Device and method for manufacturing intramedullary nail spacers

Abstract

The present invention relates to a device for manufacturing intramedullary nail spacers, the use of a mold, and a method for manufacturing intramedullary nail spacers. [Solution] The device for manufacturing an intramedullary nail spacer comprises a first tube (11), a second tube (12), and a flexible connecting piece for fluidly connecting the first tube to the second tube, wherein the first tube and the second tube can be positioned at different angles relative to each other. In this way, the intramedullary nail spacer can be manufactured with high precision during surgery.

Description

Technical Field

[0001] The present invention relates to a device for manufacturing an intramedullary nail spacer, the use of a mold, and a method for manufacturing an intramedullary nail spacer.

[0002] Intramedullary nails are used, for example, to treat fractures in trauma surgery. This occurs especially in the case of fractures of long bones such as the thigh bone (femur), the shin bone (tibia), or the upper arm bone (humerus). Intramedullary nails are typically driven longitudinally into the bone cavity, enabling the formation of new bone tissue there. After such treatment, infections of the surrounding bone and / or soft tissue can occur due to bacteria such as Staphylococcus aureus or Staphylococcus epidermidis. This is especially the case with open fractures, which require surgical procedures to remove the intramedullary nail and remove the infected tissue (debridement). Furthermore, systemic antibiotics and / or local anti-infective agents are used to specifically combat the infection.

[0003] It is known to apply antimicrobial coatings made of polymethyl methacrylate bone cement to intramedullary nails (N. Walter et al.: "Individual and commercially available antimicrobial coatings for intramedullary rods for the treatment of infected long bone non-union - a systematic review"; Injury 2022; DOI:10.1016 / j.injury.2022.05.008). Antibiotics from the bone cement are dissolved from the coating by aqueous bodily fluids such as wound secretions and blood, resulting in locally high antibiotic concentrations. In combination with systemic antibiotics, this can reduce bacteria that may remain after debridement. However, achieving a uniform coating thickness presents challenges. Intramedullary nails with excessively thick coatings cannot be implanted in previously debridemented long bones, or can only be implanted with difficulty.

[0004] After surgical repair and before reinsertion of the intramedullary nail, it is desirable to allow for temporary mechanical stabilization of the medullary cavity and to locally deliver antiinfective agents to locally suppress microorganisms remaining in the debridemented tissue. For this purpose, it is possible to manually form a rod from polymethyl methacrylate bone cement during surgery to partially replicate the previously explanted intramedullary nail. In this case as well, antibiotics can be provided for local release. However, the fitting of manually formed rods presents fundamental problems. Manual forming is not suitable for properly replicating the intramedullary nail, especially in the case of curved rods and / or larger rods. For this reason, the results are often unsatisfactory.

[0005] The features described above can be combined with various aspects of the present invention as desired.

[0006] The objective of the present invention is to manufacture intramedullary nail spacers using an improved method.

[0007] This objective is achieved by the device described in claim 1, its use, and the method described in the independent claim. Advantageous embodiments are defined in the dependent claims.

[0008] This objective is achieved by a device for manufacturing an intramedullary nail spacer. The device comprises a first tube, a second tube, and a flexible connecting piece for fluidly connecting the first tube to the second tube. The first and second tubes can be positioned at different angles to each other.

[0009] This device enables the simple and standardized manufacture of intramedullary nail spacers (hereinafter also referred to as spacers). Intramedullary nail spacers can be used in place of removed intramedullary nails to provide temporary mechanical stability of the pulp canal after surgical repair and before reinsertion of the intramedullary nail.

[0010] An intramedullary nail spacer can be fabricated from a molding material such as bone cement. The intramedullary nail spacer may contain one or more active ingredients, such as anti-infective agents or antibiotics, for local delivery. The active ingredients can be added to the molding material so as to be incorporated into the intramedullary nail spacer. This device serves as a mold. The molding material can be filled into the device and cured to form the intramedullary nail spacer. The cured intramedullary nail spacer can then be removed from the device. In particular, individual tubes and connectors can be removed individually from the intramedullary nail spacer. In this case, non-destructive removal is possible, and separation may occur, for example, with the destruction of one or both tubes and / or connectors, and / or the associated mold, for example, the connectors.

[0011] Depending on the intended implantation site, the intramedullary nail may be designed as a straight or curved hollow body. By positioning the first and second tubes at different angles to each other, it is possible to recreate the curvature of an explanted intramedullary nail, if one exists. Straight or arbitrarily curved intramedullary nail spacers can be manufactured as needed. In this way, the removed intramedullary nail can also be reconstructed during surgery to fit as precisely as possible to a specific location within the pulp canal. Manufacturing during surgery allows for the introduction of active ingredients, such as anti-infective agents or antibiotics, that are precisely matched to the bacteria present, into the spacer.

[0012] A tube is an elongated hollow body whose length is at least three times greater than its external cross-section or diameter. The tube defines an elongated cavity inside. The inner and / or outer cross-sections of the tube may be circular, but in principle, different cross-sections such as elliptical, square, rectangular, or other, especially regular polygonal, are also possible. Typically, the inner and outer cross-sections correspond to each other. The wall thickness may be constant in the axial and / or circumferential directions.

[0013] The cavities of the first and / or second tubes may be conical. If there is a circular cross-section, the inner diameter can increase continuously along the axial direction. Conical tubes are easy to demold. In other words, it is easier to remove the manufactured intramedullary nail spacer from the associated tube. In some embodiments, the tube does not contain any steps inside it. In particular, conical tubes have an angle of up to 7°, which is measured between the longitudinal axis of the tube and the inner wall of the tube.

[0014] The first tube is specifically designed to produce the distal tube, i.e., the distal portion of the intramedullary nail spacer. The second tube is specifically designed to produce the proximal tube, i.e., the proximal portion of the intramedullary nail spacer. In particular, the first tube is longer than the second tube.

[0015] The connecting piece functions to connect the first tube to the second tube and / or to form a connection between the first and second parts of the intramedullary nail spacer. A fluid connection is a connection in which the cavity of the first tube is connected to the cavity of the second tube. In particular, the connection is made at least substantially across the entire cross-section of the first tube and / or the second tube. The connecting piece is particularly tubular and can be hollow cylindrical and / or conical (in the shape of a hollow frustocone). If a conical connecting piece is present, the intramedullary nail spacer may be manufactured with parts of different diameters. This may be desirable depending on the patient's anatomical structure.

[0016] In particular, one end of the first tube is connected to one side of the connecting piece, and one end of the second tube is connected to the other side of the connecting piece. Specifically, the connection is made such that, in the connected state, there is a connected tube having two ends and a continuous cavity.

[0017] The connecting piece may be connected to and / or connectable to the first tube and / or the second tube. If the connecting piece may be connected to the first tube and / or the second tube, the components may be provided separately and connected by the user. Thus, the device may also exist as a system in a disassembled state. Regardless of whether it is connected or disconnected upon delivery, the connection between the connecting piece and each tube is preferably removable, and in particular, manually removable to facilitate demolding after the casting material has cured.

[0018] The connecting piece is flexible to allow a 40° angle to be set between the first tube and the second tube, and therefore between both sides of the connecting piece. The angle is measured between the longitudinal axes.

[0019] In particular, positioning at a specific angle can be achieved by the relative rotation of the first tube with respect to the second tube.

[0020] In particular, the first tube and / or the second tube are straight. However, the first tube and / or the second tube can also be curved. For example, there may be a bend near the connecting piece, and / or a straight section may exist in a region further away from the connecting piece.

[0021] The fitting of the manufactured intramedullary nail spacer to the removed intramedullary nail is the primary subject of this description. However, it is also possible to manufacture spacers with different shapes. In particular, the device is intended for single use.

[0022] In one embodiment, the device further comprises a fixing device for fixing the angle between the first tube and the second tube. This allows the set angle to be fixed during molding. In particular, any set angle can be fixed at least approximately. This effectively prevents any unintended angle changes. This facilitates handling during molding and allows for the production of particularly accurate replicas of the explanted intramedullary nail.

[0023] The fixing device may be configured, for example, to hold the first tube, the second tube, and / or connecting piece, and thus prevent changes in the angle between the tubes.

[0024] The fixing device may include, for example, a perforated plate and one or more pins. A tube or connecting piece can be moved to a desired angle and then positioned on the plate. The angle can be fixed by inserting one or more pins into the provided holes, thereby preventing relative rotation of the tubes. The holes may be arranged, for example, on one or more arcs. The distance between the holes may be selected so that different angles can be set, for example, in increments of 5°, for example, from 0° to 40°. The plate may also have one or more support elements that can be designed as fixed or movable pins to fix one tube, both tubes and / or connecting pieces on one side.

[0025] In one embodiment, the device has a lower housing including a first lower housing portion and a second lower housing portion. In particular, the relative rotation of the two lower housing portions is possible about the axis of rotation. In particular, the first lower housing portion is configured to hold a first tube and / or the second lower housing portion is configured to hold a second tube. A blocking device can be provided to selectively prevent the rotation of the two lower housing portions.

[0026] Each lower housing portion holds a tube. The two lower housing portions can be rotated relative to each other about the axis of rotation to set a desired angle between the tubes. The blocking device functions as a fixing device. The angle between the first tube and the second tube is achieved by preventing the rotation between the two lower housing portions.

[0027] Holding means preventing movement in at least one direction of movement. In particular, the holding device prevents the axial withdrawal of the first tube and / or the second tube. Further, the holding device can prevent the movement of the relevant tube perpendicular to the axis and / or the rotation about an axis perpendicular to the longitudinal axis and / or the longitudinal axis.

[0028] In particular, the first lower housing portion is also configured to hold one side of the connecting piece and / or the second lower housing portion is also configured to hold the other side of the connecting piece. In particular, the first lower housing portion includes a receptacle for the first tube and the side of the connecting piece facing the first tube. In particular, the second lower housing portion includes a receptacle for the second tube and the side of the connecting piece facing the second tube.

[0029] Each lower housing portion may include a disk in its central region, and the two disks may be positioned flat against each other and may be rotatable relative to each other.

[0030] The lower housing may be configured to insert, arrange, or insert the first tube, the second tube, the connecting piece, and / or any combination of these components into the lower housing in a holding position. The lower housing may have corresponding receptacles for the first tube, the second tube, and the connecting piece, in which the associated components can be arranged. In simple cases, the receptacle can be formed by a surface having two or more pins or protrusions, between which the associated tube or connecting piece can be arranged relative to the surface. The receptacle can also be adapted to the outer shape of the tube or connecting piece.

[0031] The axis of rotation is in particular a virtual axis of rotation. In other words, a physical axis of rotation is not necessarily required. The axis of rotation extends particularly through the connecting piece.

[0032] The lower housing can be positioned at the bottom when used as intended, and is therefore called the lower housing. However, this is not absolutely necessary. The device can be used as intended in any orientation. [[ID=!]]

[0033] The blocking device can, for example, fix the first lower housing part and the second lower housing part relative to each other, for example by frictional connection and / or form-fitting connection. The blocking device may, for example, comprise pins inserted into corresponding openings. For example, one or more openings may be present in the first lower housing part and the second lower housing part, and these openings can be aligned with each other by relative rotation of the lower housing parts. The pins can then be inserted through the openings of each lower housing part to prevent relative rotation.

[0034] Alternatively or additionally, the blocking device may be a screw, particularly a manually rotatable screw, which, when screwed in, secures the two lower housing portions to each other. In one embodiment, the screw can be screwed into the threads of the lower outer housing portion and press against the lower inner housing portion. This enables frictional locking. If there is also a recess on the inside of the lower housing portion, a shape-fit connection can be formed between the screw and the recess.

[0035] In one embodiment, the device has a housing upper comprising a first housing upper portion and a second housing upper portion. In particular, relative rotation of the two housing upper portions around a rotation axis is possible. Specifically, the housing upper portions are connected to and / or connected to a housing lower portion in order to jointly form a housing. A blocking device may be provided to selectively prevent the rotation of the two housing upper portions.

[0036] The upper portion of the first housing may contribute to holding the first tube, and / or the upper portion of the second housing may contribute to holding the second tube. The upper portions of the first and second housings may contribute to holding a connecting piece. For example, there may be corresponding recesses in which the associated tube or connecting piece can be positioned.

[0037] The upper housing can be designed to form a particularly compact housing that is at least partially closed together with the lower housing. The lower and upper housings can be connected to each other, for example, by pressing them together. Once connected, rotation of the lower and upper housings relative to each other can be prevented. In particular, the upper housing can be removed from the lower housing manually and / or non-destructively.

[0038] The housing typically has a first opening for a first tube and a second opening for a second tube. In particular, the housing surrounds and / or projects in all directions beyond the connecting piece. The lower part of the first housing, which includes the upper part of the first housing, can rotate relative to the lower part of the second housing, which includes the upper part of the second housing. This results in the rotation of the first tube relative to the second tube.

[0039] Each upper portion of the housing may include a disk in its central region, and the two disks may be positioned flat relative to each other or rotatable relative to each other.

[0040] In particular, the lower and upper housings include corresponding shape elements to enable connection of the first upper housing to the first lower housing, and / or connection of the second upper housing to the second lower housing. The corresponding shape elements may be, for example, projections, such as pins, on one side and recesses, such as blind holes, on the other. The molding elements may be designed so that the lower and upper housings can be pressed together. The insertion motion is particularly parallel to the axis of rotation.

[0041] In one embodiment, the first tube and / or the second tube have a shape-fitting element that protrudes outward. In particular, the shape-fitting element is held in such a way that axial pulling of the associated tube is prevented. Specifically, the device includes a second element that blocks the shape-fitting element.

[0042] The shape-fitting element cooperates particularly with the housing or a part thereof. For example, the lower and / or upper parts of the housing may have elements that cooperate with and contact the shape-fitting element, and thus prevent the shape-fitting element from being pulled out. For example, there may be recesses for accommodating the shape-fitting element. In particular, the shape-fitting element protrudes radially outward.

[0043] In particular, the way in which the tube is held by the shape-connecting element can be reversed. This means, for example, that the tube and connecting piece can be easily removed after molding, for example, after removing the upper part of the housing from the lower part of the housing.

[0044] The shape-fitting elements can be arranged circumferentially around the first tube and / or the second tube. The shape-fitting elements can be designed, for example, as annular protrusions, annular projections, or annular discs, particularly aligned perpendicular to the longitudinal axis. The shape-fitting elements may have surfaces oriented perpendicular to the longitudinal axis to prevent pull-out.

[0045] In particular, the connecting piece also has at least one outwardly projecting shape-fitting element that is held so as to prevent axial pull-out of the associated tube. This shape-fitting element may also be held by the housing or a portion thereof. The shape-fitting element of the connecting piece can be designed in the same way as the shape-fitting elements of the first and / or second tubes. In one exemplary embodiment, the connecting piece comprises two shape-fitting elements, the first shape-fitting element being held by the upper and / or lower portions of the first housing, and the second shape-fitting element being held by the upper and / or lower portions of the second housing. This prevents the connection between the connecting piece and each tube from loosening even when the injection pressure of the casting material is increased.

[0046] In one embodiment, the length of the first tube and / or the length of the second tube are adjustable. In this way, the intramedullary nail spacer can also be adapted to the patient's anatomical structure with respect to the elongation of the removed intramedullary nail and thus the relevant portion. In this manner, a particularly accurate replica of the removed intramedullary nail can be achieved. Essentially, there are various options available for adjusting the length of each tube.

[0047] In one embodiment, the first tube and / or the second tube are designed for telescopic length adjustment. The length of each tube can thus be adjusted telescopically. In particular, the tube comprises an outer tube having a larger first cross-section or diameter and a separate inner tube having a smaller second cross-section or diameter, which are aligned along a common longitudinal axis and, in particular, connected to each other. Thus, the first or second tube is a composite or multi-part tube. Relative movement between the inner and outer tubes along the longitudinal axis can occur to adjust the overall length. In other words, the inner tube can move within the outer tube. In particular, the outer tube is connected to a connecting piece, and / or the inner tube faces away from the connecting piece. This means that both tube sections can be pulled out together or individually after curing. Any closure elements or other components may be positioned on the tube facing away from the connecting piece.

[0048] In particular, the device further includes a fastening device for fastening the inner tube to the outer tube at a desired position. This prevents unintended changes in length. The fastening device may include, for example, a screw that can be screwed into the threads of the outer tube and contacts the inner tube in a forward contact area. The screw can be aligned perpendicular to the longitudinal axis of the associated tube. This allows for the formation of a friction connection. The inner tube may have a molded element on its outer wall that can engage with the contact area. This forms a shape-fit connection to prevent unintended pull-out.

[0049] In one embodiment, the first tube and / or the second tube can be shortened to adjust the length. In particular, the device has a cap element located on the shortened side.

[0050] This shortening is achieved, in particular, by a separation process such as cutting or sawing. This means that the unwanted portion of the tube is separated. The cap element is designed, in particular, to conceal the end face cut surface of the tube formed by the separation. Specifically, the cap element extends at least 2 cm in the axial direction of the tube, so that precisely perpendicular cutting is not required and / or any inaccuracies are concealed. This makes it easier for the user to use.

[0051] The user can then, for example during surgery, cut one or both tubes at the required length and cover the cut ends with the corresponding cap elements. The cap elements can be designed to connect to the tube via friction, shape-fit, and / or integral connection. The cap elements can be attached to and / or screwed onto the shortened tube.

[0052] The cap element can function as an adapter for positioning one or more additional components. The cap element may have a fastening area on the side facing away from the tube, designed, for example, as threads or as part of a bayonet connection. For example, a fastening element can be attached to the fastening area to close the tube.

[0053] In one embodiment, the first tube and / or the second tube have molded elements on their exterior to create a latching connection. The molded elements are spaced apart, in particular, along the longitudinal axis of the tube. Specifically, the cap element has one or more latching elements that can be hooked onto the associated molded element. Such a cap element may also be called a locking sleeve.

[0054] Each latch element can engage with one or more molded elements, particularly those located in the same axial position. This means that after the tube is shortened, the cap element is pressed onto the shortened tube and hooked into place, preventing unintended removal of the cap element, especially by a shape-fitting connection.

[0055] The latch element may be hook-shaped and / or may have a latch surface that is perpendicular or undercut to the longitudinal axis of the tube, for example. The molded element may be hook-shaped and / or may have a perpendicular or undercut latch surface. An undercut latch surface means a latch surface that is inclined so that self-locking occurs when an axial force is applied that attempts to pull the tube apart. An undercut latch surface typically has an angle greater than 90° with respect to the longitudinal axis.

[0056] The latch element can be designed as a circumferential groove. In this case, the latch connection can be made regardless of the relative position between the tube and the cap element. The circumferential groove can be, for example, serrated with vertical and inclined surfaces.

[0057] In one embodiment, the cap element comprises a clamping portion having a clamping area for clamping a shortened tube, the clamping portion having a first thread, for example, a male thread. In particular, the tube can be inserted into the clamping area. In one embodiment, the cap element includes a union nut having a second thread, for example, a female thread, which can be positioned on the tube. In particular, the shortened tube can be clamped by screwing the union nut onto the clamping portion, or by connecting the second thread and the first thread in the clamping area.

[0058] This allows for a simple friction connection between the cap element and the tube. The length can be set to any desired length.

[0059] The clamping region may include circumferentially distributed, possibly toothed, flexible clamping elements that can be flexibly moved radially outward or inward when the tube is inserted into the clamping region. The clamping elements may be formed by axial slots. The end of the tube is positioned between the clamping portion and a portion of the cap element located on the opposite side. By screwing a union nut, the clamping elements and the opposing portion are pressed against each other, thereby clamping the tube in the clamping region.

[0060] In one embodiment, the device includes a first end piece for placement at the end of a first tube or the end of a second tube facing away from the connecting piece. In particular, a connecting region for connection to a molding material source is located on the side of the first end piece facing away from the first tube or the second tube.

[0061] In one embodiment, the device includes a second end piece for placement at the end of a first tube or the end of a second tube facing away from the connecting piece. In particular, the second end piece partially closes the tube. Specifically, the second end piece is provided with a ventilation opening that connects the tube to the environment.

[0062] The first end piece primarily functions as an adapter for connecting to a molding material source. The first end piece is typically axially permeable. Molding material from the molding material source can be supplied to the device through the first end piece to produce a spacer. The molding material source may be, for example, a cartridge on which bone cement is manufactured. The molding material source may be connected directly or connected via an intermediate tube or hose. In particular, the molding material is press-fed from the molding material source into the device. The connection area may be designed, for example, as a female or male thread. A hose or tube from the cartridge can also be easily inserted into the corresponding opening of the end piece.

[0063] The first end piece and / or the second end piece can be closed, in particular, after the filling process is complete. For example, a closing cap or plug can be placed in the connection area of ​​the first end piece or in another area. This prevents sprue overhang or leakage of casting material and ensures a clean end of the intramedullary nail spacer. The second end piece may have a connection area for this purpose.

[0064] In one embodiment, the device comprises a first tube, a second tube, a first end piece, a second end piece, and / or a closing element for closing the cap element. This allows the associated tube to be closed on the side facing away from the connecting piece. The closing element may be a screw-in plug having male threads or a screw-in cap having female threads.

[0065] The closing element may also be designed as a plug formed from, for example, plastic or elastomer. The part that receives the plug and / or the plug may be tapered into a cone shape to facilitate insertion.

[0066] The second end piece functions, in particular, as a closure and / or vent. When the molding material is applied to the device, the displaced air must escape from the device. For this purpose, a vent opening is provided. In particular, the vent opening has a cross-section or diameter of 1 millimeter or several millimeters.

[0067] The first end piece and / or the second end piece can be positioned directly or indirectly on the associated tube. In an indirect position, one or more intermediate pieces may be present. For example, the cap element described above can be positioned as an intermediate piece between the tube and the end piece, even if shortening of the tube is not intended. Alternatively, the cap element can function as the first or second end piece. The first end piece and / or the second end piece can be formed from one or more parts.

[0068] The first end piece and / or the second end piece may have a passage for the inlay. The inlay can be passed through the end piece, for example, to be held in place in this manner. Partial passage is also possible. In this case, the inlay terminates within the passage. Once connected, the passage can be partially or completely closed or sealed by the inlay. The passage can be adapted to the inlay with respect to its extension, particularly its cross-section.

[0069] The passage may include, for example, at least one recess in the form of a groove, the recess extending axially through the threads of the connection region of the first or second tube. If the inlay is located within the passage, another component having corresponding threads can be screwed to the threads without shear forces acting on the inlay, even in the presence of the inlay. If a plug is provided, the portion that receives the plug may also extend axially through the connection region. Screwing is easier, for example, if there are multiple recesses or grooves distributed circumferentially.

[0070] In particular, the device is designed such that the inner cross-section or diameter of the region of the first tube adjacent to the connecting piece corresponds at least substantially to the inner cross-section of the adjacent portion of the connecting piece, and / or the inner cross-section or diameter of the region of the second tube adjacent to the connecting piece corresponds at least substantially to the inner cross-section of the adjacent portion of the connecting piece. In this way, a substantially constant outer cross-section or diameter of the intramedullary nail spacer can be produced.

[0071] In one embodiment, the connecting piece has a first connecting region for inserting a first tube, a second connecting region for inserting a second tube, and a central region located between the connecting regions. In particular, the inner cross-section of the connecting piece is smaller in the central region than in the first and second connecting regions.

[0072] The connecting piece is designed as a sleeve, i.e., a connecting piece positioned on the outside of the tube. The connecting piece can be used to push the first tube and / or the second tube. In particular, the connecting piece can then be removed from the first tube and / or the second tube.

[0073] The connecting piece may be formed from a flexible material, elastomer and / or silicone, such as a biocompatible rubber elastic plastic material like silicone rubber or EPDM rubber. In particular, the connecting piece is formed from a material having a Shore A hardness of 50 or higher.

[0074] In particular, the connecting piece is flexible such that, in the relevant connection area, it has an inner diameter smaller than the outer diameter of the corresponding tube in at least some areas. In this case, the connecting piece can be frictionally fastened to the tube by a restoring force directed radially inward. In this way, leakage of the molded material between the connecting piece and the tube can be prevented, even when the molded material is subjected to high injection pressure. Furthermore, unintended loosening can be prevented.

[0075] In particular, the first tube and / or the second tube are formed from a material and / or thermoplastic material having higher rigidity and / or strength than the connecting piece.

[0076] In one embodiment, the first tube, the second tube, and / or connecting piece are formed from a translucent and / or transparent material. This allows for visual monitoring of the filling process.

[0077] In particular, the difference in inner diameter corresponds to twice the wall thickness of the associated tube. In this way, a continuous outer surface of the spacer without cracks can be formed even in the transition region between the connecting piece and the associated tube.

[0078] Alternatively, the connecting piece may have a connecting region designed to be inserted into the associated tube. In this case, the associated tube may have an enlarged inner diameter in the connecting region to allow for a constant inner surface of the connection.

[0079] In one embodiment, the device includes an inlay positioned within a first tube and / or a second tube to reinforce the manufactured intramedullary nail spacer internally.

[0080] The inlay is primarily made of metal and can also be called a metal core. The inlay serves to mechanically reinforce the intramedullary nail spacer. Specifically, the inlay is positioned approximately in the center of the tube, and then approximately in the center of the spacer. The inlay can be held within the tube using appropriate holders. In particular, at least three holders or spacers are provided circumferentially to keep the inlay approximately in the center. Spacers may be attached to the inlay. The inlay can be precisely centered. However, it is acceptable if the inlay is located in a central region corresponding to half the inner diameter of the tube.

[0081] The inlay may extend over part of the length of the first and / or second tube, or over its entire length. A single inlay / that inlay may also be placed on a connecting piece. In one embodiment, a continuous inlay is provided that extends from the first tube through a connecting piece into the second tube. As the inlay, for example, Kirschner wire can be used.

[0082] In principle, mechanical stabilization of the spacer is not always necessary, as patient mobility is often not possible depending on the severity of the disease. In this case, an inlay is not required. However, it may be planned to provide inlays for all spacers as a standard. This can reduce complexity, as only one device can be used for all applications.

[0083] Further embodiments of the present invention include: -A device according to the present invention, -At least one further first tube, wherein the further first tube has a different length, a different shape, and / or a different cross-section, in particular, a different diameter from the first tube of the device, and the further first tube can be connected to a connecting piece instead of the first tube, or -At least one further second tube, wherein the further second tube has a different length, a different shape, and / or a different cross-section, in particular, a different diameter from the second tube of the device, and the further second tube may be connected to a connecting piece instead of the second tube, This is a kit that includes [the following items].

[0084] Therefore, the kit includes multiple first and / or second tubes, allowing for the selection of the most suitable tube for replicating the explanted intramedullary nail.

[0085] A further aspect of the present invention is the use of a mold for manufacturing an intramedullary nail spacer. In particular, the device according to the present invention is used as a mold. All the features, advantages and configurations of the device described above also apply to its use, and vice versa. In particular, polymethyl methacrylate bone cement is added to the mold.

[0086] A further aspect of the present invention is a method for manufacturing an intramedullary nail spacer using a device, the device comprising a first tube, a second tube, and a flexible connecting piece for fluidly connecting the first tube to the second tube. The method comprises positioning the first tube and the second tube at a desired angle relative to each other, and filling the first tube, the second tube, and the connecting piece with a casting material to manufacture an intramedullary nail rod spacer. In particular, the filling is carried out so that the entire interior of the device, i.e., both the tube and the connecting piece, is completely filled. The filling can be carried out by pressing. All the features, advantages and configurations of the device described above also apply to the method, and vice versa. In particular, the molding material comprises polymethyl methacrylate bone cement and selectively one or more pharmaceutically active ingredients.

[0087] This method may further include one or more of the following steps in any combination. - For example, shortening the tube and arranging a cap element, and / or adjusting the length of the first tube and / or the second tube by telescopic length adjustment, and optionally locking the adjusted length, - A process of fixing the set angle using a fixing device. - For example, the process of connecting the tube to the molding material source by the first end piece, - After filling, remove the molding material source and optionally close the tube or component in which the molding material source was located. - A step of removing excess molding material from the end of a device where no molding material source was located, and / or closing off components located at that end. - A process for hardening the molding material, - For example, the process of demolding the manufactured spacer by pulling the first and / or second tubes away from the spacer, optionally cutting open the connecting piece, and / or separating the connecting piece from the spacer. - The process of removing the spacer.

[0088] Exemplary embodiments of the present invention are also described in more detail below with reference to the drawings. Features of the exemplary embodiments may be individually or combined with any of the claimed subject matter unless otherwise specified. The scope of the claimed protection is not limited to the exemplary embodiments. [Brief explanation of the drawing]

[0089] [Figure 1] This is a perspective view of the device. [Figure 2] This is a disassembled perspective view of the device. [Figure 3] This is a magnified, detailed view. [Figure 4] This is a magnified, detailed view. [Figure 5] This is a magnified, detailed view. [Figure 6] This is a magnified, detailed view. [Figure 7] This is a magnified, detailed view. [Figure 8] This diagram shows the device components along with the manufactured spacers. [Figure 9] This is a magnified, detailed view. [Figure 10] This is a magnified, detailed view. [Figure 11] This is a magnified, detailed view.

[0090] Figure 1 shows a device 10 according to the present invention for manufacturing an intramedullary nail spacer. The device 10 includes a first tube 11, a second tube 12, and a flexible connecting piece that fluidly connects the first tube 11 to the second tube 12. The connecting piece is located within a housing 20, which includes a lower housing 22 and an upper housing 26. A first end piece 60 is located at the free end of the first tube 11, shown in the lower left, and this first end piece 60 has a connecting region 62 with female threads for mechanical connection to a molding material source 59. The molding material source 59 is, for example, a cartridge having bone cement, which is partially shown and has a dispensing tip with male threads. The male threads can be connected to the female threads of the connecting piece 62 to push the molding material through the first tube 11 throughout the interior of the device. In other words, the device 10 can be used as a mold for manufacturing an intramedullary nail spacer from, for example, a molding material such as bone cement.

[0091] The device 10 further includes a closing cap 68 which can be connected to a connection area 62 after the molding material has been filled. A second end piece 64 is positioned at the free end of the second tube 12 shown in the upper right, which also includes a closing cap 68.

[0092] The first tube 11 is typically the distal tube on which the distal portion of the intramedullary nail spacer is manufactured. It is usually longer than the proximal second tube 12. Typically, according to the replicated intramedullary nail, the second tube 12 has an inner diameter that corresponds to at least the inner diameter of the first tube 11.

[0093] The first tube 11 is length-adjustable. This is addressed, for example, by having molding elements 40 typically at regular intervals along its longitudinal direction, and a cap element 39 having corresponding latch elements 42. Thus, the first tube 11 can be shortened to any desired position, for example, by cutting. The tube can then be inserted into the cap element 39, and one or more latch elements 42 of the cap element 39 will catch on one or more molding elements 40 of the first tube 11. In this way, axial removal of the cap element 39 is prevented by the shape-fit connection. This is shown in an enlarged detail in Figure 4, which further shows an inlay 75 located in the center of the first tube 11 and a spacer 76 for holding the inlay 75 in the central position.

[0094] Figure 2 shows a diagram similar to Figure 1, with the individual components of the housing 20 shown in an exploded view. A connecting piece 15 is visible, located in the center between the first tube 11 and the second tube 12, fluidly connecting the internal spaces of the two tubes 11 and 12. The connecting piece 15 also has a tubular basic shape and is formed from a flexible material, such as rubber elasticity. Thus, any angle between the first tube 11 and the second tube 12 can be set within a predetermined angular range of approximately 0° to 40°.

[0095] Both the first tube 11 and the second tube 12 have annular, disc-shaped fitting elements 32 in corresponding regions facing the connecting piece 15. The connecting piece 15 also has such fitting elements 33 on each of its sides.

[0096] The lower housing 22 includes a first lower housing portion 23 that receives the first tube 11 and a second lower housing portion 24 that receives the second tube 12. The first lower housing portion 23 and the second lower housing portion 24 are rotatable relative to each other about a common axis of rotation 30. Similarly, the upper housing 26 includes a first upper housing portion 27 and a second upper housing portion 28 that is rotatable relative to the first upper housing portion 27 about the same axis of rotation 30.

[0097] The lower housing 22 and the upper housing 26 may typically be connected to each other, or, as shown, may be separated from each other as needed. This is preferably done manually and non-destructively. In the example shown here, it can be seen that the lower housing 22 includes an upward-facing pin that can be inserted into a corresponding opening in the upper housing 26 to close the housing 20. However, any other closure option is possible.

[0098] The lower housing 22 and the upper housing 26 are provided with recesses 34 for receiving shape-fitting elements 32 and 33, respectively. When the unit including the first tube 11, the connecting piece 15, and the second tube 12 is positioned in the lower housing 22 and closed in particular by the upper housing 26, neither the connection between the first tube 11 and the connecting piece 15 nor the connection between the connecting piece 15 and the second tube 12 can be released.

[0099] Figure 6 shows a cross-sectional view of such a connection between the first tube 11, the connecting piece 15, and the second tube 12. Here, on the left side, it is clearly visible that the lower portion 23 and upper portion 27 of the first housing hold both the first tube 11 (see shape-fitting element 32) and the left portion of the connecting piece 15 (see shape-fitting element 33). On the right side, however, the right portion of the connecting piece 15 and the second tube 12 are held by the upper portion 28 and lower portion 24 of the second housing. Furthermore, it can be seen that the lower portion 24 and upper portion 28 of the second housing are surrounded on the right side by the lower portion 23 and upper portion 27 of the first housing. During relative rotation, the upper portion 27 of the first housing slides against the upper portion 28 of the second housing, and the lower portion 20 of the first housing slides against the lower portion 24 of the second housing.

[0100] Furthermore, a blocking device 29 is provided that can prevent the rotation of the two lower housing portions 23, 24 and the rotation of the two upper housing portions 27, 28. The blocking device 29 is, in this case, designed as a screw aligned along the axis of rotation 30, for example, which can be screwed into the threads of the second upper housing portion 28, and then clamps the first upper housing portion 27 between the second upper housing portion 28 and the head of the screw, so that sliding is no longer possible and the angle between the first tube 11 and the second tube 12 is consequently fixed.

[0101] Figure 6 further shows that the connecting piece 15 has a first connecting region 71 for inserting the first tube 11, a second connecting region 72 for inserting the second tube 12, and a central region 73 located between them. The inner diameter of the connecting piece 15 is smaller in the central region 73 than in the first and second connecting regions 71, 72, such that the central region 73 has the same inner diameter as the adjacent regions of the first tube 11 and the second tube 12.

[0102] Figure 3 shows an alternative method for fixing the angle, i.e., an alternative blocking device. In this case, openings 82 are provided in the lower portion of the first housing and the lower portion of the second housing, and there is at least one pin similar to the illustrated pin 80 that can be inserted into the opening. Thus, the pin passes through the opening in one of the lower housing portions and enters the opening in the lower housing portion below it, and as a result, relative rotation of the two lower housing portions is no longer possible.

[0103] Figure 5 shows a magnified detail view of the second end piece 64, and it can be seen that the closing cap 68 has a ventilation opening 66 that is radially and centrally located. This allows air that has moved during the press-fitting of the molding material to escape.

[0104] Figure 7 shows, for example, a magnified detail view of the first end piece, showing how the metal inlay 75 can be held in the area of ​​the cap element 39. The threaded area shown above, for example the connection area 62, has a recess 78 in the form of a groove that extends parallel to the longitudinal axis of the tube. Then, before screwing on the closing cap 68, the inlay 75, for example Kirschner wire, is placed in the recess 78, and then the closing cap 68 is screwed on.

[0105] Figure 8 shows an overview of the first tube 11, the second tube 12, the connecting piece 15, and the manufactured intramedullary nail spacer 5 after demolding. After removing the housing, both the first tube 11 and the second tube 12 can typically be pulled outwards. The connecting piece 15 can then be peeled off or removed, for example, by cutting it open. The resulting intramedullary nail spacer 5 with a predetermined angle is completed.

[0106] Figure 9 shows further details of a tube 11, 12 in which at least one is telescopically extendable. The tube in question includes an outer tube 35 and an inner tube 36 that is axially displaceable within the outer tube 35. Preferably, a fastening device 37 is provided for fastening the outer tube 35 to the inner tube 36. In the example shown herein, this includes a screw which can be screwed into threads on the outer tube 35, for example, perpendicular to the longitudinal axis of the tube, and then presses the inner tube 36 from the outside to form a friction connection.

[0107] Figures 10 and 11 show enlarged detail views of another alternative for adjusting the length of one or both of the tubes 11, 12. The cap element 39 can be seen here as including a clamp portion 46, shown on the left, having a clamping area 48 into which the tube 11 or 12 can be inserted axially. The clamping area 48 is defined here, as an example, by a flexible clamping element 47 located on the outside and an inner opposing portion 56. The clamping element 47 is manufactured, for example, by axially slitting the outer tubular portion of the clamp portion 46. The opposing portion 56 is, for example, the inner tubular portion of the clamp portion 46. The clamp portion 46 further includes a first thread 50.

[0108] The cap element 39 further includes a union nut 52 into which the associated tube 11 or 12 is pressed, and which includes a second thread 54 corresponding to a first thread 50. When the union nut 52 is screwed onto the clamp portion 46, the clamp element 47 is pushed axially inward, and thus clamps the associated tube 11 or 12 against the opposing portion 56. Thus, the cap element 39 is connected to the tube 11 or 12 by friction connection. Furthermore, as shown in Figure 11, clamp projections 55 projecting radially inward may be present on one or more clamp elements 57, which enable friction connection and / or shape-fit connection depending on the design and properties of the material. Alternatively or additionally, the clamp area 48 may be conical to enable and / or improve connection. [Explanation of Symbols]

[0109] 5. Intramedullary nail spacer 10 devices 11. First tube 12 Second tube 15 connecting pieces 18 Fixation device 20 Housing 22 Lower part of housing 23 Lower part of the first housing 24. Lower part of the second housing 26 Upper part of housing 27. Upper part of the first housing 28. Second upper housing section 29 Blocking device 30 Rotation axis 32 Shaped mating elements 33 Shaped mating elements 34 recess 35 Outer tube 36 Inner tube 37 Fastening device 39 Cap elements 40 Molding elements 42 Latch elements 46 Clamp section 47 Clamping elements 48 clamping area 50 First thread 52 Union Nut 54 Second thread 55 Clamp protrusions 56 Opposing section 59 Molding material source 60 First end piece 62 connection areas 64 Second end piece 66 Ventilation openings 68 Closing cap 71 First connection area 72 Second connection area 73 Central area 75 Inlay 76 Spacers 78 recesses 80 pins 82 Opening

Claims

1. A device (10) for manufacturing an intramedullary nail spacer (5), comprising a first tube (11), a second tube (12), and a flexible connecting piece (15) for fluidly connecting the first tube (11) to the second tube (12), wherein the first tube (11) and the second tube (12) can be positioned at different angles relative to each other.

2. The device (10) according to claim 1, further comprising a fixing device (18) for fixing the angle between the first tube (11) and the second tube (12).

3. The device (10) according to claim 2, comprising a housing lower portion (22) including a first housing lower portion (23) and a second housing lower portion (24), wherein the two housing lower portions (23, 24) are capable of relative rotation about a rotation axis (30), the first housing lower portion (23) is designed to hold the first tube (11), and the second housing lower portion (24) is designed to hold the second tube (12), and in particular, a blocking device (29) is provided to selectively prevent the rotation of the two housing lower portions (23, 24).

4. The device (10) according to claim 3, comprising a housing upper (26) including a first housing upper portion (27) and a second housing upper portion (28), wherein the two housing upper portions (27, 28) are capable of relative rotation about the rotation axis (30), and the housing upper (26) is connected to or can be connected to the housing lower (22) to jointly form a housing (20), and in particular, a blocking device (29) is provided to selectively prevent the rotation of the two housing upper portions (27, 28).

5. The device (10) according to claim 2, wherein the first tube (11) and / or the second tube (12) are held by outwardly projecting shape fitting elements (32) that prevent axial pulling of the associated tubes (11, 12).

6. The device (10) according to claim 1, wherein the length of the first tube (11) and / or the length of the second tube (12) is adjustable.

7. The device (10) according to claim 6, wherein the first tube (11) and / or the second tube (12) are designed for telescopic length adjustment.

8. The device (10) according to claim 6, wherein the first tube (11) and / or the second tube (12) can be shortened to adjust the length, and the device (10) has a cap element (39) for positioning on the shortened side.

9. The device (10) according to claim 8, wherein the first tube (11) and / or the second tube (12) are provided on their outer surfaces with molding elements (40) for creating latch connections, which are spaced apart along the longitudinal axis of the tubes (11, 12), and the cap element (39) is provided with one or more latch elements (42) that can hook onto the associated molding elements (40).

10. The aforementioned cap element (39) is - A clamping portion (46) having a clamping area (48) for clamping the shortened tubes (11, 12), the clamping portion (46) having a first screw thread (50), - A union nut (52) having a second thread (54) into which the tubes (11, 12) can be pushed, The shortened tubes (11, 12) can be clamped in the clamping area (48) by screwing the union nut (52) onto the clamping portion (46), the device (10) according to claim 8.

11. - A first end piece (60) for placement at the end of the first tube (11) or the end of the second tube (12) facing away from the connecting piece (15), wherein a connecting region (62) for connecting to a molding material source (59) is provided on the side of the first end piece (60) facing away from the first tube (11) or the second tube (12), and / or - The device (10) according to claim 1, further comprising a second end piece (64) for placement at the end of the first tube (11) or the end of the second tube (12) facing away from the connecting piece (15), wherein a ventilation opening (66) is located on the second end piece (64) and the tubes (11, 12) are connected to the environment.

12. The device (10) according to claim 1, wherein the connecting piece (15) has a first connecting region (71) into which the first tube (11) is pressed, a second connecting region (72) into which the second tube (12) is pressed, and a central region (73) located between the connecting regions (71, 72), and the inner cross-section of the connecting piece (15) is smaller in the central region (73) than in the first and second connecting regions (71, 72).

13. The device (10) according to claim 1, further comprising an inlay (75) disposed within the first tube (11) and / or the second tube (12) for internal reinforcement of the manufactured intramedullary nail spacer (5).

14. Use of a mold for manufacturing an intramedullary nail spacer (5).

15. A method for manufacturing an intramedullary nail spacer (5) using a device (10) comprising a first tube (11), a second tube (12), and a flexible connecting piece (15) for fluidly connecting the first tube (11) to the second tube (12), wherein - Positioning the first tube (11) and the second tube (12) at a desired angle relative to each other, A method for manufacturing the intramedullary nail spacer (5), comprising filling a first tube (11), a second tube (12), and a connecting piece (15) with a molding material.

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