Elastic external fixator system, and assembly provided with such a system

Abstract

The present invention relates to an elastic external fixator system (1) suitable for distracting a first bone (3) with respect to a second bone (5) of the body (C) of a patient (P), comprising: - a first pin (7); - a second pin (9); and - a pair of fixators (11), each fixator (11) being respectively held by one end of the first pin (7) and by one end of the second pin (9), each fixator (11) comprising a first portion (21) provided with a first through-hole and a second portion (22) provided with at least one series of second through-holes, the first portion (21) consisting of a first elastomeric material, the second portion (22) consisting of a second material which has a greater hardness than the first material. The invention also relates to an assembly comprising such a system (1) and a drilling guide.

Description

[0001] Elastic external fixation system, and assembly equipped with such a system

[0002] FIELD OF INVENTION

[0003] The present invention relates to an elastic external fixing system, as well as to an assembly equipped with such a system.

[0004] STATE OF THE ART

[0005] It is known to treat fractures near a joint, such as a fracture of the middle phalanx of a finger. Such fractures are relatively rare and complex for a healthcare professional, such as a surgeon, to treat.

[0006] It is known to treat such fractures, which are often caused by percussion and / or impaction, by inserting two pins, such as Kirschner wires, into bones located on either side of the fracture and the joint. To compress the broken bone or fragments between the ligaments of the joint, which form a sleeve or sheath holding the broken bone or fragments together, a distraction device is placed between the pins. This device generates a tensile force between the pins, causing them to move apart. This tensile force then elongates the ligaments, which in turn compress the broken bone or fragments, facilitating their treatment, namely bone healing or osteosynthesis of the broken bone. This type of ligament reduction is also known as ligamentotaxis.The external fixing system formed by the pins and the distraction device is thus known as the "Suzuki frame" for Suzuki frame, or Suzuki mount.

[0007] Document GB 2489471 A describes in particular an external finger fixator, which is suitable for holding a broken, fractured or damaged finger during a healing process.

[0008] However, such an external fixation system leads to significant stiffness, primarily because it allows no joint mobility. To avoid this stiffness, an elastic—or dynamic—external fixation system is known. In this system, the distraction mechanism is designed to allow for fine adjustment while permitting a small amount of pivoting movement around the joint, even with the external fixation system present. This elastic external fixation system comprises a pair of elastic bands or springs, which provide distraction while allowing a small amount of pivoting movement around the joint.For example, in the case of a fracture of an intermediate phalanx of a finger, the intermediate phalanx can pivot with a small amplitude relative to the proximal phalanx around the joint located between the intermediate phalanx and the proximal phalanx.

[0009] However, the assembly and adjustment of such an external elastic fixator system is complex and time-consuming to perform, especially by a surgeon.

[0010] Thus, mounting an external elastic fixation system is difficult, and the time required to mount and adjust such a system is significant.

[0011] DESCRIPTION OF THE INVENTION

[0012] The present invention aims to overcome all or part of the disadvantages mentioned above.

[0013] The invention aims in particular to provide an elastic external fixing system which is both simple and quick to assemble.

[0014] According to a first aspect, the invention proposes an elastic external fixation system suitable for distracting a first bone from a second bone in a patient's body, comprising:

[0015] - a first pin designed to pass through the first bone in such a way that the ends of the first pin protrude externally from the body on either side of the first bone,

[0016] - a second pin designed to pass through the second bone in such a way that the ends of the second pin protrude externally from the body on either side of the second bone,

[0017] - a pair of fixators suitable for external fixation outside the body and positioned opposite each other on either side of the first and second bones, such that each fixator is respectively held by one end of the first pin and by one end of the second pin, each fixator extending longitudinally along a longitudinal axis and comprising a first portion situated at a first longitudinal end of the fixator and a second portion comprising a second longitudinal end of the fixator opposite the first longitudinal end, each fixator comprising:

[0018] - in the first portion, a first through hole through which the respective end of the first pin passes, or in the first portion, a first through hole suitable for the respective end of the first pin to pass through,

[0019] - in the second portion, at least one series of second through holes, among which a single second through hole is traversed by the respective end of the second pin, or in the second portion, at least one series of second through holes suitable for being selectively traversed, a single second through hole at a time, by the respective end of the second pin, preferably, the first portion being made of a first material, the first material being elastomeric such that the first pin traversing the first portion is mobile relative to the second portion by elastic deformation of the first portion, the second portion being made of a second material whose hardness is greater than that of the first material.

[0020] Thus, we have an external elastic fixing system that is both quick and easy to assemble. Because each fixator has a first hole, mounting it onto the first pin is quick and easy. And because each fixator has at least one series of second through holes, mounting it onto the second pin is also quick and easy. Furthermore, adjusting the external elastic fixing system is also quick and easy. The user simply selects, for each fixator, a single second through hole suitable for the desired adjustment from among all the available second through holes, such that this single second through hole is pierced by the respective end of the second pin.Finally, when the first portion is made of a first material, the first material being elastomeric such that the first pin passing through the first portion is mobile relative to the second portion by elastic deformation of the first portion, and the second portion is made of a second material whose hardness is greater than that of the first material, an external elastic fixing system is obtained which prevents stiffening, such as the stiffening of a joint located between the first bone and the second bone.

[0021] The system according to the invention is advantageously and optionally supplemented by the following features, taken alone or in any of their technically possible combinations:

[0022] - The second pin pivots relative to the second portion. This simplifies assembly and makes it easier to mobilize the external elastic fixation system, thus preventing stiffness.

[0023] - The second pin is designed to be fixed relative to the second bone. Thus, the assembly is simpler.

[0024] - The first pin pivots relative to the second segment, preferably relative to both the second and first segments. This simplifies assembly and facilitates mobilization of the external elastic fixation system, preventing stiffness. - The first pin is designed to be fixed relative to the first bone. This simplifies assembly.

[0025] - The first pin passing through the first portion is translationally mobile relative to the second portion, preferably only along the longitudinal axis. This allows mobilization of the elastic external fixation system while preventing any mobilization that could negatively affect the osteosynthesis.

[0026] - The first material is an elastomer, preferably a silicone elastomer. This first material allows for the simple and inexpensive production of each fixative.

[0027] - The second material is a plastic or elastomer, preferably a plastic, and more preferably polyurethane. This second material allows for the simple and inexpensive production of each fixative.

[0028] - The fixatives are symmetrical, preferably identical. This optimizes manufacturing.

[0029] - Each fixative is obtained by molding, machining or additive manufacturing, preferably by injection molding. Thus, each fixative is manufactured in a simple manner.

[0030] - Each fixator is elongated in a direction from the first portion to the second portion. Thus, each fixator has a shape compatible with the morphology of the area to be treated, particularly when it comes to phalanges, which are elongated by nature.

[0031] - Each fixative is a plate. This simplifies manufacturing.

[0032] - Each fixator is a right cylinder, preferably a right prism. By right cylinder, we mean a right cylinder in the broadest sense, and not necessarily a right circular cylinder. Thus, each fixator has a shape particularly compatible with the morphology of the area to be treated, especially when dealing with phalanges, which are similar in shape.

[0033] - Each fixator has a decreasing cross-sectional area from the first through hole towards the second transparent holes. This allows each fixator to compensate for slight misalignment of the first or second pin, while maintaining a shape that is particularly compatible with the morphology of the area being treated, especially when dealing with phalanges, which are similar in shape. - Each fixator has a decreasing height in a direction orthogonal to the longitudinal axis and the axis of the first through hole. This allows each fixator to compensate for slight misalignment of the first or second pin, while maintaining a shape that is particularly compatible with the morphology of the area being treated, especially when dealing with phalanges, which are similar in shape.

[0034] Each fixator is made of radiolucent material. By "radiolucent," we mean that this material is transparent to X-rays and does not obscure other non-radiolucent elements on radiographs taken of the external fixation system. Therefore, checking the assembly once it is in place is particularly easy, since the first and second bones are readily visible without being obscured by the fixators.

[0035] - The second through holes have the same diameter. Thus, inserting the respective end of the second pin into a single second through hole chosen from among all the second through holes is easy.

[0036] - The second through holes are identical. Thus, inserting the respective end of the second pin into a single second through hole chosen from among all the second through holes is easy.

[0037] - The second through holes in the series of second through holes, or in each series of second through holes, are aligned. In other words, the second through holes in the series of second through holes, or in each series of second through holes, are arranged so that their axes are parallel and lie in the same plane. This simplifies the adjustment of the elastic external fixator system, which is designed so that for each fixator, a single second through hole is selected from among all the second through holes. The surgeon then only needs to apply elastic and longitudinal tension to the fixator, whose first through hole is aligned with the respective end of the first pin, to select the single second through hole corresponding to the desired distraction when this single second through hole is aligned with the respective end of the second pin.

[0038] - Each fastener includes at least two sets of second through holes, preferably exactly two sets of second through holes. This allows for easy compensation of any misalignment between the first and second pins.

[0039] - A first set of second through holes is offset along the longitudinal axis relative to a second set of second through holes. Thus, an adjustment can be made with a pitch smaller than the distance between the second through holes of a set of second through holes.

[0040] - Each set of second through holes contains the same number of second through holes. Thus, assembly is simplified, since a keying system is not required.

[0041] - The series plane of a first series of second through holes is angularly offset relative to the series plane of a second series of second through holes. Thus, a parallelism offset between the first and second spindles can be compensated for in a particularly simple manner.

[0042] The series plane of a first set of second through holes is angularly offset by an angle between 1 and 10 degrees relative to the series plane of a second set of second through holes. Thus, a small parallelism difference between the first and second spindles can be compensated for in a particularly simple manner. Alternatively, the series plane of a first set of second through holes is parallel to the series plane of a second set of second through holes.

[0043] - The longitudinal axis is located between the first set of second through holes and the second set of second through holes. This simplifies assembly, as a keying system is not required.

[0044] The distance between the second through holes of the first and second sets of through holes increases towards the second end. Therefore, a parallelism offset between the first and second pins can be compensated for in a particularly simple way. Indeed, the same parallelism offset between the first and second pins results in an offset distance that increases with the distance between the first and second pins.

[0045] - The first through hole is oriented along an axis orthogonal or perpendicular to the longitudinal axis. This arrangement facilitates assembly.

[0046] - Each second through hole is oriented along an axis perpendicular to the longitudinal axis. This arrangement facilitates assembly. - Each pin is a metal rod, preferably made of steel. This makes each pin easy to assemble, particularly because it can be easily inserted into bone without deformation.

[0047] - Each pin is a Kirschner wire. Thus, each pin is simple to insert and remove, while being minimally invasive.

[0048] - Each pin has a diameter between 0.5 mm and 5 mm, preferably between 0.5 mm and 2 mm, more preferably between 1 mm and 1.5 mm, and even more preferably 1.2 mm. Such a diameter is advantageous because each pin is easy to insert while being minimally invasive to the bones.

[0049] - The second portion forms a body and the first portion forms an insert, the second portion including a receiving chamber for the first portion. Thus, each fixative is easy to manufacture while remaining inexpensive.

[0050] - The first section is complementary in shape to the reception accommodation. Thus, the first section is easily retained within the reception accommodation.

[0051] The second portion has two oblong holes, which are oblong along the longitudinal axis and are positioned opposite each other with respect to the receiving socket, such that the respective end of the first pin passes through both the first through hole and the two oblong holes. This allows for mobilization of the elastic external fixator while preventing any mobilization that could negatively affect the osteosynthesis.

[0052] The first and second bones are articulated with each other. In other words, there is a joint between the first and second bones. The external elastic fixation system is particularly advantageous in this case, as it prevents stiffening of the joint between the first and second bones.

[0053] - The first bone is a phalanx, preferably a proximal phalanx located proximal to an intermediate and a distal phalanx. Indeed, the elastic external fixation system is particularly advantageous for this specific application.

[0054] The second bone is a phalanx, preferably an intermediate phalanx, located between a distal and a proximal phalanx, or a distal phalanx located distal to a proximal and an intermediate phalanx. Indeed, the elastic external fixation system is particularly advantageous for this specific application.

[0055] The first bone is proximal and the second bone is distal. In other words, the second bone is located distal to the first bone. Indeed, the elastic external fixation system is particularly advantageous in this case, since the mounting is especially simple when the first bone is proximal and the second bone is distal.

[0056] - The distance between the first through hole and each of the second through holes is between 10 millimeters and 100 millimeters, preferably between 11 millimeters and 60 millimeters, and more preferably between 11.60 millimeters and 36.60 millimeters. Indeed, the external elastic fixation system is particularly advantageous in this case.

[0057] The first through hole and each of the second through holes have the same diameter. Therefore, the first and second pins can be identical, and it is not necessary to distinguish them from one another before assembly. However, the first and second pins can be of different lengths, preferably with the first pin being shorter than the second pin.

[0058] - The first through hole has a diameter between 0.5 mm and 5 mm, preferably between 0.5 mm and 2 mm, and most preferably 1.5 mm. Such a diameter is advantageous because the corresponding first pin is easy to mount while being minimally invasive in the first bone.

[0059] - Each second through hole has a diameter between 0.5 mm and 5 mm, preferably between 0.5 mm and 2 mm, more preferably between 1.35 mm and 1.5 mm, and even more preferably 1.5 mm. Such a diameter is advantageous because the corresponding second pin is easy to mount while being minimally invasive in the second bone.

[0060] - The second through holes in the series of second through holes, or in each series of second through holes, are regularly spaced. This facilitates assembly, as the adjustment can be selected step by step.

[0061] - The second through holes in the series of second through holes, or in each series of second through holes, are spaced between 0.5 mm and 1 mm apart, preferably 1 mm apart. This allows sufficient distraction force to be applied while avoiding damage to the fixator. - The projection of the center-to-center distance of the second through holes in the series of second through holes, or in each series of second through holes, along the longitudinal axis is between 1 mm and 1.5 mm. This provides a fine adjustment increment, improving the adaptability of the elastic external fixator system.

[0062] - Each end of the first pin is bent to hold a fixator. Preferably, each end of the first pin is oriented perpendicularly to a central part of the first pin. This makes holding each fixator in place particularly easy.

[0063] - Each end of the second pin is bent to hold a fixator. Preferably, each end of the second pin is oriented perpendicularly to a central part of the second pin. This makes holding each fixator in place particularly easy.

[0064] - Each end of the first pin has a retaining element designed to hold a fixator. This makes it particularly easy to hold each fixator in place while preventing any movement or deformation of the first pin.

[0065] - Each end of the second pin has a retaining element designed to hold a fixator. This makes it particularly easy to hold each fixator in place while preventing any movement or deformation of the second pin.

[0066] - Each fastener includes exactly one series of second through holes, the series plan including the longitudinal axis. Thus, assembly is particularly simple.

[0067] - Each fixative is made from a single piece incorporating the first and second portions. Thus, each fixative is manufactured in a particularly simple manner.

[0068] - The first and second portions came from raw materials. Thus, each fixative is made in a particularly simple way.

[0069] - The first and second parts form a single unit. Thus, each fixative is made in a particularly simple way.

[0070] - The first portion forms the first longitudinal end. Thus, each fixator is made in a particularly simple manner. - Each fixator comprises, in the first portion, a plurality of first through holes, preferably exactly three through holes, the respective end of the first pin passing through a single through hole among the plurality of first through holes. Thus, a slight parallelism difference between the first pin and the second pin can be compensated for in a particularly simple manner.

[0071] - The first through holes of the plurality of first through holes are aligned along the longitudinal axis, preferably are aligned on the longitudinal axis.

[0072] - The first through holes of the plurality of first through holes are spaced between 0.5 mm and 1 mm apart, preferably 1 mm apart. This allows sufficient distraction force to be applied while avoiding damage to the fixative.

[0073] - The number of first through holes is strictly less than the number of second through holes. Thus, it is easy to distinguish first through holes from second through holes.

[0074] According to a second aspect, the invention also proposes an assembly comprising the system as previously described and a drilling guide suitable for guiding the drilling of a first through hole of the first pin through the first bone and for guiding the drilling of a second through hole of the second pin through the second bone, the drilling guide having a guide housing suitable for removably receiving a fixator of the pair of fixators, the drilling guide having a plurality of guide holes, each guide hole being through and extending a first through hole of the fixator or a second through hole of the fixator, such that the first through hole and each second through hole is extended by a guide hole.

[0075] Thus, such an assembly makes it easier to mount the system as previously described.

[0076] The assembly according to the invention is advantageously and optionally supplemented by the following features, taken alone or in any of their technically possible combinations:

[0077] - The drilling guide includes a recess forming the guide housing. Thus, the guide housing is made in a simple manner.

[0078] - The guide housing is a longitudinal groove. This makes the guide housing particularly simple to manufacture. - The guide housing is shaped to complement the clamp. This facilitates the handling of the drill guide and clamp.

[0079] - The second longitudinal end of the fixative protrudes from the guide housing. This facilitates the separation of the drilling guide and the fixative.

[0080] - The guide housing is designed to removablely receive the fixative. This facilitates the separation of the drilling guide and the fixative.

[0081] - The drill guide is a straight cylinder, preferably a right prism. By straight cylinder, we mean a straight cylinder in the broadest sense, and not necessarily a circular straight cylinder. This makes it easier for the user to grip the drill guide.

[0082] - The drilling guide comprises two concave and opposing gripping walls, the gripping walls being arranged laterally to the guide holes. This makes it easier for the user to grip the drilling guide.

[0083] - The gripping walls are positioned laterally relative to the guide housing. This makes it easier for the user to grip the drilling guide.

[0084] - The drilling guide is made from a single piece. This simplifies the manufacturing of the drilling guide.

[0085] - The drill guide is made of an elastomer or a plastic material, preferably a plastic material, more preferably polyamide. Thus, the drill guide is made simply and inexpensively.

[0086] - The drilling guide is made from the second material. Thus, the second material allows for a simple and inexpensive way to create the drilling guide.

[0087] DESCRIPTION OF THE FIGURES

[0088] Other features, purposes and advantages of the invention will become apparent from the detailed description below, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings, given by way of non-limiting examples and on which:

[0089] - Figure 1 is a schematic top view of an elastic external fixation system according to one embodiment, which includes a pair of fixators;

[0090] - Figure 2 is a schematic perspective view of a fixative according to a first variant embodiment; - Figure 3 is a schematic longitudinal section view of the fixative shown in Figure 2;

[0091] - Figure 4 is a schematic perspective view of a fixer according to a second embodiment variant;

[0092] - Figure 5 is a perspective view of a drilling guide;

[0093] - Figure 6 is a schematic side view of the drilling guide shown in Figure 5 receiving a fixative;

[0094] - Figure 7 schematically represents the steps of a process for mounting an external elastic fixing system or an assembly comprising an external elastic fixing system and a drilling guide.

[0095] Throughout the figures, similar elements are designated by identical references.

[0096] DETAILED DESCRIPTION OF THE INVENTION

[0097] Figure 1 schematically represents an elastic external fixator system 1. System 1 is specific to the distraction of a first bone 3 from a second bone 5 of the body C of a patient P.

[0098] Preferably, the first bone 3 and the second bone 5 are articulated with respect to each other. In other words, a joint A is present between the first bone and the second bone.

[0099] Advantageously, the first bone 3 is a phalanx, preferably a proximal phalanx located proximally to an intermediate phalanx and a distal phalanx.

[0100] Advantageously, the second bone 5 is a phalanx, preferably an intermediate phalanx, situated between a distal phalanx and a proximal phalanx, or a distal phalanx situated distally to a proximal phalanx and an intermediate phalanx.

[0101] Preferably, the first bone 3 is proximal and the second bone 5 is distal. In other words, the second bone 5 is located distally to the first bone 3.

[0102] Advantageously, system 1 includes a first pin 7, a second pin 9 and a pair of fasteners 11.

[0103] As shown in particular in Figure 1, the first pin 7 is suitable for passing through the first bone 3 in such a way that the ends of the first pin 7 protrude externally out of the body C on either side of the first bone 3. Preferably, the first pin 7 is suitable for being fixed relative to the first bone 3.

[0104] Advantageously, each end of the first pin 7 is bent so as to retain a fixative 11. Preferably, each end of the first pin 7 is oriented perpendicularly with respect to a central part of the first pin 7.

[0105] Alternatively, and according to a variant not shown, each end of the first pin 7 carries a retaining element suitable for retaining a fixative 11. Such a retaining element is, for example, formed by an end ball having a retaining housing suitable for retaining one end of the first pin 7.

[0106] As shown in particular in Figure 1, the second pin 9 is designed to pass through the second bone 5 in such a way that the ends of the second pin 9 protrude externally out of the body C on either side of the second bone 5.

[0107] Preferably, the second pin 9 is designed to be fixed relative to the second bone 5.

[0108] Advantageously, each end of the second pin 9 is bent so as to retain a fixative 11. Preferably, each end of the second pin 9 is oriented perpendicularly with respect to a central part of the second pin 9.

[0109] Alternatively, and according to a variant not shown, each end of the second pin 9 carries a retaining element suitable for retaining a fixative 11. Such a retaining element is, for example, formed by an end ball having a retaining housing suitable for retaining one end of the second pin 9.

[0110] Preferably, each pin, in other words each of the first pin 7 and the second pin 9, is a metal rod, more preferably a Kirschner pin.

[0111] Advantageously, each pin, in other words each of the first pin 7 and the second pin 9, has a diameter between 0.5 millimeters and 5 millimeters, preferably between 0.5 millimeters and 2 millimeters, more preferably between 1 millimeter and 1.5 millimeters, even more preferably equal to 1.2 millimeters.

[0112] Advantageously, each fixator 11 is respectively held by one end of the first pin 7 and by one end of the second pin 9.

[0113] Preferably, the pair of fixators 11 is such that they are suitable for being fixed externally outside the body C and opposite each other on either side of the first bone 3 and the second bone 5, so that each fixator 11 is respectively held by one end of the first pin 7 and by one end of the second pin 9.

[0114] Preferably, each fixative 11 is elongated in a direction from the first portion 21 to the second portion 22.

[0115] Advantageously, the fixators 11 are symmetrical, preferably identical. In other words, the pair of fixators 11 is a pair of symmetrical fixators 11, preferably identical.

[0116] Advantageously, each fixer 11 is a right cylinder, preferably a right prism.

[0117] Preferably, each fixative 11 is a plate.

[0118] Advantageously, each fixative 11 is obtained by molding, machining or additive manufacturing, preferably by injection molding.

[0119] Advantageously, as shown in particular in Figure 2, each fixator 11 extends longitudinally along a longitudinal axis X and comprises a first portion 21 located at a first longitudinal end E1 of the fixator 11 and a second portion 22 comprising a second longitudinal end E2 of the fixator 11 opposite the first longitudinal end E1.

[0120] Advantageously, each fixator 11 includes, in the first portion 21, a first through hole 31, through which the respective end of the first pin 7 is suitable to pass or passes. In other words, each fixator 11 includes, in the first portion 21, a first through hole 31 suitable to be passed through by the respective end of the first pin 7.

[0121] Preferably, the first through hole 31 is unique. Alternatively, according to a variant not shown, each fixator 11 comprises, in the first portion 21, a plurality of first through holes 31, preferably exactly three through holes 31, the respective end of the first pin 7 passing through a single first through hole 31 among the plurality of first through holes 31. Advantageously, the first through holes 31 of the plurality of first through holes 31 are aligned along the longitudinal axis X, preferably are aligned on the longitudinal axis X. Preferably, the first through holes 31 of the plurality of first through holes 31 are separated from each other by a distance of between 0.5 mm and 1 mm, preferably a distance of 1 mm.In other words, each first through hole 31 is separated from the nearest first through hole 31 or the nearest first through holes 31 by a distance of between 0.5 millimeter and 1 millimeter, preferably a distance of 1 millimeter.

[0122] Advantageously, the number of first through holes 31 is strictly less than the number of second through holes 32.

[0123] Preferably, the first through hole 31 is oriented along an axis orthogonal or perpendicular to the longitudinal axis X.

[0124] Advantageously, each fixator 11 comprises, in the second portion 22, at least one series S1-S2 of second through holes 32, among which a single second through hole 32 is traversed or is suitable to be traversed by the respective end of the second pin 9. In other words, each fixator 11 comprises, in the second portion 22, at least one series S1-S2 of second through holes 32 suitable to be selectively traversed, preferably a single second through hole 32 at a time, by the respective end of the second pin 9.

[0125] Preferably, each second hole going through 32 is oriented along an axis orthogonal to the longitudinal axis X.

[0126] Advantageously, the second through holes 32 have the same diameter.

[0127] Preferably, the second through holes 32 are identical.

[0128] Advantageously, the second through holes 32 of the series of second through holes 32, or of each series S1-S2 of second through holes 32, are aligned. In other words, the second through holes 32 of the series of second through holes, or of each series S1-S2 of second through holes 32, are arranged so that their axes are parallel and lie in the same series plane P1-P2.

[0129] Advantageously, each fixator 11 comprises at least two series S1-S2 of second through holes 32, preferably exactly two series S1-S2 of second through holes 32. Alternatively, according to a variant not shown, each fixator 11 comprises exactly one series of second through holes 32, preferably whose series plane includes the longitudinal axis X.

[0130] Preferably, the second through holes 32 in the series of second through holes, or in each series S1-S2 of second through holes 32, are regularly spaced. Advantageously, the second through holes 32 in the series of second through holes, or in each series S1-S2 of second through holes 32, are separated from each other by a distance of between 0.5 mm and 1 mm, preferably a distance of 1 mm. In other words, within the same series S1-S2 of second through holes 32, each second through hole 32 is separated from the nearest second through hole 32 or the nearest second through holes 32 by a distance of between 0.5 mm and 1 mm, preferably a distance of 1 mm.

[0131] Advantageously, the projection of the center-to-center distance of the second through holes 32 in the series of second through holes, or of each series S1-S2 of second through holes 32, onto the longitudinal axis X is between 1 mm and 1.5 mm. In other words, within the same series S1-S2 of second through holes 32, the center-to-center distance of two consecutive second through holes 32, projected onto the longitudinal axis X, is between 1 mm and 1.5 mm.

[0132] Advantageously, each fixator 11 has a decreasing cross-section from the first through hole 31 in a direction oriented towards the second through holes 32. Preferably, the cross-section is considered orthogonal to the longitudinal axis X.

[0133] Preferably, each fixator 11 has a decreasing height in a direction orthogonal to the longitudinal axis X and to the axis of the first through hole 31.

[0134] Advantageously, each fixator 11 is such that a first series S1 of second through holes 32 is offset along the longitudinal axis X relative to a second series S2 of second through holes 32. Preferably, the first series S1 of second through holes 32 is offset along the longitudinal axis X relative to the second series S2 of second through holes 32.

[0135] Preferably, each series S1-S2 of second through holes 32 comprises the same number of second through holes 32.

[0136] Advantageously, each series S1-S2 of second through holes 32 comprises between three and twenty second through holes 32, preferably between ten and fifteen second through holes 32, more preferably exactly fourteen second through holes 32.

[0137] Advantageously, the series plane P1 of a first series S1 of second through holes 32 is angularly offset with respect to the series plane P2 of a second series S2 of second through holes 32. Preferably, the series plane P1 of the first series S1 of second through holes 32 is angularly offset by an angle between 1 degree and 10 degrees with respect to the series plane P2 of the second series S2 of second through holes 32. Alternatively, according to a variant not shown, the series plane P1 of a first series S1 of second through holes 32 is parallel to the series plane P2 of a second series S2 of second through holes 32.

[0138] Advantageously, the longitudinal axis X is located between the first series S1 of second through holes 32 and the second series S2 of second through holes 32.

[0139] Preferably, the distance between the second through holes 32 of the first series S1 of second through holes 32 and of the second series S2 of second through holes 32 increases in the direction of the second end E2.

[0140] Advantageously, the distance between the first through hole 31 and each of the second through holes 32 is between 10 millimeters and 100 millimeters, preferably between 11 millimeters and 60 millimeters, more preferably between 11.60 millimeters and 36.60 millimeters.

[0141] Advantageously, the first through hole 31 has a diameter between 0.5 millimeters and 5 millimeters, preferably between 0.5 millimeters and 2 millimeters, more preferably equal to 1.5 millimeters.

[0142] Advantageously, each second through hole 32 has a diameter between 0.5 mm and 5 mm, preferably between 0.5 mm and 2 mm, more preferably between 1.35 mm and 1.5 mm, even more preferably equal to 1.5 mm.

[0143] Preferably, the first through hole 31 and each of the second through holes 32 have the same diameter.

[0144] Advantageously, each fixative 11 is made of radiolucent material.

[0145] Preferably, the first portion 21 is made of a first material, the first material being elastomeric.

[0146] Advantageously, the first material is an elastomer, preferably a silicone elastomer. The first portion 21 is made such that the first pin 7 passing through the first portion 21 is movable relative to the second portion 22 by elastic deformation of the first portion 21. For this purpose, the second portion 22 is made of a second material whose hardness is greater than that of the first material. By "greater," we mean strictly greater.

[0147] Advantageously, the second material is a plastic material or an elastomer, preferably a plastic material, more preferably polyurethane.

[0148] Advantageously, the second spindle 9 is pivotal relative to the second portion 22.

[0149] Preferably, the first pin 7 is pivotable relative to the second portion 22, preferably relative to the second portion 22 and the first portion 21.

[0150] Advantageously, the first pin 7 passing through the first portion 21 is translationally mobile relative to the second portion 22, preferably only along the longitudinal axis X. This translational mobility is made possible by elastic deformation of the first portion.

[0151] Figure 2 represents a fixer 11 according to a first variant embodiment.

[0152] According to this first variant embodiment, the second portion 22 forms a body and the first portion 21 forms an insert, the second portion 22 comprising a receiving housing 33 receiving the first portion 21.

[0153] Preferably, the second portion 22 has two oblong holes 35, which are oblong along the longitudinal axis X and are opposite each other with respect to the receiving housing 33, such that the respective end of the first pin 7 passes or is suitable to pass through both the first through hole 31 and the two oblong holes 35. In other words, both the first through hole 31 and the two oblong holes 35 are suitable to be traversed by the respective end of the first pin 7.

[0154] Advantageously, the first portion 21 is complementary in shape to the receiving housing 33, as can be seen in particular in figure 3. Thus, the first portion 21 is held by adhesion in the receiving housing 33.

[0155] Figure 4 shows a fixative 11 according to a second embodiment. According to this embodiment, each fixative 11 differs from the fixative 11 according to the first embodiment in that it consists of a single piece incorporating the first portion 21 and the second portion 22.

[0156] Preferably, according to this second variant, the first portion 21 and the second portion 22 form a single unit.

[0157] Advantageously, according to this second variant, the first portion 21 and the second portion 22 originated from material. For example, the first portion 21 originated from material with the second portion 22 at a bonding surface S.

[0158] Preferably, according to this second variant, the first portion 21 forms the first longitudinal end E1.

[0159] According to a third variant not shown but which can visually correspond to the representation in Figure 4, each fixative 11 differs from the fixative 11 according to the second embodiment in that it includes a third portion forming a rigid core, the third portion being made of a third material whose hardness is greater than that of the first material.

[0160] Advantageously, the third material has a higher hardness than the second material.

[0161] Preferably, the third portion is an insert embedded in the first portion, the second portion, or both the first and second portions. Such an insert allows for local reinforcement of the mechanical strength of the fixator 11 without affecting the elastic deformability of the first portion.

[0162] Figure 5 schematically represents a drilling guide 37.

[0163] Thus, an assembly comprises a system 1 as previously described and such a drilling guide 37.

[0164] The drilling guide 37 is suitable for guiding the drilling of a first through hole of the first pin 7 through the first bone 3 and for guiding the drilling of a second through hole of the second pin 9 through the second bone 5.

[0165] Advantageously, the drilling guide 37 has a guide housing 39 suitable for removably receiving a fixator 11 from the pair of fixators 11. Preferably, the drilling guide 37 has a plurality of guide holes 41, each guide hole being through and extending a first through hole 31 or a second through hole 32 of the fixator 11, such that the first through hole 31 and each second through hole 32 is extended by a guide hole 41.

[0166] Advantageously, the drilling guide 37 includes a recess forming the housing for guide 39.

[0167] Preferably, the guide housing 39 is a longitudinal groove.

[0168] Advantageously, the guide housing 39 is of complementary shape to the fixator 11.

[0169] Preferably, the second longitudinal end E2 of the fixator 11 protrudes out of the guide housing 39, as shown in Figure 6.

[0170] Advantageously, the guide housing 39 is suitable for removably receiving the fixator 11.

[0171] Preferably, the drilling guide 37 is a straight cylinder, preferably a right prism.

[0172] Advantageously, the drilling guide 37 comprises two concave and opposing gripping walls 43, the gripping walls 43 being arranged laterally with respect to the guide holes 41. Preferably, the guide holes extend parallel to the gripping walls 43.

[0173] Advantageously, the gripping walls 43 are arranged laterally relative to the guide housing 39. Preferably, the gripping walls 43 are distant from the guide housing 39.

[0174] Preferably, the drilling guide 37 is made of a single piece.

[0175] Advantageously, the drill guide 37 is made of an elastomer or a plastic material, preferably a plastic material, more preferably polyamide. According to one variant, the drill guide 37 is made of the second material.

[0176] A method for mounting an elastic external fixator system as previously described advantageously comprises the following steps:

[0177] - P20 pierce a first bone 3,

[0178] - P30 pierce a second bone 5,

[0179] - P50 insert a first pin 7 through the first bone 3 such that the ends of the first pin 7 protrude externally from the body on either side of the first bone 3,

[0180] - P60 insert a second pin 9 through the second bone 5 such that the ends of the second pin 9 protrude externally from the body on either side of the second bone 5,

[0181] - P70 fix a pair of fixators 11 externally out of the body and opposite on either side of the first bone 3 and the second bone 5, such that each fixator 11 is respectively held by one end of the first pin 7 and by one end of the second pin 9, the respective end of the first pin 7 passing through a first through hole 31 of the fixator 11, the respective end of the second pin 9 passing through a single second through hole 32 among at least a series S1-S2 of second through holes 32.

[0182] Preferably, the assembly process also includes the following step:

[0183] - during step P70, bend each end of the first pin 7 and each end of the second pin 9 so as to retain each fixative 11.

[0184] Advantageously, the assembly process also includes the following step:

[0185] - during step P20, use a drilling guide 37 as previously described to guide the drilling of the first through hole of the first pin 7 through the first bone 3.

[0186] Preferably, the assembly process also includes the following step:

[0187] - after step P20 and before step P70, P40 separate the drilling guide 37 from the fixative 11 housed in the guide housing 39.

[0188] Advantageously, the assembly process also includes the following step:

[0189] - during step P30, use a drilling guide 37 as previously described to guide the drilling of the second through hole of the second pin 9 through the second bone 5.

[0190] Preferably, the assembly process also includes the following step:

[0191] - after step P30 and before step P70, P40 separate the drilling guide 37 from the fixative 11 housed in the guide housing 39.

[0192] Advantageously, the assembly process also includes the following step:

[0193] - before step P20, before step P30, or before steps P20 and P30, P10, house a fastener 11 in the guide slot 39 of a drilling guide 37 as previously described. The invention is not limited to the embodiments and variants presented, and other embodiments will be obvious to those skilled in the art. In particular, it is possible to combine the embodiments and variants with each other.

Claims

DEMANDS 1. An elastic external fixator system (1) designed for the distraction of a first bone (3) from a second bone (5) of the body (C) of a patient, the system (1) comprising: - a first pin (7) suitable for passing through the first bone (3) such that the ends of the first pin (7) protrude externally from the body (C) on either side of the first bone (3), - a second pin (9) suitable for passing through the second bone (5) such that the ends of the second pin (9) protrude externally from the body (C) on either side of the second bone (5), - a pair of fixators (11) adapted to be fixed externally outside the body (C) and opposite each other on either side of the first bone (3) and the second bone (5), such that each fixator (11) is respectively held by one end of the first pin (7) and by one end of the second pin (9), each fixator (11) extending longitudinally along a longitudinal axis (X) and comprising a first portion (21) located at a first longitudinal end (E1) of the fixator (11) and a second portion (22) comprising a second longitudinal end (E2) of the fixator (11) opposite the first longitudinal end (E1), each fixator (11) comprising: - in the first portion (21), a first through hole (31) suitable for being traversed by the respective end of the first pin (7), - in the second portion (22), at least one series (S1-S2) of second through holes (32) suitable for being selectively traversed, a single second through hole (32) at a time, by the respective end of the second pin (9), the first portion (21) being made of a first material, the system (1) being characterized in that the first material is elastomeric such that the first pin (7) traversing the first portion (21) is mobile relative to the second portion (22) by elastic deformation of the first portion (21), the second portion (22) being made of a second material whose hardness is greater than that of the first material.

2. System (1) according to claim 1, wherein the second through holes (32) of the series of second through holes (32) or of each series (S1-S2) of second through holes (32) are regularly spaced.

3. System (1) according to claim 1 or 2, wherein the second through holes (32) of the series of second through holes (32) or of each series (S1-S2) of second through holes (32) are arranged so that their axes are parallel and are in the same series plane (P1-P2).

4. System (1) according to claim 3, wherein each fixator (11) comprises exactly two series (S1-S2) of second through holes (32), the series plane (P1) of a first series (S1) of second through holes (32) being angularly offset with respect to the series plane (P2) of a second series (S2) of second through holes (32).

5. System (1) according to claim 4, wherein the distance between the second through holes (32) of the first series (S1) of second through holes (32) and of the second series (S2) of second through holes (32) increases in the direction of the second longitudinal end (E2).

6. System (1) according to any one of claims 1 to 5, wherein the second portion (22) forms a body and the first portion (21) forms an insert, the second portion (22) comprising a receiving housing (33) receiving the first portion (21).

7. System (1) according to claim 6, wherein the first portion (21) is of complementary shape to the receiving housing (33).

8. System (1) according to any one of claims 1 to 5, wherein each fixator (11) is made of a single piece incorporating the first portion (21) and the second portion (22), and wherein the first portion (21) forms the first longitudinal end (E1).

9. System (1) according to any one of claims 1 to 8, wherein the first pin (7) passing through the first portion (21) is movable in translation relative to the second portion (22) only along the longitudinal axis (X).

10. Assembly comprising the system (1) according to any one of claims 1 to 9 and a drilling guide (37) adapted to guide a drilling of a first through hole of the first pin (7) through the first bone (3) and to guide a drilling of a second through hole of the second pin (9) through the second bone (5), the drilling guide (37) having a guide housing (39) adapted to removably receive a fixator (11) of the pair of fixators (11), the drilling guide (37) having a plurality of guide holes (41), each guide hole (41) being through and extending a first through hole (31) of the fixator (11) or a second through hole (32) of the fixator (11), such that the first through hole (31) and each second through hole (32) is extended by a guide hole (41).

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