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

Abstract

The invention relates to a method for manufacturing an orthopedic splint, the splint being made of two non-identical alveolar plastic shells (3, 4), the two shells (3, 4) extending substantially longitudinally and intended to enclose a limb (2) of a patient, the shells (3, 4) being connected to each other by a plurality of fasteners, wherein said method comprises a subsequent thermoforming step of the two shells (3, 4) during which the two shells (3, 4) are fitted around the patient's limb (2) 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 the abstract: Fig. 7

Description

Title of the invention: Method and system for manufacturing an orthopedic splint and its orthopedic splint. Technical field.

[0001] The present invention relates to an orthopedic splint, its manufacturing method and the system for implementing the manufacturing method.

[0002] It concerns the technical field of splints, that is to say orthopedic devices intended to immobilize a limb or a joint. These splints are mainly used in cases of traumatic injury or suspected traumatic injury (direct or indirect trauma, sprain, dislocation, contusion, crushing, burns, etc.) but are also worn after the medical diagnosis has been made, in particular in cases of rheumatism to rest the joint, tendinitis, fracture, tendon sutures, flexum to gain greater joint range. More particularly, the present invention applies to splints called "cuffs" for the hand, "BABP" i.e. Brachio Anté-Brachio Palmar for the joint immobilization of the wrist and elbow and "Boot" for the ankle and leg. State of the art.

[0003] It is known to produce splints from conventional plaster, polymerization resin, corset type and plexiglass splints or even thermoformed splints.

[0004] Plaster splints are inexpensive but have the main disadvantages of being heavy and unhygienic because they cause significant maceration after a few days and generate compression of the limb to be treated.

[0005] Resin splints are relatively light but equally unhygienic (significant maceration) and cause unwanted compression and harmful heat for the limb.

[0006] Plexiglas splints or splints are light and robust but they are expensive, complex to install and do not solve the problem of limb hygiene due to the continued significant maceration.

[0007] Thermoformable splints are classically light but always present a problem relating to hygiene due to persistent maceration and more limited immobilization because they are semi-circumferential.

[0008] Documents US10758396, US20180357348, US 20160074203 or even US 20200100847 are also known, which present splints made up of two shells, but all the splints presented in these documents surround the entire limb over at least one transverse section of the splint. Thus, at least locally, such splints induce hygiene / maceration problems and the inability to reach the limb without removing the splint.

[0009] Conventional splints, being circular and mechanically closing on the limb, do not allow for post-position adjustment to overcome the problem of amyotrophy of the limb, the muscle mass of which melts after a few days after its immobilization.

[0010] The invention aims to remedy this state of affairs.

[0011] In particular, an objective of the invention is to propose a manufacturing method and system for providing an orthopedic splint fulfilling its primary therapeutic function while being suitable for prolonged contact with the skin, without maceration or hygiene problems.

[0012] An essential objective is to propose a splint scrupulously respecting the orthopedic obligations and goals while leaving free all the joints not necessary for these obligations and goals, allowing in particular to maintain the writing activity and avoiding non-orthopedically necessary ankylosis.

[0013] A complementary objective is to propose a biodegradable splint.

[0014] Another objective is to propose 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 burn victims (for example treatments of the epidermis).

[0015] A complementary objective is to propose an orthopedic splint produced quickly, light and inexpensively.

[0016] An additional objective is to overcome the problem of limb amyotrophy (muscle mass which melts after a few days) and to propose a fastening system which allows tension adjustment throughout the treatment. Presentation of the invention.

[0017] It has thus been noted by the applicant, after various experiments and manipulations, that it is particularly interesting to produce a splint with two shells, not surrounding and which is perfectly adapted and adaptable to the patient's limb.

[0018] The solution proposed by the invention is a method of manufacturing an orthopedic splint, the splint being made up 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 connected to each other by a plurality of adjustable fasteners.

[0019] The method is remarkable in that it 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 placed; • a step of defining the shape (or even the contours) and the dimensions of the two shells of the splint based on the digitalization 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, one on top of the other from a first bead placed 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 between 50°C and 70°C so as to modify the shape of said portion while preserving the circumferential limits of the two shells.

[0020] The expression "cellular shell" means a shell that is perforated or hollowed out in many places so as to present a stretched mesh appearance whose mesh has heterogeneous dimensions. These cells or recesses mean that the surface defined by the circumferential limits of a shell is covered with polymer material over at most 60%, or even over at most 50%, or even over at most 40% depending on the nature of the splint ("cuff", "BABP", "boot" or others) depending on the orthopedic specifications and constraints.

[0021] Such a variable geometry honeycomb mesh, inspired by bone fiber, allows the introduction of electrotherapy electrodes. Thus, physiotherapy can be started immediately, thereby reducing amyotrophy and shortening the duration of rehabilitation, work stoppage and therefore the overall cost of treatment for the community.

[0022] The term "desired orthopedic immobilization position" in connection with the digitization step means that the limb is placed and maintained in the appropriate position as defined by the rules of orthopedic surgery.

[0023] The expression "non-identical" in relation to the shells is understood to mean that these shells do not have the same shapes and dimensions, on the one hand because each one adapts to a limb contour, which is classically non-symmetrical, and on the other hand because the alveoli or recesses present on each shell depend on the areas where access must be authorized as well as on the limb locally (strength or on the contrary local fragility). The areas at risk of pressure sores or the surgical incision areas are left free to avoid any post-operative scarring and infectious complications. Dressing care and scar monitoring are all the easier.

[0024] The term “simultaneous additive construction” is understood to mean in relation to 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 one on top of the other passing from one shell to the other, the two shells being placed opposite each other on the heating plate.

[0025] Thanks to the particular characteristics of the manufacturing method 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, on the one hand according to the orthopedic needs and on the other hand according to the changes in the limb, in particular due to local amyotrophy.

[0026] 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.

[0027] The orthopedic splint according to the invention is ventilated and allows normal hand washing, which is crucial during an epidemic.

[0028] The splint is breathable, prevents maceration and odors. It makes desquamation possible and allows the patient to take showers, bathe and begin rehabilitation more quickly with partial weight-bearing in balneotherapy. Its water resistance avoids the need for plaster cast removals / re-casts, thus reducing the risk of secondary displacement of fractures.

[0029] Improving hygiene is important in the hot season, particularly in regions with a temperate climate, but becomes essential during epidemics. By reducing pruritus, the incidence of complications linked to the introduction of foreign bodies into the cast is reduced, particularly in pediatrics.

[0030] 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 in the description and in 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:

[0031] Even once printed, the characteristics of the splint obtained by the manufacturing process 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, or with a simple conventional hair dryer, without changing the splint.

[0032] Advantageously, the heating of at least a portion of at least one of the two shells is carried out at a temperature between 55°C and 65°C.

[0033] Preferably, during the above-mentioned subsequent thermoforming step, the heating of said portion lasts between 1 and 4 minutes, preferably between 2 and 3 minutes.

[0034] According to one embodiment, the above-mentioned heating plate has, on its surface in contact with the above-mentioned first cord, a temperature of between 60°C and 80°C.

[0035] Advantageously, the above-mentioned polymer, when it leaves the nozzle, has a temperature of between 200°C and 235°C.

[0036] According to a particularly interesting aspect of the invention, the polymer cords are delivered at a speed varying between 50 and 90 millimeters per second.

[0037] Advantageously, during the above-mentioned 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.

[0038] The present invention also relates to a system for manufacturing an orthopedic splint, the splint being made up 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 connected to each other by a plurality of adjustable fasteners.

[0039] The manufacturing system is remarkable in that it includes: • a device for scanning the patient's limb around which the orthopedic splint is intended to be installed, the scanning device comprising three-dimensional sensors placed on the patient's limb to determine the circumferential limits of each of the two shells of the splint in a digital file representative of the shape and dimensions of the two shells of the splint; • a hot plate; • a machine for simultaneous additive printing of the two shells, from the aforementioned digital file, comprising a nozzle for delivering beads of polylactic acid polymer to be arranged on top of each other from a first bead arranged on the heating plate 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 between 50°C and 70°C.

[0040] Advantageously, the nozzle consists of a double-headed nozzle having a diameter respectively between 0.3 and 0.5 mm and 0.7 and 0.9 mm, inclusive.

[0041] 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.

[0042] Finally, the present invention relates to an orthopedic splint, obtained by the method succinctly presented above or by the manufacturing system above mentioned, the splint being made of two non-identical plastic honeycomb shells, the two shells extending substantially longitudinally and being intended to surround a limb of a patient, the shells being connected to each other by a plurality of fasteners, in which no transverse section of the shells completely surrounds the corresponding section of the patient's limb, the two shells being made of polylactic acid (PLA) polymer.

[0043] The splint according to the invention is designed to adapt to the amyotrophy that occurs during orthopedic treatment. Thus, such a splint is designed in a non-surrounding manner, that is to say non-circumferential with respect to the limb around which it is applied, and this on all transverse sections of the splint or of the two shells extending longitudinally.

[0044] 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 hollows - 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 reduced as the orthopedic treatment progresses. The proportion of the surface of the limb not covered 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 orthopedic immobilization.

[0045] 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 the figures.

[0046] Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which follows, with reference to the appended drawings, produced as indicative and non-limiting examples and in which: [Fig.l] is a photograph illustrating the installation of three-dimensional sensors on the forearm of a patient so as to define the circumferential limits of each of the two shells forming the “cuff” type splint according to the invention. [Fig.2] 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. [Fig.3] is a first photograph illustrating the installation 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. [Fig.4] is a second photograph illustrating a placement of three-dimensional sensors on the foot of the patient in [Fig.3] in order to define the circumferential limits of each of the two shells forming the “boot” type splint according to the invention. [Fig.5] is a photograph illustrating the manufacture of the two shells forming the splint according to the invention, at a first stage. [Fig.6] is a photograph illustrating the manufacture of the two shells forming the splint according to the invention, at a stage subsequent to the first stage. [Fig.7] is a photograph illustrating a “cuff” type splint according to the invention placed or mounted on the forearm of a patient. [Fig.8] is a schematic representation of a “BABP” type splint according to the invention. [Fig.9] is a schematic representation of a “cuff” type splint according to the invention. [Fig. 10] is a schematic representation of a “boot” type splint according to the invention. [Fig. 11] is a schematic representation of one embodiment of the fasteners used for a splint according to the invention. Description of the embodiments.

[0047] As presented previously, 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 adapting to other parts or limbs of a patient.

[0048] Concerning the "cuff" type splint, visible in particular in [Fig.9], at the level of the hand, the manufacturing process takes into account the reduction of edema and the low amyotrophy of the intrinsic muscles of the hand, in particular to the extent that the digital chains are left free here. Indeed the design (shapes and dimensions) of the splint according to the invention allows complete mobility of the thumb column and does not cover the thenar eminence. This allows the patient in particular to be able to write although immobilized.

[0049] The surface area of ​​the patient's limb covered by the splint decreases from distal to proximal at the level of the forearm since the circumference and diameter of the forearm increases progressively from the wrist to the elbow. The muscular compartments of the forearm are made up of both the flexors and extensors of the wrist which present a certain rapid amyotrophy whereas conversely the extrinsic flexors and extensors of the fingers continuing to be mobilized during the orthopedic treatment do not present any amyotrophy. This is why the "cuff" type splint has a decreasing thickness and / or covering surface from the hand towards the elbow.

[0050] According to another important aspect, for the “cuff” type splint, the areas incision in the context of osteosynthesis of the ulna opposite the ulnar edge of the arm are left free with the splint according to the invention and this guarantees greater comfort.

[0051] Concerning the "BABP" type splint, visible in [Fig.8], this splint uses the principle of the cuff. The technical features described previously remain valid, since these splints are equivalent or identical from the wrist or 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 arm compartment. Indeed, the extensors and even more so 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 likely to present rapid and certain amyotrophy to the extent that flexion of the elbow is made completely impossible by immobilization.

[0052] 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 orthopedic immobilization. The adaptation of the splint according to the invention at this level must therefore be major. This is allowed by the manufacturing method and system including an adjustment of the fixation - given the fixation of the circumferential limits of each shell and / or due to the subsequent step of thermoforming the PLA polymer - which guarantees at this level a great deal of freedom and therefore optimal support during orthopedic treatment. At the level of the bicipital relief, the coverage is therefore low because of the significant amyotrophy.

[0053] The same applies to 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 area free by protecting it with an ellipse which avoids any contact at this level and therefore any risk of bedsores and healing problems. 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.

[0054] Concerning the "boot" type splint, visible in [Fig. 10], the intrinsic muscles of the foot present minimal fluctuations during orthopedic immobilization. Here it is more the edema of the foot which must be taken into account. The area where the variations linked to amyotrophy are the most important is located at the level 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 muscles ex intrinsic to the foot remains minimal. Thus, it is in the part of the proximal third of the splint according to the invention that the uncovered area is the largest. Again, the "boot" type splint has a decreasing thickness and / or 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, above, at the level of the tibia.

[0055] The most common fracture in the lower limb is the malleolar fracture. It is therefore consistent and judicious to ensure that the most common incision sites, namely the external malleolus and the internal malleolus, are left free. Compression of its bony reliefs is extremely poorly tolerated regardless of the immobilizations used. Indeed, most patients immobilized by a plaster cast or resin complain of friction aggravated by amyotrophy which allows mobility in circular immobilization. Furthermore, the U-shaped thermoformed splints of the state of the art fold over the malleoli, which is frequently the cause of bedsores, healing disorders or even sepsis. The splint according to the invention leaves its bony reliefs free, allowing on the one hand the care of dressings and guaranteeing greater comfort while reducing the rate of local complications.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 (see [Fig. 10]) - is shorter in order to avoid being bothersome at the level of the popliteal fossa, again with an aesthetic angulation.

[0056] 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 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.

[0057] Indeed, the additive printing manufacturing process allows shapes corresponding to rackets without weakening the robustness of the splint by respecting the principle of mimicry of the articular spans. Thus for the splints of the upper limb, the column of the thumb is left entirely free with a very clear clearance 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 palmar shell respects the criteria of length 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 the pollicis longus grips and thus increase the feeling of freedom and autonomy despite orthopedic immobilization.

[0058] During the step of digitizing 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. For example, the three-dimensional sensors 1 may consist of electrode washers or pads having a nipple or the like. These three-dimensional sensors 1 are advantageously provided with an adhesive or sticky portion suitable for temporarily attaching to a portion of a human body and have a protuberance (nipple or the like) defining by connections 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.

[0059] During the performance of the capture which allows the recording of a three-dimensional impression of a limb 2, these relief sensors 1 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 limb 2 of the patient - as visible in Figures 1 to 4 - during the performance of the capture (step of digitizing the patient's limb) corresponds to the desirable positioning for maintenance during the orthopedic treatment. This system thus makes it possible to optimize the shape of the splint according to the invention and facilitates the application and removal of the splint, including in a fractured patient.

[0060] In [Fig. 1], one can see a face or a side of a forearm 10 of a patient on which four three-dimensional sensors 1 are present, 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. Generally speaking, for a forearm 10 of a patient, in other words for a “cuff” type splint, the manufacturing method according to the invention provides at least eight three-dimensional sensors 1, i.e. 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, ten, twelve, fourteen or even more three-dimensional sensors 1 can be used for such a “cuff” type splint.

[0061] In the same way for [Fig.2] relating to a “BABP” type splint, there are five three-dimensional sensors 1 on one face or one side of an arm 11 (including one three-dimensional sensor located at the top between the two sides or faces) so that there are 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 around thirty sensors 1, or fifteen three-dimensional sensors 1 for each shell 3, 4, anterior and posterior or even upper and lower.

[0062] Figures 3 and 4 illustrate the three-dimensional sensors 1 positioned on the foot 12 of a patient, according to two different viewing angles. We thus note five sensors 1 visible in [Fig.3] and five sensors 1 visible in [Fig.4]. Thus, to produce a “boot” type splint 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 can be used, or even many more sensors 1 to refine said limits. We can note here the presence of a strap or ribbon 20 intended to keep the foot 12 stable in the desired position for maintaining the limb / foot 2 / 12, without displacement during the scanning operations of the patient’s foot 12 and for perfect localization of the sensors 1 so as to define the circumferential limits of each shell 3, 4 forming the splint.

[0063] The means for digitizing the patient's limb and defining 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 digitizing the patient's limb 2 and defining 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 physically reproduce it by the additive manufacturing process layer by layer.

[0064] In Figures 5 and 6, the nozzle 5 can be seen simultaneously manufacturing or producing 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 tracking of the line, defined height by height, or horizontal line by horizontal line, to form the two shells 3, 4 of the splint. In other words, the nozzle 5 substantially rotates, to successively form the layers on top of each other, taking into account the fact that the two shells 3, 4 are substantially inscribed in a cylinder, this being particularly true for the “cuff” and “BABP” type splints, as well as at least in part for the “boot” type splint.

[0065] 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 are finalized, to release the two shells 3, 4, like the base 6 from which the shells 3, 4 are manufactured / produced.

[0066] [Fig.7] illustrates a "cuff" type splint fixed on the forearm of a patient. It can be noted that, in general, a splint according to the invention has a thickness of between 1 millimeter (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 mechanical strength / stress throughout its duration of use.

[0067] It should also be noted that the splints according to the invention may be presented in a specific color, for example chosen by the patient for aesthetic reasons or for technical reasons, for example a bright color, such as vermilion red, in order to attract the attention of other people present in a workplace.

[0068] In the same way, the recesses or cells 8 are also positioned in such a way that they are of larger dimensions - in width and / or in length - in the locations subject to less mechanical stress or to allow a subsequent medical operation such as, for example, the application / replacement of a dressing or the application / replacement of treatment electrodes.

[0069] 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.

[0070] The fasteners 20 shown in [Fig.l 1] are one 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 of the slots intended to form the female part 22 allowing the fixing of the male part 21. Conventionally, the use of one or other of these slots 22 makes it possible to arrange the two shells 3, 4 more or less at a distance from each other, depending in particular on the therapeutic requirements of the splint, possibly a distance which changes 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. Taking into account 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.

[0071] The splint according to the invention is in the form of an immobilization by two shells 3, 4: anterior and posterior, upper and lower or even medial and lateral. Each of these shells 3, 4 have a particular congruence ensuring almost by itself sufficient immobilization according to the principles of orthopedic restraint but the quality of the immobilization is very clearly improved by the addition of a second shell 3 or 4. Furthermore, this principle will allow the operated patient to benefit from dressing care in complete safety. For example, current thermoformed immobilizers 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 restraint avoiding secondary displacement while allowing dressing changes.

[0072] The splint according to the invention is positioned and removed very easily, even in trauma patients.

[0073] The pattern of the splint according to the invention does not simply reproduce that of the bone trabeculae for purely aesthetic reasons, but pushes the mimicry to the point of respecting physiological biomechanical principles.

[0074] Indeed, bone is a living tissue. It becomes denser in areas of high biomechanical stress and, on the contrary, becomes more aerated in areas of low stress or in the event of a decrease in activity. The shape and dimensions of the splint according to the invention also follow engineering considerations which allow maximum benefits to be obtained.

[0075] The splint according to the invention comprises a three-dimensional pattern which densifies and thickens in areas of high stress, as does a biological bone. The histological study does not reveal bone tubes but rather bone trabeculae or laminae whose densification and thickening in space thus respond to the stresses and this in order to prevent any fatigue fractures. The bone trabeculae is oriented according to the lines of force and stress in order to be able to absorb them physiologically without resulting in a fatigue fracture. Thus, considerable energy is required to fracture a tibia in the direction of height but tiny energy is required to break it in a movement with a rotary component. This is made possible in particular by the principle of printing according to a vertical additive mode.

[0076] Thus reproducing the axis of the natural constraints of the long bones (mostly vertical in the locomotor system) which define the orientation of the bone trabeculae in response to the constraints undergone by the bone. The covering surface of the splint according to the invention varies for anatomical reasons. To maintain constant pressure, it is necessary to thicken the trabeculae and reduce the surface area of ​​the alveoli 8. Fractures occur in areas of high stress, the thickness of the trabeculae is deliberately increased to reduce pressure and reduce ischemia as well as prevent compartment syndrome.

[0077] Thus, the pattern inspired by the spongy bone of the splints according to the invention ensures optimization of the material and the weight-resistance ratio. In the same way, the pattern of the splint according to the invention does not just 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 breathable nature of the splint, prevent maceration and also preserve 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.Variations in temperature, speed and size of the nozzle 5 of the manufacturing machine allow: . • better resistance to stresses by adding flexing to certain areas by adjusting the speed of application, its temperature and the frequency of application of the polymer, advantageously PLA, and • ensure comfort by maintaining sufficient ventilation in low-stress areas.

[0078] Very advantageously, the PLA polymer was selected after numerous trials and tests from among all the plastic and elastomer materials. PLA can be thermoformed during orthopedic treatment. Indeed, amyotrophy is likely to make certain bone 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 circumferential limits defined / obtained during manufacture. Thermoforming thus makes it possible to optimize the splint produced for the patient's limb.

[0079] Although the invention has been described in connection with several particular embodiments, it is quite 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.

[0080] 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 may be made to these elements and / or means and / or steps, without departing from the spirit and scope of the invention. In particular: - 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, shape and / or even functions of the so-called three-dimensional sensors 1, provided that these sensors 1 allow, during the scanning of the patient's limb 2 or following this operation, the circumferential limits of each of the two shells 3, 4 to be precisely defined; - the shape, dimensions and / or nature of the heating plate 7 which may be made of metal (aluminium or steel for example) or ceramic; or - the shape, dimensions and / or nature of the fasteners 20 intended to hold the two shells 3, 4 together, around the patient's limb.

[0081] The use of the verb “comprise”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0082] In the claims, any reference sign in parentheses cannot be in interpreted as a limitation of the claim.

[0083]

Claims

Claims

1. A 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 connected to each other by a plurality of adjustable fasteners, characterized in that the method comprises the following successive steps: • a step of digitizing the limb (2) of the patient, installed in a desired orthopedic immobilization position, around which the orthopedic splint is intended to be placed; • 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), one on the other from a first bead (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 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 preserving the circumferential limits of the two shells (3, 4).;

2. A manufacturing method according to claim 1, wherein said temperature is between 55°C and 65°C.

3. Method according to claim 1 or 2, wherein, during the said subsequent thermoforming step, the heating of said portion lasts between 1 and 4 minutes, preferably between 2 and 3 minutes.

4. A manufacturing method according to any one of the preceding claims- preceding, in which the above-mentioned heating plate (7) has, on its surface in contact with the above-mentioned first cord (6), a temperature between 60°C and 80°C.

5. Manufacturing method according to any one of the preceding claims, in which the above-mentioned polymer, when it leaves the nozzle (5), has a temperature of between 200°C and 235°C.

6. A manufacturing method according to any preceding claim, wherein the polymer beads are delivered at a speed varying between 50 and 90 millimeters per second.

7. Manufacturing method according to any one of the preceding claims, in which, during the above-mentioned scanning step, a plurality of three-dimensional sensors (1) are applied to the patient's limb (2), 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).

8. 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 connected to each other 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 digital 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 above-mentioned digital file, comprising a nozzle (5) for delivering beads of polylactic acid polymer to be arranged on top of each other from a first bead (6) arranged 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.

9. A system for manufacturing an orthopedic splint according to claim 8, wherein the nozzle (5) consists of a double-headed nozzle (5) having a diameter respectively between 0.3 and 0.5 mm and 0.7 and 0.9 mm, inclusive.

10. 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) shells (3, 4) made of plastic, the two shells (3, 4) extending substantially longitudinally and being intended to envelop a limb (2) of a patient, the shells (3, 4) being connected to each other by a plurality of adjustable fasteners, in which no transverse section of the shells (3, 4) completely surrounds the corresponding section of the limb (2) of the patient, the two shells (3, 4) being made of polylactic acid (PLA) polymer.

11. An orthopedic splint according to claim 10, wherein the fasteners are made of an elastomeric or rubber material, advantageously consisting of a natural or synthetic polyisoprene, a polybutadiene or a styrene-butadiene copolymer.

Images