3D printing of a proximal tibial tumor segment replacement type micro-porous-scaffold composite prosthesis

Abstract

The present application relates to a kind of 3D printing proximal tibia tumor segment replacement microporous-scaffold composite prosthesis, the composite prosthesis includes proximal microporous section, scaffold section and microporous bone conduction section, proximal microporous section, scaffold section and microporous bone conduction section are provided with from top to bottom through channel for passing through the handle body of tibial plateau prosthesis and with the shape of handle body is matched;The upper end of proximal microporous section is matched with the shape of the platform body of tibial plateau prosthesis;Scaffold section is grid structure, and patellar tendon screw fixing seat is provided in the front end of scaffold section, and ligament fixing seat is provided in the inner side of scaffold section;The lower end of microporous bone conduction section is contacted with the osteotomy plane of patient's tibia, and the diameter of the channel of microporous bone conduction section is greater than the diameter of medullary cavity in osteotomy plane and less than the outer diameter of bone cortex.The composite prosthesis of the present application can change mechanical fixation into biological fixation, reduce the probability of long-term prosthesis failure, and the structure is stable, and light in weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of artificial prosthesis, in particular to a 3D printed tibial proximal tumor segment replacement type microporous-scaffold composite prosthesis. BACKGROUND

[0002] Knee joint is a common site of bone tumor, and after tumor resection reaches a safe surgical boundary, a large bone defect will occur. In the treatment of tibial proximal segmental bone defect caused by limb salvage treatment of tibial proximal tumor or other reasons, prosthesis replacement is widely used, but there are often many complications such as infection, loosening, and prosthesis fracture. The incidence of prosthesis loosening and prosthesis fracture is about 5%, which is related to the activity intensity of the patient. The failure rate of prosthesis of young patients will be higher. It is very important to maintain and prolong the service life of the prosthesis while preserving the limb.

[0003] After implanting the prosthesis, the stress is mainly transmitted by the prosthesis. The bone tissue remodeling caused by stress change will cause the cortical bone to thin, the medullary cavity to expand, and the bone strength to decrease. One of the factors of stress shielding is that the elastic modulus of the prosthesis and the bone tissue is too different. Due to the less coverage of local soft tissue of tibia, combined with the attachment of patellar tendon and medial collateral ligament to the proximal tibia, the tendon needs to be reconstructed after resection. The common prosthesis currently used has two holes passing through the surface of the prosthesis for tendon repair points, and the surface is smooth. The tendon is connected to the prosthesis only by the suture line of the ligament. The suture line of the ligament or the ligament passing point will eventually break, which will cause the patellar tendon to break, the patella to move up, and the stability of the knee joint to decrease. In addition, the weight of the solid prosthesis is significantly higher than that of the resected bone segment. After the operation, the patient often feels that the affected limb is heavy and the activity is not smooth. SUMMARY

[0004] In view of the above problems, the present application provides a 3D printed tibial proximal tumor segment replacement type microporous-scaffold composite prosthesis.

[0005] To solve the above problems, the present application adopts the following technical scheme:

[0006] A 3D printed tibial proximal tumor segment replacement type microporous-scaffold composite prosthesis, comprising a proximal microporous segment, a scaffold segment and a microporous bone conduction segment, the proximal microporous segment and the microporous bone conduction segment are 3D printed integrally with the scaffold segment near the proximal end of the femur on one side and near the distal end of the femur on the other side, respectively, the proximal microporous segment, the scaffold segment and the microporous bone conduction segment are provided with a self-top-to-bottom through channel for passing through the stem body of the tibial plateau prosthesis and matching the outer shape of the stem body, and the stem body is fixed between the proximal microporous segment, the scaffold segment and the microporous bone conduction segment by bone cement;

[0007] The upper end of the proximal microporous segment matches the shape of the platform body of the tibial platform prosthesis, and is used to support the tibial platform prosthesis;

[0008] The bracket segment is a mesh structure, a patellar tendon screw fixing seat for threadedly cooperating with a screw for fixing the patellar tendon is arranged at the proximal front of the bracket segment, and a ligament fixing seat for threadedly cooperating with a screw for fixing the medial collateral ligament is arranged at the proximal inner side of the bracket segment.

[0009] The lower end of the microporous bone conduction segment is in contact with the osteotomy plane of the tibia of the patient, and the diameter of the channel of the microporous bone conduction segment is greater than the diameter of the medullary cavity in the osteotomy plane and smaller than the outer diameter of the bone cortex.

[0010] Compared with the prior art, the present application has the following beneficial effects:

[0011] The 3D printed tibial proximal tumor segment replacement type microporous-bracket composite prosthesis can be widely used for segmental bone defects of the tibial proximal tumor caused by tumor, trauma or prosthesis revision, the microporous-bone contact interface has bone conduction function, the autologous bone implanted in the bracket segment has bone conduction function, and after bone ingrowth, mechanical fixation is changed into biological fixation, so that the long-term prosthesis failure probability is reduced; the bracket segment is provided with a patellar tendon screw fixing seat and a ligament fixing seat, the patellar tendon and the medial collateral ligament are fixed by using a screw and a ligament suture thread threadedly cooperating with the fixing seat, the fixation is much more stable than that of the ligament suture thread alone, and the ligament contact interface of the prosthesis is a rough surface of a mesh structure, which is helpful to the fixation of the ligament by long-term fibrous tissue, and the biological ingrowth of the stable prosthesis structure, bone tissue and ligament tissue can meet the higher requirements of young patients on the function and activity of the knee joint as much as possible; the proximal microporous segment and the microporous bone conduction segment of the composite prosthesis adopt microporous structures, and the bracket segment adopts a mesh structure, so that the prosthesis has good bone ingrowth characteristics while the overall weight of the prosthesis is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a schematic view of the medial surface direction of the 3D printed tibial proximal tumor segment replacement type microporous-bracket composite prosthesis of the present application;

[0013] Figure 2 It is a schematic view of the bottom surface direction of the 3D printed tibial proximal tumor segment replacement type microporous-bracket composite prosthesis of the present application;

[0014] Figure 3 It is a schematic view of the top surface direction of the 3D printed tibial proximal tumor segment replacement type microporous-bracket composite prosthesis of the present application;

[0015] Figure 4 It is a schematic view of the front surface direction of the 3D printed tibial proximal tumor segment replacement type microporous-bracket composite prosthesis of the present application. DETAILED DESCRIPTION

[0016] The technical solutions of the present application will be described in detail below in combination with the drawings and preferred embodiments.

[0017] The present application provides a 3D printed proximal tibial tumor segment replacement type microporous-scaffold composite prosthesis for the treatment of proximal tibial segmental bone defects. The composite prosthesis is used in cooperation with a tibial platform prosthesis. The tibial platform prosthesis is a prosthesis obtained by three-dimensional reconstruction according to the CT data of the patient's knee joint, such as the tibial platform prosthesis disclosed in the patent with publication number CN110448392A, which includes a platform body and a shank body fixedly connected with the platform body. Since the tibial platform prosthesis in the present application is a prior art, it will not be described here.

[0018] The composite prosthesis of the present application matches the shape of the proximal tibial defect segment, and the composite prosthesis has an inner side, a bottom, a top, a front, and several other sides, as shown in Figures 1-4 The composite prosthesis includes a proximal microporous segment 1, a scaffold segment 2, and a microporous bone conduction segment 3. The proximal microporous segment 1 and the scaffold segment 2 are 3D printed integrally on the side close to the proximal femur. The microporous bone conduction segment 3 and the scaffold segment 2 are 3D printed integrally on the side close to the distal femur. The proximal microporous segment 1, the scaffold segment 2, and the microporous bone conduction segment 3 are provided with a self-top-to-bottom through channel for passing through the shank body of the tibial platform prosthesis and matching the shape of the shank body. The shank body is fixed between the proximal microporous segment 1, the scaffold segment 2, and the microporous bone conduction segment 3 by bone cement. Optionally, the thickness of the bone cement is 2-4 mm.

[0019] The upper end of the proximal microporous segment 1 matches the shape of the platform body of the tibial platform prosthesis. The micropores and the bone cement form a micro-lock to stabilize and support the tibial platform prosthesis. Optionally, the proximal microporous segment 1 is set as follows: height 2-4 mm, pore size 600-800 microns, porosity 60%. The proximal microporous segment 1 and the microporous bone conduction segment 3 both adopt a microporous structure, and the scaffold segment 2 adopts a grid-like structure, which greatly reduces the overall weight of the prosthesis while ensuring that the prosthesis has good bone ingrowth characteristics.

[0020] The lower end of the microporous bone conduction segment 3 contacts the osteotomy plane of the patient's tibia, and the diameter of the channel of the microporous bone conduction segment 3 is greater than the diameter of the medullary cavity in the osteotomy plane and less than the outer diameter of the bone cortex. Optionally, the microporous bone conduction segment 3 is set as follows: height 6 mm, pore size 600-800 microns, porosity 60%.

[0021] The bracket segment 2 is a mesh structure and is also 3D printed, and the pore size is 4-6 mm, and autologous bone is implanted in the pores. The bracket segment 2 is provided with a patellar tendon screw fixing seat 4 in front of the proximal end, and the patellar tendon screw fixing seat 4 is used for threaded cooperation with a screw for fixing the patellar tendon. In the fixing process, the screw is screwed into the patellar tendon screw fixing seat 4, and the surrounding bracket is fixed with the patellar tendon by using a ligament suture line. The bracket segment 2 is provided with a ligament fixing seat 5 in the medial side of the proximal end, and the ligament fixing seat 5 is used for threaded cooperation with a screw for fixing the medial collateral ligament. In the fixing process, the screw is screwed into the ligament fixing seat 5, and the surrounding bracket is fixed with the medial collateral ligament by using a ligament suture line. The bracket segment 2 fixes the patellar tendon and the medial collateral ligament by using the screw threaded with the fixing seat and the ligament suture line, and the fixation is much more stable than the fixation by using the ligament suture line alone. The contact interface between the ligament and the prosthesis is a rough surface of the mesh structure, which is helpful for the fixation of the ligament by the long-term fibrous tissue. The biological growth of the stable prosthesis structure, bone tissue and ligament tissue can meet the higher requirements of young patients on the function and activity of the knee joint as much as possible.

[0022] The number of the patellar tendon screw fixing seat 4 and the ligament fixing seat 5 can be set according to actual needs. For example, still referring to Figure 4 , four patellar tendon screw fixing seats 4 are distributed in a rectangular or square shape on the bracket segment 2, and the number of the ligament fixing seat 5 is two.

[0023] In order to further reduce the weight of the composite prosthesis and improve the strength of the composite prosthesis, the material of the proximal microporous segment 1, the bracket segment 2 and the microporous bone conduction segment 3 is titanium alloy.

[0024] The 3D printed proximal tibial tumor segment replacement type microporous-bracket composite prosthesis can be widely used for segmental bone defects caused by tumors, trauma or multiple prosthesis revisions of the proximal tibia. The microporous-bone contact interface has a bone conduction function, the autologous bone implanted in the bracket segment has a bone conduction function, and after the bone grows in the later period, the mechanical fixation is changed to biological fixation, and the long-term prosthesis failure rate is reduced.

[0025] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the description.

[0026] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A 3D printed proximal tibial tumor segment replacement type porous-scaffold composite prosthesis, characterized by, The application relates to a tibial plateau prosthesis, which comprises a proximal microporous segment (1), a stent segment (2) and a microporous bone conduction segment (3), the proximal microporous segment (1) and the microporous bone conduction segment (3) are integrally formed with the stent segment (2) on the side close to the proximal end of the femur and the side close to the distal end of the femur by 3D printing, the proximal microporous segment (1), the stent segment (2) and the microporous bone conduction segment (3) are provided with a self-upward-through channel for penetrating the shank body of the tibial plateau prosthesis and matching the outer shape of the shank body, and the shank body is fixed between the proximal microporous segment (1), the stent segment (2) and the microporous bone conduction segment (3) by bone cement. The upper end of the proximal microporous segment (1) matches the outer shape of the platform body of the tibial plateau prosthesis, so as to support the tibial plateau prosthesis. The stent segment (2) is a grid structure, autogenous bone is implanted in the holes, a patellar tendon screw fixing seat (4) for threadedly cooperating with a screw for fixing the patellar tendon is arranged at the front end of the proximal end of the stent segment (2), a ligament fixing seat (5) for threadedly cooperating with a screw for fixing the medial collateral ligament is arranged at the inner side of the proximal end of the stent segment (2), and the stent segment (2) is fixed with the patellar tendon and the medial collateral ligament through the screw and the ligament suture. The lower end of the microporous bone conduction segment (3) is in contact with the osteotomy plane of the tibia of a patient, and the diameter of the channel of the microporous bone conduction segment (3) is greater than the diameter of the medullary cavity in the osteotomy plane and smaller than the outer diameter of the bone cortex.

2. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The height of the proximal microporous segment (1) is 2-4 mm, the pore size is 600-800 microns, and the porosity is 60%.

3. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The height of the microporous bone conduction segment (3) is 6 mm, the pore size is 600-800 microns, and the porosity is 60%.

4. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The pore size of the stent segment (2) is 4-6 mm.

5. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The thickness of the bone cement is 2-4 mm.

6. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The number of the patellar tendon screw fixing seats (4) is four, and the patellar tendon screw fixing seats (4) are distributed in a rectangular or square shape on the stent segment (2), and the number of the ligament fixing seats (5) is two.

7. The 3D printed proximal tibial tumor segment replacement type porous- scaffold composite prosthesis according to claim 1, characterized in that, The material of the proximal microporous segment (1), the stent segment (2) and the microporous bone conduction segment (3) is titanium alloy.

Images