CN110811935A

CN110811935A - 3D prints half pelvis false body

Info

Publication number: CN110811935A
Application number: CN201911191554.3A
Authority: CN
Inventors: 范宏斌; 朱东泽; 付军; 王玲; 张煜珅; 孙立国; 刘鑫成; 党竞医
Original assignee: Fourth Military Medical University FMMU
Current assignee: Fourth Military Medical University FMMU
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-02-21

Abstract

The invention discloses a 3D printing semi-pelvic prosthesis which comprises a prosthesis contact surface matched with a sacrum, a prosthesis contact surface matched with the opposite pubis, a semi-circular acetabular cup structure and a cylindrical structure connecting the prosthesis contact surface and the semi-circular acetabular cup structure. The prosthesis contact surfaces at two ends are designed with porous structures, the outsides of the porous structures are provided with covered edges, the middle of the porous structures is provided with two screw holes, and the columnar structures are formed by finite element mechanical analysis and topological structure optimization design. The prosthesis contact surfaces at two ends designed by the imaging data collected in the earlier stage can be perfectly attached to the sacrum and the opposite pubis of a patient respectively, the prosthesis and the contacted bone can be fixed by using screws, the position of the center of the reconstructed posterior semicircular acetabular cup structure is consistent with the position of the original acetabular cup center, so that better hip joint function and early stability can be obtained, and the porous structure of the prosthesis contact surface is beneficial to the growth of later-stage bones, so that the long-term stability is achieved.

Description

3D prints half pelvis false body

Technical Field

The invention relates to manufacturing of medical internal fixation implants, in particular to a 3D printing semi-pelvic prosthesis.

Background

The pelvis is the origin of a large number of muscles, which have abundant blood vessels for communication with each other and lack of a natural tissue barrier, and malignant tumors occurring in bone tissue can easily break bone into soft tissue, while tumors from soft tissue can easily invade bones. Pelvic tumors are divided into primary tumors and metastatic tumors, the primary tumors are mainly seen in chondrosarcoma, osteosarcoma and Ewing sarcoma; the metastasis is often found in bone metastasis of malignant tumors such as breast cancer, thyroid cancer, kidney cancer, prostate cancer, lung cancer and the like. Pelvic tumors are often insidious due to the complex anatomy and deep position of the pelvis. Patients often spend a long time from the first appearance of symptoms to the visit and definitive diagnosis.

Surgical resection is currently the primary means of treating pelvic malignancies. The surgical treatment firstly completely removes the tumor, the removal range mainly depends on the growth position and the invasion range of the tumor, and the pelvis reconstruction is considered on the basis. The encoking classifies the pelvic tumor resection into type 4, which has good guiding significance for selecting the reconstruction mode. This reconstruction should be considered in both cases: (1) interruption of continuity of the acetabulum and sacrum following resection; (2) the acetabulum is lost due to resection.

Post-pelvic tumor resection reconstruction methods can be categorized into three major groups: biological reconstruction, composite reconstruction, and prosthetic mechanical reconstruction. In recent years, there has been a greater trend towards the reconstruction of bone defects following pelvic tumor resection using artificial hemi-pelvic prostheses. Artificial hemi-pelvic prostheses are of various types, are called differently and have no unified specification,for example:

the artificial pelvis comprises a customized partial pelvis prosthesis, an adjustable artificial hemipelvis prosthesis, a wing plate-shaped customized artificial hemipelvis prosthesis and a combined artificial hemipelvis prosthesis. Compared with other reconstruction methods, the artificial hemi-pelvic prosthesis reconstruction can obtain early stability and retain better hip joint function. However, clinical applications of artificial hemi-pelvic prostheses suffer from a number of problems, such as: the infection rate is high, and complications such as prosthesis loosening, screw loosening, fatigue fracture and the like easily appear in a long term.

In order to obtain a good mechanical reconstruction and to achieve a better match of the prosthesis to the remaining pelvis of the patient, researchers have begun to design prostheses by means of computer-aided design techniques. The computer aided design technology can provide relatively accurate parameters for the resection of the pelvic tumor and the design and manufacture of the individualized pelvic prosthesis, and improve the precision of the resection and reconstruction. However, if the individual prosthesis is customized to exactly the pelvic defect created by the surgical resection, the problem of higher infection rates following implantation of larger volume prostheses occurs as the resection area increases, and the weight of the prosthesis also increases. Meanwhile, in the face of a complex pelvic structure, the number of screws required for objectively fixing the prosthesis is also large, but actually, there is not enough bone surface (e.g., sacrum, lateral pubis) to fix, so that the center of the acetabular cup structure cannot be accurately positioned at the original acetabular center of the patient, and thus, a good hip joint function cannot be obtained.

Disclosure of Invention

The invention aims to provide a 3D printing semi-pelvic prosthesis which is small in size, light in weight, not easy to cause complications such as infection after being implanted and capable of quickly reconstructing and recovering hip joint functions.

In order to achieve the purpose, the invention adopts the following technical scheme:

this half pelvis prosthesis includes acetabular cup structure, sacrum side column structure and pubic bone side column structure, the one end of sacrum side column structure links to each other with acetabular cup structure, and the other end of sacrum side column structure is provided with the prosthesis contact surface body who matches with the sacrum, and the one end of pubic bone side column structure links to each other with acetabular cup structure, and the other end of pubic bone side column structure is provided with the prosthesis contact surface body who matches with the pubic bone, is provided with the bone connecting piece on each prosthesis contact surface body.

Preferably, the bone attachment member is selected from a screw.

Preferably, each prosthesis contact surface body is further provided with a plurality of (for example, 1-2) nail holes, each nail hole is provided with a nail channel designed through mechanical analysis, and the corresponding prosthesis contact surface body can be fixed with the adjacent bone surface of the sacrum or the pubis by using screws.

Preferably, each prosthesis contact surface body is further provided with a wrapping structure, and the wrapping structure is a flange which can wrap around the bone surface matched with the corresponding prosthesis contact surface body (for example, the area contacted with the ilium before the sacrum operation and the area contacted with the opposite pubic bone before the pubic bone operation).

Preferably, each prosthesis contact surface body is further provided with a porous structure which is beneficial to bone ingrowth.

Preferably, the sacral lateral column structure, the pubic lateral column structure (such as the peripheral shape and the size) and the joint position of the sacral lateral column structure, the acetabular cup structure and the corresponding prosthesis contact surface body are designed through finite element mechanical analysis and topological structure optimization, and the sacral lateral column structure, the pubic lateral column structure and the joint position of the sacral lateral column structure, the acetabular cup structure and the corresponding prosthesis contact surface body have the characteristics of being few in materials, light in weight and strong in bearing.

Preferably, the two cylindrical structures of the semi-pelvic prosthesis respectively connect prosthesis contact surfaces at two ends with the middle semi-circular acetabular cup structure into a whole, and the semi-pelvic prosthesis can be integrally formed.

Preferably, the semi-pelvic prosthesis is made of medical titanium alloy powder and is manufactured through 3D printing.

The invention has the beneficial effects that:

the structure of the individualized hemi-pelvic prosthesis is redesigned on the basis of the anatomical structure characteristics of the pelvis of a human body, prosthesis contact surfaces which can be matched with the sacrum and the pubis respectively can be utilized (the prosthesis contact surfaces at two ends of the prosthesis can be designed through imaging data acquired in the early stage and can be perfectly attached to the sacrum and the opposite pubis of a patient respectively), and the position of the center of the acetabular cup is accurately positioned, so that the acetabular cup can be consistent with the central position of the original acetabulum after hip joint reconstruction.

Furthermore, the nail hole structure of the invention not only can fix the prosthesis and the contacted bone by using the screw, but also can bear partial force and increase the initial stability of the prosthesis.

Furthermore, the edge covering structure can embed the bone contact surface, so that the initial stability of the implanted prosthesis can be improved, the positioning precision of the center of the acetabular cup structure can be improved, and the problems of prosthesis loosening, fatigue fracture, screw loosening and the like which are easy to occur in a long term can be overcome.

Furthermore, the surfaces of the two ends of the prosthesis, which are in contact with the bone, are provided with porous structures, so that the bone ingrowth probability can be increased, the later bone ingrowth is facilitated, and the long-term stability of the prosthesis is increased.

Drawings

FIG. 1 is a front view of a 3D printed hemi-pelvic prosthesis in an embodiment of the invention;

FIG. 2 is a rear view of a 3D printed hemi-pelvic prosthesis in an embodiment of the invention;

FIG. 3 is a top view of a 3D printed hemi-pelvic prosthesis in an embodiment of the invention;

FIG. 4 is a bottom view of a 3D printed hemi-pelvic prosthesis in an embodiment of the invention;

FIG. 5 is a top view of a reconstructed pelvis in an embodiment of the present invention;

FIG. 6 is a bottom view of a reconstructed pelvis in accordance with an embodiment of the present invention;

FIG. 7 is a side view of a reconstructed pelvis in an embodiment of the present invention;

in the figure: 1 is the prosthesis contact surface, 2 is the nail hole, 3 is the column structure, 4 is acetabular cup structure, 5 is bordure structure, 6 is sacrum, 7 is ilium, 8 is ischium, 9 is the pubis.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Referring to fig. 1, 2, 3 and 4, the 3D printed semi-pelvic prosthesis of the present invention is designed based on preoperative CT and MRI three-dimensional image fusion digital models to perform preoperative planning, determine operative resection range, obtain parameters such as pelvic osteotomy plane, acetabular position, etc., design an individualized customized prosthesis for a specific patient according to the parameters, perform computer simulation installation after the design is completed, and prepare a prosthesis real object by using a metal 3D printing device. The guide plate or the computer-aided navigation system printed in 3D mode is used for finishing accurate resection in the operation, and the osteotomy plane can be perfectly attached to the contact surface of the prosthesis.

The 3D printing half-pelvis prosthesis comprises a prosthesis contact surface 1 matched with a sacrum, a prosthesis contact surface 1 matched with the opposite pubis, a semicircular acetabular cup structure 4 and a cylindrical structure 3 connecting the prosthesis contact surface 1 and the semicircular acetabular cup structure 4.

In the 3D printing semi-pelvic prosthesis, the part of the prosthesis contact surface 1 respectively matched with the sacrum and the pubis is designed through preoperative imaging data and can be perfectly attached to the corresponding parts of the sacrum and the pubis, the edge covering structure 5 around the prosthesis contact surface 1 is convenient for embedding the adjacent bone surface, the early stability of the prosthesis can be realized, two nail holes 2 are designed in the middle of the prosthesis contact surface 1, the prosthesis contact surface 1 is fixed with the adjacent bone surface through screws entering the bone along the nail holes 2 (or can be fixed through silk threads), the initial stability is increased, a porous structure or other structures beneficial to bone growth are designed on the prosthesis contact surface 1, the bone growth probability can be increased, and the firmness of the prosthesis after implantation is enhanced.

The semicircular acetabular cup structure 4 is designed through preoperative imaging data, an osteotomy plane after accurate resection in an operation can be perfectly attached to the prosthesis contact surface 1, and when the prosthesis contact surfaces 1 at two ends are perfectly attached to the sacrum and the opposite side pubis, the central position of the semicircular acetabular cup structure 4 can coincide with the central position of the original acetabulum of a patient.

The cylindrical structure 3 is designed through computer mechanics analysis (finite element mechanics analysis and topological structure optimization), manufacturing materials are saved most, the weight is light, and the bearing capacity is strongest through optimization, the cylindrical structure 3 connects the prosthesis contact surfaces 1 at two ends and the middle semicircular acetabular cup structure 4 into a whole, and the prosthesis can be integrally formed through a 3D printing technology by using titanium alloy powder.

Referring to fig. 5, 6 and 7, during reconstruction, the prosthesis contact surfaces 1 at the two ends are respectively matched with the sacrum 6 and the opposite pubis 9, and are accurately and firmly fixed with the bony structures through the surrounding edge covering structure 5 and are strengthened and fixed by screws. After the accurate combination of the prosthesis contact surfaces 1 at the two ends and the surface of the bone is finished, the central position of the semicircular acetabulum cup structure 4 is consistent with the central position of the original acetabulum, the reconstruction of the acetabulum is finished on the basis, and the function of the hip joint of the patient is recovered.

In a word, the 3D printing half-pelvis prosthesis provided by the invention not only can be well attached to the normal human bony structure in appearance, but also can realize accurate installation of the 3D printing half-pelvis prosthesis, so that the implantation operation time can be shortened, the bleeding in the implantation operation can be reduced, the half pelvis can be accurately reconstructed, the central position of the semicircular acetabular cup can be coincided with the central position of the acetabulum of a preoperative patient, and better hip joint function and early stability can be obtained.

Claims

1. A3D prints half pelvic prosthesis which characterized in that: the semi-pelvic prosthesis comprises an acetabulum cup structure (4), a sacrum side cylindrical structure (3) and a pubis side cylindrical structure (3), wherein one end of the sacrum side cylindrical structure (3) is connected with the acetabulum cup structure (4), the other end of the sacrum side cylindrical structure (3) is provided with a prosthesis contact surface body matched with the sacrum, one end of the pubis side cylindrical structure (3) is connected with the acetabulum cup structure (4), the other end of the pubis side cylindrical structure (3) is provided with a prosthesis contact surface body matched with the pubis, and each prosthesis contact surface body is provided with a bone connecting piece.

2. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: the bone attachment member is selected from a screw.

3. The 3D printed hemi-pelvic prosthesis of claim 2, wherein: each prosthesis contact surface body is also provided with a nail hole (2) which is provided with a nail path designed through mechanical analysis.

4. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: each prosthesis contact surface body is also provided with a wrapping structure (5), and the wrapping structure (5) is a flange positioned on the outer side of the bone surface matched with the corresponding prosthesis contact surface body.

5. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: each prosthesis contact surface body is also provided with a porous structure which is beneficial to bone ingrowth.

6. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: the sacrum lateral cylindrical structure (3), the pubis lateral cylindrical structure (3) and the joint position of the sacrum lateral cylindrical structure, the acetabulum cup structure (4) and the corresponding prosthesis contact surface body are designed through finite element mechanical analysis and topological structure optimization.

7. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: the semi-pelvic prosthesis is integrally formed.

8. The 3D printed hemi-pelvic prosthesis of claim 1, wherein: the hemi-pelvic prosthesis is made from titanium alloy powder and by 3D printing.