CN217908092U

CN217908092U - Viscoelastic lumbar posterior three-joint reconstruction prosthesis

Info

Publication number: CN217908092U
Application number: CN202221158376.1U
Authority: CN
Inventors: 黄鑫怡; 雷伟; 张扬; 杨意鹏; 刘大铭; 邱海洋; 卢昌波; 王靖
Original assignee: Air Force Medical University of PLA
Current assignee: Air Force Medical University of PLA
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2022-11-29
Anticipated expiration: 2032-05-13

Abstract

The utility model discloses a viscoelastic lumbar posterior three-joint reconstruction prosthesis, which comprises a pair of same prosthesis devices, wherein each prosthesis device comprises an intervertebral disc component, a joint protrusion component and a fixing component, the intervertebral disc component comprises an upper end plate, a viscoelastic core and a lower end plate, and the lower end plate comprises a functional part and a connecting part which are connected from front to back; the rear end of the connecting part is provided with a screw channel which is inclined towards the front lower part; the joint protrusion part comprises an upper joint body, an elastic layer and a lower joint body which are bonded from top to bottom, and is arranged at the rear end of the connecting part of the intervertebral disc part; the fixing component comprises a first screw and a second screw, and the first screw is matched with the screw channel of the connecting part; the second screw mates with the screw hole of the upper joint body. The utility model discloses creatively rebuilds intervertebral disc and facet joint simultaneously to choose the viscoelastic material of similar natural intervertebral disc for use, keep backbone mobility and buffering shock energy, it is bionical to reach mechanics as far as, reduction backbone function.

Description

Viscoelastic lumbar posterior three-joint reconstruction prosthesis

Technical Field

The utility model belongs to the technical field of orthopedics backbone operation implant, concretely relates to false body is rebuild to three joints of viscoelasticity lumbar vertebrae way of escape.

Background

For lumbar degenerative diseases, more surgical treatment methods are available, wherein the traditional spinal vertebral fusion is still the gold standard for treating the diseases. However, more and more clinical evidence indicates that the limited movement of the fused lumbar part can cause abnormal changes of the spinal dynamics and accelerated degeneration of the adjacent segments, which may lead to the recurrence of unstable lumbar vertebrae and spinal stenosis, even requiring secondary revision surgery. In view of the above, there is a need to find an alternative that can meet the therapeutic requirements while effectively preserving spinal motion. The anterior disc replacement is one of the non-fusion techniques for treating lumbar diseases, and the novel artificial intervertebral disc prosthesis can basically meet the activity requirement, but the treatment method has limited indications and cannot solve the facet joint process lesion, so the method is only suitable for relatively few patients with simple intervertebral disc degeneration. In response to this problem, it is contemplated that a posterior-based option for preserving motion, both to allow for neural decompression and resection of the diseased articular processes, while simultaneously reconstructing the resected disc and facet joints, may play a role. The intervertebral discs and pairs of zygapophyseal joints of the spinal motion unit together comprise a three-joint complex, but no motion-preserving posterior lumbar joint reconstruction devices have been found that can be implanted following direct laminectomy, facet arthroplasty, and total discectomy.

Disclosure of Invention

To solve the problems existing in the prior art, the present invention provides a viscoelastic lumbar posterior three-joint reconstruction prosthesis to replace the intervertebral disc and facet joint after extensive decompression of laminectomy.

In order to realize the purpose, the utility model adopts the following technical scheme to solve:

a viscoelastic lumbar posterior three-joint reconstruction prosthesis comprises a pair of identical prosthesis devices, wherein each prosthesis device comprises an intervertebral disc component, an articular process component and a fixing component, the intervertebral disc component comprises an upper endplate, a viscoelastic core and a lower endplate, and the lower endplate comprises a functional part and a connecting part which are connected from front to back; the upper end plate, the viscoelastic core and the functional part are sequentially bonded and connected from top to bottom to form a whole, and the length of the upper end plate is equal to that of the lower end plate and is greater than that of the viscoelastic core;

the rear end of the connecting part is provided with a screw channel which is inclined towards the front lower part, the rear end of the screw channel is opened on the rear end surface of the connecting part, and the front end of the screw channel is opened on the lower surface of the connecting part;

the joint protrusion part comprises an upper joint body, an elastic layer and a lower joint body which are bonded from top to bottom, and the joint protrusion part is arranged at the rear end of the connecting part of the intervertebral disc part; the rear end edges of the upper joint body and the lower joint body are respectively provided with an anchoring plate, and the anchoring plate of the upper joint body is provided with a screw hole which is inclined to the front and the upper part; the lower surface of the lower joint body is contacted with the upper surface of the rear end of the connecting part of the intervertebral disc component, the inner wall of an anchoring plate of the lower joint body is contacted with the rear end surface of the connecting part, a screw hole which is inclined forwards and downwards is arranged on the anchoring plate, the screw hole corresponds to the rear end opening position of a screw channel of the connecting part, the inclination angles of the screw hole and the screw channel are consistent, and when the anchoring plate is abutted against the rear end surface of the lower end plate, the screw hole and the screw channel can be superposed to form a channel;

the fixing component comprises a first screw and a second screw, and the length of the first screw is greater than that of the second screw; the first screw is matched with the screw channel of the connecting part; the second screw is matched with the screw hole on the anchoring plate of the upper joint body.

Furthermore, grooves are formed in the lower surface of the upper end plate and the upper surface of the lower end plate, and the shapes of the two grooves are matched with the shapes of the upper surface and the lower surface of the viscoelastic core respectively.

Furthermore, the inclination angle of the screw channel and the horizontal plane form 10-30 degrees; the screw holes obliquely arranged in the front and the upper direction on the anchoring plate of the upper joint body form an angle of 10-30 degrees with the horizontal direction.

Furthermore, the inner wall of the screw channel is also provided with threads.

Furthermore, the upper surface of the upper end plate and the lower surface of the lower end plate are both provided with a first reinforcing device.

Furthermore, the upper surface of the upper end plate and the lower surface of the lower end plate are coated with titanium plasma spraying coatings.

Further, a second reinforcing device is arranged on the upper surface of the upper joint body of the articular process component.

Further, the upper surface of the upper joint body is coated with a titanium plasma spraying coating.

Furthermore, the bottom surface of the lower joint body is provided with a cross tooth protrusion, the upper surface of the tail part of the connecting part is provided with a cross groove matched with the cross tooth protrusion, and the cross groove is positioned at the front part of the screw channel.

Further, the first screw is a long spinal fixation screw; the second screw is a short spinal fixation screw.

Compared with the prior art, the utility model discloses a profitable technological effect as follows:

(1) Compared with the vertebral body fusion, the normal physiological motion of the spine can be kept, and abnormal change of the spine dynamics and accelerated degeneration of adjacent segments caused by loss of the mobility of diseased segments are avoided.

(2) Compared with intervertebral disc replacement, the application is wider. Not only can directly reduce the pressure of the diseased intervertebral disc, but also can simultaneously solve the pathological changes of the facet joint process and carry out the extensive pressure reduction of posterior laminectomy, and is also suitable for bilateral crypt/central spinal stenosis.

(3) The intervertebral disc and the facet joint are creatively reconstructed at the same time after laminectomy, facet joint resection and discectomy, and viscoelastic materials similar to natural intervertebral discs are selected, so that the mobility and the vibration buffering capacity of the spine are kept, the mechanical bionics is achieved as far as possible, and the function of the spine is restored.

(4) The implantation of the prosthesis still enters the way through the intervertebral foramen on both sides, does not need to increase extra anterior operation, and simplifies the whole operability of the operation; meanwhile, due to the structural design of the prosthesis, the use process is convenient and fast, and the wide clinical application can be met.

Drawings

Fig. 1 is a schematic view of the structure of a normal human lumbar intervertebral disc and articular process.

Fig. 2 is a schematic view (side view) of the structure of a normal human lumbar intervertebral disc and articular process.

Fig. 3 is a schematic perspective view of the prosthesis of the present invention.

Fig. 4 is a perspective view of the components of the prosthesis of the present invention.

Fig. 5 is a top view of the lower endplate.

Fig. 6 is a schematic view of the prosthesis of the present invention assembled and secured.

Figure 7 is a top view of the prosthesis of the present invention.

Figure 8 is a top perspective view of the prosthesis of the present invention implanted in a lumbar spine.

The invention is further explained below with reference to the drawings and the detailed description.

Detailed Description

As shown in fig. 3-7, the utility model provides a viscoelasticity lumbar vertebrae way of escape three joint reconstruction prosthesis, including a pair of the same prosthesis device, they are suitable for bilateral symmetry to be placed in the intervertebral disc space between upper and lower centrum bone, and this prosthesis device includes intervertebral disc part 1, articular process part 2 and fixed part, and wherein, intervertebral disc part 1 includes upper endplate 4, viscoelasticity core 5 and lower endplate 6, and lower endplate 6 includes by function portion 6-1 and the connecting portion 6-2 of extension of connecting forward backward. The upper end plate 4, the viscoelastic core 5 and the functional part 6-1 are sequentially connected and bonded from top to bottom to form a whole, and the length of the upper end plate 4 is equal to that of the lower end plate 6 and is greater than that of the viscoelastic core 5. In the structural design, the viscoelastic core 5 of the intervertebral disc component 1 is positioned in the middle of the functional parts 6-1 of the upper end plate 4 and the lower end plate 6, the upper end plate 4 and the lower end plate 6 are connected through bonding forming or strong bonding agent, and the viscoelastic intervertebral disc component 1 is formed by the three in the intervertebral space in a sandwich mode.

Preferably, the lower surface of the upper end plate 4 and the upper surface of the lower end plate 6 are both provided with grooves, the shapes of the two grooves are respectively matched with the shapes of the upper surface and the lower surface of the viscoelastic core 5, the viscoelastic core 5 is limited between the upper groove and the lower groove, the stability is improved, and the displacement can be prevented.

Specifically, the whole formed by the upper end plate 4, the viscoelastic core 5 and the functional part 6-1 is completely arranged in the intervertebral space when being implanted and applied; the rear end of the connecting part 6-2 is provided with a screw channel 6-3 which is inclined towards the front lower part, and the inclined angle is 10-30 degrees with the horizontal plane; the rear end of the screw channel 6-3 is opened on the rear end face of the connecting part 6-2, and the front end of the screw channel is opened on the lower surface of the connecting part 6-2; preferably, the inner wall of the screw channel 6-3 is also provided with threads, so that the fixation between the screw channel and a matched screw can be more stable.

Preferably, the superior endplate 4 and inferior endplate 6 of the disc component 1 are made of a high strength Polyetheretherketone (PEEK) hard material (including but not limited to PEEK carbon, titanium and titanium alloys, stainless steel), wherein PEEK material is advantageous in that it is also magnetic resonance examination compatible, i.e., no metal artifacts are present, and better imaging information can be displayed. Specifically, the upper surface of the upper end plate 4 and the lower surface of the lower end plate 6 are both provided with a first reinforcing device 4-1 for immediate fixation (preferably keels, anchors and inverted teeth, if keels, at least one keel or a plurality of parallel keels can be provided, and if anchors or inverted teeth are selected, a plurality of anchors or inverted teeth are uniformly distributed on the surfaces). Further, the upper surface of the upper end plate 4 and the lower surface of the lower end plate 6 are coated with titanium plasma spraying coatings (including but not limited to hydroxyapatite coatings and porous titanium coatings) to promote bone ingrowth and achieve osseointegration between the prosthesis and the vertebral body, thereby achieving long-term fixation.

Preferably, the viscoelastic core 5 is made of polycarbonate polyurethane PCU (polyurethane PU, silicone, rubber, hydrogel) material, which can provide mobility and shock damping capability through elastic deformation. In particular, the disc component 1 allows flexion, extension, compression, extension, left and right lateral bending and torsional movement of the upper and lower vertebral bodies relative to one another after installation application. Meanwhile, the thickness of the periphery of the grooves of the upper end plate 4 and the lower end plate 6 can firstly collide with each other to play a role in limiting excessive movement to a certain extent when the lumbar vertebrae is excessively bent and extended and laterally bent.

The articular process component 2 comprises an upper joint body 2-1, an elastic layer 2-2 and a lower joint body 2-3 which are connected from top to bottom, and the articular process component 2 is arranged at the rear end of a connecting part 6-2 of the intervertebral disc component 1; preferably, the superior and inferior articular bodies 2-1, 2-3 are formed of a high strength, hard material such as Polyetheretherketone (PEEK) (including, but not limited to, PEEK carbon, titanium alloys, stainless steel) in conformity with the superior and

inferior endplates

4, 6 of the disc component 1.

In particular, the upper surface of the upper joint body 2-1 of the articular process component 2 is also provided with second reinforcement means 2-7 (preferably keels, anchors, inverted teeth) for immediate fixation. Further, the upper surface of the upper joint body 2-1 is also coated with a titanium plasma spraying coating (including but not limited to hydroxyapatite coating and porous titanium coating).

Particularly, the bottom surface of the lower joint body 2-3 is provided with a cross tooth protrusion 2-4, the upper surface of the tail part of the connecting part 6-2 is provided with a cross groove 6-4 matched with the cross tooth protrusion 2-4, and the cross groove 6-4 is positioned at the front part of the screw channel to provide a fixing point for the articular process part 2, so that the articular process part 2 is fixed on the intervertebral disc part 1, and meanwhile, the connection of the two parts can be more stable and displacement is prevented.

The rear end edges of the upper joint body 2-1 and the lower joint body 2-3 are respectively provided with an anchoring plate 2-5, the anchoring plate 2-5 of the upper joint body 2-1 is provided with a screw hole 2-6 which is inclined forwards and upwards, and the inclined angle is also 10-30 degrees with the horizontal direction; the lower surface of the lower joint body 2-3 is contacted with the upper surface of the rear end of the connecting part 6-2 of the intervertebral disc component 1, the inner wall of the anchoring plate 2-5 of the lower joint body 2-3 is contacted with the rear end surface of the connecting part 6-2, the anchoring plate 2-5 is provided with a screw hole 2-6 which inclines forwards and downwards, the screw hole 2-6 corresponds to the rear end opening position of the screw channel 6-3 of the connecting part 6-2, the inclination angles of the screw hole 2-6 and the screw channel 6-3 are consistent, and when the anchoring plate 2-5 is abutted against the rear end surface of the lower end plate 6, the screw hole 2-6 and the screw channel 6-3 can be coincided to form a channel.

The fixing component comprises a first screw and a second screw, and the length of the first screw is greater than that of the second screw; the first screw is matched with the screw channel 6-3 of the connecting part 6-2, and the second screw is matched with the screw hole 2-6 on the anchoring plate 2-5 of the upper joint body 2-1. The first screw is obliquely screwed in from the screw hole 2-6 of the lower joint body 2-3 through the screw channel 6-3, so that the upper joint body 2-1 is fixed on the pedicle of the upper vertebral body, and the intervertebral disc component 1 is fixed on the lower vertebral body and the articular process component 2 is fixed on the intervertebral disc component 1; the second screw is screwed obliquely upwards into the pedicle of the lower vertebral body through the screw hole 2-6 of the upper joint body 2-1, thereby fixing the prosthetic device with the vertebral body.

Preferably, the first screw is a long spinal fixation screw (including but not limited to, ordinary screws, universal screws, cortical screws, and for osteopenic patients such as osteoporosis, spinal expansion screws may also be used). The second screw is selected from short spinal fixation screws (including but not limited to common screws and cortical screws).

Preferably, the elastic layer 2-2 of the articular process component 2 is bonded to the upper articular body 2-1 and the lower articular body 2-3 by adhesive bonding or strong adhesives, as is the case with the viscoelastic core 5 of the intervertebral disc component 1. Preferably, the elastic layer 2-2 is also made of polycarbonate polyurethane PCU (polyurethane PU, silicone, rubber, hydrogel), and compared with a simple titanium rod used in the existing prosthesis, the design of the elastic layer 2-2 is more flexible, which allows the degree of mobility and shock buffering capability to be provided through elastic deformation without completely limiting the flexion and torsion motions of the upper and lower vertebral bodies, and the proper deformation adjustment allows the requirement of the upper joint body 2-1 fixing position of the articular process component 2 to be relatively loose, thereby improving the operability in the operation.

After all fixation is completed, the intervertebral disc component 1 reconstructs the viscoelastic intervertebral disc, and the articular process component 2 reconstructs bilateral articular process joints.

Specifically, the utility model discloses a viscoelastic lumbar vertebrae way of escape three joints rebuild false body's use as follows:

first step-reduced pressure excision: following laminectomy and bilateral facet arthroplasty, the intervertebral disc space is accessed via a bilateral approach to transforaminal lumbar interbody fusion to resect the diseased disc, but the external annulus and anterior longitudinal ligament are preserved to maintain soft tissue tension and stability.

Second step-endplate preparation: after completion of the discectomy on the human lumbar spine as shown in fig. 1 or fig. 2, a special burr is used to prepare the upper and lower endplates of the vertebral body, an osteotomy is performed to "parallelize" the endplates and keel slots (or roughened surfaces for anchors or teeth) are pre-cut into the vertebral body to allow for an initial press-fit of the prosthesis. The length and height test is used to determine the appropriate size of the implant. At this step, bilateral soft tissue balancing is accomplished: efforts are made to restore disc height and bilateral soft tissue tension without overfilling the disc space.

Third step-implant disc component: after corrective osteotomy, keel cut, soft tissue tensioning and dimensional testing, the treated segment received two prosthetic devices as implants implanted bilaterally along the pedicle axis with the midpoint of the implant positioned about 40% ventral of the posterior vertebral body (coincident with the physiological center of rotation), with initial fixation by a press fit of the keel as shown in fig. 8.

Fourth step-fixing articular process component: after the intervertebral disc component 1 is implanted, the articular process component 2 is taken, the articular process component is preliminarily connected to the intervertebral disc component through cross clamping, (namely, the cross tooth protrusions 2-4 on the bottom surface of the lower joint body 2-3 are placed in the cross grooves 6-4 on the tail part of the connecting part 6-2), and meanwhile, the anchoring plate of the lower joint body 2-3 is ensured to be tightly abutted against the rear end surface of the lower end plate 6 of the intervertebral disc component, so that the screw hole on the anchoring plate of the lower joint body 2-3 and the screw channel 6-3 of the connecting part 6-2 can be superposed to form a channel. A first screw is then taken through this passage, i.e. simultaneously through the disc part 1 and the articular process part 2, obliquely through the pedicle and screwed into the inferior vertebral body, achieving a further fixation of the two parts and simultaneously a common fixation of the two parts to the vertebral body. Then a second screw is taken and screwed into the pedicle of the upper vertebral body obliquely upwards through a screw hole of the upper joint body 2-1, so that the upper end of the articular process part is fixed.

The implant allows the treatment segment to perform near normal six-degree-of-freedom motion post-operatively, with the disc component 1 disposed in the disc space, maintaining the height of the disc space while retaining its physiological motion and shock-dampening capabilities; the apophyseal component 2 replaces the bilateral facet joints on the posterior side of the vertebral body and serves to maintain stability and limit excessive motion. Therefore, the prosthesis of the utility model can effectively replace the functions of the resected intervertebral disc and the zygapophyseal joint.

Claims

1. A viscoelastic lumbar posterior three-joint reconstruction prosthesis is characterized by comprising a pair of identical prosthesis devices, wherein each prosthesis device comprises an intervertebral disc component (1), an articular process component (2) and a fixing component, the intervertebral disc component (1) comprises an upper end plate (4), a viscoelastic core (5) and a lower end plate (6), and the lower end plate (6) comprises a functional part (6-1) and a connecting part (6-2) which are connected from front to back; the upper end plate (4), the viscoelastic core (5) and the functional part (6-1) are sequentially connected from top to bottom to form a whole, and the length of the upper end plate (4) is equal to that of the lower end plate (6) and is greater than that of the viscoelastic core (5);

the rear end of the connecting part (6-2) is provided with a screw channel (6-3) which is inclined towards the front lower part, the rear end of the screw channel (6-3) is opened on the rear end surface of the connecting part (6-2), and the front end of the screw channel is opened on the lower surface of the connecting part (6-2);

the articular process component (2) comprises an upper joint body (2-1), an elastic layer (2-2) and a lower joint body (2-3) which are connected from top to bottom, and the articular process component (2) is arranged at the rear end of the connecting part (6-2) of the intervertebral disc component (1); the rear end edges of the upper joint body (2-1) and the lower joint body (2-3) are respectively provided with an anchoring plate (2-5), and the anchoring plate (2-5) of the upper joint body (2-1) is provided with a screw hole (2-6) which is inclined to the front and the upper part; the lower surface of the lower joint body (2-3) is contacted with the upper surface of the rear end of the connecting part (6-2) of the intervertebral disc component (1), the inner wall of the anchoring plate (2-5) of the lower joint body (2-3) is contacted with the rear end surface of the connecting part (6-2), the anchoring plate (2-5) is provided with a screw hole (2-6) which is inclined forwards and downwards, the screw hole (2-6) corresponds to the rear end opening position of the screw channel (6-3) of the connecting part (6-2) and the inclination angles of the screw hole and the screw channel are consistent, when the anchoring plate (2-5) is tightly close to the rear end surface of the lower end plate (6), the screw hole (2-6) and the screw channel (6-3) can be superposed to form a channel;

the fixing component comprises a first screw and a second screw, and the length of the first screw is greater than that of the second screw; the first screw is matched with a screw channel (6-3) of the connecting part (6-2); the second screw is matched with the screw hole (2-6) on the anchoring plate (2-5) of the upper joint body (2-1).

2. The viscoelastic lumbar posterior three-joint reconstructive prosthesis according to claim 1, characterized in that the lower surface of the upper endplate (4) and the upper surface of the lower endplate (6) are provided with grooves, the shape of which matches the shape of the upper surface and the lower surface of the viscoelastic core (5), respectively.

3. The viscoelastic posterior lumbar three-joint reconstructive prosthesis according to claim 1, characterized in that the inclination angle of the screw channel (6-3) is 10-30 degrees from the horizontal plane; the screw holes (2-6) which are obliquely arranged in the front and the upper direction on the anchoring plate (2-5) of the upper joint body (2-1) form an angle of 10-30 degrees with the horizontal direction.

4. The viscoelastic lumbar posterior three-joint reconstructive prosthesis of claim 1, characterized in that the inner wall of the screw channel (6-3) is further threaded.

5. The viscoelastic lumbar posterior three-joint reconstructive prosthesis according to claim 1, characterized in that the upper surface of the upper endplate (4) and the lower surface of the lower endplate (6) are provided with first reinforcement means (4-1).

6. The viscoelastic posterior lumbar three-joint reconstructive prosthesis according to claim 1, characterized in that the upper surface of the upper endplate (4) and the lower surface of the lower endplate (6) are coated with a titanium plasma spray coating.

7. The viscoelastic lumbar posterior three-joint reconstructive prosthesis according to claim 1, characterized in that the upper surface of the upper joint body (2-1) of the articular process component (2) is provided with second reinforcement means (2-7).

8. The viscoelastic posterior lumbar three-joint reconstructive prosthesis according to claim 1, characterized in that the upper surface of the upper joint body (2-1) is coated with a titanium plasma sprayed coating.

9. The viscoelastic posterior lumbar three-joint reconstructive prosthesis according to claim 1, characterized in that the lower joint body (2-3) is provided with a cross-shaped protrusion (2-4) at the bottom surface thereof, and the upper surface of the tail portion of the connecting portion (6-2) is provided with a cross-shaped groove (6-4) matching with the cross-shaped protrusion (2-4), the cross-shaped groove (6-4) being located at the front portion of the screw channel.

10. The viscoelastic posterior lumbar three-joint reconstructive prosthesis of claim 1, wherein said first screw is selected from a long spinal fixation screw; the second screw is a short spinal fixation screw.