Flexible spacer for administering active substances

Abstract

The present invention provides a spacer that enables repeated or continuous release of an active substance on its outer surface. [Solution] The present invention relates to an embedded spacer 100 for delivering medical fluid to a patient, comprising a first sub-element 120, a second sub-element 130, an outer surface 104, a channel 101, a plurality of delivery valves 110, and a connecting element 107 having a joint, wherein the connecting element movably connects the first sub-element to the second sub-element.

Description

Technical Field

[0001] The present invention relates to a spacer for the repeated or continuous local release of an active substance. Further, a method for the local release of an active substance is described.

[0002] The term "spacer" usually refers to an orthopedic implant that can be implanted into a patient as a temporary placeholder after debridement of an infected tissue wound. The spacer can be modeled to the shape of the hip and knee joints or other joints, or can have the shape of an intramedullary rod for use especially in infected long bones. A further application of the spacer is to reduce infections by the local release of an antibacterial active substance in previously debrided bone and soft tissue. Conventional spacers are usually made of PMMA bone cement and contain one or more antibiotics embedded in the spacer material. These antibacterial active substances are released from the PMMA bone cement after implantation by exposure to aqueous body fluids such as wound exudate and blood. The release of the active substance occurs through a diffusion process, resulting in an initial large release of the active substance followed by a small release. However, it is more desirable to temporarily release a sufficiently high amount of the active substance in a constant manner to ensure a consistent local active substance concentration over a period of several days to several weeks.

[0003] European Patent No. 3763335 (B1) describes a knee joint for drug release having a supply line for an active substance solution, through which the active substance solution can reach a plurality of outlet openings via a channel system. The problem here is that the openings located in the immediate vicinity of the supply line release a larger amount of liquid, while the more distant outlet openings can release only a small amount of liquid or no liquid at all. Further, coagulated blood or ingrown connective tissue can block the outlet openings.

[0004] A similar knee joint spacer system is disclosed in U.S. Patent No. 10864314 (B2).

[0005] International Publication No. 2016 / 205077(A) describes a spacer having a rinsing function, in which a rinsing liquid is guided along the spacer surface through grooves on the spacer surface.

[0006] European Patent No. 3542759(B1) proposes a similar spacer system having an outlet opening and an opening for discharging rinse fluid.

[0007] Intramedullary rods intended to reduce infections are also disclosed. These intramedullary rods have a perforated wall with an opening. An antibiotic or disinfectant solution can be introduced into the intramedullary rod from outside the patient through a connected tube (U.S. Patent No. 5,681,289(A), Chinese Patent No. 2,857,862(Y), Chinese Patent No. 2013,706,24(Y), International Publication No. 2016 / 205077(A1)). The antibiotic or disinfectant solution exits through an opening in the wall of the intramedullary rod. Problems with these concepts are that the opening may be blocked by clotted blood, and that the opening may be partially or completely closed after several days by internally growing connective tissue. Furthermore, it is problematic that the antibiotic or disinfectant solution tends to leak from the opening of the intramedullary rod located immediately next to the tube connector. Since the solution exits the intramedullary rod via the shortest path after the introduction tube, only a small amount of antibiotic or disinfectant is released through openings further away from the introduction tube. Therefore, it cannot be guaranteed that a constant volume of antibiotic or disinfectant solution will be released along the entire length of the intramedullary rod.

[0008] Preferred Embodiment The object of the present invention is to solve one or more of the above-mentioned problems and further problems of the prior art, and to provide further advantages.

[0009] The present invention is particularly based on the objective of providing a spacer that allows for repeated or continuous release of an active substance on the outer surface of the spacer over a period of several days to several weeks. For this purpose, a medical fluid, such as an aqueous solution of the active substance, can be introduced into the spacer from the outside, for example, via a supply line, and the fluid can then be delivered from a plurality of discharge valves on the outer surface of the spacer.

[0010] In particular, some of the spacers described herein allow their shapes to be adapted to the specific anatomical conditions of the patient being treated.

[0011] The spacer according to the present invention is preferably designed so that substantially equal volumes of the active substance solution can be delivered simultaneously from all delivery valves. Furthermore, clogging of the delivery valves by coagulated blood and infiltrated connective tissue can preferably be avoided. It is also desirable that external liquids cannot penetrate into the interior of the spacer through the delivery valves. The delivery valves can be designed so that they do not protrude beyond the outer surface of the spacer, and so that the components of the spacer are not pushed into the surrounding tissue during the delivery of the medical fluid. The spacer can enable the delivery of relatively small volumes of medical fluid, for example, up to a maximum of 50 mL per application. The spacer is also suitable for the delivery of medical fluids having high concentrations of active substances. The spacer according to the present invention is preferably suitable for the precisely controlled delivery of the active substance, and uniform delivery can preferably occur at different locations on the spacer. This is an advantage over conventional spacer systems that aim to provide a rinsing function by introducing a larger volume into the spacer to rinse the surrounding tissue. According to the present invention, the spacer described herein preferably does not require any further elements for draining or reabsorbing the rinsing fluid. Spacers may be suitable for temporary implantation in previously infected and debridemented bone cavities.

[0012] These objectives are achieved by the methods, apparatus, kits and medical uses described herein, in particular by the methods, apparatus, kits and medical uses described in the claims.

[0013] Preferred embodiments of the present invention are described below.

[0014] A first embodiment of a first aspect of the present invention relates to an implantable spacer for delivering medical fluid to a patient, comprising a first sub-element, a second sub-element, an outer surface, a channel, a plurality of delivery valves, and a connecting element having a joint, wherein the connecting element movably connects the first sub-element to the second sub-element.

[0015] A second embodiment of the present invention relates to a spacer according to the first embodiment, wherein the channel extends from a first sub-element through a connecting element into a second sub-element.

[0016] A third embodiment of the present invention relates to a spacer according to a prior embodiment, wherein the channel defines a connecting axis along its extending direction from a first sub-element through a connecting element, and the connecting element is designed and configured to allow movement of the second sub-element by at least 20°, preferably at least 30°, or at least 40° at an angle with respect to the connecting axis.

[0017] A fourth embodiment of the present invention relates to an embedded spacer according to any one of the preceding embodiments, wherein the dispensing valve each comprises a first rubber-elastic material, and the first material further comprises a slit.

[0018] A fifth embodiment of the present invention relates to an embedded spacer according to the fourth embodiment, wherein the slit is configured to open and close by the elastic restoring force of the first material.

[0019] A sixth embodiment of the present invention relates to an embedded spacer according to any one of the prior embodiments, wherein the spacer is designed and configured to deliver substantially the same amount of fluid simultaneously from each of the discharge valves.

[0020] A seventh embodiment of the present invention relates to an embedded spacer according to any one of the preceding embodiments, wherein the joint includes, or preferably consists of, a second rubber-elastic material.

[0021] The eighth embodiment of the present invention relates to an embedded spacer according to the seventh embodiment, in which the second material with rubber elasticity has a Shore A hardness in the range of 15 to 80, preferably in the range of 20 to 70, or in the range of 30 to 60.

[0022] The ninth embodiment of the present invention relates to an embedded spacer according to the seventh or eighth embodiment, in which the second material with rubber elasticity has a closed porosity.

[0023] The tenth embodiment of the present invention relates to an embedded spacer according to any one of the preceding embodiments, in which the joined body has an outer diameter that is 0.25 times to 0.75 times the outer diameter of the surrounding first sub-element or second sub-element.

[0024] The eleventh embodiment of the present invention relates to an embedded spacer according to any one of the preceding embodiments, in which the channel has a diameter with a ratio to the outer diameter of the joined body within the range of 1:1 to 1:6.

[0025] The twelfth embodiment of the present invention relates to an embedded spacer according to the eleventh embodiment, which further includes a fixture for connecting the joined body to the first sub-element or the second sub-element, preferably a direct connection.

[0026] The thirteenth embodiment relates to an embedded spacer according to any one of the preceding embodiments, in which the channel extends through the fixture.

[0027] The fourteenth embodiment relates to an embedded spacer according to any one of the preceding embodiments, in which the delivery valves are each fluidly connected to each other by the channels.

[0028] The fifteenth embodiment relates to an embedded spacer according to any one of the preceding embodiments, in which the delivery valves are designed and configured to reversibly open in response to the pressure of the fluid in the channel in order to deliver fluid from the delivery valves.

Brief Description of the Drawings

[0029] [Figure 1] Shown is a spacer according to the present invention, designed as an intramedullary rod spacer. [Figure 2] Shown is a spacer according to the present invention, designed as a hip joint spacer. [Figure 3] Shown is a spacer according to the present invention, having sub-elements that are moved relative to each other by joining elements. [Figure 4] Shown is a spacer according to the present invention, having an internal branched channel. [Figure 5] Shown is a modular delivery valve. [Figure 6] Shown are the details of a spacer according to the present invention, having a modular delivery valve. [Figure 7] Shown is a delivery valve in a fully open state. [Figure 8] Shown is a delivery valve in a partially open state. [Figure 9] Shown is a delivery valve in a closed state.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Regarding the embodiments described herein, elements “having,” “containing,” or “comprising” a particular feature (e.g., material) are, in principle, always contemplated to have further embodiments in which the relevant element consists only of that feature, i.e., does not contain other components. The terms “comprise” or “comprising” are used synonymously herein with the terms “contain,” “containing,” “have,” or “having.”

[0031] "Operationally connected" or "operationally connectable" means, in this specification, that two related elements have a functional relationship with one another. For example, a first element may be configured to control or move a second element through such an operationally connected connection. The term "control" here also includes blocking or enabling a function, such as allowing or restricting the movement of an element or other functions.

[0032] In one embodiment, where an element is indicated in the singular form, embodiments in which two or more such elements exist are also intended. The use of terminology for plural elements essentially also encompasses embodiments in which only a single corresponding element is included.

[0033] Unless otherwise indicated or explicitly excluded from the context, features of different embodiments may, in principle, also be present in other embodiments described herein, and this possibility is explicitly intended here. Similarly, all features described herein in relation to methods are, in principle, considered applicable to the products, apparatus, kits and uses described herein, and vice versa. For the sake of brevity of explanation, not all such considered combinations are explicitly enumerated in every case. Technical solutions known to be equivalent to the features described herein are also intended to be, in principle, encompassed by the scope of the present invention.

[0034] For example, the technical standards and specifications described herein in relation to test procedures refer to the most recent versions as of the priority date of this application.

[0035] One aspect of the present invention relates to an implantable spacer for delivering medical fluid to a patient, comprising a first sub-element, a second sub-element, an outer surface, a channel, a plurality of delivery valves, and a connecting element having a joint, wherein the connecting element movably connects the first sub-element to the second sub-element.

[0036] The term “spacer” as used herein refers to a medical implant designed and configured to be implanted in a patient as a temporary placeholder in place of bone, joint, or part thereof. In one embodiment, the spacer comprises a biocompatible material such as PMMA, stainless steel, or titanium. The spacer may include, or consist of, metal, plastic, or metal-plastic composite materials. Examples of biocompatible metals include 316L steel, cobalt-chromium steel, titanium, and titanium alloys. Examples of biocompatible plastics are polymethyl methacrylate, polyamide 12, polyethersulfone, and polyetherketone. In one embodiment, the spacer consists of at least 90% (mass / mass) PMMA.

[0037] In one embodiment, the spacer according to the present invention may be manufactured, or is manufactured, from stainless steel, titanium, or other biocompatible metals or alloys by SLM (Selective Laser Melting) or EBM (Electron Beam Melting). In one embodiment, the spacer according to the present invention may be manufactured, or is manufactured, from a suitable plastic such as polyamide 12 or polymethyl methacrylate by SLS (Selective Laser Sintering). In one embodiment, the spacer according to the present invention may be manufactured, or is manufactured, from a thermoplastic resin by plastic injection molding. The spacer may be assembled from a plurality of injection-molded parts, which may be connected to each other, for example, by welding or bonding.

[0038] The spacers described herein are preferably designed and configured for delivering medical fluids. “Medical fluid” as used herein refers to a fluid intended for medical use and possessing medicinal properties.

[0039] In this specification, the term “medical fluid” refers in particular to aqueous and non-aqueous liquids that may contain dissolved active ingredients, especially pharmaceutically active ingredients, or that may themselves possess medicinal properties. The term also includes gases and gas-liquid mixtures that may exert pharmacological effects in human or animal organisms. In one embodiment, the medical fluid contains an active ingredient. In one embodiment, the active substance is selected from the group consisting of antibiotics, antifungal agents, cell proliferation inhibitors, anesthetics, osteoinducing active substances, and anti-inflammatory agents.

[0040] In one embodiment, the active ingredient is an antibiotic. In one embodiment, the antibiotic is selected from the group consisting of penicillin, cephalosporin, carbapenem, quinolone, macrolide, lincosamide, aminoglycoside, and glycopeptide. Examples of penicillin are amoxicillin and benzylpenicillin. Examples of cephalosporin are ceftriaxone and cefuroxime. Examples of carbapenem are meropenem and imipenem. Examples of quinolone are ciprofloxacin and levofloxacin. Examples of macrolide are azithromycin and clarithromycin. Examples of glycopeptides are vancomycin and teicoplanin. Examples of aminoglycosides are gentamicin and tobramycin. An example of an aminoglycoside is clindamycin.

[0041] In one embodiment, the active ingredient is an antifungal agent. Examples of antifungal agents include polyenes (e.g., amphotericin B, nystatin, natamycin), azoles (e.g., fluconazole, voriconazole), echinocandins (e.g., caspofungin, micafungin), and allylamines (e.g., terbinafine).

[0042] In one embodiment, the active substance is a cell proliferation inhibitor. Examples of cell proliferation inhibitors include alkylated substances, antimetabolites, natural products, protein kinase inhibitors, and monoclonal antibodies. Examples of alkylated substances include cyclophosphamide, melphalan, and busulfan. Examples of antimetabolites include methotrexate, 5-fluorouracil, and gemcitabine. Examples of natural products include paclitaxel, doxorubicin, and vincristine. Examples of protein kinase inhibitors include imatinib, gefitinib, and sunitinib. Examples of monoclonal antibodies include rituximab, trastuzumab, and bevacizumab.

[0043] In one embodiment, the active substance is an anesthetic. Examples of anesthetics include lidocaine, bupivacaine, ropivacaine, propofol, etomidate, ketamine, morphine, fentanyl, and remifentanil.

[0044] In further embodiments, the active ingredient is an osteoinducible active ingredient. Examples of osteoinducible active ingredients include bone morphogenetic proteins (BMPs), parathyroid hormone-related compounds, anti-sclerostin antibodies, and growth factors. Examples of bone morphogenetic proteins include BMP-2 and BMP-7. An example of a parathyroid hormone-related peptide is teriparatide (PTH 1-34). An example of an anti-sclerostin antibody is romosozumab. Examples of growth factors include fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF).

[0045] In further embodiments, the active substance is an anti-inflammatory agent. Examples of anti-inflammatory agents include nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, selective COX-2 inhibitors, biological agents (e.g., TNF-α inhibitors), and Janus kinase inhibitors. Examples of nonsteroidal anti-inflammatory drugs (NSAIDs) include ibuprofen, diclofenac, and naproxen. Examples of glucocorticoids include prednisone, dexamethasone, and hydrocortisone. Examples of selective COX-2 inhibitors include celecoxib and etoricoxib. Examples of TNF-α inhibitors include infliximab, adalimumab, and etanercept. Examples of Janus kinase inhibitors include tofacitinib and baricitinib.

[0046] In one embodiment, the active ingredient is suitable for treating bone diseases. In one embodiment, the active ingredient is selected from the group consisting of bisphosphonates (e.g., alendronate, zoledronate), calcitonin, selective estrogen receptor modulators (e.g., raloxifene), and strontium ranerate. In one embodiment, the active ingredient comprises hyaluronic acid or a corticosteroid (e.g., betamethasone, triamcinolone). In one embodiment, the active ingredient comprises a calcium salt. Examples of suitable calcium salts include calcium phosphate and calcium sulfate. Examples of calcium phosphate include β-TCP (beta-tricalcium phosphate) and hydroxyapatite.

[0047] In one embodiment, the active substance is selected from the group consisting of gentamicin, tobramycin, amikacin, clindamycin, daptomycin, vancomycin, teicoplanin, dalbavancin, fosfomycin, linezolid, eperezolid, colistin, meropenem, fluconazole, micafungin, caspofungin, metronidazole, moxifloxacin, ofloxacin, levofloxacin, ciprofloxacin, rifamycin, and rifampicin.

[0048] In one embodiment, the medical fluid includes an aqueous solution of the active substance described herein.

[0049] The spacer has an outer surface. Multiple delivery valves are arranged on this outer surface. The delivery valves are designed and configured to deliver medical fluids. The delivery valves are interconnected via channels. The channels are located inside the spacer. In some embodiments, the spacer includes an inlet opening. The inlet opening is preferably located on the outer surface of the spacer. The inlet opening is designed and configured to introduce medical fluids into the channels. In embodiments having inlet openings and multiple delivery valves, the channels connect the delivery valves to each other and to the inlet openings.

[0050] In some embodiments, the discharge valve is designed and configured to reversibly open in response to the pressure of the fluid in the channel in order to deliver fluid from the discharge valve. This allows for controlled delivery of fluid from the spacer.

[0051] In some embodiments, the discharge valves are arranged to be substantially uniformly distributed across the entire outer surface of the spacer so that the fluid can be uniformly delivered around the spacer. The fluid can be delivered in all spatial directions.

[0052] To ensure uniform delivery of medical fluids to the spacer environment, it may also be advantageous to provide a sufficient number of dispensing valves relative to the surface area of ​​the spacer. Therefore, in one embodiment, the spacer has an outer surface of 16.0 cm². 2 At least one dispensing valve per unit, more preferably with an outer surface of 9.0 cm of spacer. 2 Each unit is equipped with at least one dispensing valve.

[0053] The discharge valve can form a unit with the spacer material, i.e., it can be integrated with the spacer. An example of this is the slit valve described herein, in which, for example, the opening on the outer surface of the spacer is coated and covered with a rubber elastic material. Such a rubber elastic material suitable for the manufacture of a slit valve is also referred to herein as the “first material”.

[0054] The dispensing valve can be modular, and as a result, the remaining portion of the spacer can be manufactured separately from the dispensing valve, and then the valve can be joined to the remaining portion of the spacer. This allows for flexible and cost-effective production, for example, by using the same modular dispensing valve with spacers of different shapes.

[0055] In some embodiments, each dispensing valve has a sleeve-shaped housing. In some embodiments, the spacer has a plurality of receptacles that allow such dispensing valves to be coupled to the spacer. In some embodiments, the dispensing valves are connectable to or connected to the spacer by positive engagement and / or non-positive engagement of the housing into the receptacles.

[0056] The dispensing valve is preferably a pressure relief valve, i.e., a valve that opens when a specified pressure is exceeded. This pressure is referred to herein as the “threshold pressure.” Preferably, all dispensing valves of the spacer have the same threshold pressure. Furthermore, it is preferable that the valve is “non-contact” with respect to the surroundings of the spacer, i.e., designed so that there is no part that moves toward the surrounding tissue when the valve is opened. This can prevent irritation of the patient’s sensitive tissue, especially in the presence of inflammation. An example of such a dispensing valve has a rubber elastic membrane with a slit-shaped opening located inside, as described below.

[0057] In one embodiment, the discharge valve is designed and configured to open when the fluid pressure inside the channel exceeds a threshold pressure, which is 1 bar (10^5 Pa) higher than the pressure outside the spacer, and to close fluid-tight when it falls below this threshold pressure. This means that the discharge valve is closed when the overpressure of the fluid in the channel is less than 1 bar, and the discharge valve is open when the overpressure of the fluid in the channel is 1 bar or greater. "Overpressure" as used herein refers to the difference between atmospheric pressure and the pressure of the fluid in the channel of the spacer.

[0058] In some embodiments, the dispensing valve each comprises a first material, which is rubber-elastic. The rubber-elastic material is characterized in particular by its ability to automatically return to its original shape after mechanical deformation. In some embodiments, as will be further described below, this property provides a slit positioned in the elastic material with the ability to open or close in response to pressure.

[0059] The discharge valve may include a first material, for example, in the form of a coating on the outer surface of a spacer. The channel of the spacer may open to an opening on the outer surface of the spacer, and such an opening may be provided with the coating. The coating can form the boundary of such an opening and seal it.

[0060] In one embodiment, each dispensing valve has a housing into which such a first material is introduced. For example, the housing may have a substantially cup-shaped form with an opening. In such an embodiment, the first material can fluidly seal the opening of the housing of the dispensing valve. The first material may be disc-shaped or cup-shaped.

[0061] The dispensing valve may be connected to the spacer by positive connection, non-positive connection, and / or physically bonded connection. For example, the dispensing valve may be connected to the spacer by pressing and / or bonding and / or welding and / or screwing. In particular, such a connection may be present between the housing of the dispensing valve and the receptacle of the spacer described herein.

[0062] In one embodiment, the first material has a Shore A hardness of 30 to 80. In another embodiment, the first material has a Shore A hardness of 40 to 70, or 50 to 60, for example, about 55. The Shore A hardness is determined according to ASTM D2240. Elastomers with Shore A hardness in this range have very good resilience and are very suitable for the manufacture of rubber elastic discs or rubber elastic coatings, such as those described herein as part of a dispensing valve. Slits in such elastomers close automatically and quickly when the pressure acting on them decreases. In another embodiment, the first material has a Shore A hardness in the range of 75 to 95.

[0063] The first material is preferably a polymer, particularly an elastomer. Preferably, the first material includes or consists of a medically acceptable elastomer. Examples of medically acceptable elastomers include silicone elastomers, thermoplastic elastomers (TPE), polyisoprene, butyl rubber, nitrile rubber, ethylene propylene diene monomer (EPDM), chloroprene rubber, fluoroelastomers, perfluoroelastomers, and polyacrylate elastomers. Examples of silicone elastomers include polydimethylsiloxane (PDMS) and liquid silicone rubber (LSR).

[0064] Examples of thermoplastic elastomers (TPEs) include styrene block copolymers (SBCs) such as styrene-ethylene-butylene-styrene (SEBS), thermoplastic polyurethanes (TPUs), and thermoplastic copolyesters (TCEs). Examples of polyisoprenes include natural rubber and synthetic polyisoprenes. Examples of butyl rubbers include bromobutyl rubber (BIIR) and chlorobutyl rubber (CIIR). A preferred polyurethane is polyether urethane. Polyether urethanes can be produced by a polyaddition reaction between a polyether polyol and a diisocyanate.

[0065] In one embodiment, the first material has a thermoplastic elastomer. In one embodiment, the first material consists of a thermoplastic elastomer. In one embodiment, the first material has a polyether urethane or ethylene propylene diene rubber. In one embodiment, the first material includes a polyether urethane. In one embodiment, the first material consists of a polyether urethane.

[0066] In one embodiment, the first material has only a single elastomer, i.e., the second elastomer is not mixed with the first material. In one embodiment, the first material has at least two different materials, for example, two different elastomers. This allows, for example, the hardness of the first material to be set to a desired target value. The first material may include a copolymer. The copolymer may be a thermoplastic elastomer. A copolymer containing soft segments and hard segments in its molecular chain is preferred. The ratio between soft segments and hard segments in the molecular chain of the copolymer can be used to adjust the physical properties of such copolymer, for example, the Shore A hardness of the copolymer. The hard segments can be connected to the soft segments using connectors (linkers).

[0067] Furthermore, the first material may contain additives to adjust its hardness. Examples of such additives are fillers and plasticizers. Examples of fillers include silica, titanium dioxide, calcium carbonate, barium sulfate, and carbon.

[0068] Examples of plasticizers include adipates, trimellitates, citrate-based plasticizers, and esters of polyhydric alcohols.

[0069] For example, TOTM (tris(2-ethylhexyl) trimellitate), DINCH (diisononylcyclohexane-1,2-dicarboxylate), ATBC (acetyl tributyl citrate), or DEHA (di(2-ethylhexyl) adipate) can be used as plasticizers.

[0070] In one embodiment, the first material does not contain plasticizers. In one embodiment, the first material does not contain fillers. In one embodiment, the first material does not contain endocrine disruptors such as phthalates or bisphenols.

[0071] In one embodiment, the first material may further contain a lubricant. Preferably, the lubricant is medically acceptable. Preferably, the lubricant does not contain polyhalogenated substances and silicones. In one embodiment, the lubricant is a natural product, such as a lipid, triglyceride, or biopolymer.

[0072] In one embodiment, the first material may have a Young's modulus of elasticity of 1.2 × 10^7 Pa to 2.1 × 10^7 Pa, for example, 1.3 × 10^7 Pa to 2.0 × 10^7, 1.4 × 10^7 Pa to 1.9 × 10^7 Pa, 1.5 × 10^7 Pa to 1.8 × 10^7 Pa, or 1.5 × 10^7 Pa to 1.7 × 10^7 Pa. In one embodiment, the first material may have a Young's modulus of elasticity of about 1.6 × 10^7 Pa. In one embodiment, the first material may have a Young's modulus of elasticity of 2000 to 2500 psi. The latter corresponds to about 1.4 × 10^7 Pa to 1.7 × 10^7 Pa.

[0073] The Young's modulus of elasticity can be determined according to ASTM D412.

[0074] The first material is preferably sterilizable using common sterilization processes, i.e., resistant to UV radiation, gamma radiation, and ethylene oxide treatment within the scope of these processes.

[0075] The first material is preferably moldable using a standard extrusion and / or injection molding process.

[0076] The first material may include slits. In one embodiment, the slits have a straight, curved, star-shaped, cross-shaped, or horseshoe-shaped form. In one embodiment, each slit has an overall length in the range of 0.4 mm to 3.0 mm, for example, in the range of 0.8 mm to 2.5 mm, or in the range of 1.0 mm to 2.0 mm.

[0077] In one embodiment, each of the dispensing valves includes a first material having slits. In one embodiment, each of the dispensing valves has exactly one, i.e., one or fewer slits in the first material.

[0078] In one embodiment, all slits of the discharge valve each have substantially the same length. In one embodiment, all slits have a length that deviates by no more than 25% above or below a certain value, for example, a length of 1.00 mm + / - 25%, i.e., a length of 0.75 mm to 1.25 mm.

[0079] In one embodiment, the slit is configured to be reversibly opened and closed by the elastic restoring force of the first material. The slit can be opened by overpressure of the fluid in the channel, by the fact that the first material is pushed away by the fluid when the fluid pressure exceeds a predetermined threshold pressure.

[0080] In one embodiment, the slit may be manufactured by partially cutting the first material or without removing any part of the first material. The slit may be formed, for example, by punching with a blade. Such a slit is completely closed unless there is a pressure difference on either side of the first material. This prevents tissue or fluid from penetrating the spacer from the outside.

[0081] In one embodiment, the slits have walls which move to contact each other when the discharge valve is closed and to move away from each other when the discharge valve is opened.

[0082] In further embodiments, the channel has an inlet opening for receiving fluid, and the inlet opening is preferably located on the outer surface of the spacer.

[0083] Furthermore, the spacer may have a fluid connector. The fluid connector may be used to connect a container or fluid conduction connection to receive liquid into the spacer. An example of a fluid connector is a syringe connector, such as a Luer lock connector. Using such a connector, a commercially available Luer lock syringe can be connected to the inlet opening of the spacer in a liquid-tight and fluid conduction manner. The fluid connector may be removablely connectable to the inlet opening. The fluid connector may be operably connectable to the spacer.

[0084] The spacer may further comprise a supply line, which is connectable to or connected to the inlet opening. Preferably, the supply line may be operably connectable to or connected to the inlet opening. In one embodiment, the spacer has a fluid connector, which is connectable to or connected to the inlet opening via the supply line. The supply line may have a tube made of, for example, a medically suitable material.

[0085] In one embodiment, the spacer may be equipped with a check valve. The check valve is preferably designed to prevent fluid from flowing out of the spacer through the inlet opening. The check valve may or may be operably connected to the inlet opening. The check valve may be located directly within the inlet opening or within a supply line or fluid connector. Thus, fluid can be introduced into the spacer through the inlet opening without backflow through the inlet opening.

[0086] To ensure secure connection of the supply line to the inlet opening, the spacer may further comprise a latch mechanism, preferably located at the inlet opening. In one embodiment, the latch mechanism comprises, for example, one or more movable latch elements, which are designed and configured to move radially inward when the supply line is inserted into the inlet opening and to engage with corresponding grooves or recesses in the inlet opening. The latch mechanism may preferably be spring-biased to enable engagement of the latch elements at the inlet opening.

[0087] A latching mechanism may have release means designed and configured to release a latching element.

[0088] The supply line may be connected to or connected to the inlet opening to ensure a fluid conduction connection at a pressure of at least 1 bar.

[0089] In further embodiments, the spacer further includes a trocar. The trocar has a pointed end that allows it to penetrate tissue. Furthermore, the trocar includes a shaft along which the trocar can be guided. The shaft may have a cylindrical cavity, similar to that of a cannula.

[0090] The trocar is preferably connectable to the supply line described herein. Preferably, the trocar may be detachably connected to the distal end of the supply line. Using the trocar, a medical user can insert the supply line into the patient's tissue and, accordingly, position and secure the supply line at the desired location. The trocar can enable gentle and precise penetration of the target tissue. In this case, a channel can be created to the desired administration site, and accordingly, a spacer for administering the medical fluid can be positioned. The supply line may be inserted into the patient's tissue through the channel created by the trocar. Preferably, the trocar is detachable so that, after positioning using the trocar, it can receive the medical fluid through the supply line. For example, the trocar may be detached from the supply line and replaced with a fluid connector, such as a Luer lock connector. The medical fluid may then be added to the supply line, for example, using a Luer lock syringe, in order to deliver the medical fluid to the target location on the patient's tissue using the device.

[0091] In one embodiment, the inlet opening described herein may be configured identically to the receptacle described herein. In one embodiment, the inlet opening is configured differently from the receptacle described herein.

[0092] Spacers can be adapted to different sites of use. In one embodiment, the spacer is selected from the group consisting of knee joint spacers, hip joint spacers, vertebral body spacers, and intramedullary rod spacers.

[0093] A knee joint spacer may be a one-piece or multi-piece knee joint spacer. A hip joint spacer may be a one-piece or multi-piece hip joint spacer. A vertebral body spacer may be a one-piece or two-piece vertebral body spacer. The delivery system described herein may be present in only one of the two parts of a multi-piece spacer, or in both parts.

[0094] The spacers described herein, for example, a hip joint spacer or a knee joint spacer, may each have a first sub-element and a second sub-element. The first sub-element and / or the second sub-element may be intended to be inserted into the patient's bone. Fixation may be performed with bone cement.

[0095] In one embodiment, both the first sub-element and the second sub-element are equipped with a discharge valve.

[0096] In one embodiment, the spacer further comprises a cemented area that does not have a delivery valve or inlet opening. This cemented area is preferably designed and configured to be fixed to the bone of the patient being treated using bone cement. In this way, the spacer can be held in place at the desired target location after implantation.

[0097] Furthermore, the inventions described herein can be designed as implants intended to remain permanently in a patient's body. For example, a bone fixation plate as described herein may be provided with the channels and delivery valves described herein. Thus, in one embodiment, the present invention also provides an implant for delivering medical fluids to a patient, the implant having an outer surface and a plurality of delivery valves disposed on the outer surface, each delivery valve being fluidically connected to one another by channels disposed within the implant, and the delivery valves are designed and configured to reversibly open in response to the pressure of the fluid in the channels in order to deliver fluid from the delivery valves. The implant may be designed as a fixation implant, for example, as a hip joint implant, a shoulder joint implant, or a knee joint implant.

[0098] In further embodiments, the spacers or implants described herein are designed and configured to deliver substantially identical amounts of fluid simultaneously from each of the dispensing valves. For example, substantially identical amounts may be amounts having a statistical standard deviation of less than 10% of the arithmetic mean.

[0099] In further embodiments, the spacers or implants described herein are designed and configured to open and / or close all dispensing valves simultaneously. Depending on the pressure of the fluid in the channel, the dispensing valves are either open or closed accordingly, as described herein.

[0100] In one embodiment, each delivery valve is positioned flush with the outer surface of the spacer. Such a design prevents the delivery valve from forming protrusions relative to the spacer, which could result in damage or irritation to the patient's tissue.

[0101] In one embodiment of the present invention, the channel has a plurality of branches. In this case, each branch preferably has a discharge valve or inlet opening according to the embodiments described herein. This means, in particular, that in the case of branches, the discharge valve or inlet opening is located on each side arm of the channel, and each discharge valve or inlet opening is preferably located on the outer surface of the spacer.

[0102] In one embodiment, the discharge valve is designed and configured to allow liquid to pass through the discharge valve in only one direction. This means that the discharge valve in this case is designed as a non-return valve. According to the present invention, this means that liquid cannot enter the channel from the outside through such a discharge valve as long as the pressure of the fluid in the channel is greater than or equal to the ambient pressure outside the spacer.

[0103] In one embodiment, the spacer or implant has a connecting element. The connecting element may have a joint. The connecting element can movably connect a first sub-element to a second sub-element. A channel may extend from the first sub-element through the connecting element into the second sub-element. The channel may be positioned along the central axis of the connecting element.

[0104] In one embodiment, the channel defines a connecting axis along its extending direction from the first sub-element through the connecting element. This axis is defined when no external force is acting on the spacer. The connecting element may be designed and configured to allow movement of the second sub-element by at least 20° at an angle to this connecting axis. In one embodiment, this angle is at least 30° or at least 40°. For example, the second sub-element may be laterally bent by at least 20°, at least 30°, or at least 40° relative to the first sub-element. The spacer may be designed and configured to allow such bending without closing the channel. To enable such movement, the joint may include a rubber-elastic second material. In one embodiment, the joint consists of the second material. The second material may be identical to the first material described herein, or the second material may be different from the first material described herein. The second material may have a Shore A hardness in the range of 15 to 80. In one embodiment, the second material has a Shore A hardness in the range of 20 to 70, or in the range of 30 to 60. The second material may have closed porosity.

[0105] The channel may have a deformable region, such as a flexible region.

[0106] The joint may have an outer diameter of 0.25 to 0.75 times the outer diameter of the surrounding first or second sub-element. Preferably, these two outer diameters are defined in directions perpendicular to the aforementioned connecting axis. Preferably, these two outer diameters are defined along the same line.

[0107] In one embodiment, the channel has a diameter that has a ratio to the outer diameter of the joint, within the range of [1:1] to [1:6]. The diameter of the channel is defined as the inner width of the channel.

[0108] In one embodiment, the spacer has a fastener that connects the joint to a first sub-element and / or a second sub-element. In one embodiment, the fastener directly connects the joint to the first sub-element or the second sub-element. In one embodiment, the fastener connects the joint to the first sub-element. In one embodiment, the fastener connects the joint to the second sub-element. In one embodiment, the first fastener connects the first joint to the first sub-element, and the second fastener connects the second joint to the second sub-element.

[0109] In one embodiment, the channel extends through a fastener. In one embodiment, the channel extends through a joint. In one embodiment, the channel extends through a fastener and through a joint. In one embodiment, the fastener has a substantially cylindrical shape. The fastener may be designed, for example, as a screw or bolt. Thus, the fastener may include threads. The fastener may also include peripheral grooves, projections, or other latching means. The fastener may include cavities for forming a portion of the channel as described herein.

[0110] The fasteners may be connected to the second material by positive connections, non-positive connections, and / or physically bonded connections. The fasteners may be connected to the first sub-element by positive connections, non-positive connections, and / or physically bonded connections. The fasteners may be connected to the second sub-element by positive connections, non-positive connections, and / or physically bonded connections.

[0111] In one embodiment, the fastener is enclosed by a joint and a first sub-element. In another embodiment, the fastener is enclosed by a joint and a second sub-element.

[0112] In one embodiment, the spacer is designed and configured to maintain the channel in a fluid conduction state when the first sub-element is moved relative to the second sub-element.

[0113] In one embodiment, the fastener has a higher Shore A hardness than the joint. In one embodiment, the fastener has a Shore A hardness at least 10%, 20%, 30%, 40%, or 50% higher than the Shore A hardness of the joint. This prevents the channel from closing due to movement of the joint element, as shown in Figure 3 as an example.

[0114] In one embodiment, a joint element, preferably a joint of joint elements, may have a discharge valve as described herein. The discharge valve may be located within a second material, the second material may include a slit. In one embodiment, the slit is configured to be reversibly opened and closed by the elastic restoring force of the second material.

[0115] In one embodiment, the spacer comprises a plurality of connecting elements. The connecting elements may be connected to each other directly or indirectly. For example, a plurality of connecting members may be directly connected to each other. For this purpose, the connecting members may have latching elements such as threads or recesses and / or protrusions. The connecting members may be connected to each other by interposed fasteners as described herein.

[0116] In addition to the first and second sub-elements, the spacer may comprise further such sub-elements, each connected to one another by the connecting elements described herein. This allows for greater mobility of the spacer. For example, in such embodiments, the spacer may bend simultaneously in different directions in a manner similar to how the vertebral joints of the spine enable it.

[0117] Further aspects of the present invention relate to a kit for manufacturing a spacer as described herein, comprising a plurality of sub-elements and one or more connecting elements as described herein. In one embodiment, the kit includes a plurality of interchangeable sub-elements. These sub-elements may have different sizes and / or shapes, for example, different lengths and / or thicknesses. This allows a medical user to individually fit the spacer to the patient being treated.

[0118] In one embodiment, the kit is designed and configured to manufacture an implantable spacer for delivering medical fluid to a patient, the spacer comprising an outer surface and a plurality of delivery valves located on the outer surface, each of which is fluidically connected to one another by channels located within the implant, and the delivery valves are preferably designed and configured to reversibly open in response to the pressure of the fluid in the channels in order to deliver fluid from the delivery valves.

[0119] A second aspect of the present invention relates to a medical fluid for use in a medical method, wherein the method is: The steps of providing the spacer described herein, The steps include introducing medical fluid into the channel of the spacer, The procedure includes the step of delivering fluid from the device to the patient.

[0120] The medical method may further include pressurizing the medical fluid in the channel and opening the device's discharge valve as a function of the pressure to deliver the fluid to the patient.

[0121] The medical method preferably includes the treatment of inflammation, mechanical injury (trauma), infection, or cancer. This method preferably includes the treatment of affected bone or joint. Infections may be, for example, osteomyelitis or osteitis. Furthermore, this method may include the treatment of pain.

[0122] In one embodiment, the medical method is related to joint infections, such as hip joint infections, knee joint infections, shoulder joint infections, or spondylodiscitis. In one embodiment, the treated joint infection is caused by surgical procedures, such as surgical procedures to implant an artificial joint. In some embodiments, the joint infection is treated using a medical fluid containing antibiotics and / or antifungal agents.

[0123] A further embodiment according to a second aspect of the present invention relates to a medical fluid for use in the medical methods described above, wherein the fluid comprises an active substance. In principle, all of the active substances described herein can be used. In one embodiment, the fluid comprises an active substance selected from the group consisting of antibiotics, anti-inflammatory agents, anesthetics, and cell proliferation inhibitors.

[0124] In one embodiment, the active substance is selected from the group consisting of gentamicin, tobramycin, amikacin, clindamycin, daptomycin, vancomycin, teicoplanin, dalbavancin, fosfomycin, linezolid, eperezolid, colistin, meropenem, fluconazole, micafungin, caspofungin, metronidazole, moxifloxacin, ofloxacin, levofloxacin, ciprofloxacin, rifamycin, and rifampicin.

[0125] In one embodiment, the medical fluid is an aqueous solution of the active substance described herein.

[0126] In one embodiment, the medical method includes implanting a spacer in the patient's tissue, preferably in the area of ​​a joint or in the tissue of a fracture site. In one embodiment, the medical method includes using a trocar to penetrate the patient's tissue and guide the supply line of the spacer from the inside of the patient's body through the skin to the outside.

[0127] In one embodiment, the medical fluid is introduced into the spacer channel using a pump, for example, a syringe pump. In one embodiment, the medical fluid is delivered to the patient continuously over a period of several minutes, several hours, or several days. In one embodiment, the medical fluid is delivered to the patient repeatedly. For example, the medical fluid may be delivered to the patient once a day, or multiple times a day, for example, two, three, or four or more times a day. In one embodiment, the medical fluid is delivered according to the patient's health parameters. Health parameters may be, for example, diagnostic measurements or the patient's pain level.

[0128] In one embodiment, the medical fluid is administered using a manual or automatic controller.

[0129] A further aspect of the present invention relates to a medical method, the method being: The steps of providing a spacer, implant, or kit as described herein, The steps include introducing medical fluid into the channel of a spacer or implant, The process includes the steps of pressurizing a medical fluid within a channel and delivering the fluid to a patient.

[0130] The method may further include the step of opening the device's discharge valve as a function of pressure and pressurizing the medical fluid in the channel to deliver the fluid to the patient.

[0131] The above description regarding medical fluids for use in medical procedures shall apply accordingly.

[0132] figure Figure 1 shows a cross-section of a first embodiment of the spacer 100 according to the present invention, designed as an intramedullary rod spacer. The spacer 100 has a first sub-element 120 and a second sub-element 130, the first sub-element 120 being connected to the second sub-element 130 via a connecting element 107. The connecting element 107 is connected in each case to the first sub-element 120 and the second sub-element 130 by a fastener 108. The first sub-element 120 has an inlet opening 103 together with a supply line 201 and a fluid connector 202, the inlet opening 103 being fluidically connected to a plurality of discharge valves 110 via a channel 101, the discharge valves 110 being located in both the first sub-element 120 and the second sub-element 130. The delivery valve 110 is distributed uniformly across the outer surface 104 of the spacer, i.e., across the outer surfaces of the first sub-element 120 and the second sub-element 130, in order to obtain the most uniform possible delivery of the medical fluid around the spacer 100.

[0133] Channel 101 has a branch 106. The spacer has an outer surface 104 on which receptacles 102 are arranged. The receptacles 102 have delivery valves 110 inserted therein. In the example shown in this figure, one of the receptacles 102 is configured as an inlet opening 103 for establishing a fluid conduction connection with a supply line 201. The proximal end of the supply line 201 engages positively or unpositively into the inlet opening 103. The supply line 201 has a distal end that is fluidically connected to a fluid connector 202. The fluid connector 202 is designed in this case as a Luer lock connector. The delivery valves 110 are positioned at different locations on the outer surface 104 of the spacer to allow for the most uniform distribution and delivery of medical fluid around the spacer. The channel 101 connects the inlet opening 103 to the discharge valve 110 so that the fluid received through the inlet opening 103 can flow through the channel 101 to the discharge valve 110.

[0134] Figure 2 shows a cross-sectional view of a further embodiment of the spacer according to the present invention, designed as a knee joint spacer. This embodiment has a plurality of discharge valves 110 connected to each other and connected to an inlet opening 103 via channels 101. Furthermore, the spacer in the embodiment shown in this figure comprises a connecting element 107 having a rubber elastic material. The connecting element 107 is connected to a second sub-element 130 of the spacer via a positive connection. Furthermore, the connecting element 107 is connected to a first sub-element 120 of the spacer via a fixture 108 by positive and / or non-positive connections. The channels 101 extend within the spacer through the first sub-element 120, the fixture 108, the connecting element 107, and the second sub-element 130. The connecting element 107 allows for lateral rotational movement of the second sub-element 130 relative to the first sub-element 120. The channels 101 remain open at any position so that fluid can be guided through the connecting element 107. The embodiment shown in this figure has two identical second sub-elements 130, which are connected to the same first sub-element 120 via a fastener 108 and a connecting element 107, respectively, as described above.

[0135] Figure 3 shows a cross-sectional view of an embodiment of the spacer 100 according to the present invention as shown in Figure 2. The second sub-element 130 is moved laterally relative to the first sub-element 120 by the connecting element 107, and the connecting element 107 enables the lateral rotational movement of the second sub-element 130. This makes it possible to implant the spacer shown in this figure into the patient with higher precision than would be possible with conventional rigid spacers, without impairing the fluid conduction characteristics of the spacer.

[0136] Figure 4 shows a cross-section of a spacer filled with medical fluid 200. The spacer design shown in this figure allows for the injection of medical fluid into the channel 101 via a syringe through the fluid connector 202, the supply line 201, and the inlet opening 103. Pressurization of the fluid 200 in the channel 101 causes the delivery valve 110 to open to deliver the fluid from the spacer 100 to the patient's target tissue. The delivery valve 110 is designed and configured to open at a pressure exceeding a predetermined pressure of the fluid 200 in the channel 101. This allows for the achievement of temporally and quantitatively uniform delivery of the fluid 200 through all delivery valves 110.

[0137] Figure 5 shows a cross-sectional view of an embodiment of the discharge valve 110. This embodiment of the discharge valve 110 is constructed in a modular design so that it can be manufactured separately and integrated into the spacer 100 according to the present invention. The discharge valve 110 has a housing 111, the housing 111 having a projection 114 designed for a rigid connection with the spacer's receptacle. A first rubber-elastic material 112 having a slit 113 is located inside the discharge valve. The slit 113 is designed and configured to open or close as a function of pressure, as shown in more detail in Figures 7 to 9. The slit 113 is shown in a partially open state in this figure.

[0138] Figure 6 shows details of an embodiment of the spacer 100 according to the present invention, in which a modular delivery valve 110 is non-positively engaged within the spacer's receptacle 102. In this case, the delivery valve 110 is positioned such that its housing 111 is flush with the outer surface 104 of the spacer. This prevents the delivery valve 110 from being positioned within the receptacle 102 in a manner that would form a protrusion that could pose a risk of injury to the patient. The slit 113 is shown in a partially open state in this figure.

[0139] Figure 7 shows an embodiment of the discharge valve 110 in a fully open state. As the pressure of the fluid 200 flowing into the discharge valve 110 from the spacer channel increases, slits 113 located in the rubber-elastic first material 112 open. The slits 113 have slit walls that separate from each other as the pressure of the fluid 200 increases, resulting in the slits 113 opening and allowing the fluid 200 to be delivered from the discharge valve 110.

[0140] Figure 8 shows an embodiment of the discharge valve 110 in a partially open state. In the drawing shown here, the pressure of the fluid 200 is only slightly above the threshold pressure at which the slit 113 opens. The two slit walls 115 are positioned close to each other, allowing only a relatively small amount and a low delivery rate of fluid 200 from the discharge valve 110 compared to the state shown in Figure 5.

[0141] Figure 9 shows an embodiment of the discharge valve 110 in a closed state. In the drawing shown here, the pressure of the fluid 200 is below the threshold pressure at which the slit 113 would open. The two slit walls 115 are in contact with each other and are in complete contact with each other, and as a result, the slit 113 is closed and does not allow any flow of fluid 200. [Explanation of symbols]

[0142] 100 Spacer 101 channels 102 Receptacle 103 Inlet opening 104 Exterior 105 Cement Area 106 Branches 107 Joint elements 108 Fixtures 110 Discharge valve 111 Housing 112 First material 113 Slits 114 Protrusion 115 Slit wall 120 First sub-element 130 Second sub-element 200 fluid 201 Supply Line 202 Fluid Connector

Claims

1. An embedded spacer (100) for delivering medical fluid to a patient, comprising a first sub-element (120), a second sub-element (130), an outer surface (104), a channel (101), a plurality of delivery valves (110), and a connecting element (107) having a joint (109), wherein the connecting element (107) movably connects the first sub-element (120) to the second sub-element (130).

2. The embedded spacer according to claim 1, wherein the channel (101) extends from the first sub-element (120) through the joining element (107) into the second sub-element (130).

3. The embedded spacer according to claim 2, wherein the channel (101) defines a connecting axis (310) along its extending direction from the first sub-element (120) through the connecting element (107), and the connecting element (107) is designed and configured to allow the movement of the second sub-element (130) by at least 20°, preferably at least 30°, or at least 40° with respect to the connecting axis (310).

4. The embedded spacer according to claim 1, wherein each of the discharge valves (110) comprises a first rubber-elastic material (112), and the first material further comprises a slit (113).

5. The embedded spacer according to claim 4, wherein the slit (113) is configured to be reversibly opened and closed by the elastic restoring force of the first material (112).

6. The embedded spacer according to claim 1, wherein the spacer is designed and configured to deliver substantially the same amount of fluid simultaneously from each of the discharge valves (110).

7. The embedded spacer according to claim 1, wherein the joint (109) includes a second rubber-elastic material (116), or preferably consists of a second rubber-elastic material (116).

8. The embedded spacer according to claim 7, wherein the rubber-elastic second material (116) has a Shore A hardness in the range of 15 to 80, preferably in the range of 20 to 70, or in the range of 30 to 60.

9. The embedded spacer according to claim 7, wherein the second rubber-elastic material (116) has closed porosity.

10. The embedded spacer according to claim 1, wherein the joining body (109) has an outer diameter (320) that is 0.25 to 0.75 times the outer diameter of the surrounding first sub-element (120) or second sub-element (130).

11. The embedded spacer according to claim 1, wherein the channel (101) has a diameter (330) having a ratio to the outer diameter (320) of the joint (109) that is in the range of 1:1 to 1:

6.

12. The embedded spacer according to claim 1, further comprising a fastener (108) that connects, preferably directly, the joint (109) to the first sub-element (120) and / or the second sub-element (130), wherein the channel (101) more preferably extends through the fastener (108).

13. The embedded spacer according to claim 1, wherein each of the discharge valves (110) is fluidly connected to one another by the channels (101).

14. The embedded spacer according to claim 1, wherein the discharge valve (110) is designed and configured to reversibly open in response to the pressure of the fluid (200) in the channel (101) in order to deliver the fluid (200) from the discharge valve (110).

15. The embedded spacer according to claim 1, further comprising an inlet opening (103) for receiving fluid, wherein the inlet opening (103) is preferably located on the outer surface (104) of the spacer.

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