Hip spacer

Abstract

The application relates to the technical field of medical devices, in particular to a hip joint spacer. The hip joint spacer comprises a spacer head, a femoral stem connected with the spacer head, Kirschner wires arranged in the spacer head and the femoral stem, an inner layer of the spacer head, an outer layer wrapped outside the inner layer, a through hole arranged on the outer layer to form a reserved channel, and the outer layer is communicated with the inner layer through the reserved channel. Compared with the prior art, the hip joint spacer has the advantages that the spacer head has an inner layer and an outer layer, the inner layer and the outer layer are made of different materials, the release time of antibiotics can be prolonged, the hip joint can maintain a high concentration of antibiotics, Kirschner wires are arranged in the spacer head and the femoral stem, the hip joint spacer has better mechanical strength than the prior art, can bear the weight of a patient, and can support the walking ability of the patient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a hip joint spacer. BACKGROUND

[0002] Deep infection after artificial hip joint replacement is a disastrous complication. Once the infection occurs, it is disastrous for the patient and a nightmare for the doctor. Through the unremitting efforts of scholars at home and abroad, the treatment of infection has experienced the exploration from the first stage revision to the second stage revision. The first stage surgery removes the artificial hip joint prosthesis and performs thorough debridement. The second stage surgery is the second surgery after the infection is controlled. At this time, a new prosthesis will be implanted. Clinical shows that after debridement in the first stage surgery, the empty space of the removed prosthesis should be occupied by other objects, otherwise the soft tissue around the joint will contract, which will cause difficulties for the second stage surgery. Therefore, the hip joint spacer is born. Through clinical verification, the hip joint spacer plays a significant role in dealing with this tricky complication. At present, using a joint type antibiotic spacer for second stage revision surgery has become an internationally recognized method.

[0003] In the hip joint infection revision surgery, the previous joint prosthesis is usually removed first. At this time, a huge cavity consistent with the shape of the prosthesis will be left inside the joint, and some bacteria and infectious substances will be left around the cavity. Therefore, doctors usually use antibiotic-containing bone cement to manually knead a spacer. The shape of the spacer is roughly the same as that of the cavity. After the spacer is placed in the cavity, the spacer surgery is completed, thereby achieving the purpose of controlling infection. The shape of the manually made spacer is irregular, and it is not convenient to install.

[0004] The current hip joint spacer is mostly made of bone cement and has a whole layer structure. The release time of antibiotics in the bone cement is short, and the concentration of antibiotics decreases quickly. It cannot maintain a high concentration of antibiotics in the hip joint for a long time. At the same time, the current hip joint spacer cannot completely bear weight and walk, nor can it bear weight for a long time. It is easy to break and cause secondary injury to the patient.

[0005] Based on this, the present application provides a hip joint spacer to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a hip joint spacer. The present application is integrally made by using a mold. The shape of the spacer is regular. The present application adopts a double-layer structure, which can prolong the release time of antibiotics, maintain a high concentration of antibiotics in the hip joint for a long time, and use Kirschner wires as the framework inside the spacer to enhance the mechanical strength of the spacer, which can bear the weight of the patient and ensure the daily walking function of the patient. The present application solves the problems raised in the background.

[0007] To solve the above problems, the present application provides the following technical solutions:

[0008] A hip joint spacer, comprising a spacer head, and a femoral stem connected with the spacer head, wherein a Kirschner wire is arranged in the spacer head and the interior of the femoral stem;

[0009] The spacer head comprises an inner layer and an outer layer wrapped outside the inner layer, wherein a through hole is arranged on the outer layer, the through hole forms a reserved channel in the outer layer, and the outer layer is in communication with the inner layer through the reserved channel.

[0010] The hip joint spacer provided by the present application also has the following technical features:

[0011] Further, the femoral stem is composed of a proximal femur and a distal femur, and the diameter of the proximal femur gradually decreases to the distal femur.

[0012] Further, the inner and outer layers of the spacer head are spherical structures, and the diameter of the inner layer is at least 1 cm.

[0013] Further, the diameter of the reserved channel is smaller than the diameter of the inner layer.

[0014] Further, the outer layer is made of antibiotic bone cement material, and the inner layer is made of antibiotic calcium sulfate material.

[0015] Further, the Kirschner wire is divided into a first Kirschner wire and a second Kirschner wire, the first Kirschner wire and the second Kirschner wire are respectively located on the inner side and the outer side of the interior of the hip joint spacer, the first Kirschner wire and the second Kirschner wire are located in the hip joint spacer and enclose a circle, and the diameter of the first Kirschner wire and the second Kirschner wire is at least 3 mm.

[0016] Further, the hip joint spacer is integrally formed in a mold.

[0017] Further, the number of the reserved channels is four, and the reserved channels form a cross shape in the spacer head.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] 1) The hip joint spacer head adopts a double-layer structure, the inner and outer layers are made of different materials, and a reserved channel is arranged, so that the inner layer can contact with the liquid in the hip joint cavity, the inner layer can be dissolved, and the antibiotic can be released from the outer layer after about one week, the inner layer can start to release the antibiotic, and the high concentration of antibiotic in the hip joint can be effectively maintained.

[0020] 2) The hip joint spacer has Kirschner pins placed inside the product as a framework, which can simulate the structure of the tension trabecula and pressure trabecula in the femoral head, bear pressure and tension, have better mechanical strength than existing products, can bear the weight of the patient, and can maintain the walking ability of the patient. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0022] Figure 1 It is a schematic diagram of the overall structure of the hip joint spacer of the present application.

[0023] Figure 2 It is a sectional view of the hip joint spacer of the present application.

[0024] Figure 3 It is a sectional view of the head of the hip joint spacer of the present application.

[0025] In the drawings:

[0026] 1 - spacer head, 11 - outer layer, 12 - inner layer, 13 - reserved channel, 2 - femoral stem, 21 - proximal femur, 22 - distal femur, 3 - Kirschner pin, 31 - first Kirschner pin, 32 - second Kirschner pin. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0029] In the description of the present application, it should be noted that the terms "first", "second", etc. are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

[0030] The drawings needed to be used in the following embodiment description will be briefly introduced below in combination with the drawings. Figure 1 to the drawings Figure 3 The present application will be discussed in detail below in combination with specific embodiments:

[0031] The application provides a hip joint spacer, which comprises a spacer head 1 at the top end of the hip joint spacer and a femoral stem 2 connected with the spacer head 1, the hip joint spacer is similar in shape to an artificial hip joint prosthesis, and is used for playing a role of spacer support and antibiotic release after the original prosthesis in the human body is removed when a primary debridement is performed on a periprosthetic hip joint infection, and avoiding the soft tissues around the joint from being contracted after the original hip joint prosthesis is removed, thereby causing difficulty in subsequent surgery. Kirschner wires 3 are arranged in the spacer head 1 and the femoral stem 2, the Kirschner wires 3 are used for simulating human body tension trabeculae and pressure trabeculae in the hip joint spacer of the embodiment, play a role of increasing the mechanical strength of the hip joint spacer, and enable the hip joint spacer to support the body weight of the patient and maintain the walking ability of the patient after the hip joint spacer is implanted in the patient. In the embodiment, the spacer head 1 adopts a double-layer structure, the spacer head 1 is divided into an inner layer 12 and an outer layer 11 wrapped outside the inner layer 12, the outer layer 11 is an antibiotic bone cement material, the material is made by mixing antibiotics and bone cement, and the mixing ratio of the two materials and the type of the used antibiotics are not specifically limited and can be determined by the person skilled in the art as appropriate during production; the inner layer 12 is an antibiotic calcium sulfate material, the material is made by mixing calcium sulfate and antibiotics, and the mixing ratio of the two materials and the type of the used antibiotics are not specifically limited and can be determined by the person skilled in the art as appropriate during production. A through hole is arranged on the outer layer 11, the through hole forms a reserved channel 13 in the outer layer 11, the outer layer 11 communicates with the inner layer 12 through the reserved channel 13, the reserved channel 13 is only in the outer layer 11 and does not penetrate the inner layer 12, that is, the inner layer 12 can contact liquid in the hip joint cavity through the reserved channel 13. Within one week after the hip joint spacer is implanted in the human body, antibiotics are released from the outer layer 11 first, one week later, the inner layer 12 starts to dissolve by contacting liquid in the hip joint cavity of the human body through the reserved channel 13, thereby releasing antibiotics contained in the inner layer 12, the antibiotics released from the inner layer 12 are released into the hip joint cavity through the reserved channel 13, maintain a high concentration of antibiotics in the hip joint, and avoid the situation that bacteria cannot be effectively killed due to too fast reduction of the concentration of antibiotics, thereby causing infection of the patient.

[0032] In the embodiment, the femoral stem 2 is composed of a proximal femur 21 and a distal femur 22, the shape of the femoral stem 2 is simulated to the shape of a hip joint prosthesis, and the diameter of the proximal femur 21 to the distal femur 22 gradually decreases, thereby facilitating the hip joint spacer to be smoothly implanted in the human body.

[0033] The inner layer 12 of the placeholder head 1 in the embodiment is a spherical structure, and the regular shape is beneficial to the smooth movement of the patient after the hip placeholder is implanted in the human body, and the patient does not feel uncomfortable due to the hip placeholder in the human body, thereby affecting the movement of the patient.

[0034] The diameter of the reserved channel 13 is smaller than that of the inner layer 12, the liquid in the hip joint cavity contacts the inner layer 12 through the reserved channel 13, the antibiotic on the inner layer 12 is dissolved and released after one week, and then the antibiotic is transferred to the hip joint cavity through the reserved channel 13 to kill bacteria.

[0035] The Kirschner needle 3 is divided into a first Kirschner needle 31 and a second Kirschner needle 32, and the first Kirschner needle 31 and the second Kirschner needle 32 are located in the hip placeholder and surround a circle. The first Kirschner needle 31 and the second Kirschner needle 32 are located on the inner side and the outer side of the hip placeholder, respectively, for simulating the structure of the tension trabecula and the pressure trabecula in the femoral head, respectively bearing the pressure and tension of the patient, having a high enough mechanical strength to bear the weight of the patient, and being able to support the walking ability of the patient. The diameters of the first Kirschner needle 31 and the second Kirschner needle 32 are at least 3 mm, and a Kirschner needle 3 with a diameter of at least 3 mm can be used as a skeleton to support the function.

[0036] In the embodiment, the hip placeholder is integrally formed by a mold, which avoids the irregular shape of the manually made hip placeholder, is inconvenient to implant in the human body, and is prone to incomplete placeholder and dislocation.

[0037] In the embodiment, the number of the reserved channels 13 is four, and the reserved channels 13 form a cross shape in the placeholder head 1.

[0038] In the manufacturing process, first, the internal structure 12 of the hip placeholder is manufactured, calcium sulfate and antibiotics are mixed to form a spherical structure with a diameter of about 1 cm, a Kirschner needle 3 with a diameter of 3 mm is pre-bent in the mold, an outer layer 11 is prepared by mixing antibiotics and bone cement, the antibiotics containing bone cement are filled into the mold, the Kirschner needle 3 skeleton and the inner layer 12 are placed, and a double-layer hip placeholder is manufactured.

[0039] When a doctor performs a hip joint infection revision surgery, the original infected prosthesis in the human body is removed, all residual foreign bodies in the hip joint are removed, the infected hip joint is thoroughly debrided, and the acetabular bone surface and femoral marrow cavity are flushed. The hip placeholder can be implanted in the hip joint of the human body.

[0040] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A hip spacer, characterized by: The hip joint spacer comprises a spacer head and a femoral stem connected with the spacer head, and Kirschner wires are arranged in the spacer head and the interior of the femoral stem; The spacer head comprises an inner layer and an outer layer wrapped outside the inner layer, and through holes are arranged on the outer layer to form reserved channels in the outer layer, and the outer layer communicates with the inner layer through the reserved channels; The outer layer is made of antibiotic bone cement material, and the inner layer is made of antibiotic calcium sulfate material; The number of the reserved channels is four, and the reserved channels form a cross shape in the spacer head; The Kirschner wires are divided into first Kirschner wires and second Kirschner wires, the first Kirschner wires and the second Kirschner wires are located in the hip joint spacer and enclose a circle, the first Kirschner wires and the second Kirschner wires are located on the inner side and the outer side of the interior of the hip joint spacer respectively, and are used for simulating the structure of the tension trabecula and the pressure trabecula in the femoral head, and respectively bearing the pressure and the tension of the patient, the diameter of the first Kirschner wires and the second Kirschner wires is at least 3 mm; The reserved channels are only in the outer layer, and the inner layer is not penetrated, that is, the inner layer contacts the liquid in the hip joint cavity through the reserved channels; within one week after the hip joint spacer is implanted into the human body, the antibiotic is released from the outer layer first, and after one week, the inner layer starts to dissolve by contacting the liquid in the hip joint cavity of the human body through the reserved channels, so that the antibiotic contained in the inner layer is released, the antibiotic released from the inner layer is released into the hip joint cavity through the reserved channels, the high concentration of the antibiotic in the hip joint is maintained, and the situation that the bacteria cannot be effectively killed due to the too fast decrease of the antibiotic concentration and the patient is infected is avoided.

2. The hip spacer of claim 1, wherein: The femoral stem is composed of a proximal femur and a distal femur, and the diameter of the proximal femur gradually decreases to the distal femur.

3. The hip spacer of claim 1, wherein: The inner layer and the outer layer of the spacer head are spherical structures, and the diameter of the inner layer is at least 1 cm.

4. The hip spacer of claim 3, wherein: The diameter of the reserved channels is smaller than the diameter of the inner layer.

5. The hip spacer of claim 1, wherein: The hip joint spacer is integrally formed in a mold.

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