Taper-locked osseointegrated prosthesis

Abstract

The present application relates to the field of medical devices, and provides a taper-locked bone integration prosthesis. The bone integration prosthesis comprises an implanted prosthesis, a percutaneous device and an abutment screw, the implanted prosthesis is provided with a plurality of fixing ridges on the periphery, the bone fixation is achieved by press-fitting, and the taper locking structure is combined to prevent the implanted body from sinking, so as to ensure that the position of the implanted prosthesis is fixed after implantation; the periphery of the implanted prosthesis is also provided with a flushing hole in communication with an internal flushing chamber, which can be used for injecting drugs, implanting bone materials and the like into the medullary cavity or for flushing treatment of possible intramedullary infection in the later period. The percutaneous device is connected with the implanted prosthesis through an anti-rotation structure and a taper locking structure, the percutaneous segment has a surface state formed by surface treatment, which reduces the stimulation to the surrounding soft tissue and improves the anti-infection ability, and the percutaneous sealing effect is improved. The present application optimizes the implanted structure and the percutaneous interface design, reduces the operation difficulty and operation time during the operation, and at the same time reduces the percutaneous stoma and the risk of infection.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more specifically to a tapered locking osseointegrated prosthesis for orthopedic implantation. Background Technology

[0002] Due to factors such as traffic accidents, diseases, war, and industrial accidents, the number of amputees is increasing year by year. Prosthetic limbs can restore motor function to amputees to a certain extent. Traditional cavity prostheses generally suffer from drawbacks such as uneven force distribution and limited range of motion after long-term use; therefore, osseointegrated prostheses are gradually becoming an alternative. Osseointegrated prostheses can avoid the biomechanical mismatch problems caused by cavity prostheses and are more in line with human biomechanical characteristics. Their basic principle is to insert and fix one end of the osseointegrated prosthesis into the medullary cavity of the tubular bone in the amputation stump, while the other end passes through the subcutaneous soft tissue and skin to connect with the external prosthesis, enabling amputees to obtain proprioception and bone sensation through bone conduction.

[0003] Currently, two types of osseointegrated prostheses are commonly used in clinical practice: OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) and OPL (Osseointegration Prosthetic Limb). OPRA osseointegrated prostheses insert a threaded cylindrical implant into the medullary cavity of the residual limb, relying on the threads to lock the implant to the bone and prevent sinking after long-term implantation. However, the medullary cavity needs to be tapped before implanting the threaded implant. For irregular tubular medullary cavities, machining complete, continuous, and precisely matched threads during surgery is difficult and time-consuming, affecting surgical efficiency and safety.

[0004] OPL osseointegrated prostheses employ an interference fit between the cylindrical prosthesis and the medullary cavity to achieve initial mechanical compression stability. However, the stepped structure on the cylindrical prosthesis used to mate with the stump end face results in a larger percutaneous stoma opening after implantation, and this stepped structure is prone to slippage in the percutaneous area, thereby increasing the risk of infection at the percutaneous stoma site.

[0005] To address the shortcomings of the existing technology, this invention proposes a tapered-locking osseointegrated prosthesis. This prosthesis features an array of fixation ridges around its periphery, which can be inserted into the bone to achieve compression fixation and provide anti-rotation capability. Simultaneously, the tapered locking design prevents sinking, thereby reducing the likelihood of post-implantation displacement, lowering the requirements for intraosseous cavity processing, simplifying surgical procedures, reducing surgical difficulty, and shortening intraoperative time. After implantation, the prosthesis forms an intraosseous gap with the stump end face, facilitating skin-bone interface integration, thereby reducing percutaneous stoma size, preventing percutaneous slippage, and ultimately lowering the risk of infection at the stoma site. Summary of the Invention

[0006] This invention addresses the aforementioned problems by providing a tapered-locking osseointegrative prosthesis. This prosthesis achieves fixation between the implant and the medullary cavity through a press-fit method and utilizes a tapered structure to prevent subsidence, thereby effectively reducing surgical difficulty and shortening intraoperative time. Furthermore, after implantation, this prosthesis forms a structure conducive to skin-bone interface integration, preventing slippage at the percutaneous stoma and reducing the occurrence of infection.

[0007] To address the aforementioned problems, this invention provides a tapered-locking osseointegrated prosthesis, characterized by comprising: an implantable prosthesis, a percutaneous device, and an abutment screw; wherein, the implantable prosthesis is used for implantation into the medullary cavity of the stump bone in an amputee patient; the periphery of the implantable prosthesis is provided with multiple axially extending fixation ridges, which achieve fixation of the implantable prosthesis within the bone and provide anti-rotation capability through press-fitting with bone tissue; the implantable prosthesis is provided with multiple tapered locking structures, which are used to prevent axial sinking of the implantable prosthesis after implantation; the periphery of the implantable prosthesis is provided with multiple arrayed irrigation holes, which communicate with an irrigation chamber provided inside the implantable prosthesis; one end of the percutaneous device is provided with an anti-rotation structure and a tapered locking structure, which are used to cooperate with corresponding structures within the implantable prosthesis to achieve anti-rotation and tapered-locking connection between the percutaneous device and the implantable prosthesis; the abutment screw passes through the percutaneous device and connects to a threaded hole within the implantable prosthesis to achieve a pressurized and fixed connection between the percutaneous device and the implantable prosthesis.

[0008] The present invention also provides a method for using the above-mentioned tapered locking osseointegrated prosthesis, characterized in that it includes: using a fixation ridge provided on the periphery of the implanted prosthesis to fix the implanted prosthesis in the medullary cavity by press fitting, and using a tapered locking structure on the implanted prosthesis to restrict its axial sinking; introducing fluid through a flushing chamber communicating with the interior of the implanted prosthesis and a flushing hole provided on the periphery to flush the implanted area; and using a percutaneous device to cooperate with the anti-rotation structure and tapered locking structure in the implanted prosthesis, and using a base screw to achieve a fixed connection between the percutaneous device and the implanted prosthesis for connection with an external prosthesis.

[0009] This invention provides a tapered-locking osseointegrated prosthesis. The tapered locking structure achieves stable fixation of the implant, thereby reducing intraoperative difficulty and shortening intraoperative time. Simultaneously, by constructing a skin-bone interface after implantation, it promotes biomechanical interlocking between the skin and the residual limb bone end face, effectively preventing slippage and granulation tissue formation at the percutaneous stoma site. Furthermore, this invention further reduces the risk of infection at the percutaneous stoma site by optimizing the materials and surface treatment processes of the percutaneous device. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of an embodiment of the present invention where an osseointegrated prosthesis is implanted into the stump bone of an amputee patient;

[0011] Figure 2 This is a schematic diagram of the overall structure of the implanted prosthesis with a double-cone stepped structure in one embodiment of the present invention from different perspectives;

[0012] Figure 3 yes Figure 2 A schematic cross-sectional view of the implanted prosthesis shown.

[0013] Figure 4 This is a schematic diagram of the overall structure of a single-cone implantable prosthesis in one embodiment of the present invention from different perspectives;

[0014] Figure 5 yes Figure 4 A cross-sectional schematic diagram of the implanted prosthesis with a single cone structure shown.

[0015] Figure 6 This is a schematic diagram of the primary implantation of an osseointegrated prosthesis into the medullary cavity of the residual limb in one embodiment of the present invention;

[0016] Figure 7 This is a schematic diagram of the assembly and explosion of the components used for implantation into the medullary cavity of the residual limb in a first-stage surgery according to an embodiment of the present invention;

[0017] Figure 8 These are an isometric view and a sectional view of a transdermal device according to an embodiment of the present invention;

[0018] Figure 9 This is a schematic diagram of the base screw structure in one embodiment of the present invention. Detailed Implementation

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily understand the present invention.

[0020] This document only describes the parts necessary for understanding the technical content of the present invention, and the description of the remaining parts will be omitted to avoid confusion about the essence of the present invention. This should be noted. Moreover, in this process, for the sake of clarity and convenience of description, the thickness of the lines or the size of the constituent elements shown in the figures may be exaggerated.

[0021] The terminology used herein is for describing embodiments and is not intended to limit or restrict the invention. When describing a component as being "connected," "combined," or "joined" with another component, this includes not only direct connections but also indirect connections where other components are present in between. Furthermore, terms such as "comprising," "including," or "having" indicate the presence of features, numbers, steps, operations, components, or combinations thereof described in the specification, and do not exclude the existence or additional possibility of one or more other features, numbers, steps, operations, components, or combinations thereof. Additionally, terms such as "first" and "second," which may be used herein, are used only to distinguish one component from another and, unless specifically stated otherwise, do not limit the order or importance of the components. Therefore, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0022] The structure and method of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of an osseointegrated prosthesis implanted in the stump bone of an amputee patient according to one embodiment of the present invention.

[0024] like Figure 1 As shown, an osseointegrated prosthesis is implanted into the stump bone of an amputee. The osseointegrated prosthesis includes an implant, percutaneous devices, and abutment screws.

[0025] The implantable prosthesis is used to be inserted into the medullary cavity of the residual bone. It has at least three fixation ridges evenly distributed around its circumference. The fixation ridges fix the implantable prosthesis in the bone through press-fitting with the bone tissue and provide anti-rotation capability. The implantable prosthesis has a tapered overall shape. After being inserted into the bone, the tapered structure locks the implant in place, thereby preventing axial sinking.

[0026] An array of irrigation holes is provided around the implanted prosthesis. During the implantation process, sterile low-temperature saline solution is introduced to irrigate the implantation area to reduce bone temperature and remove bone debris, thereby creating conditions for bone cells to attach to the surface of the implant after the prosthesis is implanted into the bone.

[0027] The implanted prosthesis and the percutaneous device are connected by a hexagonal anti-rotation structure and a tapered locking structure. The abutment screw passes through the percutaneous device and is screwed into a threaded hole in the implanted prosthesis to achieve a fixed connection between the percutaneous device and the implanted prosthesis.

[0028] Figure 2 This is a diagram showing the overall structure and cross-sectional position of the implanted prosthesis with a double-cone stepped structure in an embodiment (Scheme 1) of the present invention from different perspectives; Figure 3 It shows along Figure 2 The diagram shows the cross-sectional views of the implanted prosthesis obtained by cutting lines AA, BB, CC, DD, EE, and FF.

[0029] like Figure 2 and Figure 3 As shown, in this embodiment, the implant is an osteointegrated implant with a tapered locking structure. It has an elongated shape and is used for implantation into the medullary cavity of the stump bone in amputees. The outer periphery of the implant has more than three evenly distributed fixation ridges arranged in an axial array; in this embodiment, eight ridges are shown. Each fixation ridge extends along the axial direction of the implant and gradually narrows distally.

[0030] In this embodiment, the tooth tip width of each fixation ridge is 1-3 mm, and the tooth root width is 1-6 mm. The tooth tip width and tooth root width of each fixation ridge can be the same or different. Through the press-fit between the fixation ridge and the bone tissue, initial stable fixation of the implanted prosthesis within the bone is achieved, providing anti-rotation capability. Along Figure 2 The sectional view shown is obtained by cutting along the EE section line. Figure 3 As shown in EE, the outer side of the fixed spine forms an outer ridge taper, which is between 1° and 5°. The example shown is 2.5°, which allows the implanted prosthesis to gradually form a stable radial pressure force during the process of being pressed into the medullary cavity, thereby further improving the implantation stability.

[0031] In this embodiment, the inner core of the implanted prosthesis uses a double-cone stepped structure to achieve taper locking. For example... Figure 3 As shown in the FF cross-sectional view, the inner core of the implanted prosthesis sequentially forms a first frustum structure and a second frustum structure. The first frustum structure and the second frustum structure have the same taper or the first taper is slightly larger than the second taper. In the embodiment, the taper is the same, both being 2.5°. Through the double-cone step configuration of the inner core, a reliable taper lock is formed after implantation to prevent the implanted prosthesis from sinking axially within the bone.

[0032] like Figure 3 As shown, along Figure 2 The cross-sections taken by the AA, BB, CC, and DD sections show the internal structure at different locations proximal to the implanted prosthesis: In the AA section, the proximal inner hole forms a tapered locking structure for engaging with the tapered locking part of the percutaneous device; in the BB section, a hexagonal anti-rotation structure is provided for engaging with the hexagonal anti-rotation part of the percutaneous device to prevent relative rotation; in the CC section, a transition hole is provided as a connecting segment, which communicates with the distal irrigation chamber; in the DD section, the irrigation chamber structure inside the implanted prosthesis is visible, used to contain and distribute irrigation fluid.

[0033] At the same time, such as Figure 2 and Figure 3 As shown, multiple irrigation holes are arrayed around the periphery of the implanted prosthesis. In this embodiment, there are 24 irrigation holes, distributed along the axial and circumferential directions of the implanted prosthesis and connected to the irrigation chamber inside the implanted prosthesis. During the implantation procedure, sterile low-temperature saline is introduced into the implantation area through the irrigation holes to continuously irrigate the area, effectively reducing the temperature of the bone tissue and removing bone debris generated during implantation. This creates favorable conditions for the attachment of osteocytes to the surface of the implant after the prosthesis is implanted into the bone. Furthermore, drugs or implanted bone materials can be injected into the medullary cavity through the irrigation holes and the connected irrigation chamber, and the medullary cavity can be used for irrigation treatment in case of post-implantation infection.

[0034] Figure 4 This is a schematic diagram of the overall structure of a single-cone implantable prosthesis in one embodiment of the present invention from different perspectives; Figure 5 yes Figure 4 The diagram shows a cross-sectional view of the implanted prosthesis with a single cone structure.

[0035] like Figure 4 and Figure 5As shown, this embodiment provides an osteointegrated implant prosthesis with a tapered locking structure. As a second option, its overall structure, functional composition, and usage are basically the same as those of the first option. The main difference lies in the tapered form of the implanted prosthesis core and the tapered parameter settings of the peripheral fixation ridge.

[0036] like Figure 4 The A–A section position shown and Figure 5 The cross-sectional structure shown in this embodiment indicates that the inner core of the implanted prosthesis adopts a single-cone structure with a taper between 1° and 5°, and 3° is shown in this embodiment. After the implanted prosthesis is inserted into the medullary cavity, the taper lock is formed by the engagement of the conical surfaces between the inner core single-cone structure and the corresponding structure, thereby preventing the implanted prosthesis from sinking axially within the medullary cavity.

[0037] like Figure 4 As shown in the B–B section, the inner core of the implanted prosthesis is provided with a hexagonal anti-rotation structure. The hexagonal anti-rotation structure is used to cooperate with the corresponding hexagonal structure on the percutaneous device or spacer to achieve an anti-rotation connection between the implanted prosthesis and the percutaneous device or spacer.

[0038] like Figure 4 The C–C section shown indicates that a transition hole structure is provided in the middle of the inner core of the implanted prosthesis. The transition hole is used to connect the irrigation chamber with other functional structures of the inner core and serves as a structural transition and flow guide.

[0039] like Figure 4 As shown in the D–D section, the implanted prosthesis has an internal irrigation chamber. The irrigation chamber is used to communicate with an external irrigation system during the implantation process to introduce sterile low-temperature saline to rinse and cool the implantation area, and to remove bone debris generated during the implantation process.

[0040] like Figure 4 and Figure 5 As shown, at least three fixation ridges are arranged axially around the periphery of the implanted prosthesis; in this embodiment, eight ridges are shown. These fixation ridges extend axially along the implanted prosthesis. Each fixation ridge has a tapered structure with a taper between 1° and 5°; in this embodiment, it is 2°. Through the compression fit between the fixation ridges and the bone tissue, the implanted prosthesis gradually develops a stable radial compression force during implantation, thereby achieving stable fixation of the implanted prosthesis within the bone and providing anti-rotation capability.

[0041] like Figure 4 and Figure 5As shown, a plurality of irrigation holes are arrayed on the outer periphery of the implanted prosthesis. The number of irrigation holes is 24. These holes are distributed along the axial and circumferential directions of the implanted prosthesis and communicate with the irrigation chamber inside the implanted prosthesis. During the implantation procedure, sterile, low-temperature saline solution can be introduced into the implantation area through these irrigation holes to continuously irrigate the area, thereby lowering the bone tissue temperature and removing bone debris. This creates favorable conditions for osteocyte adhesion to the implant surface after the prosthesis is implanted into the bone.

[0042] like Figure 5 As shown in the E–E section, the outer periphery of the implanted prosthesis has a tapered shape, which allows the implanted prosthesis to gradually form a stable radial pressure force during the process of being pressed into the medullary cavity, which is beneficial to improving the mechanical stability in the early stage of implantation.

[0043] like Figure 5 As shown in the F–F section, the inner core single-cone structure of the implanted prosthesis extends axially with a taper of 3°, and together with the taper locking structure, achieves axial locking of the implanted prosthesis within the bone.

[0044] Therefore, the implantable prosthesis of the present invention can adopt a single cone structure, a double cone step structure or a combination thereof according to different application requirements, thereby forming a variety of tapered locking structures to prevent the implantable prosthesis from sinking axially after implantation.

[0045] The implants in both Scheme 1 and Scheme 2 have the same internal structural design, with an irrigation chamber, transition hole, hexagonal anti-rotation structure and tapered locking structure inside the implant.

[0046] Regarding specific parameter settings, the length of the implanted prosthesis ranges from 80 to 200 mm; the anti-rotation structure is not limited to common anti-rotation structures such as triangles, quadrilaterals, and hexagons, but a hexagon is shown in the embodiment; the depth of the anti-rotation structure is between 4 and 12 mm; and the cone length of the tapered locking structure is between 10 and 20 mm.

[0047] The implant prostheses in both Option 1 and Option 2 maintain consistency in material selection and processing methods. The implant prostheses can be processed using 3D printing or machining. The implant prosthesis material is commercially pure titanium (Cp-Ti) or titanium alloy (Ti-6Al-4V), which possesses good biocompatibility and an elastic modulus closer to that of human cortical bone than stainless steel and cobalt-chromium alloys, thus facilitating mechanical adaptation.

[0048] In one embodiment, the surface of the implant prosthesis may be coated with a coating that promotes osteoconduction. The coating material may be hydroxyapatite (HA) or tricalcium phosphate (TCP). The thickness of the HA coating is 70–200 μm, and the thickness of the TCP coating is generally 5–20 μm. Alternatively, after the implant prosthesis substrate is sandblasted or vacuum plasma sprayed, a chemical coating (HA or TCP) that promotes osseointegration may be applied by vacuum plasma or electrophoresis.

[0049] In another embodiment, the surface morphology of the implant prosthesis can be modified to form a micron- or nano-scale topological structure to promote bone ingrowth. The surface morphology modification can be achieved through sandblasting / acid etching (SLA) or 3D printing of porous structures. Sandblasting / acid etching uses physical or chemical methods to create micron- and nano-scale rough structures on the implant prosthesis surface; 3D printing of porous structures can employ electron beam melting (EBM) technology to create controllable and interconnected pores on the implant prosthesis surface, with a pore size ranging from 200 to 600 μm.

[0050] Figure 6 This is a schematic diagram of the primary implantation of an osseointegrated prosthesis into the medullary cavity of the residual limb in one embodiment of the present invention; Figure 7 This is a schematic diagram of the assembly and explosion of the components used for implantation into the medullary cavity of the residual limb in a first-stage surgery according to an embodiment of the present invention.

[0051] like Figure 6 and Figure 7 As shown, in this embodiment, the surgical implantation process of the osseointegration prosthesis is divided into two stages: the implantation and closure stage of the prosthesis, and the installation stage of the percutaneous device.

[0052] Phase 1: Implantation and Sealing of the Prosthesis

[0053] Before the surgery, the diameter, length and cortical bone thickness of the medullary cavity of the residual limb are measured and evaluated based on computed tomography (CT) and X-ray images of the patient's residual limb, and the diameter and length parameters of the implanted prosthesis are selected according to the measurement results.

[0054] Under general anesthesia, an incision was made at the distal end of the residual limb to expose the bone ends. Subsequently, a series of reamers were used to progressively expand the medullary cavity of the residual limb along the bone axis until the predetermined size corresponding to the selected implantable prosthesis was reached. Throughout the reaming process, the reamed area was continuously flushed and cooled with sterile saline to prevent thermal necrosis of the bone tissue due to temperature rise.

[0055] After the medullary reaming procedure is completed, the implant is inserted into the expanded medullary cavity by pressing and fitting, so that the implant gains initial mechanical stability through the pressing and fitting between the peripheral fixation spine and bone tissue.

[0056] Subsequently, as Figure 6 As shown, sterile saline solution is connected to the irrigation chamber inside the implanted prosthesis via a pump, and the implanted area is rinsed and cooled through the irrigation chamber and the irrigation port connected to it. After rinsing, a sealing screw is screwed into the threaded hole in the implanted prosthesis to seal the irrigation chamber.

[0057] Next, the spacer is inserted into the implanted prosthesis. (Example) Figure 7 As shown, the outer side of the spacer post is provided with an anti-rotation structure and a tapered locking structure, wherein the tapered locking structure is a Morse taper structure. The retaining ring is pressed to the end position of the spacer post, and the fixing screw is passed through the inner hole of the retaining ring and the inner hole of the spacer post in sequence and screwed into the threaded hole in the implanted prosthesis, thereby achieving the closed fixation of the medullary cavity end of the implanted prosthesis.

[0058] After completing the above implantation and closure procedures, the muscles, fascia, and skin are sutured in layers to ensure that the implanted prosthesis is completely encased in the body, with no other components remaining outside the body.

[0059] like Figure 6 As shown, in this embodiment, after the implanted prosthesis is inserted into the medullary cavity, a gap of approximately 5mm-30mm is formed between its tail and the end face of the residual limb bone. This medullary cavity gap can be filled with cancellous bone particles with a particle size of 2-5mm. The skin closes and adheres tightly to the end face of the residual limb bone, thereby constructing a skin-bone interface to achieve biomechanical interlocking between the skin and bone tissue.

[0060] Phase Two: Installation of Transdermal Devices

[0061] The second stage of surgery is performed after the first stage of surgery is completed and the expected healing period has elapsed.

[0062] A small incision is made at the skin of the stump to remove the fixation screws, retaining rings, and spacer inserted during the first stage of the surgery. The percutaneous device is then inserted through the skin incision and aligned with the corresponding structure within the implanted prosthesis.

[0063] like Figure 7 As shown, the abutment screw passes through the inner hole of the percutaneous device and is screwed into the internal threaded hole in the implanted prosthesis, thereby achieving a fixed connection between the percutaneous device and the implanted prosthesis, so that the percutaneous device is stably fixed on the implanted prosthesis for subsequent connection with the external prosthesis.

[0064] Figure 8 This is an isometric view and a sectional view of a transdermal device according to an embodiment of the present invention.

[0065] like Figure 8 As shown, in this embodiment, the percutaneous device includes a percutaneous segment, a hexagonal anti-rotation structure, a tapered locking structure, and a locking structure.

[0066] The percutaneous device is arranged axially, with one end being the proximal end for connection to the implanted prosthesis and the other end being the distal end for passing through the skin and connecting to the external prosthesis.

[0067] like Figure 8 As shown, the proximal outer side of the percutaneous device is provided with a hexagonal anti-rotation structure and a tapered locking structure. The hexagonal anti-rotation structure is used to cooperate with the corresponding hexagonal anti-rotation structure in the implanted prosthesis to limit the relative rotation of the percutaneous device with respect to the implanted prosthesis. The tapered locking structure is used to cooperate with the corresponding tapered structure in the implanted prosthesis to form a tapered locking connection, thereby improving the stability of the connection between the percutaneous device and the implanted prosthesis.

[0068] like Figure 8 As shown, the percutaneous device has a through hole running through its interior along the axial direction for the abutment screw to pass through, so as to achieve a fixed connection between the percutaneous device and the implanted prosthesis.

[0069] In this embodiment, a locking structure is provided at the distal end of the percutaneous device to cooperate with the base screw to lock and fix the percutaneous device.

[0070] like Figure 8 As shown, the transdermal device includes a transdermal segment that is disposed through the skin in use to construct a transdermal channel.

[0071] In this embodiment, the percutaneous device can be made of titanium or titanium alloy, which possesses good biocompatibility and mechanical properties. In another embodiment, molybdenum-rhenium alloy can also be used. In yet another embodiment, the percutaneous device can also be made of implantable metal alloys with good biocompatibility, such as titanium-copper alloy. Compared to titanium alloy, molybdenum-rhenium alloy has higher strength and stiffness, thus allowing for a further reduction in the overall size of the percutaneous device while ensuring sufficient structural strength to resist bending and deformation during daily activities. Reducing the size of the percutaneous device helps to decrease the size of the percutaneous stoma, thereby lowering the risk of infection at the stoma site.

[0072] The transdermal device can be manufactured by machining or 3D printing.

[0073] In this embodiment, the percutaneous segment of the percutaneous device can be surface-treated through various processing techniques to promote soft tissue sealing and improve resistance to infection. The surface treatment techniques include at least one of the following:

[0074] Precision polishing is used to achieve a mirror or sub-mirror finish on the surface of the transdermal segment, thereby reducing the initial adhesion of bacteria.

[0075] Laser micromachining is used to create specific microgrooves or micropore arrays on the surface of the percutaneous segment. These arrays are sized to the cellular scale and are used to guide fibroblasts to align in an orderly manner, forming collagen cuffs, while inhibiting the downward migration of epithelial cells.

[0076] By covalently grafting extracellular matrix proteins such as collagen and fibronectin, or antimicrobial peptides, onto the surface of the percutaneous segment, cell behavior can be actively regulated and antimicrobial properties enhanced.

[0077] Anodizing is used to form an array of titanium dioxide nanotubes on the surface of the transdermal segment, which can be used to load and release antibiotics or growth factors.

[0078] By constructing a pH-responsive smart coating to suppress percutaneous ostomy infection, positively charged chitosan (a pH-sensitive material) and negatively charged vancomycin-loaded mesoporous silica nanoparticles are alternately deposited on its surface to form a multilayer film, which is then grafted with polyethylene glycol (PEG) to form an antifouling top layer. During percutaneous ostomy infection, the local pH decreases, causing the chitosan to protonate and swell, while the PEG layer is destroyed, allowing the drug to be released and achieving sterilization. Furthermore, in another embodiment, a ceramic functional coating, such as a titanium-based nitride coating (including a titanium-niobium-nitrogen coating), can be applied to the surface of the percutaneous segment of the device to further improve wear resistance, biocompatibility, and anti-infection capabilities.

[0079] Figure 9 This is a schematic diagram of the base screw structure in one embodiment of the present invention.

[0080] like Figure 9 As shown, the base screw is set along the axial direction, with one end being the connection end and the other end being the operation end.

[0081] like Figure 9 As shown, the connecting end of the abutment screw is provided with an external thread for connecting with the corresponding internal thread hole in the implanted prosthesis, thereby realizing the threaded fixation between the abutment screw and the implanted prosthesis.

[0082] like Figure 9 As shown, the operating end of the abutment screw is provided with a wrench interface, which is used to apply a tightening torque to the abutment screw through a wrench, so that the abutment screw is fastened to the locking structure section of the percutaneous device, thereby realizing a reliable fixed connection between the percutaneous device and the implanted prosthesis.

[0083] This invention provides a tapered-locking osseointegrated prosthesis. The tapered locking structure achieves stable fixation of the implant, thereby reducing intraoperative difficulty and shortening intraoperative time. Simultaneously, by constructing a skin-bone interface after implantation, it promotes biomechanical interlocking between the skin and the residual limb bone end face, effectively preventing slippage and granulation tissue formation at the percutaneous stoma site. Furthermore, this invention further reduces the risk of infection at the percutaneous stoma site by optimizing the materials and surface treatment processes of the percutaneous device.

[0084] The scope of the claims of this invention is not limited to the specific embodiments described above. Various other embodiments, including modifications or alterations that can be made by those skilled in the art without departing from the spirit and intent of the invention as described in the claims, should also be included within the scope of the claims of this invention.

Claims

1. A tapered-locking osseointegrative prosthesis, characterized in that, include: Implanted prostheses, percutaneous devices, and abutment screws; in, The implantable prosthesis is used to be implanted into the medullary cavity of the stump bone of an amputee. The periphery of the implantable prosthesis is provided with multiple axially extending fixation ridges. The fixation ridges achieve fixation of the implantable prosthesis in the bone and provide anti-rotation capability through press-fit with the bone tissue. The fixation ridges are set with a tapered structure with a taper between 1° and 5°, so that the implantable prosthesis gradually forms a stable radial press-fit force during the process of being pressed into the medullary cavity. The implanted prosthesis is equipped with various tapered locking structures, which are either double-tapered stepped structures or single-tapered structures; the tapered locking structures are used to prevent the implanted prosthesis from sinking axially after implantation; The implanted prosthesis has multiple arrayed irrigation holes on its outer periphery. These irrigation holes are arranged in an array along the axial and circumferential directions of the implanted prosthesis and can be used for intramedullary injection of drugs, implantation of bone materials, or irrigation treatment in case of intramedullary infection. The irrigation holes are connected to an irrigation chamber inside the implanted prosthesis. One end of the percutaneous device is provided with an anti-rotation structure and a taper locking structure, which are used to cooperate with the corresponding structures in the implanted prosthesis to achieve anti-rotation and taper locking connection of the percutaneous device relative to the implanted prosthesis. The abutment screw passes through the percutaneous device and connects to the threaded hole in the implanted prosthesis to achieve a pressure-fixed connection between the percutaneous device and the implanted prosthesis. After the implanted prosthesis is implanted into the medullary cavity, a gap of 5mm-30mm is formed between its tail and the end face of the residual limb bone. The gap in the medullary cavity can be filled with cancellous bone particles with a particle size of 2-5mm. The skin closes and adheres tightly to the end face of the residual limb bone, thereby constructing a skin-bone interface to achieve biomechanical interlocking between the skin and bone tissue.

2. The taper-locking osseointegrated prosthesis as described in claim 1, characterized in that, The fixation ridges are distributed in a circumferential array along the implanted prosthesis, and the number of fixation ridges is not less than 3.

3. The taper-locking osseointegrated prosthesis as described in claim 2, characterized in that, The fixed ridge has a structure that gradually narrows from the tooth root to the tooth tip to form a press-fit fixation.

4. The taper-locking osseointegrated prosthesis as described in claim 1, characterized in that, The materials of the percutaneous device include, but are not limited to, implantable metal materials such as titanium, titanium alloy, molybdenum-rhenium alloy, and titanium-copper alloy.

5. The taper-locking osseointegrated prosthesis as described in claim 1, characterized in that, The percutaneous segment of the percutaneous device has a surface condition formed by surface treatment, which is used to promote soft tissue sealing and improve resistance to infection.

6. The taper-locking osseointegrated prosthesis as described in claim 5, characterized in that, Surface treatment processes include at least one or a combination of the following: precision polishing, laser micromachining, biomolecular coating, anodizing, titanium-niobium-nitrogen coating, and functionalized antibacterial coating.

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