A 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis

Abstract

The present invention discloses a 3D printing fixed fusion integrated posterior cervical occipital fusion prosthesis, including a fusion portion installed between the occipital bone and the spinous process, the fusion portion is a porous metal structure for facilitating bone growth, the upper end of the fusion portion is attached to the bone cortex below the occipital tubercle, and the lower end of the fusion portion is provided with a dovetail opening structure engaged with the spinous process; and a fixing portion integrally formed with the fusion portion on the curved surface of the fusion portion, the fixing portion is a solid metal structure, and the fixing portion includes a longitudinal beam located on the central axis of the fusion portion and a transverse connecting beam symmetrically arranged transversely about the longitudinal beam; the longitudinal beam includes a nailing portion located at the upper end of the transverse connecting beam and a load-bearing beam located at the lower end of the nailing portion, and an occipital screw hole is provided on the nailing portion; cervical vertebra connecting rod joints are provided at both ends of the transverse connecting beam, and the prosthesis is fixedly connected to the cervical vertebra screw rod system through the cervical vertebra connecting rod joint. The present invention integrates fixation and fusion functions, simplifies the surgical process, and avoids adverse reactions caused by bone grafting.

Description

Technical Field

[0001] The invention relates to an orthopedic implant, and in particular to a 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis. Background Art

[0002] In the process of orthopedic clinical diagnosis and treatment, upper cervical spine injuries and instability caused by various diseases such as trauma, tumors, and inflammation are often seen, requiring posterior cervical fusion surgery to restore the patient's head and neck stability.

[0003] Currently, cervical occipital fusion surgery mainly includes two parts. One is to fix the cervical spine and occipital bone through a screw rod or screw plate system. However, the stability of simple screw rod or screw plate fixation is relatively poor, and the implant may become loose, displaced or even broken after the operation. In order to avoid the above situation, after the fixation is completed, autologous ilium, allogeneic or artificial bone blocks are usually selected and placed between the occipital bone and the normal cervical spinous process and lamina for bone grafting and fusion to further enhance the stability of the head and neck after the operation.

[0004] However, the source of autologous bone is limited and causes secondary trauma; allogeneic bone may cause consequences such as bone graft rejection, bone graft absorption and poor healing. Due to the defects and limitations of bone graft fusion itself, the current surgical effect of cervical occipital fusion is difficult to meet the surgical needs of clinicians and the health needs of patients themselves. Summary of the invention

[0005] In view of the above problems existing in the prior art, the object of the present invention is to provide a 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis which does not require bone grafting and integrates fixation and fusion functions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis, comprising

[0008] The fusion part is installed between the occipital bone and the spinous process and has a curved shape. The fusion part is a porous metal structure that facilitates bone growth. The upper end of the fusion part is attached to the bone cortex below the occipital tubercle, and the lower end of the fusion part is provided with a dovetail-shaped opening structure that engages with the spinous process;

[0009] and a fixing portion formed integrally with the fusion portion and located on the curved surface of the fusion portion, the fixing portion being a solid metal structure, the fixing portion comprising a longitudinal beam located on the central axis of the fusion portion and a transverse connecting beam arranged transversely and symmetrically with respect to the longitudinal beam;

[0010] The longitudinal beam comprises a nail placement portion located at the upper end of the transverse connecting beam and a load-bearing beam located at the lower end of the nail placement portion, and an occipital screw hole is opened on the nail placement portion;

[0011] Cervical vertebrae connecting rod joints are arranged at both ends of the transverse connecting beam, and the prosthesis is fixedly connected to the cervical vertebrae screw-rod system via the cervical vertebrae connecting rod joints.

[0012] Furthermore, the upper and lower surfaces of the nail placement portion are smoothly connected with the upper and lower surfaces of the fusion portion respectively, and the load-bearing beam and the transverse connecting beam are embedded in the upper surface of the fusion portion, and their upper surfaces are smoothly connected with the upper surface of the fusion portion.

[0013] Furthermore, the screw placement portion is provided with two occipital screw holes arranged in the longitudinal direction.

[0014] Furthermore, the cervical connecting rod joint is a cylindrical structure, and is provided with a connecting hole for the cervical connecting rod in the cervical screw-rod system to pass horizontally, and the cervical connecting rod is fixedly connected to the cervical connecting rod joint by a connecting screw.

[0015] Furthermore, the longitudinal beams, transverse connecting beams and cervical vertebra connecting rod joints in the fusion part and the fixing part are integrally prepared and formed by metal 3D printing technology based on laser selective melting or electron beam melting technology.

[0016] Furthermore, the load-bearing beam has a width of 4-6 mm and a thickness of 2-5 mm.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] Compared with the current posterior cervical occipital fusion (including two parts, 1 is the fixation of the cervical vertebrae and the occipital bone, 2 is the bone grafting fusion between the occipital bone and the cervical vertebrae), the present invention simplifies the surgical procedure, so that the cervical vertebra-occipital fixation and occipital-cervical fusion can be completed at one time through the prosthesis; and through the cervical vertebra connecting rod joint, the prosthesis of the present invention can be matched with the traditional cervical vertebrae screw-rod system for use, and has strong applicability; and the fusion part with a porous structure is conducive to the bone ingrowth of the bonding interface, avoiding the iatrogenic trauma caused by autologous bone grafting and the adverse reactions such as bone graft rejection, poor bone graft healing, and allogeneic bone absorption that may occur in large-scale allogeneic bone grafting; and the mechanical strength of the metal prosthesis is higher than that of autologous and allogeneic bone blocks, and the short-term stability after cervical occipital fusion surgery is better; in the long term, the porous structure is conducive to the bone ingrowth of the occipital bone and the cervical spinous process and vertebral lamina, and can form a biological fusion locking, further enhancing the stability of the prosthesis and the internal fixation system, and ensuring the long-term safety and stability of the patient after cervical occipital fusion surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis according to an embodiment of the present invention;

[0020] Figure 2It is a side view of the 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis involved in an embodiment of the present invention;

[0021] Figure 3 It is a front view of the 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis in use according to an embodiment of the present invention;

[0022] Figure 4 It is a side view of the 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis in use according to an embodiment of the present invention.

[0023] In the figure: 1, fusion part; 2, load-bearing beam; 3, nail placement part; 4, cervical vertebra connecting rod joint; 5, occipital screw hole; 6, transverse connecting beam; 7, connecting screw; 8, cervical vertebra connecting rod; 9, cervical vertebra screw. DETAILED DESCRIPTION

[0024] The specific contents of the present invention are further explained in detail below in conjunction with the accompanying drawings and embodiments.

[0025] Reference Figure 1-4 The present embodiment provides a 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis, comprising a fusion portion 1 with a curved shape installed between the occipital bone and the spinous process, and the specific size and curvature of the fusion portion 1 are individually designed according to the patient's cervical spine three-dimensional CT and surgical plan; wherein the fusion portion 1 is a porous metal structure for easy bone growth, the upper end of the fusion portion 1 is attached to the bone cortex below the occipital tubercle, and the lower end of the fusion portion 1 is provided with a dovetail-shaped opening structure engaged with the spinous process, and the specific opening angle, shape, size of the opening structure and the fusion interface morphology between the spinous process and the lamina are individually designed according to the patient's cervical spine three-dimensional CT to ensure that the prosthesis is engaged with the spinous process and is firmly attached and tightly for easy fusion;

[0026] and a fixing part formed integrally with the fusion part 1 and located on the curved surface of the fusion part 1, the fixing part being a solid metal structure and used to enhance the support strength of the prosthesis; the fixing part comprises a longitudinal beam located on the central axis of the fusion part 1 and a transverse connecting beam 6 arranged transversely and symmetrically with respect to the longitudinal beam;

[0027] The longitudinal beam includes a nailing portion 3 located at the upper end of the transverse connecting beam 6 and a load-bearing beam 2 located at the lower end of the nailing portion 3. The nailing portion 3 is provided with two occipital screw holes 5 arranged in the longitudinal direction. The prosthesis can be fixed below the occipital tubercle through the occipital screw holes 5. The specific opening position of the occipital screw holes 5 is designed before surgery based on the three-dimensional CT modeling of the cervical spine; the upper and lower surfaces of the nailing portion 3 are smoothly connected with the upper and lower surfaces of the fusion portion 1, that is, the lower surface of the nailing portion 3 is also attached to the bone cortex below the occipital tubercle, which makes the fixation of the prosthesis to the occipital bone more firmly; the load-bearing beam 2 and the transverse connecting beam 6 are embedded in the upper surface of the fusion portion 1, and the upper surfaces of the load-bearing beam 2 and the transverse connecting beam 6 are smoothly connected with the upper surface of the fusion portion 1; preferably, the width of the load-bearing beam 2 is 4-6mm and the thickness is 2-5mm;

[0028] Cervical connecting rod joints 4 are provided at both ends of the transverse connecting beam 6, and the prosthesis is fixedly connected to the cervical screw-rod system through the cervical connecting rod joints 4; wherein, the cervical screw-rod system is a device for fixing the cervical vertebra in the prior art, including a cervical connecting rod 8 and a cervical screw 9; specifically, the cervical connecting rod joint 4 is a cylindrical structure perpendicular to the surrounding fusion portion 1, and a connecting hole is provided on the cervical connecting rod joint 4 for the cervical connecting rod 8 to pass horizontally, and a threaded hole is provided on the top of the cervical connecting rod joint 4, and the cervical connecting rod 8 is fixed by a connecting screw 7 matching the threaded hole.

[0029] The longitudinal beams in the fusion part 1 and the fixing part, the transverse connecting beam 6 and the cervical vertebra connecting rod joint 4 are integrally prepared and formed by metal 3D printing technology based on laser selective melting or electron beam melting technology.

[0030] The base material used for the 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis provided in this embodiment is generally titanium alloy, which can be replaced with tantalum metal or other medical metal materials according to the surgical design requirements;

[0031] In addition, in order to promote the fusion between the prosthesis and the host bone, the present invention also involves surface modification and compounding of osteogenic factors on the porous interface between the prosthesis and the bone.

[0032] The design and preparation procedures of the 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis involved in the present invention are as follows:

[0033] Preoperatively, the patient's cervical spine was modeled based on three-dimensional CT (scanning layer thickness 0.625 mm), and the three-dimensional model of the posterior cervical fusion prosthesis was designed on the computer using Mimcs software according to its anatomical structure and surgical plan; finally, the digital three-dimensional model was imported into the titanium alloy or tantalum metal 3D printing equipment for integrated preparation and production.

[0034] In addition, for emergency patients, considering that the prosthesis design and preparation cycle is long, and the prosthesis structure involved in the present invention is simple and adaptable, three sizes of prostheses, large, medium and small, can be prefabricated based on the anatomical structure of the upper cervical spine of the normal population for easy clinical use.

Claims

1. A 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis, characterized by: include A fusion portion (1) having a curved surface shape installed between the occipital bone and the spinous process, the fusion portion (1) being a porous metal structure that facilitates bone ingrowth, the upper end of the fusion portion (1) being attached to the bone cortex below the occipital tubercle, and the lower end of the fusion portion (1) being provided with a dovetail-shaped opening structure that engages with the spinous process; and a fixing portion formed integrally with the fusion portion (1) and located on the curved surface of the fusion portion (1), the fixing portion being a solid metal structure, the fixing portion comprising a longitudinal beam located on the central axis of the fusion portion (1) and a transverse connecting beam (6) arranged transversely and symmetrically with respect to the longitudinal beam; The longitudinal beam comprises a nail placement portion (3) located at the upper end of the transverse connecting beam (6) and a load-bearing beam (2) located at the lower end of the nail placement portion (3); the nail placement portion (3) is provided with two occipital screw holes (5) arranged in the longitudinal direction; Cervical vertebrae connecting rod joints (4) are provided at both ends of the transverse connecting beam (6), and the prosthesis is fixedly connected to the cervical vertebrae screw-rod system via the cervical vertebrae connecting rod joints (4).

2. The 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis according to claim 1, characterized in that: The lower surfaces of the nail placement parts (3) are respectively smoothly connected with the upper surfaces of the fusion parts (1); the load-bearing beams (2) and the transverse connecting beams (6) are embedded in the upper surface of the fusion parts (1), and their lower surfaces are smoothly connected with the upper surface of the fusion parts (1).

3. The 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis according to claim 1, characterized in that: The cervical vertebra connecting rod joint (4) is a cylindrical structure, and is provided with a connecting hole for a cervical vertebra connecting rod (8) in a cervical vertebra screw-rod system to pass transversely therethrough, and the cervical vertebra connecting rod (8) is fixedly connected to the cervical vertebra connecting rod joint (4) via a connecting screw (7).

4. The 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis according to claim 1, characterized in that: The fusion part (1) and the longitudinal beam, transverse connection beam (6) and cervical vertebra connection rod joint (4) in the fixing part are integrally prepared and formed by metal 3D printing technology based on laser selective melting or electron beam melting technology.

5. The 3D printed fixed fusion integrated posterior cervical occipital fusion prosthesis according to any one of claims 1 to 2, characterized in that: The load-bearing beam (2) has a width of 4-6 mm and a thickness of 2-5 mm.

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