CN217040257U

CN217040257U - 3D prints porous associative nature low modulus osseointegration pedicle of vertebral arch screw of entity

Info

Publication number: CN217040257U
Application number: CN202123426435.7U
Authority: CN
Inventors: 李成; 李雷
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-07-26
Anticipated expiration: 2031-12-31

Abstract

The utility model belongs to the technical field of the medical interior fixture is made, a 3D prints bone trabecula pedicle of vertebral arch screw for backbone internal fixation usefulness is related to. The method is characterized in that a plurality of hollow holes with 3D printing porous structures are arranged in a nail rod part for the first time, so that the osseointegration effect of the screw is increased on the premise of not influencing or slightly reducing the fixing strength of the screw; the porous structure design is applied to the screw head base part for the first time, so that the screw base part is fully contacted with the cancellous bone on the surface of the articular process after the pedicle is placed into the pedicle, a good bone-screw fusion interface is formed on the screw head and the screw rod, the screw looseness caused by the seesaw effect is reduced, and the stability of the internal fixing system is better promoted.

Description

Porous combination nature low modulus osteointegration pedicle of vertebral arch screw of 3D printing entity

Technical Field

The utility model belongs to the technical field of the medical interior fixture is made, concretely relates to a 3D prints porous associative low modulus osseointegration pedicle of vertebral arch screw of entity for backbone internal fixation usefulness.

Background

With the growing population of elderly people in china and worldwide, and the increasing incidence of other risk factors, such as vitamin D deficiency, reduced mobility, smoking, etc., spinal surgeons have had to face more osteoporotic spine disease. With improvements in surgical techniques, anesthesia and perioperative care, patients and surgeons have become more prone to surgical treatment for diseases that have previously been prone to conservative treatment. Pedicle screw internal fixation fusion is the basic operation mode of spinal fusion, however, pedicle screw loosening is a common complication after spinal internal fixation, and the failure of an internal fixation system causes postoperative complications and the possibility of revision to be increased, thereby not only bringing great trouble to doctors and patients, but also increasing heavy burden to a medical system. The problem of screw loosening is more obvious in osteoporosis people, and with the progress of the aging society of China, the incidence rate of osteoporosis also increases year by year, so that the complication is more worthy of attention. The treatment of osteoporotic spine disease faces a number of additional problems, where osteoporosis complicates spinal surgery, particularly where internal fixation surgical treatment is involved, it can more easily lead to loosening of screws, pullout, pseudoarthroplasty, and the like. Osteoporosis can alter the biomechanics of the bone implant interface, increasing the incidence of poor contact at the bone screw interface, leading to varying degrees of fixation failure.

The existing pedicle screws in the market are basically made of titanium alloy materials, have certain biocompatibility with human tissues, but cannot enable bone tissues to grow into the pedicle screws. At present, the most widely used internal fixation titanium alloy material is Ti6Al4V, although the titanium alloy has good tissue compatibility with human body, the elastic modulus of Ti6Al4V is much higher than that of human skeleton, so that the defects of stress shielding, bone fusion and bone healing influence and the like exist in the use process.

Patent CN209074847U published on 7, 9, 2019 provides a pedicle screw, but lacks a porous structure, which is not conducive to bony tissue ingrowth. All the porous fusion type pedicle screws mentioned in the previous patent select all or part of the screw rod as a porous structure, so that the growth of bone tissues is facilitated, but the excessive porous structure of the screw rod part inevitably reduces the mechanical strength of the pedicle screws, thereby increasing the incidence of screw fracture, so that the currently designed porous pedicle screws cannot meet the clinical biomechanical requirements. In addition, the porous fusion type pedicle screws mentioned in the previous patents neglect the influence of the head part on the osseointegration of the whole screw, so that a "seesaw" effect may be generated, thereby being unfavorable for the osseointegration of the screw.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model provides a 3D prints porous low modulus osseointegration pedicle screw of combining together nature of entity, in the nail pole part, through setting up a plurality of inside hollow holes that print porous structure for 3D, increase the osseointegration effect of screw, aim at solves among the prior art because nail pole porous structure is too much, pedicle screw's mechanical strength is low, the cracked incidence of screw increases, the problem that the osseointegration effect of screw is unfavorable for by pin fin portion "seesaw" effect.

The technical scheme is as follows:

the utility model provides a porous associative nature low modulus osteointegration pedicle of vertebral arch screw of 3D printing entity which characterized in that: the pedicle screw is of a structure formed by 3D printing, the base of the screw seat is of a porous structure, and the side face of the screw body is provided with a plurality of hollow holes; the pedicle screw consists of a screw seat, a screw body and a pressing ring, wherein the head of the screw body is hinged in the screw seat and is limited by the pressed pressing ring.

The external side of the nail body is provided with a plurality of hollow holes which run through the transverse diameter of the nail body, so that the screw stepped uniform distribution is formed on the nail body, the hollow holes are internally provided with porous structures capable of inducing bone growth, the diameter of each hollow hole is 1.75mm, the number of the holes on each side is 3-5, and the included angle of the hollow holes on the adjacent sides is 90 degrees.

The size of the nail body is 4.0-7.0mm in diameter and 25-60mm in length, wherein the thread of the pedicle screw rod is a four-line cortical bone thread, and the distance between the threads is 1.3 mm; the screw thread of the vertebral body nail rod is double-thread cancellous bone screw thread, and the distance between the screw threads is 2.6 mm.

The base of the nail seat is of a porous structure, the porosity is 400-800 mu m, and the porosity is 20-50%.

The Ti2448 medical titanium alloy is adopted as a whole.

The utility model has the advantages that:

1. the screw tail base is provided with the porous structure at the bottom, the base is tightly attached to the articular process after the screw body is placed into a centrum, the base and the porous region of the screw body can form double bone fusion, the contact range of the porous bone and the bone is increased, so that a good bone-screw fusion interface is formed at the nail head and the nail tail, the screw looseness caused by the seesaw effect is reduced, and the stability of an internal fixing system is better promoted.

2. At the nail pole part, print porous structure's hollow hole for 3D through setting up a plurality of insides, under the prerequisite that does not influence or reduce screw fixation intensity by a small margin, increase the osseointegration effect of screw. The 3D printing low-modulus titanium alloy osseointegration pedicle screw is designed, stress shielding is reduced, a porous structure is fully utilized, screw-bone interface integration is promoted, the incidence rate of screw loosening is reduced, and a new choice is provided for surgical treatment of related diseases of the spine.

3. The nail rod is made of titanium alloy material, has certain biocompatibility with human tissues, and is of a porous structure so as to be beneficial to the ingrowth of bone tissues. The Ti2448(Ti-24Nb-4Zr-8Sn) titanium alloy has excellent biocompatibility and mechanical compatibility with human tissues, and is a novel biomedical metal material with the bionic characteristic of human skeletons. The alloy has excellent performances of high strength, high damping, super elasticity and the like, and is easy to process, weld and the like, and the Ti2448 alloy has more excellent biomechanical property and more remarkable multifunctional property.

Drawings

FIG. 1 is a schematic view of the cross-sectional structure of the pedicle screw of the present invention;

fig. 2a and 2b are schematic structural views of the pedicle screw of the present invention;

FIG. 3 is a schematic view of the three-dimensional structure of the pedicle screw of the present invention;

fig. 4a, 4b and 4c are schematic views of the nail seat structure of the present invention;

fig. 5a and 5b are schematic views of the nail body structure of the present invention;

fig. 6a and 6b are schematic diagrams of the structure of the press ring of the present invention;

fig. 7 is a schematic structural diagram of another embodiment of the present invention;

fig. 8 is a schematic structural diagram of another embodiment of the present invention;

description of the reference numerals: a nail seat 100; a base 101; a nail body 200; a pedicle screw rod 201; a vertebral body nail shaft 202; a nail head 203; a hollow bore 204; a pressure ring 300.

The specific implementation mode is as follows:

the utility model provides a porous low modulus osseointegration pedicle of vertebral arch screw of associativity of 3D printing entity. The method is characterized in that a plurality of hollow holes with 3D printing porous structures are arranged in a nail rod part for the first time, so that the osseointegration effect of the screw is increased on the premise of not influencing or slightly reducing the fixing strength of the screw; the porous structure design is applied to the screw head base part for the first time, so that the screw base part is fully contacted with the cancellous bone on the surface of the articular process after the pedicle is placed into the pedicle, a good bone-screw fusion interface is formed on the screw head and the screw rod, the screw looseness caused by the seesaw effect is reduced, and the stability of the internal fixing system is better promoted.

The lower half part of the nail seat, namely the part in contact with the bone surface is printed with a trabecular bone hollow structure in a 3D mode, the middle part of the nail body is provided with a plurality of hollow holes, the trabecular bone hollow structure is printed in the same mode, and then the manufactured three parts are assembled together.

The size of the screw is 4.0-7.0mm, the pedicle area of the screw with the length of 25-60mm is designed into four-line threads, the thread interval is 1.3mm (cortical bone threads), and the holding force of the pedicle area of the vertebra arch is increased; the screw thread of the screw body in the vertebral body area is double-thread, the distance between the screw threads is 2.6mm (cancellous bone screw thread), and the cancellous bone holding force is increased. The nail tail base is of a porous structure, after the nail tail base is placed into a vertebral body, the base is tightly attached to the articular process, the base and the nail body are subjected to double bone fusion, the contact range of the multiple holes and bones is enlarged, the nail bone fusion is promoted, the seesaw effect is reduced, and the stability is further improved. The side hole threads are spirally distributed on the nail body (3-5 side holes, the number of the side holes can be increased or decreased according to the size of the screw, the screw with the length of 25-30mm is provided with 3 side holes, the screw with the length of 35-45mm is provided with 4 side holes, and the screw with the length of 50-60mm is provided with 5 side holes). The diameter of the side hole is 1.75mm, the porous porosity is designed to be 400-800 microns, and the porosity is 50-75 percent, so that the bone ingrowth can be induced.

Firstly, the ball stud is installed in the stud seat, and then the pressing ring is pressed into the stud seat, so that the ball stud cannot be separated. After the installation, the nail seat can have a certain movable angle around the ball head, so that the installation of the connecting system in an operation is facilitated.

Porous structure can be than solid structure mechanical properties poor, and the nail body part of the past patent is all porous structure, and mechanical properties is poor, is not enough to satisfy the clinical mechanical needs to the internal fixture, and this patent is the side opening structure, and the side opening structure all is located the lower cancellous bone screw thread region of atress distribution, is similar to the hollow bone cement pedicle of vertebral arch screw of present clinical application, has good biomechanics performance, can satisfy the needs of clinical spinal internal fixation.

A porous structure with bone ingrowth capability is added to the base part of the nail body. After the pedicle screw is placed into the vertebral body, the bottom of the screw seat can be tightly contacted with the articular process, so that the screw-bone integration of the part is formed.

The ability of porous metals to promote bone growth and bone fusion has been widely studied and recognized. Compared with solid materials, the porous metal has the interconnected micro-channel structure, which is beneficial to bone growth and formation of new blood vessels, and ensures faster bone formation speed.

The present invention will be further explained with reference to the accompanying drawings:

example 1:

as shown in fig. 1, a 3D printed solid porous associated low modulus osseointegration pedicle screw is a 3D printed structure with a plurality of hollow holes 204 on the side; the pedicle screw consists of three parts, namely a screw seat 100, a screw body 200 and a pressing ring 300, wherein the head 203 of the screw body 200 is hinged in the screw seat 100 and is limited by the pressed-in pressing ring 300, as shown in figures 2, 3 and 6.

As shown in fig. 5, the diameter of the hollow holes 204 at the outer side of the nail body 200 is 1.75mm, the hollow holes are uniformly distributed on the nail body 200 in a spiral step shape, the number of the holes at each side is 3, and the included angle of the hollow holes 204 at the adjacent sides is 90 °. The size of the nail body 200 is 4.0mm in diameter and 25mm in length, wherein the thread of the pedicle screw rod 201 is a four-line cortical bone thread, and the thread interval is 1.3 mm; the thread of the vertebral body nail rod 202 is double cancellous bone thread, and the distance between the threads is 2.6 mm.

As shown in FIG. 4, the base of the nail seat 100 has a porous structure with a porosity of 400-800 μm and a porosity of 20% -50%.

The Ti2448 medical titanium alloy is adopted as a whole.

Example 2:

A3D printing trabecular pedicle screw for bone is a 3D printing structure, and the side surface of the pedicle screw is provided with a plurality of hollow holes 204; the pedicle screw consists of three parts, namely a screw seat 100, a screw body 200 and a pressing ring 300, wherein the head 203 of the screw body 200 is hinged in the screw seat 100 and is limited by the pressed-in pressing ring 300.

As shown in fig. 7, the diameter of the hollow holes 204 outside the nail body 200 is 1.75mm, the hollow holes are uniformly distributed on the nail body 200 in a spiral step shape, the number of the holes on each side is 4, and the included angle of the hollow holes 204 on the adjacent sides is 90 °. The size of the nail body 200 is 5.5mm in diameter and 40mm in length, wherein the thread of the pedicle nail rod 201 is a four-line cortical bone thread, and the thread interval is 1.3 mm; the thread of the vertebral body nail rod 202 is double cancellous bone thread, and the distance between the threads is 2.6 mm.

The base of the nail seat 100 is a porous structure with a porous pore size of 400-.

The Ti2448 medical titanium alloy is adopted as a whole.

Example 3:

As shown in fig. 8, the diameter of the hollow holes 204 outside the nail body 200 is 1.75mm, the hollow holes are uniformly distributed on the nail body 200 in a spiral step shape, the number of the holes on each side is 5, and the included angle of the hollow holes 204 on the adjacent sides is 90 °. The size of the nail body 200 is 7.0mm in diameter and 60mm in length, wherein the thread of the pedicle nail rod 201 is a four-line cortical bone thread, and the thread interval is 1.3 mm; the thread of the vertebral body nail rod 202 is double-thread cancellous bone thread, and the distance between the threads is 2.6 mm.

The base of the nail seat 100 is a porous structure with a porosity of 400-800 μm and a porosity of 20-50%.

The Ti2448 medical titanium alloy is adopted as a whole.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and it is to be understood that the present invention is not limited to the above embodiments, but may be modified within the scope of the present invention.

Claims

1. The utility model provides a porous associative nature low modulus osteointegration pedicle of vertebral arch screw of 3D printing entity which characterized in that: the pedicle screw is a structure formed by 3D printing, the base (101) of the screw seat (100) is of a porous structure, and the side surface of the screw body (200) is provided with a plurality of hollow holes (204); the pedicle screw consists of a screw seat (100), a screw body (200) and a pressing ring (300), wherein the head (203) of the screw body (200) is hinged in the screw seat (100) and is limited by the pressed-in pressing ring (300).

2. The 3D printed solid porous associative low-modulus osseointegration pedicle screw according to claim 1, wherein: the nail body (200) outside cloth has a plurality of hollow holes (204) that run through the horizontal footpath of the nail body (200), becomes spiral notch cuttype evenly distributed on the nail body (200), the inside porous structure for having the induced bone ability of going into of hollow hole (204), the diameter of hollow hole (204) is 1.75mm, and the hole number of every side is 3-5, and hollow hole (204) contained angle of the adjacent side is 90.

3. The 3D printed solid multihole combination low modulus osseointegration pedicle screw as claimed in claim 2, wherein: the size of the nail body (200) is 4.0-7.0mm in diameter and 25-60mm in length, wherein the thread of the pedicle nail rod (201) is a four-line cortical bone thread, and the thread interval is 1.3 mm; the thread of the vertebral body nail rod (202) is double cancellous bone thread, and the distance between the threads is 2.6 mm.

4. The 3D printed solid porous associative low-modulus osseointegration pedicle screw according to claim 1, wherein: the base (101) of the nail seat (100) is of a porous structure, the porous pore size is 400-800 mu m, and the porosity is 20-50%.

5. The 3D printed solid porous associative low-modulus osseointegration pedicle screw according to claim 1, wherein: the Ti2448 medical titanium alloy is adopted as a whole.