Alar bone body prosthesis facilitating ankle joint ligament reconstruction and neck body fixing and healing

Abstract

The invention relates to the technical field of medical prostheses, and particularly discloses a talus prosthesis facilitating ankle joint ligament reconstruction and neck body fixing and healing. According to the technical scheme, a three-point fixing mode of a fixing bolt and two locking screws is adopted for connection of the talus prosthesis and the section of the talus neck of the talus prosthesis, the layout, angle and size of the fixing bolt and the locking screws are accurately controlled, mechanical distribution is optimized, the stress concentration phenomenon is reduced, a trabecula structure is further arranged on the talus prosthesis, and therefore the mechanical distribution is optimized. The stability at the initial stage of the operation is ensured, and conditions are provided for bone tissue ingrowth, so that short-term and long-term biological fixation is realized, and the postoperative recovery of a patient as soon as possible is facilitated. Besides, by reserving a tendon reconstruction channel, a tendon suture hole and a ligament suture hole, ligament reconstruction and fixation can be conveniently carried out in an operation, so that the normal biomechanical structure and function of the ankle joint are recovered, the stability of the ankle joint is enhanced, and the living quality of a patient is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical prostheses, and in particular discloses a talus body prosthesis which is convenient for reconstruction of ankle joint ligaments and fixation and healing of the neck and body. Background Art

[0002] The talus is located in the center of the ankle joint and can be divided into three parts: head, neck, and body. It has a total of 7 articular surfaces. As a key structure connecting the lower leg and the foot, it is the hub for the body's gravity to be transmitted to the foot and has important biomechanical functions. Its stability and flexibility directly affect the function of the ankle joint and the patient's walking ability. However, it has no muscle tendon attachment, only ligament attachment.

[0003] Necrotic collapse of the talus is a common clinical problem, which brings serious functional impairment and decreased quality of life to patients. Surgical treatment mainly includes arthrodesis and prosthesis replacement. Among them, the advantages of arthrodesis are relatively simple operation and definite curative effect, but the disadvantages are long recovery time after surgery, loss of joint mobility of patients, great impact on life, and accelerated secondary degeneration of surrounding joints. Prosthesis replacement surgery is a good method for talus reconstruction and ankle function recovery. Talus body replacement provides a treatment option that can maintain the range of motion of the ankle joint while solving the patient's local pain.

[0004] The first talar prosthesis replacement surgery was reported in 1974. Due to the design defects of the prosthesis, the fixation failure and bone nonunion occurred at the junction of the talar prosthesis and the autologous talar neck. Because there is no ligament fixation between the transplanted talar prosthesis and the ankle joint, the transplanted talar prosthesis and the ankle joint are unstable, affecting the patient's daily life and exercise, aggravating the degeneration around the ankle joint, and further affecting the patient's rehabilitation process and long-term efficacy. Therefore, most scholars changed the design concept and designed a total talar replacement, but the total talar replacement will sacrifice the talonavicular joint, and if it fails, secondary revision is difficult. Summary of the invention

[0005] In order to solve the problems of fixation failure at the junction of the talar body prosthesis and the autologous talar neck, bone nonunion and joint instability after prosthesis transplantation caused by design defects of traditional talar body prostheses, the present invention proposes a talar body prosthesis that facilitates ankle ligament reconstruction and neck fixation and healing.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] A talar prosthesis for facilitating ankle ligament reconstruction and neck fixation and healing, comprising a talar prosthesis body and a locking screw made by 3D printing technology, wherein the morphology of the talar prosthesis body is obtained based on three-dimensional CT data of the affected ankle joint and adjacent joint surfaces, the talar prosthesis body is an entity consisting of a tibiotalar joint surface, a subtalar joint surface and a front end surface, the tibiotalar joint surface is adapted to the tibiotalar joint, the subtalar joint surface is adapted to the subtalar joint, the front end surface is a plane structure adapted to the osteotomy surface of the talar neck body of the autologous retained part, a cylindrical fixing bolt is fixedly provided at the center position of the front end surface, the fixing bolt is inserted into the center position of the talar neck body of the autologous retained part, a locking screw channel penetrating the talar prosthesis body is provided on both sides of the fixing bolt, an internal thread adapted to the external thread of the locking screw is provided in the locking screw channel, the locking screw extends from the front end surface through the locking screw channel to be connected to the talar neck body of the autologous retained part, and the fixing bolt and the two locking screws are opened in a "pin" shape toward the front end surface.

[0008] Furthermore, the front end surface and / or the surface of the fixing bolt is provided with a trabecular structure.

[0009] Furthermore, there is an angle between the central axis of the fixing bolt and any two central axes among the three central axes of the two locking screw channels.

[0010] Furthermore, the central axis of the fixing bolt is located in the vertical plane of the front end surface, the clockwise angle range between the central axis and the projection of the central axis on the front end surface is 60-90°, the clockwise angle range between the central axis of the locking screw channel and the projection of the central axis on the front end surface is 70-145°, and the angle range between the central axes of the two locking screw channels is 5-45°.

[0011] Furthermore, the diameter of the fixing bolt is 3-6 mm, the length of the fixing bolt is 6-15 mm, and the length of the locking screw is 6-25 mm.

[0012] Furthermore, a tendon-penetrating channel is provided between the inner side and the outer side of the talar prosthesis body, tendon suture holes are provided around the tendon-penetrating channel, and ligament suture holes are provided on the talar prosthesis body.

[0013] Furthermore, the diameter of the transtendon channel is 4-6mm, the diameter of the tendon suture hole is 1-3mm, the diameter of the ligament suture hole is 1-2mm, and a trabecular structure is provided around the inner wall of the transtendon channel and / or the end of the transtendon channel on the surface of the talar prosthesis body.

[0014] Furthermore, the number of the ligament suture holes is 2-20.

[0015] Further, a Kirschner wire through-hole penetrating through the front and back is provided above the locking screw channel.

[0016] Further, all the joint surfaces of the talar body prosthesis body are subjected to mirror high polishing treatment.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The present invention adopts a total of three connecting parts, namely a fixing bolt and two locking screws, which are arranged in a "pin" shape and open towards the front end face. This fixing method can improve the bonding strength between the prosthesis and the remaining part of the talar neck and body of the patient's own, ensuring the stability in the initial stage of the operation. The bone trabecular structure provided on the prosthesis provides conditions for the ingrowth of bone tissue, thereby achieving short-term and long-term biological fixation, which is beneficial to the patient's early recovery after the operation. In addition, by precisely controlling the angle, size of the fixing bolt, and the layout and size of the locking screws, the mechanical distribution is optimized, the stress concentration phenomenon is reduced, the service life of the prosthesis is increased, the incidence of postoperative complications such as pain and infection is reduced, and the possibility of iatrogenic fractures is also reduced.

[0019] 2. By reserving tendon reconstruction channels, tendon suture holes, and ligament suture holes, the present invention enables convenient ligament reconstruction and fixation during the operation, thereby restoring the normal biomechanical structure and function of the ankle joint. Moreover, a bone trabecular structure is provided on the inner wall of the tendon reconstruction channel and / or around the end of the tendon reconstruction channel on the surface of the talar body prosthesis to promote the attachment and growth of tendon and ligament tissues. This design enhances the stability of the ankle joint, helps to promote postoperative rehabilitation, and improves the quality of life of the patient.

[0020] 3. Through the three-point fixing structure and the design of ligament reconstruction and attachment, the stability of the prosthesis and the patient's own ankle joint can be improved, and the risks of loosening and falling off can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The three-dimensional structural schematic diagram when the talar body prosthesis of the present invention is applied is shown;

[0022] Figure 2 The three-dimensional structural schematic diagram of the talar body prosthesis of the present invention (the bone trabeculae are not shown) is shown;

[0023] Figure 3 The three-dimensional structural schematic diagram of the inner side of the talar body prosthesis of the present invention is shown;

[0024] Figure 4 The three-dimensional structural schematic diagram of the outer side of the talar body prosthesis of the present invention is shown;

[0025] Figure 5 The three-dimensional structural schematic diagram of the front end face of the talar body prosthesis of the present invention is shown;

[0026] Figure 6 A schematic diagram of the top view of the three-dimensional structure of the talar body prosthesis of the present invention when in use is shown; DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0028] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the invention.

[0029] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0030] See attached Figures 1 to 6, this embodiment provides a talar body prosthesis 111 facilitating ankle ligament reconstruction and fixation and healing of the neck and body parts, including a talar body prosthesis main body 1 made by 3D printing technology and locking screws 2. The shape of the talar body prosthesis main body 1 is obtained based on the three-dimensional CT data of the affected ankle joint and adjacent joint surfaces. The talar body prosthesis main body 1 is a solid body composed of a tibio-talar joint surface 3, a subtalar joint surface 4, and a front end surface 5. The tibio-talar joint surface 3 is adapted to the tibio-talar joint 31, the subtalar joint surface 4 is adapted to the subtalar joint 41, and the front end surface 5 is a planar structure and is adapted to the osteotomy surface 52 of the self-retained part of the talar neck and body 51. A cylindrical fixing bolt 6 is fixedly provided at the center position of the front end surface 5. The fixing bolt 6 is inserted into the center position of the self-retained part of the talar neck and body 51. On each side of the fixing bolt 6, there is a locking screw channel 7 penetrating the talar body prosthesis main body 1. The locking screw channel 7 is provided with internal threads adapted to the external threads of the locking screw. The locking screw 2 extends out from the front end surface 5 through the locking screw channel 7 and is connected to the self-retained part of the talar neck and body 51. The fixing bolt 6 and the two locking screws 2 are spread out in a "pin" shape towards the front end surface 5. The diameter of the fixing bolt 6 is 3 - 6 mm, and the diameter in this embodiment is 4.5 mm. The length of the fixing bolt 6 is 6 - 15 mm, and the length in this embodiment is 10 mm. The central axis of the fixing bolt 6 and the central axes of the two locking screw channels 7 form an angle between any two of the three central axes. The central axis of the fixing bolt 6 is located in a vertical plane perpendicular to the front end surface 5. The clockwise angle range between the central axis of the fixing bolt 6 and the projection of the central axis on the front end surface 5 is 60 - 90°, that is, the angle range between the central axis of the fixing bolt 6 and the projection line of the central axis below the prosthesis is 60 - 90°, and the angle in this embodiment is 90°. The angle range between the central axis of the locking screw channel 7 and the projection of the central axis on the front end surface 5 is 70 - 145°, that is, the angle range between the central axis of the locking screw channel 7 and the projection line of the central axis below the prosthesis is 70 - 145°, and the angle in this embodiment is 110°. The angle range between the central axes of the two locking screw channels 7 is 5 - 45°, and the angle in this embodiment is 25°. The length of the locking screw 2 is 6 - 25 mm, and the length in this embodiment is 16 mm. The angle and size of the fixing bolt 6 and the layout and size of the locking screw 2 are determined personalizedly according to the three-dimensional CT data of the affected ankle joint to adapt to the anatomical structures of different patients, achieve optimized mechanical distribution, reduce the stress concentration phenomenon. The front end surface 5 and the surface of the fixing bolt 6 are provided with a trabecular bone 8 structure, which provides conditions for bone tissue ingrowth. Thus, short-term and long-term biological fixation is realized, the service life of the talar body prosthesis 111 is improved, the incidence rate of postoperative complications such as pain and infection is reduced, and at the same time, the possibility of iatrogenic fractures is also reduced.

[0031] At least one tendon-penetrating channel 9 is provided between the inner and outer sides of the talar prosthesis body 1, and tendon suture holes 10 are provided around the tendon-penetrating channel 9. A plurality of ligament suture holes 11 are provided on the talar prosthesis body. The positions and number of the ligament suture holes 11 are determined according to the actual conditions of the affected ligaments of the patient. Generally, the number of ligament suture holes 11 is 2-20. In this embodiment, the number of tendon-penetrating channels 9 is 1, the number of tendon suture holes 10 is 4, and the number of ligament suture holes is 14. The tendon-penetrating channel 9 runs through the talar prosthesis body 1 to guide and promote ligament reconstruction. The diameter of the tendon-penetrating channel 9 is 4-6 mm, and the diameter of the tendon-penetrating channel 9 in this embodiment is 6 mm. The diameter of the tendon suture hole 10 is 1-3 mm, and the diameter of the tendon suture hole 10 in this embodiment is 2 mm. The diameter of the ligament suture hole 11 is 1-2 mm, and the diameter of the ligament suture hole 11 in this embodiment is 1.5 mm. The number, position and size of the tendon passage 9, the tendon suture hole 10 and the ligament suture hole 11 need to be individually optimized and designed according to the patient's tendon and ligament reconstruction needs to ensure the reconstruction effect. By reserving the tendon passage 9, the tendon suture hole 10 and the ligament suture hole 11, ligament reconstruction and fixation can be conveniently performed during surgery, thereby restoring the normal biomechanical structure and function of the ankle joint. In addition, a trabecular bone 12 structure is provided around the inner wall of the tendon passage 9 and the end of the tendon passage 9 on the surface of the talar body prosthesis body 1. This design can promote the attachment and growth of tendon and ligament tissues, which not only enhances the stability of the ankle joint and reduces the risk of loosening and falling off, but also helps to promote postoperative rehabilitation and improve the patient's quality of life.

[0032] A Kirschner wire through hole 13 is provided above the locking screw channel 7 and runs through the channel from front to back. The Kirschner wire through hole 13 intersects or is adjacent to the locking screw channel 7, which is convenient for intraoperative guidance and temporary fixation.

[0033] All articular surfaces on the talar prosthesis body 1 are subjected to mirror-like high-polishing treatment.

[0034] The talar prosthesis body 1 is made of a material with good biocompatibility and excellent mechanical properties, such as titanium alloy, bioceramics or polymer composite materials.

[0035] The preparation process of the present invention is described below:

[0036] Step 1: Extract the CT scan data of the patient's affected side talus structure and surrounding joints, reconstruct the original 3D data of the intact talus on the affected side through data registration technology, and establish a 3D model of the talus and perform parallel smoothing optimization processing;

[0037] Step 2: Determine the osteotomy position based on the CT scan data of the patient's affected side. According to the relevant parameters of the osteotomy position and the optimization principle of mechanical distribution, accurately design the size and angle of the fixing bolt 6 and the layout, angle, size and trabecular arrangement parameters of the locking screw 2. Then further optimize the 3D reconstructed talus model obtained in step 1 in combination with the design data;

[0038] Step 3: According to the CT scan data of the affected side of the patient, the parameters of the ligament reconstruction, fixation area, number and size of the prosthesis three-dimensional model are determined. According to the preset parameters such as pore form, number, size and trabecular arrangement, the three-dimensional reconstructed talus model obtained in step 2 is further optimized and processed in combination with the design data to obtain the final talus prosthesis model;

[0039] Step 4: The talar body prosthesis model is transferred to a 3D printing device for printing. After printing, the initial talar body prosthesis body is obtained. All joint contact surfaces of the initial prosthesis body are subjected to mirror high polishing. Then, an internal thread that matches the external thread of the locking screw is processed in the locking screw channel 7 by a processing device. After processing, a talar body prosthesis 111 is obtained that is convenient for ankle ligament reconstruction and neck fixation and healing.

[0040] The application process of the present invention is described below:

[0041] Step 1: Expose the talar neck, body and distal tibial articular surface through a lateral or medial osteotomy approach;

[0042] Step 2: Clean the synovial membrane and osteophytes of the ankle joint;

[0043] Step 3: Determine the osteotomy position based on the preoperative 3D CT data on the extent of talar necrosis, fix the osteotomy guide, and use an oscillating saw to perform talar neck osteotomy based on the osteotomy guide;

[0044] Step 4: After the exploratory osteotomy is completed, the necrotic part of the talus is removed;

[0045] Step 5: Install the prosthesis fixation guide plate on the retained talar neck, fix it when you are satisfied, and use a drill bit to drill holes in the position where the fixation bolts are installed in the retained talar part according to the prosthesis fixation guide plate;

[0046] Step 6: Implant the 3D printed talar prosthesis and insert the Kirschner wire along the Kirschner wire through hole to facilitate intraoperative guidance and temporary fixation;

[0047] Step 7: Drill holes according to the location of the locking screw channel and secure with two locking screws;

[0048] Step 8: Reconstruct and fix the ligament by reserving the tendon channel, tendon suture hole and ligament suture hole;

[0049] Step 9: Confirm that the prosthesis is in a satisfactory position and has good stability, and then complete the closed approach operation.

[0050] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A talar prosthesis that facilitates ankle ligament reconstruction and neck and body fixation and healing, characterized in that: The invention comprises a talar prosthesis body and a locking screw made by 3D printing technology. The shape of the talar prosthesis body is obtained according to the three-dimensional CT data of the affected ankle joint and the adjacent joint surface. The talar prosthesis body is an entity composed of a tibiotalar joint surface, a subtalar joint surface and a front end surface. The tibiotalar joint surface is adapted to the tibiotalar joint, the subtalar joint surface is adapted to the subtalar joint, the front end surface is a plane structure, adapted to the osteotomy surface of the talar neck body of the autologous retained part, a cylindrical fixing bolt is fixedly arranged at the center position of the front end surface, the fixing bolt is inserted into the center position of the talar neck body of the autologous retained part, a locking screw channel penetrating the talar prosthesis body is arranged on both sides of the fixing bolt, an internal thread adapted to the external thread of the locking screw is arranged in the locking screw channel, the locking screw extends from the front end surface through the locking screw channel to be connected with the talar neck body of the autologous retained part, and the fixing bolt and the two locking screws are opened in a "pin" shape toward the front end surface.

2. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 1, characterized in that: The front end surface and / or the surface of the fixing bolt are provided with a trabecular structure.

3. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 2, characterized in that: There is an angle between the central axis of the fixing bolt and any two central axes among the three central axes of the two locking screw channels.

4. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 3, characterized in that: The central axis of the fixing bolt is located in the vertical plane of the front end surface, the clockwise angle range between the central axis and the projection of the central axis on the front end surface is 60-90°, the clockwise angle range between the central axis of the locking screw channel and the projection of the central axis on the front end surface is 70-145°, and the angle range between the central axes of the two locking screw channels is 5-45°.

5. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 4, characterized in that: The diameter of the fixing bolt is 3-6 mm, the length of the fixing bolt is 6-15 mm, and the length of the locking screw is 6-25 mm.

6. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to any one of claims 1 to 5, characterized in that: A tendon-penetrating channel is provided between the inner side and the outer side of the talar prosthesis body, tendon suture holes are provided around the tendon-penetrating channel, and ligament suture holes are also provided on the talar prosthesis body.

7. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 6, characterized in that: The diameter of the tendon passage is 4-6mm, the diameter of the tendon suture hole is 1-3mm, the diameter of the ligament suture hole is 1-2mm, and a trabecular structure is provided around the inner wall of the tendon passage and / or the end of the tendon passage on the surface of the talar prosthesis body.

8. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 7, characterized in that: The number of the ligament suture holes is 2-20.

9. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 8, characterized in that: A Kirschner wire through hole is arranged above the locking screw channel and passes through the channel from front to back.

10. The talar body prosthesis for facilitating ankle ligament reconstruction and neck and body fixation and healing according to claim 9, characterized in that: All articular surfaces of the talar prosthesis body are subjected to mirror-like high-polishing treatment.

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