interconnected by a plurality of adjustable fasteners.

• un appareil de numérisation du membre du patient autour duquel l’attelle orthopédique est destinée à être installée, l’appareil de numérisation comportant des capteurs tridimensionnels placés sur le membre du patient pour déterminer les limites circonférentielles de chacune des deux coques de l’attelle dans un fichier numérisé représentatif de la forme et des dimensions des deux coques de l’attelle ;
• une plaque chauffante ;
• une machine d’impression additive simultanée des deux coques, à partir du susdit fichier numérisé, comportant une buse pour la délivrance de cordons de polymère d’acide polylactique à disposer les uns sur les autres à partir d’un premier cordon disposé sur la plaque chauffante de manière à former verticalement lesdites deux coques ; et
• un dispositif de chauffe, de préférence un dispositif de chauffe émettant un jet d’air chaud, pour chauffer au moins une portion d’au moins une des deux coques à une température comprise entre 50°C et 70°C.

The crafting system is remarkable in that it includes:

• an apparatus for scanning the limb of the patient around which the orthopedic splint is intended to be installed, the scanning apparatus comprising three-dimensional sensors placed on the limb of the patient to determine the circumferential limits of each of the two shells of the splint in a digitized file representative of the shape and dimensions of the two shells of the splint;
• a heating plate;
• a machine for simultaneous additive printing of the two shells, from the aforesaid digitized file, comprising a nozzle for the delivery of beads of polylactic acid polymer to be placed on top of each other from a first bead placed on the plate heating so as to vertically form said two shells; And
• a heating device, preferably a heating device emitting a jet of hot air, for heating at least a portion of at least one of the two shells to a temperature of between 50°C and 70°C.

Advantageously, the nozzle consists of a double-headed nozzle having a diameter of between 0.3 and 0.5 mm and 0.7 and 0.9 mm respectively, terminals included.

Of course, the characteristics presented above in connection with the manufacturing method apply mutatis mutandis to the manufacturing system according to the invention, and vice versa.

Finally, the present invention relates to an orthopedic splint, obtained by the method briefly presented above or by the aforementioned manufacturing system, the splint consisting of two non-identical plastic alveolar shells, the two shells extending substantially longitudinally and being intended to surround a limb of a patient, the shells being interconnected by a plurality of fasteners, in which no transverse section of the shells completely surrounds the corresponding section of the limb of the patient, the two shells being of polymer of polylactic acid (PLA).

The splint according to the invention is designed to adapt to amyotrophy which occurs during orthopedic treatment. Thus, such a splint is designed in a non-surrounding way, that is to say non-circumferential with respect to the limb around which it is applied, and this on all the transverse sections of the splint or of the two shells. extending longitudinally.

On the contrary, the splint according to the invention respects the principle according to which amyotrophy appears from the ^7th day of immobilization. The surface coverage rate of the limb - defined by a proportion or a rate of alveolar recesses - depends on its proximo-distal location and the physiological volume of the muscle compartments (and the fat mass/dry mass ratio specific to each patient) which will be brought decrease as orthopedic treatment progresses. The part of the surface of the uncovered limb is therefore not linear and constant over the entire splint but directly linked from an anatomical and physiological point of view to the propensity of a muscle to melt during the splint. orthopedic immobilization.

Advantageously, the fasteners are made of elastomeric or rubber material, advantageously consisting of a natural or synthetic polyisoprene, a polybutadiene or a styrene-butadiene copolymer.

Brief description of figures.

Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which will follow, with reference to the appended drawings, produced by way of indicative and non-limiting examples and in which:
is a photograph illustrating the placement of three-dimensional sensors on a patient's forearm so as to define the circumferential limits of each of the two shells forming the “cuff” type splint according to the invention.
is a photograph illustrating the placement of three-dimensional sensors on a patient's arm so as to define the circumferential limits of each of the two shells forming the “BABP” type splint according to the invention.
is a first photograph illustrating the placement of three-dimensional sensors on a patient's foot so as to define the circumferential limits of each of the two shells forming the “boot” type splint according to the invention.
is a second photograph illustrating a placement of three-dimensional sensors on the patient's foot from the so as to define the circumferential limits of each of the two shells forming the “boot” type splint according to the invention.
is a photograph illustrating the manufacture of the two shells forming the splint according to the invention, at a first stage.
is a photograph illustrating the manufacture of the two shells forming the splint according to the invention, at a later stage than the first stage.
is a photograph illustrating a splint of the “cuff” type according to the invention placed or mounted on the forearm of a patient.
is a schematic representation of a “BABP” type splint according to the invention.
is a schematic representation of a “cuff” type splint according to the invention.
is a schematic representation of a “boot” type splint according to the invention.
is a schematic representation of one embodiment of the fasteners used for a splint according to the invention.

Description of embodiments.

As presented above, the invention is described below with three types of splints, conventionally used orthopedically, but the invention can of course be envisaged for other types of splints, in other words for a splint fitting on other parts or limbs of a patient.

Concerning the "cuff" type splint, visible in particular on the , at the level of the hand, the manufacturing process takes into account the reduction of edema and the weak atrophy of the intrinsic muscles of the hand, in particular insofar as the digital chains are left free here. In fact, the very design (shapes and dimensions) of the splint according to the invention allows complete mobility of the column of the thumb and does not cover the thenar eminence. This allows the patient in particular to be able to write although immobilized.

The surface of the patient's limb covered by the splint decreases from distal to proximal at the level of the forearm since the circumference and the diameter of the forearm gradually increase from the wrist to the elbow. The muscular compartments of the forearm are made up of both the flexors and the extensors of the wrist, which present certain rapid amyotrophy, while conversely the flexors and the extrinsic extensors of the fingers continue to be mobilized during the orthopedic treatment do not show any amyotrophy. This is why the “cuff” type splint has a thickness and/or a decreasing covering surface from the hand to the elbow.

According to another important aspect, for the "cuff" type splint, the incision zones within the framework of the osteosynthesis of the ulna facing the ulnar edge of the arm are left free with the splint according to the invention and this guarantees greater comfort.

Concerning the "BABP" type splint, visible on the , this splint uses the principle of the cuff. The technical particularities described previously remain valid, since these splints are equivalent or identical from the wrist or from the hand to the elbow, the latter not being covered or surrounded in the case of a “cuff” type splint. On the other hand, there is a specific characteristic at the level of the lodge of the arm. Indeed, the extensors and even more the flexors of the elbow have a large volume, this being even more the case in the sports patient. But these extensors/flexors of the elbow are brought to present a rapid and certain atrophy insofar as the flexion of the elbow is made completely impossible by the immobilization.

Thus, the compartments of the arm - the muscles of the arm are distributed in two compartments separated by two intermuscular partitions - are those which will present the greatest fluctuation in circumference during an orthopedic immobilization. The adaptation of the splint according to the invention at this level must therefore be major. This is allowed by the process and the manufacturing system including an adjustment of the fixing - given the fixing of the circumferential limits of each shell and/or because of the subsequent stage of thermoforming of the PLA polymer - which guarantees this great freedom and therefore optimal support during orthopedic treatment. At the level of the bicipital relief, the coverage is therefore low because the amyotrophy is significant.

The same goes for the proximal part of the ulna, namely the olecranon: This is a frequent site of fracture. The particularity at this level is that the bone is immediately located under the skin. Thus the contact of the splint at this level is extremely unpleasant, which is why the method and the system for manufacturing the splint according to the invention leave this zone free by protecting it with an ellipse which avoids any contact at this level and therefore any risk of bedsores and healing disorders. In addition, the medial shell - thus defined as one of the two shells forming the splint - in contact with the armpit is shorter so as not to be bothersome at the level of the armpit, with an aesthetic angulation.

Concerning the "boot" type splint, visible on the , the intrinsic muscles of the foot show minimal fluctuations during orthopedic immobilization. Here it is more the edema of the foot which is to be taken into account. The zone where the variations linked to amyotrophy are the most significant is located at the height of the musculoaponeurotic junction of the triceps surae. Indeed, the flexion of the ankle and the dorsal flexion of the ankle are completely limited by the splint. Only the mobility of the toes remains permitted. Nevertheless, the respective volume of the extrinsic muscles of the foot remains minimal. Thus, it is in the part of the proximal third of the splint according to the invention that the uncovered zone is the greatest. Again, the "boot" type splint has a decreasing thickness and/or a covering surface from the proximal end of the heel of the foot towards the proximal end of the toes as well as from the proximal end of the heel towards the end located at the top, at the level of the tibia.

The most common fracture in the lower limb is the malleolar fracture. It is therefore consistent and judicious to ensure that the most frequent incision sites, namely that of the external malleolus and that of the internal malleolus, are left free. The compressions of his bony reliefs are extremely poorly tolerated regardless of the immobilizations used. Indeed most of the patients immobilized by a plaster or a resin complain of friction aggravated by amyotrophy which allows mobility in the circular immobilization. Furthermore, the thermoformed U-shaped splints of the state of the art fold over the malleolus, which is frequently the cause of bedsores, healing disorders or even sepsis. The splint according to the invention leaves free its bony reliefs allowing on the one hand dressing care and guaranteeing greater comfort while reducing the local complication rate. In the same way as at the level of the olecranon at the elbow, malleolar reliefs are thus preserved thanks to two ellipses. In addition, the posterior shell 3 – one of the two shells forming the splint according to the invention (cf. ) - is shorter in order to avoid disturbing the popliteal fossa, again with aesthetic angulation.

The other fundamental point of the splints according to the invention lies in the scrupulous respect of the orthopedic specifications. Thus all the joints not subject to a desired and necessary immobilization must remain completely free. This advance is made possible by the method and the system for manufacturing the splint according to the invention, compared to those of the state of the art.

Indeed, the manufacturing process by additive printing allows shapes corresponding to snowshoes without weakening the robustness of the splint by respecting the principle of mimicry of the articular spans. Thus for upper limb splints, the thumb column is left entirely free with a very clear release of the thenar eminence allowing complete mobility of the thumb allowing writing and opposition of the thumb in the activities of daily life. In the same way, the distal edge of the volar shell respects the length criteria of the metacarpal arch. Indeed, the ^2nd and ^3rd metacarpals being longer than the ^5th in particular, the splint according to the invention has an oblique shape allowing the ^4th and ^5th metacarpal rays, which are the most mobile, to partially roll up in order to allow pollicis longus grips and thus increase the feeling of freedom and autonomy despite orthopedic immobilization.

During the digitization step of the patient's limb or just after this digitization, three-dimensional sensors 1 are positioned on the patient's limb 2 to define the circumferential limits of the two shells 3, 4 forming the splint. By way of example, the three-dimensional sensors 1 may consist of electrode washers or pellets having a stud or the like. These three-dimensional sensors 1 are advantageously provided with an adhesive or sticky portion adapted to be temporarily attached to a portion of a human body and have a protuberance (nipple or the like) defining by links between the different protuberances of each of the sensors 1 dedicated to each of the two shells 3, 4 the circumferential limits of the splint and/or of the two shells 3, 4 forming it.

During the realization of the capture which allows the recording of a three-dimensional imprint of a limb 2, these sensors 1 in relief thus make it possible to facilitate and specify the modeling on this virtual mold of the future splint. These three-dimensional sensors 1 make it possible to optimize the design, the contours of the splint, guaranteeing on the one hand its optimal positioning, absolute comfort and freedom of movement. It can be noted that the positioning of the patient's limb 2 – as seen in FIGS. 1 to 4 – during the capture (digitization step of the patient's limb) corresponds to the desirable positioning for the support during the orthopedic treatment. This system thus makes it possible to optimize the shape of the splint according to the invention and facilitates the fitting and removal of the splint, including in a fractured patient.

On the , one can see a face or a side of a forearm 10 of a patient on which are present four three-dimensional sensors 1 but of course there are at least as many of said three-dimensional sensors 1 on the other face or side of this forearm 10. In general, for a forearm 10 of a patient, in other words for a splint of the “cuff” type, the manufacturing method according to the invention provides at least eight three-dimensional sensors 1, namely four sensors 1 for each of the shells 3, 4. Of course, to better refine the circumferential limits of the splint or of the two shells 3, 4, it is possible to use ten, twelve, fourteen or even more three-dimensional sensors 1 for such a “cuff” type splint.

In the same way for the relating to a "BABP" type splint, there are five three-dimensional sensors 1 on one face or one side of an arm 11 (including a three-dimensional sensor located at the top between the two sides or faces) so that there is at least nine to ten three-dimensional sensors 1 to produce a "BABP" type splint, but many more sensors 1 can be provided, up to about thirty sensors 1, i.e. fifteen three-dimensional sensors 1 for each shell 3, 4, anterior and posterior or superior and inferior.

Figures 3 and 4 illustrate the three-dimensional sensors 1 positioned on the foot 12 of a patient, according to two different viewing angles. There are thus five sensors 1 visible on the and five sensors 1 visible on the . Thus, to produce a splint of the "boot" type, it is necessary to use at least ten sensors 1 to delimit the circumferential limits of the two shells 3, 4, it being again understood that more, or even more, can be used. of sensors 1 to refine said limits. It may be noted here the presence of a strap or tape 20 intended to keep the foot 12 stable in the desired holding position of the limb/foot 2/12, without displacement during the scanning operations of the patient's foot 12 and for a perfect location of the sensors 1 so as to define the circumferential limits of each shell 3, 4 forming the splint.

The means for scanning the patient's limb as well as the definition of the shape and dimensions of the splint are known to those skilled in the art. In this case, according to one embodiment, these means comprise a plurality of laser transmitters/sensors, intended to determine the contours of the patient's limb 2 and the location of the three-dimensional sensors 1, in connection with a computer server capable of carrying out digitization of the patient's limb 2 and to define the circumferential limits of each of the shells 3, 4 as well as the shapes and internal dimensions of the latter. The server can thus create a virtual splint which is then sent to the additive manufacturing machine of the splint, so that the latter is based on the virtual splint to reproduce it physically by the additive manufacturing process layer by layer.

In FIGS. 5 and 6, the nozzle 5 can be seen in the process of manufacturing or producing simultaneously the two shells 3, 4 forming the splint. Conventionally, the first layer is formed by a first bead 6 forming the base, on the heating plate 7, from which the nozzle 5 begins its lineage tracking, defined height after height, or horizontal line by horizontal line, to form the two shells 3, 4 of the splint. In other words, the nozzle 5 substantially performs a rotation, to successively form the layers on top of each other, given the fact that the two shells 3, 4 are substantially inscribed in a cylinder, this being particularly true for splints of the type "cuff" and "BABP", as well as at least in part for the "boot" type splint.

When the two shells 3, 4 are entirely manufactured/produced by the machine, the latter 3, 4 are fixed to each other but the portions connecting them are easily separable, once the two shells 3, 4 have been finalized, to releasing the two shells 3, 4, like the base 6 from which the shells 3, 4 are manufactured/produced.

There illustrates a "cuff" type splint attached to a patient's forearm. It can be noted that, in general, a splint according to the invention has a thickness of between 1 millimeters (mm) and 4 millimeters (mm), advantageously between 1.5 mm and 3 mm, here depending on the location considered. on the patient's forearm, in order to be more resistant for reasons of resistance/mechanical stress throughout its duration of use.

It should also be noted that the splints according to the invention can be presented with a specific color, for example chosen by the patient for aesthetic consideration or even for technical reasons, for example a bright color, such as vermeil red, in order to attract the attention of others in a workplace.

In the same way, the recesses or the cells 8 are also positioned in such a way that they are of greater dimensions - in width and/or in length - at the locations less stressed mechanically or even to authorize a subsequent medical operation such as by example the placement/replacement of a dressing or the placement/replacement of treatment electrodes.

Figures 8 to 10 illustrate the two shells 3, 4 of a splint for the three types of splints defined as conventional, it being understood that their shapes and dimensions are specific to their use for a limb 2 of a particular patient, even if the latter is not visible in these figures.

Fasteners 20 presented on the are an embodiment of the latter but it is understood that these fasteners 20 can be made in different ways both in terms of their shape, dimensions and their nature/material. Here the fasteners 20 extend linearly, of substantially rectangular or parallelepipedal shape, and are of the elastomer type, for example latex, and comprise a distal portion having a male part 21 intended to be fixed to or in one slots intended to form the female part 22 allowing the fixing of the male part 21. Conventionally, the use of one or the other of these slots 22 makes it possible to arrange the two shells 3, 4 more or less at distance from each other, depending in particular on the therapeutic requirements of the splint, possibly a progressive distance throughout the immobilization time required for the orthopedic splint. The elastic nature of these fasteners 20 is particularly advantageous for facilitating the operations of fixing the two shells 3, 4 together, so as to surround the limb 2 of the patient. Given the two shells 3, 4 forming the splint, at least four fasteners 20 are necessary to fix the shells 3, 4 together, each of the fasteners 20 being respectively located at the four ends of each of the two shells 3, 4 and connecting these ends of the two shells 3, 4 to each other, respectively.

The splint according to the invention is in the form of immobilization by two shells 3, 4: anterior and posterior, superior and inferior or even medial and lateral. Each of these shells 3, 4 have a particular congruence ensuring almost on its own sufficient immobilization according to the principles of orthopedic compression, but the quality of the immobilization is very markedly improved by the addition of a second shell 3 or 4. By elsewhere this principle will allow the operated patient to be able to benefit from dressing care in complete safety. For example, current thermoformed immobilizations and mass-produced splints require their removal in order to proceed with dressing care, this constituting a risk of secondary displacement. The congruence of each shell 3, 4 guarantees sufficient compression avoiding secondary displacement while allowing dressing changes.

The splint according to the invention is positioned and removed very easily, including in traumatized patients.

The pattern of the splint according to the invention is not content to repeat that of the bone spans for purely aesthetic reasons, but pushes the mimicry to the point of respecting physiological biomechanical principles.

Indeed, bone is a living tissue. It densifies in areas with high biomechanical stress and, on the contrary, becomes more airy in areas with low stress or in the event of a drop in activity. The shape and dimensions of the splint according to the invention also follow an engineering reflection which makes it possible to derive maximum advantages.

The splint according to the invention comprises a three-dimensional pattern which densifies and thickens in areas of high stress, as does biological bone. The histological study does not highlight bony tubes but indeed spans or bone blades whose densification and thickening in space thus respond to the constraints and this in order to prevent any stress fractures. The bone span is oriented according to the lines of force and stress in order to be able to absorb them physiologically without leading to a stress fracture. Thus, it takes considerable energy to fracture a tibia in the direction of the height but a negligible energy to break it in a movement with a rotational component. This is permitted in particular by the principle of printing in a vertical additive mode.

Thus reproducing the axis of the natural stresses of the long bones (mostly vertical in the musculoskeletal system) which define the orientation of the bone spans in response to the stresses undergone by the bone. The coverage area of the splint according to the invention varies for anatomical reasons. To maintain a constant pressure, it is necessary to thicken the spans and reduce the surface of the alveoli 8. Fractures occur in areas of high stress, the thickness of the spans is voluntarily increased to reduce the pressure and reduce ischemia as well as prevent the compartment syndrome.

Thus, the pattern inspired by the spongy bone of the splints according to the invention ensures an optimization of the material and of the weight-strength ratio. In the same way, the pattern of the splint according to the invention is not content to thicken in two dimensions (along the x and y axes) but especially in thickness (z) and this in order on the one hand to preserve the breathability of the splint, prevent maceration and also maintain an aesthetic and harmonious appearance. For example, at the level of the boot, the zone of maximum stress is located at the level of the heel and the Achilles tendon, the malleoli are not covered. Thus the thickening of the spans of the splint according to the invention is done in the thickness more than in the width, thus guaranteeing greater breathability and thus a reduction in maceration. This principle is also repeated at the level of the elbow on its internal and external face of the “BABP” type splint. The variations in temperature, speed and size of the nozzle 5 of the manufacturing machine allow:
• better resistance to stresses by adding bending to certain areas by adjusting the speed of installation, its temperature and the frequency of removal of the polymer, advantageously in PLA, and
• to ensure comfort by maintaining sufficient ventilation in low stress areas.

Very advantageously, the PLA polymer was selected after numerous trials and tests among all plastics and elastomers. PLA can be thermoformed during orthopedic treatment. Indeed, amyotrophy is likely to make certain bony reliefs more prominent. Thus it becomes possible to modify certain areas of the splint during treatment, that is to say throughout the life or use of the manufactured splint, while remaining within the defined circumferential limits / obtained during manufacture. Thermoforming thus makes it possible to optimize the splint made for the patient's limb.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

• la matière polymère utilisée pour former les deux coques 3, 4 de l’attelle peut éventuellement être en un mélange de PLA présentant notamment des températures de fusion et de transition vitreuse différentes ;
• le nombre, la forme et/ou même les fonctions des capteurs 1 dits tridimensionnels pour autant que ces capteurs 1 permettent, lors de la numérisation du membre 2 du patient ou à la suite de cette opération, de définir précisément les limites circonférentielles de chacune des deux coques 3, 4 ;
• la forme, les dimensions et/ou la nature de la plaque chauffante 7 qui peut être en métal (aluminium ou acier par exemple) ou en céramique ; ou encore
• la forme, les dimension et/ou la nature des attaches 20 destinées à retenir les deux coques 3, 4 entre elles, autour du membre du patient.

The arrangement of the various elements and/or means and/or steps of the invention, in the embodiments described above, should not be understood as requiring such an arrangement in all implementations. In any event, it will be understood that various modifications can be made to these elements and/or means and/or steps, without departing from the spirit and scope of the invention. Especially :

• the polymer material used to form the two shells 3, 4 of the splint may optionally be made of a mixture of PLA having in particular different melting and glass transition temperatures;
• the number, the shape and/or even the functions of the so-called three-dimensional sensors 1 provided that these sensors 1 make it possible, during the digitization of the limb 2 of the patient or following this operation, to precisely define the circumferential limits of each of the two shells 3, 4;
• the shape, the dimensions and/or the nature of the heating plate 7 which can be made of metal (aluminum or steel for example) or of ceramic; or
• the shape, size and/or nature of the fasteners 20 intended to hold the two shells 3, 4 together, around the patient's limb.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (11)

Method of manufacturing an orthopedic splint,
the splint being made up of two non-identical alveolar (8) shells (3, 4) made of plastic, the two shells (3, 4) extending substantially longitudinally and being intended to partially envelop a limb (2) of a patient , the shells (3, 4) being interconnected by a plurality of adjustable fasteners,
characterized in that the method comprises the following successive steps:

• a step of scanning the limb (2) of the patient, installed in a desired orthopedic immobilization position, around which the orthopedic splint is intended to be put in place;
• a step of defining the shape and dimensions of the two shells (3, 4) of the splint on the basis of the digitization of the limb (2) of the patient;
• a step of simultaneous additive construction of the two shells (3, 4), by successive application of beads of at least one polymer consisting of polylactic acid (PLA), delivered by a nozzle (5), on top of each other from a first cord (6) arranged on a heating plate (7) so as to vertically form said two shells (3, 4);

wherein said method comprises a subsequent step of thermoforming the two shells (3, 4) during which, once the two shells (3, 4) are installed around the limb (2) of the patient, at least a portion of at least at least one of the two shells (3, 4) at a temperature between 50°C and 70°C so as to modify the shape of said portion while maintaining the circumferential limits of the two shells (3, 4). Manufacturing process according to claim 1, wherein said temperature is between 55°C and 65°C. Process according to Claim 1 or 2, in which, during the said subsequent thermoforming step, the heating of the said portion lasts between 1 and 4 minutes, preferably between 2 and 3 minutes. Manufacturing process according to any one of the preceding claims, in which the aforesaid heating plate (7) has, on its surface in contact with the aforesaid first bead (6), a temperature of between 60°C and 80°C. Manufacturing process according to any one of the preceding claims, in which the aforesaid polymer, when it leaves the nozzle (5), has a temperature of between 200°C and 235°C. Manufacturing process according to any one of the preceding claims, in which the beads of polymer are delivered at a speed varying between 50 and 90 millimeters per second. Manufacturing process according to any one of the preceding claims, in which, during the aforesaid digitization step, a plurality of three-dimensional sensors (1) are applied to the limb (2) of the patient, the said sensors (1) determining, during the step of defining the shape and dimensions of the two shells (3, 4), the circumferential limits of each of the two shells (3, 4). System for manufacturing an orthopedic splint,
the splint being made up of two non-identical alveolar (8) shells (3, 4) made of plastic, the two shells (3, 4) extending substantially longitudinally and being intended to partially envelop a limb (2) of a patient , the shells (3, 4) being interconnected by a plurality of adjustable fasteners, said manufacturing system comprising:

• an apparatus for scanning the limb (2) of the patient around which the orthopedic splint is intended to be installed, the scanning apparatus comprising three-dimensional sensors (1) placed on the limb (2) of the patient to determine the circumferential limits of each of the two shells (3, 4) of the splint in a digitized file representative of the shape and dimensions of the two shells (3, 4) of the splint;
• a heating plate (7);
• a machine for simultaneous additive printing of the two shells (3, 4), from the aforesaid digitized file, comprising a nozzle (5) for the delivery of beads of polylactic acid polymer to be arranged on top of each other from a first cord (6) placed on the heating plate (7) so as to vertically form said two shells (3, 4); And
• a heating device, preferably a heating device emitting a jet of hot air, for heating at least a portion of at least one of the two shells (3, 4) to a temperature between 50°C and 70°C .

System for manufacturing an orthopedic splint according to claim 8, in which the nozzle (5) consists of a double-headed nozzle (5) having a diameter respectively comprised between 0.3 and 0.5 mm and 0.7 and 0 .9 mm including terminals. Orthopedic splint, obtained by the method according to at least one of Claims 1 to 7 or by the system according to Claim 8 or 9,
the splint consisting of two non-identical alveolar (8) plastic shells (3, 4), the two shells (3, 4) extending substantially longitudinally and being intended to envelop a limb (2) of a patient, the shells (3, 4) being interconnected by a plurality of adjustable fasteners,
wherein no cross-section of the shells (3, 4) completely surrounds the corresponding section of the limb (2) of the patient, both shells (3, 4) being made of polymer of polylactic acid (PLA). Orthopedic splint according to Claim 10, in which the fasteners are made of elastomeric or rubber material, advantageously consisting of a natural or synthetic polyisoprene, a polybutadiene or a styrene-butadiene copolymer.