Distractor device

Abstract

The invention relates to a distractor device (10) for implanting into a patient, comprising a first bone plate (11) and a second bone plate (12) which consist at least partially of a bioresorbable material, and a spindle (15) with an external thread, wherein a first end of the spindle (15) is rotatably received in the first bone plate (11), wherein the second bone plate (12) has a housing (14) with an internal thread that interacts with the external thread of the spindle (15) in order to bring about a displacement of the second bone plate (12) relative to the first bone plate (11) in the direction of the spindle (15) by rotating the spindle (15); and wherein the spindle (15) is made at least partially from polyether ether ketone.

Description

[0001] Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0002] - 1 -

[0003] Distractor device

[0004] The present invention relates to a distractor device for implantation in a patient.

[0005] Distractors are used in medicine, particularly for separating bone fragments through external mechanical force. Linear distractors, which cause a linear displacement, and nonlinear or curvilinear distractors, which cause a nonlinear displacement along a curved path, such as a circular segment, are particularly well-known.

[0006] A distractor device with bioresorbable plates is described, for example, in US 2006015118 A1 and US 2006079902 A1.

[0007] In addition to bioresorbability, it can also be desirable that no tissue grows on the moving parts of the distractor. This prevents tissue damage from moving parts of the distractor. Furthermore, parts of the distractor can be removed after treatment with minimal damage to healthy tissue.

[0008] There is therefore a need for an improved distractor that does not cause damage to surrounding tissue, particularly through moving parts such as the threaded rod.

[0009] According to the invention, a distractor device for implantation in a patient is provided according to claim 1. Specifically, a distractor device for implantation in a patient is proposed, comprising a first bone plate, a second bone plate, and a spindle with an external thread. The first and second bone plates consist at least partially of a bioresorbable material. A first end of the spindle is rotatably mounted in the first bone plate. The second bone plate has a housing with an internal thread, which interacts with the external thread of the spindle, such that rotation of the spindle causes a displacement of the second bone plate relative to the first bone plate in the direction of the spindle. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0010] - 2 -

[0011] According to the invention, the spindle is at least partially made of polyetheretherketone, PEEK. Particularly preferably, the spindle can be made entirely of PEEK.

[0012] PEEK is particularly resistant to common sterilization methods as well as X-rays and gamma radiation. Furthermore, PEEK exhibits very good fatigue properties and excellent ductility. In addition, PEEK has very high abrasion resistance, which largely prevents the introduction of foreign bodies into the patient's body. This property makes PEEK particularly suitable for spindles.

[0013] Advantageously, little to no tissue or bone cells grow on the PEEK spindle. Therefore, the spindle can be removed from the patient particularly easily after treatment and at least partial resorption of the bone plates.

[0014] The PEEK spindle can preferably have different thread types, for example a metric ISO thread, a metric ISO fine thread, a trapezoidal thread, a single-start thread, a double-start thread, a triple-start thread, etc.

[0015] The spindle is preferably designed and dimensioned such that its elasticity, when implanted in the distractor device, allows for a non-linear distraction path. For distracting two segments of the mandible, for example, a spindle with a core diameter of 2.0 to 10 mm is used. With this dimension, the spindle is elastic enough to allow for a non-linear distraction path and stable enough to prevent buckling.

[0016] In particular, the spindle can be made of fiber-reinforced or non-fiber-reinforced PEEK. Fiber-reinforced PEEK can exhibit particularly high mechanical strength, whereas non-fiber-reinforced PEEK can exhibit higher elasticity. Depending on the application, a particularly favorable PEEK composition with advantageous material properties can thus be selected. Preferably, the PEEK has a composition visible in X-ray images. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0017] - 3 -

[0018] The first and second bone plates preferably have a multitude of through-holes for attaching the bone plates to the patient's bones or bone fragments. The bone plates can be fixed to the bone, for example, using resorbable pins or screws. The pins or screws can be made of magnesium, molybdenum, or one or more resorbable polymers.

[0019] According to a preferred embodiment, the first bone plate and / or the second bone plate can consist at least partially, preferably predominantly, of magnesium or a magnesium alloy. Alternatively, the first bone plate and / or the second bone plate can consist at least partially, preferably predominantly, of molybdenum or a molybdenum alloy. Furthermore, compounds or alloys containing both magnesium and molybdenum can be used. Thus, bioresorbable bone plates can advantageously be provided, enabling a particularly gentle treatment. The resorbable metal components of the distractor can be modified with calcium phosphates in a defined manner, for example, depending on the material thickness, material composition, or surface treatment.This allows biological tissue-active synergies to be initiated during treatment.

[0020] A mechanically stable bone distraction implant (distractor device) can be manufactured from the various material options mentioned above. The degradation products of bone plates made of Mg or Mo, or an alloy containing at least one of these metals, do not exhibit acidification due to the presence of temporary intermediates. This can significantly reduce the inflammatory immune response in the patient's body.

[0021] The degradation of magnesium and its alloys in the body is non-constant, as the resorption process from the superficial magnesium oxide layer is slower than the resorption process of magnesium located beneath the oxide layer. This initially slow resorption process is advantageous because the bone plates and their interfaces with the spindle initially exhibit high strength, ensuring that the distraction process is not negatively affected by resorption. (Karl Leibinger Asset Management KLS0039P-WO GmbH & Co. KG 2025-09-02)

[0022] - 4 -

[0023] Once the patient's treatment is complete, only the spindle needs to be removed, for example by unscrewing or pulling it out. This can easily be done on an outpatient basis. A complex procedure to remove the bone plates is therefore unnecessary.

[0024] The degradation of molybdenum and its alloys occurs more evenly and gradually in the body compared to magnesium and its alloys. This allows for the easier removal of molybdenum bone plates through a simplified procedure, as the degradation processes on the molybdenum surface reduce their interaction with biological tissues.

[0025] According to preferred embodiments, the first and second bone plates can have at least partial surface treatments. The degradation of the bone plates can be specifically modified and optimized through various types of surface treatment or surface finishing. Additionally, a pro-osteoactive environment can be created by the targeted, temporary release of, for example, magnesium, calcium, phosphate, and / or strontium ions. Through additional components and topographies in the surface of the metallic bone plates, the release of these pro-osteoactive ions can be time-controlled. This can be achieved technically through specific surface finishing processes and protocols.

[0026] A PEO (plasma electrolytic oxidation) process, also known as MAO (micro arc oxidation), can preferably be used as a surface treatment. Such a surface treatment can advantageously slow down the degradation or corrosion of the bone plates.

[0027] The surfaces of magnesium or molybdenum bone plates can preferably be completely or locally modified by electrochemical processes. Different chemical compositions of the electrolytes allow for the deposition of specific ion ratios and the introduction of different modification layers onto the bone plates. Such layers can be located on the surface in a range of 100 nm to 35 pm. It has been shown that electrochemical processes can create particularly stable conditions on the surface of the bone plates. The concentration ratios of the individual components can be determined according to Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0028] - 5 - depending on the application. For example, bone plates made of molybdenum are mechanically different from bone plates made of magnesium. The pro-ostegenic properties can also be achieved in bone plates made of molybdenum by the structured deposition of magnesium phosphates in the electrolyte.

[0029] The distractor device may preferably have at least temporary antibacterial properties, for example by adding ions that exhibit antimicrobial activity. These could be, for example, silver or copper ions in the surface modification or present throughout the entire bone plate.

[0030] Preferably, the internal threads of the first and / or second bone plates are excluded from surface treatment using plasma electrolytic oxidation (PEO) in order not to impair the sliding properties of the spindle in the internal thread.

[0031] As an alternative to the metallic design described above, the first and / or the second bone plate can consist at least partially, preferably to a predominant extent, of a resorbable polymer, for example PDLLA, PLLA-PGA, PCL, or of a resorbable photopolymer, for example PGA.

[0032] The bone plates preferably have a flexible grid structure to adapt to the patient's anatomy or bone shape. This allows for the provision of an elastic yet stable distractor device.

[0033] The bone plates preferably have a thickness of 0.2 mm to 3 mm in the plate-shaped section, particularly when metallic materials are used. When polymers are used as the material for the bone plates, a thickness in the range of 0.2 mm to 6 mm is preferred, with a higher thickness being locally selected in the area of ​​the spindle mount to ensure reliable force transmission.

[0034] The spindle is rotatably mounted at one end in the first bone plate around its longitudinal axis. This allows for easy rotation of the spindle. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0035] - 6 -

[0036] A drive head can preferably be arranged at one end of the spindle, providing an interface for an external tool to rotate the spindle. The drive head preferably incorporates a metal sleeve as the interface to the external tool, for example, recessed into the drive head. The metal sleeve can have an internal hexagon socket or the like to provide a pluggable and torque-transmitting connection between the external tool and the spindle. The metallic sleeve improves the torque transmission between the external tool and the spindle, since a conventional plug connection such as a hexagon socket could expand directly within the polyetheretherketone depending on the required torque, thus failing to ensure reliable distraction.

[0037] Preferably, the spindle can have a first section without external threads at its first end. This first unthreaded section can be used to mount the spindle in a housing of the first bone plate. The housing preferably has a suitable receptacle for this purpose, which can be cylindrical, for example. In this way, a simple sliding bearing is formed.

[0038] According to a preferred embodiment, the housing of the first bone plate has a first section with an internal thread, designed to engage with the external thread of the spindle. Adjacent to the first section, a second section without an internal thread can be formed, the inner diameter of which is larger than the outer diameter of the spindle's external thread. Furthermore, a recess can be formed on the closed side adjacent to the second section to receive and support the first section of the spindle. This design of the first housing allows the spindle to be screwed into the first bone plate while preventing it from unintentionally unscrewing.

[0039] According to a preferred embodiment, the spindle has a second section with an external thread adjacent to the first section, extending longitudinally from the first end to the second end. The length of the second section of the spindle is less than the length of the second section of the housing of the first bone plate. Thus, the second section of the spindle with the external thread can lie within the second section of the housing without interacting with an internal thread. In other words, after the spindle Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0040] - 7 - screwed into the first bone plate, it is only stored in the corresponding receptacle in the housing of the first bone plate at the first section.

[0041] In a preferred embodiment, the spindle can have a third section without an external thread, extending longitudinally from the first end to the second end adjacent to the second section. Preferably, the length of the third section of the spindle is greater than the length of the first section of the first housing. Furthermore, preferably, the outer diameter of the third section is smaller than the inner diameter of the first section of the housing of the first bone plate. This embodiment can prevent the spindle from unintentionally falling out of the housing.

[0042] Adjacent to the third section, running longitudinally from the first end to the second end, the spindle can have a fourth section with an external thread, extending at most to the second end of the spindle. This fourth externally threaded section interacts with the internal thread in the housing of the second bone plate, thereby causing distraction. During this process, the first end of the spindle presses against an inner wall in the housing of the first bone plate.

[0043] The spindle therefore preferably has sections with external threads and bare sections without external threads. This design allows for easy assembly and disassembly of the distractor device.

[0044] A preferred distractor device may further include a backstop configured to prevent rotation of the spindle in a direction opposing the distraction. This ensures that the spindle is always actuated in the direction intended for treatment.

[0045] The backstop prevents the patient or doctor from turning the spindle in the wrong direction. This ensures that turning the spindle always results in only positive distraction and never negative distraction. Positive distraction here means an increase in the distance between the two bone plates. Negative distraction, conversely, means a decrease in the distance between the bone plates. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0046] - 8 -

[0047] Preferably, the spindle has a core diameter between 2.0 and 10 millimeters, more preferably a core diameter between 2.0 and 5 millimeters, more preferably a core diameter between 2.5 and 5 millimeters, and most preferably a core diameter between 2.5 and 4 millimeters. With these dimensions, the distraction device can support the required distraction forces without buckling. With the selected dimensions, the spindle can be designed to be flexible enough to adapt to the individual needs of a patient. If the spindle has a large core diameter, for example between 5 and 10 millimeters, it can be hollow.

[0048] The thread pitch of the spindle can preferably be selected such that an even number of full rotations of the spindle or drive shaft achieves a predetermined distraction. Thus, for example, the patient or the treating physician can perform a predetermined number of rotations once or several times a day to achieve the desired daily distraction for the therapy.

[0049] The bone plates have through-holes for receiving fasteners. The fasteners are inserted through the through-holes and attached to the bone, thus fixing the bone plates to the bone. Preferably, the first and / or the second bone plate is designed such that the through-holes are arranged only on one side of the spindle. This allows for a particularly compact design of the distractor device. Preferably, the first and / or the second bone plate has exactly one through-hole, or exactly two through-holes, or exactly three through-holes. The bone plates can also have more than three through-holes.

[0050] Preferably, the first bone plate and / or the second bone plate has a sleeve-shaped reinforcement in the area of ​​the spindle receptacle. This improves the force transmission between the spindle and the respective bone plate.

[0051] According to one possible embodiment, the sleeve-shaped reinforcement is an integral component of the first and / or second bone plate. In such a design, the respective bone plate is thus formed in one piece, with the respective bone plate having a sleeve-shaped reinforcement in the area of ​​the spindle receptacle. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0052] - 9 - and has a lower wall thickness in the plate-shaped area compared to the spindle mount.

[0053] According to a second possible embodiment, the sleeve-shaped reinforcement is formed as a separate sleeve made of a different resorbable material than the plate-shaped section of the first and / or second bone plate. This other resorbable material preferably has a higher mechanical strength than the material of the plate-shaped section. For example, the sleeve can be made of magnesium, zinc, or a fiber-reinforced resorbable polymer.

[0054] In the second possible embodiment, the sleeve is preferably permanently connected to the first and / or second bone plate. A permanent connection is understood here to be one that can only be broken by destroying the bone plate. The sleeve can, for example, be fused into the plate-shaped section of the bone plate or be connected to the plate-shaped section of the bone plate by means of resorbable pins, creating a form-fit and material-locking connection. To create the connection, the resorbable pins can, for example, be liquefied by means of ultrasound excitation.

[0055] Preferably, the first bone plate and / or the second bone plate has a constant wall thickness. This allows for uniform resorption.

[0056] Preferably, the first and / or second bone plate has an increased wall thickness in the area of ​​the through-holes, so that a bone bearing surface of the respective bone plate is raised from a base surface of the respective bone plate. This increases the flexibility of the bone plate in the area between the through-holes and the spindle receptacle, allowing the bone plate to conform better to the bone geometry.

[0057] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures. These figures show:

[0058] Fig. 1 shows a perspective view of a distractor device according to a first embodiment; Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0059] - 10 -

[0060] Fig. 2 shows a side view of the second bone plate of the distractor device;

[0061] Fig. 3 shows a detailed view of a drive head formed on the spindle;

[0062] Fig. 4 shows a lateral sectional view through the first bone plate and the spindle;

[0063] Fig. 5 shows an image of a treated surface of a bone plate;

[0064] Fig. 6 Microscopic images of the surface of a bone plate;

[0065] Fig. 7 shows a top view of a distractor device according to a second embodiment;

[0066] Fig. 8 shows a perspective view of a distractor device according to a third embodiment;

[0067] Fig. 9 shows a detailed view of a special design of a bone plate;

[0068] Fig. 10 shows a view of a distractor device according to a fourth

[0069] Example implementation;

[0070] Fig. 11 shows a detailed view of the distractor device according to the fourth embodiment;

[0071] Fig. 12 shows a view of a distractor device according to a fifth embodiment; and

[0072] Fig. 13 shows a detailed view of the distractor device according to the fifth embodiment.

[0073] The accompanying figures are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain the principles and concepts of Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0074] - 11 -

[0075] Invention. Other embodiments and many of the aforementioned advantages become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale.

[0076] In the figures of the drawing, identical, functionally equivalent and similarly acting elements, features and components - unless otherwise stated - are each provided with the same reference symbols.

[0077] Fig. 1 shows a perspective view of a distractor device 10 according to a first embodiment. The distractor device 10 comprises a first bone plate 11, a second bone plate 12, and a spindle 15 rotatably mounted along the longitudinal axis on the first and second bone plates 11 and 12, the spindle having an external thread.

[0078] The first bone plate 11 has a housing 13 open on one side, in which a first end of the spindle 15 is mounted. The mounting of the spindle 15 in the housing 13 is described in more detail below with reference to Fig. 4.

[0079] The second bone plate 12 has a housing 14 open at both ends with an internal thread that interacts with the external thread of the spindle 15 to cause a displacement of the second bone plate 12 relative to the first bone plate 11 by rotating the spindle 15 about its longitudinal axis. In other words, by rotating the spindle 15, the second bone plate 12 is moved to the right away from the first bone plate 11 in Fig. 1.

[0080] Fig. 2 shows a side view of the second bone plate 12 of the distractor device 10 from Fig. 1. In Fig. 2, the second bone plate 12 is still arranged directly to the right of the first bone plate 11. The housing 14 is a substantially cylindrical body formed on the second bone plate 12, through which the spindle 15 passes.

[0081] The spindle 15 is at least partially made of polyetheretherketone (PEEK), which prevents tissue growth on the movable spindle 15 and thus avoids tissue damage. Furthermore, removal of the spindle 15 after treatment is facilitated. The bone plates 11 and 12 are made of Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0082] - 12 - made from a bioresorbable material, for example magnesium, molybdenum, or their alloys.

[0083] In the first embodiment, the first bone plate 11 and the second bone plate 12 each have four through holes 20 for attaching the bone plates 11, 12 to bones or bone parts of the patient. Furthermore, recesses are formed to minimize the amount of foreign material introduced into the patient.

[0084] Fig. 3 shows a detailed view of a drive head 19 formed on the spindle 15. The drive head 19 is formed at a second end of the spindle 15. A metal sleeve 18 is inserted into the drive head 19, serving as an interface for an external tool to actuate the distractor device 10. In the illustrated embodiment, the metal sleeve 18 has an internal hexagon socket and can be actuated, for example, with a suitable Allen key. In alternative embodiments, other interfaces for alternative tools may also be provided.

[0085] Fig. 4 shows a side sectional view through the first bone plate 11 and the spindle 15. The portion of the spindle 15 shown here has four sections. A first section 151 without an external thread is formed at the first end of the spindle 15 and serves to support the spindle 15 in a correspondingly shaped recess in the housing 13 of the first bone plate 11. The first section 151 is essentially a rounded cylindrical tip at the first end of the spindle 151, which engages in a corresponding cylindrical recess or bore in the housing 13 and supports rotation about the longitudinal axis of the spindle 15.

[0086] In the housing 13, a first section 131 with an internal thread is formed on the open side, designed to engage with the external thread of the spindle 15. Adjacent to the first section 131, a second section 132 without an internal thread is formed in the housing 13. The inner diameter of the second section 132 is larger than the outer diameter of the external thread of the spindle 15, so that no friction occurs between the spindle 15 and the housing 13 in the second section 132. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0087] - 13 -

[0088] Adjacent to the second section 132, the recess is formed on the closed side of the housing 13 as a depression or bore for bearing the first section 151 of the spindle 15.

[0089] In Fig. 4, the spindle 15 has a second section 152 with an external thread adjacent to the first section 151 in the longitudinal direction from the first end to the second end. This second section 152 with an external thread serves to screw the spindle 15 into the housing 13, utilizing the internal thread in the first section 131 of the housing 13. Once the second section 152 is screwed in and reaches the second section 132 of the housing 13, the first section 131 of the housing 13 prevents the spindle 15 from falling out or being pulled out of the first bone plate 11.

[0090] The length of the second section 152 in the longitudinal direction of the spindle 15 is less than the length of the second section 132 of the housing 13 in the longitudinal direction. Thus, an interaction between the thread and the inner wall of the second section 132 can be prevented.

[0091] Adjacent to the second section 152, the spindle 15 has a third section 153 extending longitudinally from the first end to the second end, without external threads. In other words, the spindle 15 is bare in the third section 153. In Fig. 4, this third section 153 is located in the first section 131 of the housing 13. The length of the third section 153 in the longitudinal direction of the spindle 15 is greater than the length of the first section 131 of the housing 13.

[0092] The illustrated design of the spindle 15 allows the spindle 15 to be easily screwed into the first bone plate 11. As soon as the first end or the first section 151 of the spindle has reached the recess provided for this purpose in the housing 13, the spindle 15 can be freely rotated essentially without force acting on an internal thread of the first bone plate 11.

[0093] Adjacent to the third section 153, the spindle 15 has a fourth section 154 with an external thread extending longitudinally from the first end to the second end. The fourth section 154 can extend to the second end of the spindle 15. The fourth section 154 with the external thread interacts with the internal thread (not shown) in Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0094] - 14 -

[0095] Housing 14 of the second bone plate 12. A rotation about the longitudinal axis of the spindle 15 thus causes a displacement of the second bone plate 12 relative to the first bone plate 11, whereby the desired discration can be achieved.

[0096] Not shown in the figures is an optional backstop that can prevent the spindle 15 from rotating in a direction opposing the distraction.

[0097] Fig. 5 shows a light micrograph of surface layers of a bone plate 11, 12 treated by plasma electrolytic oxidation (PEO). Four layers a, b, c, d are visible. Layer a is an embedding resin. Layer b is a porous part of the PEO layer. Layer c is an inner thin protective layer. Layer d is the substrate of the bone plate 11, 12, made of a magnesium alloy.

[0098] PEO is a process that, when high voltages are applied, transforms the surface of light metals such as magnesium, aluminum, or titanium into a stable metal oxide layer. Therefore, it is not a coating process, but rather a surface modification process. The process takes place in aqueous electrolytes, the composition of which also influences the composition of the resulting layer. The electrodes of the electrolytic process are usually chosen so that the workpiece is attached to the anode and the electrolyte bath forms the cathode. The process can be carried out using either current or voltage control, as well as pulsed or non-pulsed operation.

[0099] During the PEO process, short-lived spark discharges at very high temperatures occur on the surface of the workpiece, creating a plasma environment. The sparks penetrate the passive layers formed before the process and melt the surface of the material. In reaction with the surrounding electrolyte, a stable metal oxide layer forms. The resulting layer can be divided into two or three sublayers. The innermost part of the layer, directly adjacent to the substrate, is very thin and dense; this is where the corrosion protection / resistance, one of the primary goals of the process, is initially created. The middle part of the layer is not always visible but is also relatively thin and dense. The outer part of the layer is porous and constitutes the majority of the layer thickness. It offers an increased surface area for cell ingrowth.The pore size, layer thickness, and material input and output can be adjusted via process parameters. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02.

[0100] - 15 -

[0101] The surface treatment process described above can be applied, for example, to magnesium alloys such as the medically approved alloys WE43, MgCaZn and MgCa alloys, as well as to pure titanium, Ti6Al4V, and to aluminum and its alloys.

[0102] Preferably, the internal threads of the bone plate 11, 12 are excluded from surface treatment by means of plasma electrolytic oxidation, PEO, in order not to impair the sliding properties of the spindle 15.

[0103] Fig. 6 shows scanning electron microscope images of the surface of a bone plate 11, 12 at 1000x magnification (left) and 200x magnification (right). The surfaces shown were subjected to a PEO surface treatment process described above. When using a phosphorus-containing electrolyte, the layer consists of magnesium (Mg), oxygen (O), and phosphorus (P), specifically magnesium oxide (MgO) and magnesium phosphate (Mg3(PO4)2).

[0104] Fig. 7 shows a top view of a distractor device 10 according to a second embodiment, in which only the first bone plate 11 and part of the spindle 15 are shown. In this second embodiment, the first bone plate 11 has a total of six through holes 20, each containing a fastening screw 30. The large number of through holes 20 improves the surgeon's flexibility in determining where to use the fastening screw 30. It is generally not necessary to use all six through holes 20 for fastening to the bone.

[0105] Fig. 8 shows a perspective view of a distractor device 10 according to a third embodiment, which essentially corresponds to the embodiment shown in Fig. 1. However, the first bone plate 11 has only a single through-hole 20. The second bone plate 12 has exactly two through-holes 20, which are arranged on one side of the spindle 15. This results in a particularly compact design of the distractor device 10. Alternatively, the first bone plate 11 could also have two through-holes in such a design, for example in the same one-sided arrangement as the second bone plate 12. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02

[0106] - 16 -

[0107] Fig. 9 shows a detailed view of a particular embodiment of a bone plate 11, 12 for a distractor device 10. This plate has a sleeve-shaped reinforcement 16 in the area of ​​the spindle receptacle, which also includes the internal thread for receiving the spindle's external thread. In the present embodiment, the bone plate 11, 12 is formed from a resorbable polymer, with the sleeve-shaped reinforcement being an integral part of the bone plate 11, 12.

[0108] Figures 10 and 11 each show a view of a distractor device 10 according to a fourth embodiment. In this fourth embodiment, a plate-shaped section 21 of the bone plates 11, 12 is formed from a resorbable polymer. The bone plates 11, 12 have a sleeve 16 in the area of ​​the spindle receptacle, which is made, for example, of a fiber-reinforced resorbable material, degradable metals, resorbable polymers, or resorbable and non-resorbable ceramics. This sleeve is different from the material of the plate-shaped section 21 and exhibits higher mechanical strength. The bone plates 11, 12 of the distractor device 10 according to the fourth embodiment are therefore composed of multiple parts. The connection between the sleeve 16 and the respective bone plate 11, 12 is made by several resorbable pins 17, as illustrated by way of example in Figure 11.To create the connection, the pins 17 can be inserted into designated openings and liquefied by applying ultrasound, thus forming a form-fit and material-locking connection between the sleeve 16 and the plate-shaped section 21. Alternatively, the sleeve 16 can be placed in an injection mold and subsequently overmolded with the material of the bone plate 11, 12. For the sake of clarity, this is not explicitly shown.

[0109] Figures 12 and 13 each show a view of a distractor device 10 according to a fifth embodiment. Figure 13 shows the distractor device 10 from the side that is to be placed on the bone. The bone plates 11, 12 have an increased wall thickness in the area of ​​the through holes 20, so that a bone-bearing surface 24 of the bone plates 11, 12 is raised from a base surface 23 of the bone plates 11, 12 facing the bone. Karl Leibinger Asset Management KLS0039P-WO GmbH & Co. KG 2025-09-02

[0110] - 17 -

[0111] If the present application contains a list of alternatives marked with the term “or”, it should be understood that the listed alternatives should be understood to be taken individually, but also, where appropriate, as a combination of several or all of the listed alternatives.

Claims

Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02 - 18 - Patent claims 1. Distractor device (10) for implantation into a patient, comprising a first bone plate (11) and a second bone plate (12), which are at least partially made of a bioresorbable material, and a spindle (15) with an external thread, wherein a first end of the spindle (15) is rotatably received in the first bone plate (11), wherein the second bone plate (12) has a housing (14) with an internal thread which interacts with the external thread of the spindle (15) to cause a displacement of the second bone plate (12) relative to the first bone plate (11) in the direction of the spindle (15) by rotating the spindle (15), wherein the spindle (15) is at least partially made of polyetheretherketone.

2. Distractor device (10) according to claim 1 , characterized in that the spindle (15) is made entirely of polyetheretherketone.

3. Distractor device (10) according to claim 1 or claim 2, characterized in that the spindle (15) is designed and dimensioned such that a non-linear distraction path is enabled by an elasticity of the spindle (15) in the implanted state of the distractor device (10).

4. Distractor device (10) according to one of claims 1 to 3, characterized in that the first bone plate (11) and / or the second bone plate (12) consist at least partially, preferably predominantly, of magnesium or a magnesium alloy; or wherein the first bone plate (11) and / or the second bone plate (12) consist at least partially, preferably predominantly, of molybdenum or a molybdenum alloy; or wherein the first bone plate (11) and / or the second bone plate (12) consist at least partially, preferably predominantly, of a resorbable polymer, preferably PCL, or of a resorbable photopolymer, for example PGA.

5. Distractor device (10) according to one of claims 1 to 4, characterized in that the distractor device (10) includes fastening means (30), for example pins or Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02 - 19 - screws for fastening the bone plates (11, 12) to bone, wherein the fastening means (30) are made of the same material as the bone plates (11, 12).

6. Distractor device (10) according to one of the preceding claims, characterized in that the first bone plate (11) and the second bone plate (12) are made of a metallic material and have at least partially a surface treatment by means of plasma electrolytic oxidation.

7. Distractor device (10) according to claim 6, characterized in that the internal thread of the second bone plate (12) is excluded from the surface treatment.

8. Distractor device (10) according to one of the preceding claims, characterized in that the spindle (15) consists of fiber-reinforced polyetheretherketone or of non-fiber-reinforced polyetheretherketone.

9. Distractor device (10) according to one of the preceding claims, characterized in that a drive head (19) is arranged at one end of the spindle (15), which has an interface (18) to a distractor device-external tool for rotating the spindle (15), wherein the drive head (19) has a metallic sleeve (18) into which the distractor device-external tool can be inserted for torque transmission.

10. Distractor device (10) according to one of the preceding claims, characterized in that the spindle (15) has at its first end a first section (151) without external thread for bearing the spindle in the first bone plate (11).

11. Distractor device (10) according to claim 10, characterized in that the first bone plate (11) has a housing (13) for receiving the spindle (15), wherein a first section (131) with an internal thread is formed in this housing (13) for interacting with the external thread of the spindle (15), wherein a second section (132) without an internal thread is formed adjacent to the first section (131), wherein the inner diameter of the second section (132) is larger than an outer diameter of the external thread of the spindle (15) and wherein adjacent to the Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02 - 20 - second section (131) is formed as a recess for holding the first section (151) of the spindle (15).

12. Distractor device (10) according to claim 11, wherein the spindle (15) has a second section (152) with an external thread adjacent to the first section (151) in the longitudinal direction from the first end to the second end, wherein a length of the second section (152) of the spindle (15) is less than a length of the second section (132) of the housing (13) of the first bone plate (11), wherein a third section (153) without an external thread has a third section (153) without an external thread adjacent to the second section (152) in the longitudinal direction from the first end to the second end, wherein a length of the third section (153) of the spindle is greater than a length of the first section (131) of the housing (13) of the first bone plate (11), and wherein a fourth section (154) with an external thread has a fourth section (154) with an external thread adjacent to the third section (153) in the longitudinal direction from the first end to the second end, which extends at most to the second end of the spindle (15).

13. Distractor device (10) according to one of the preceding claims, characterized in that the spindle (15) has a core diameter between 2.0 and 10 millimeters, preferably a core diameter between 2.0 and 5 millimeters, particularly preferably between 2.5 and 5 millimeters, particularly preferably a core diameter between 2.5 and 4 millimeters.

14. Distractor device (10) according to one of the preceding claims, characterized in that the first bone plate (11) and / or the second bone plate (12) are designed such that through holes (20) of the first bone plate (11) and / or the second bone plate (12) are arranged only on one side of the spindle (15), wherein the first bone plate (11) and / or the second bone plate (12) preferably has exactly one through hole (20), or exactly two through holes (20), or exactly three through holes (20).

15. Distractor device (10) according to one of the preceding claims, characterized in that the first bone plate (11) and / or the second bone plate (12) each has a sleeve-shaped reinforcement (16) in the area of ​​the spindle receptacle. Karl Leibinger Asset Management KLS0039P-WG GmbH & Co. KG 2025-09-02 - 21 - 16. Distractor device (10) according to claim 15, characterized in that the sleeve-shaped reinforcement (16) is an integral part of the first and / or second bone plate (11 , 12).

17. Distractor device (10) according to one of claims 1 to 15, characterized in that the sleeve-shaped reinforcement is formed as a separate sleeve (16) which is formed from a different resorbable material than a plate-shaped section (21) of the first and / or second bone plate (10, 11), for example from magnesium, zinc, molybdenum, or from a fiber-reinforced resorbable polymer, or from a resorbable or non-resorbable ceramic.

18. Distractor device (10) according to claim 17, characterized in that the sleeve (16) is inseparably connected to the plate-shaped section (21) of the first and / or second bone plate (11 , 12).

19. Distractor device (10) according to claim 17 or claim 18, characterized in that the sleeve (16) is melted into a corresponding receptacle of the plate-shaped section (21) of the first and / or second bone plate (11 , 12), or that the sleeve (16) is connected to the plate-shaped section (21) of the first and / or second bone plate (11 , 12) by means of resorbable pins (17).

20. Distractor device (10) according to claim 1, characterized in that the first bone plate (11) and / or the second bone plate (12) have a constant wall thickness.

21. Distractor device (10) according to one of claims 1 to 19, characterized in that the first bone plate (11) and / or the second bone plate (12) has an increased wall thickness in the area of ​​the through holes (20), so that a bone bearing surface (24) of the respective bone plate (11, 12) is lifted off a bottom surface (23) of the respective bone plate (11, 12).

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