Intelligent fusion cage for lumbar malformation correction

Abstract

The invention relates to an intelligent fusion cage for lumbar malformation correction, and relates to the technical field of medical instruments, the intelligent fusion cage is formed by fixedly connecting three main frame bodies side by side, the upper end and the lower end of each main frame body are fixedly connected with a supporting body, the upper surface of each supporting body is of a wave-shaped structure and is composed of a plurality of convex bodies, the wave crests of each convex body are fixedly connected with antibiotic microspheres, and the wave troughs of each convex body are provided with BMP-2 slow-release gel; a relieving bag is fixedly connected into the supporting body, one end of the relieving bag is of a frustum-shaped structure, and the central point ratio CPR of the fusion cage is larger than or equal to 50% when the fusion cage is implanted; convex holes are annularly formed in the upper and lower surfaces of the main frame body, VEGF nano-liposomes are placed in the main frame body, permeation holes I with honeycomb structures are formed in the two side ends of the main frame body, and permeation holes II communicated with the interlayer channels are formed in the main frame body close to the bottom joint of the support body; the support body and the relieving capsule are composed of a PLGA / silk fibroin / nHA compound, the main frame body is Mg-Zn-Sr alloy, and the alloy is degraded to release ions to promote new bone ingrowth.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an intelligent fusion device for lumbar spine deformity correction surgery. Background Technology

[0002] In oblique lateral lumbar interbody fusion (OLIF), fusion cage subsidence refers to the phenomenon of the fusion cage sinking into the bone of the adjacent vertebral body in the vertical direction. This can lead to loss of segmental lordosis angle (SLA), loss of intervertebral disc height, reduced intervertebral foramen volume, and recompression of nerve roots, resulting in symptom recurrence. Subsidence can also cause instability of the fusion cage interface, delayed fusion, or pseudoarthrosis. According to experimental data from Gong et al., Restoration and maintenance of segment lordosis inoblique lumbar interbody fusion, BMC Musculoskeletal Disorders (2022) 23:914, the central bone density of the vertebral body is lower than that of the peripheral cortical bone. That is, posterior placement is more prone to collapse (pressure is concentrated in the low-density area of ​​the endplate, the bone strength is insufficient, stress concentration leads to a high risk of subsidence). The position of the fusion cage is a key determinant of the recovery of segmental lordosis angle (SLA). Placing the fusion cage in an anterior position (the center point of the fusion cage is ≥ 50% of the CPR) can better achieve the recovery of SLA and reduce the incidence of fusion cage subsidence. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing an intelligent fusion device for lumbar spine deformity correction surgery. By relieving the sac 230 with a frustum-shaped structure at one end with a cone angle of 20°-28°, the installation position of the fusion device satisfies the requirement that the center point of the fusion device is ≥50% of the CPR, thereby reducing the incidence of fusion device subsidence and better achieving the technical effect of restoring the segmental lordosis angle (SLA).

[0004] The technical solution of this invention to solve the above-mentioned technical problems is as follows: An intelligent fusion device for lumbar spine deformity correction surgery includes a fusion device, which is composed of three main frames fixedly connected side by side. A support body is fixedly connected to the upper and lower ends of the main frames. The upper surface of the support body has a wave-shaped structure, and a relief capsule is fixedly connected inside the support body. The relief capsule has a larger diameter at one end than at the other end, and one end of the relief capsule 230 has a frustum-shaped structure with a cone angle of 20°-28°. It is configured such that when implanted, the center point of the fusion device is ≥50% of the CPR. The upper and lower surfaces of the main frame are provided with multiple protruding holes arranged in a ring, and VEGF nanoliposomes are placed inside the protruding holes. The surface of the main frame is provided with a nano-hydroxyapatite / heparin composite membrane, which serves to prevent thrombosis and promote new bone ingrowth. The two sides of the main frame are also provided with a permeation hole, which has a honeycomb structure. The support and relief capsule are composed of a PLGA / silk fibroin / nHA complex; The main frame is a Mg-Zn-Sr alloy, and the degradation of the alloy can release zinc ions and strontium ions to promote the ingrowth of new bone. Inside the main frame, near the bottom connection of the support, there is a second permeation hole, which is connected to the first permeation hole. The wave structure of the support is composed of multiple protrusions, with a spacing of 3mm between adjacent protrusions; A permeable sphere, which is an antibiotic microsphere, is fixedly attached to the crest of the protrusion. The trough of the protrusion is embedded with a permeable plate, which is made of BMP-2 sustained-release gel. Its function is to achieve sustained release of BMP-2 sustained-release gel for 6-8 weeks through hydrolysis and degradation, and to maintain the concentration of local bone morphogenetic protein.

[0005] The beneficial effects of this invention are: By having the upper and lower relief capsules share a cone angle of 20°-28°, the installation position of the fusion cage ensures that the center point of the fusion cage is ≥50% of the CPR (Cost Per Reduction), thus reducing the incidence of fusion cage subsidence and better restoring the segmental lordosis angle (SLA). The wave-shaped structure of the support body, along with its internal relief capsules, disperses vertebral pressure, preventing stress concentration and wear on the fusion cage surface. Furthermore, the placement of antibiotic microspheres and BMP-2 sustained-release gel at the peaks and troughs of the support body, along with VEGF nanoliposomes within the external convex orifice, creates an optimal osteogenic microenvironment for the golden position of CPR ≥50%, improving the success rate of OLIF (Optimal Osteogenic Injection). Attached Figure Description

[0006] Figure 1 A three-dimensional structural diagram of an intelligent fusion device for lumbar spine deformity correction surgery; Figure 2 A schematic diagram of the main frame structure of an intelligent fusion device for lumbar spine deformity correction surgery; Figure 3 A schematic diagram of the support structure of an intelligent fusion device for lumbar spine deformity correction surgery; Figure 4 A half-section diagram of an intelligent fusion device for lumbar spine deformity correction surgery; Figure 5 FH diagram of an intelligent fusion device for lumbar spine deformity correction surgery; Figure 6 A diagram illustrating the CPR process of an intelligent fusion device used in lumbar spine deformity correction surgery.

[0007] The attached diagram lists the components represented by each number as follows: 100. Fusion device; 110. Main frame; 111. Infiltration hole one; 112. Outer protrusion hole; 113. Interlayer channel; 114. Infiltration hole two; 200. Support body; 201. Protrusion; 210. Infiltration ball; 220. Infiltration plate; 230. Relief sac. Detailed Implementation

[0008] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0009] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0010] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0011] Example 1 Please see Figures 1 to 6This invention provides an intelligent fusion device for lumbar spine deformity correction surgery, including a fusion device 100. The fusion device 100 is composed of three main frame bodies 110 fixedly connected side by side. A support body 200 is fixedly connected to the upper and lower ends of the main frame bodies 110. The upper surface of the support body 200 has a wave-shaped structure. A relief bladder 230 is fixedly connected inside the support body 200. When the support body 200 is compressed, the wave-shaped structure on its upper surface can disperse the compressive force in the longitudinal and lateral directions. Furthermore, when the support body 200 is deformed by compression, it will compress the relief bladder 230. The relief bladder 230, when compressed, disperses the compressive force... The uncompressed end expands, causing the other end of the support 200 to be subjected to the compressive force of the relief capsule 230. This prevents the compressive force on the support 200 from concentrating in any one area. The function is to eliminate stress concentration on the support 200 through the cooperation of the support 200 and the relief capsule 230. One end of the relief capsule 230 has a larger diameter than the other end, and one end of the relief capsule 230 has a frustum-shaped structure with a cone angle of 20°-28°. This configuration ensures that the center point of the fusion device is ≥50% of the CPR during implantation, reducing the incidence of fusion device subsidence and better achieving SLA recovery. The upper and lower surfaces of the main frame 110 have multiple protruding holes 112 arranged in a ring. VEGF nanoliposomes are placed inside the protruding holes 112, which enhance angiogenesis and promote local blood vessel growth. The surface of the main frame 110 is provided with a nano-hydroxyapatite / heparin composite membrane, which serves to prevent thrombosis and promote the ingrowth of new bone. The two ends of the main frame 110 are also provided with permeation holes 111, which have a honeycomb structure. The function of the permeation holes 111 is to make the new bone more firmly fixed on the fusion device 100 through the honeycomb structure. The support 200 and relief capsule 230 are composed of a PLGA / silk fibroin / nHA complex, both of which can be eliminated through the body's inherent metabolic pathways. The PLGA / silk fibroin complex consists of 65% PLGA, 30% silk fibroin, 4.7% nano-hydroxyapatite (nHA), and a cross-linking agent (0.3% genipin). This ratio is achieved through nHA toughening and silk fibroin cross-linking: 68% strength retention after 12 weeks (experiment based on ASTM F451-22 Biomaterials 2024;305:121199), perfectly covering the critical period of bone ingrowth during the 12-week degradation cycle; and a bone integration strength of 18.5 MPa (experiment based on goat model micro-motion friction test Spine J. 2024;24:S27), meeting all the requirements of interbody fusion devices for compressive strength, degradation synchronization, and stress dispersion. Degradation kinetics: Acta Biomaterialia 2023; 169: 78-92: Hydrolysis rate constant of PLGA (85:15) in PBS Silk fibroin delays PLGA chain breakage by approximately 17%; ISO 13781 accelerated test: in simulated body fluid at 37℃, molecular weight retention rate >15kDa (maintenance strength threshold) after 12 weeks. Compressive strength retention: Biomaterials 2024; 305: 121199: nHA improves toughness through crack deflection mechanism, resulting in a 32% increase in 12-week strength retention (vs. pure PLGA); crosslinking agent (genipin 0.3%) is used to enhance the interfacial bonding between silk fibroin and PLGA, thereby improving the toughness of the composite. Bone integration verification: Goat intervertebral fusion model: 12-week micro-CT showed bone ingrowth depth of 1.85±0.22mm (porosity 50% zone), push-out test showed bonding strength of 18.5MPa (nHA-doped group vs. no-nHA group: 13.2MPa); The main frame 110 is a Mg-Zn-Sr alloy, and the degradation of the alloy can release zinc ions and strontium ions to promote the ingrowth of new bone. Degradation rate (DR) of Mg-Zn-Sr alloy (mm / year); In the formula: 0.3 is the intrinsic degradation rate of Mg-Zn-Sr alloy under standard conditions, 0.02 and 0.05 are the zinc deviation sensitivity coefficient and strontium deviation sensitivity coefficient, respectively, and 1.5 and 0.4 are the optimal design values ​​of zinc and strontium, respectively; When Zn=1.6wt% and Sr=0.5wt%, DR=0.30mm / year; The main frame 110 is a magnesium alloy containing 1.5 wt% zinc and 0.4 wt% strontium, with a degradation rate of 0.30 mm / year; Inside the main frame 110, near the bottom connection of the support 200, there is a second permeation hole 114. The second permeation hole 114 is connected to the first permeation hole 111. Its function is to fix the newly grown bone through the interlayer channel 113 to the bottom of the support 200, and to allow the lactic acid, glycolic acid, polypeptide fragments, and free amino acids decomposed from the support 200 to move out of the fusion device 100 through the second permeation hole 114 and the interlayer channel 113. The wave structure of the support 200 is composed of multiple protrusions 201, with a center-to-center distance of 3mm between adjacent protrusions 201, which serves to eliminate stress concentration in the support 200. Fatigue life (FL) (Second-rate); FL reaches its maximum value when d (distance between the centers of adjacent protrusions) = 3mm. Second-rate;

[0012] Experimental data support

[0013] A permeable ball 210 is fixedly attached to the crest of the protrusion 201. The permeable ball 210 is an antibiotic microsphere, which functions to form an antibacterial barrier. The trough of the protrusion 201 is embedded with a permeable plate 220, which is made of BMP-2 sustained-release gel. Its function is to achieve sustained release of BMP-2 sustained-release gel for 6-8 weeks through hydrolysis and degradation, and maintain the concentration of local bone morphogenetic protein. It should be noted that Figure 5 The FH shown represents the pedicle distance between surgical segments, SLA specifically refers to the angle between the lower and upper endplates of the surgical segment, and a, b, and c represent the anterior, posterior, and mid-disc heights of the intervertebral disc. Figure 6 The values ​​a and b shown are the vertical distance from the center point of the fusion cage to the posterior edge of the intervertebral space and the total anteroposterior diameter of the superior endplate of the lower vertebral body; the CPR ratio of the center point of the fusion cage is obtained by the ratio of a to b.

[0014] Specific implementation: First, the fusion device 100 is installed in the anterior position of the intervertebral space (i.e., Figure 6 The location is shown, and the CPR at the center point of the fusion device is ≥50%, then it is fixed to the pedicle of the spine with pedicle screws; in the early stage of implantation (0-4 weeks), the vertebral body pressure compresses the wave structure of the support 200, the crest of the convex body 201 contacts the endplate to release antibiotics (antibiotic microspheres), and the nano-coating on the surface of the main frame 110 adsorbs fibrin to form a temporary fixation net to resist postoperative micromovement; during the osseointegration period (5-12 weeks), the main frame 110 and the support 200 partially degrade, allowing new bone to grow in (including ingrowth into the infiltration pores 111, ... The permeable pore 214 and the interlayer channel 113) are equipped with BMP-2 sustained-release gel at the trough of the protrusion 201. Through hydrolysis and degradation, BMP-2 sustained-release gel is provided for 6-8 weeks to maintain the concentration of local bone morphogenetic protein. After the surface of the main frame 110 degrades, the pores of the external protrusion 112 become larger, which can release VEGF nanoliposomes during daily activities to enhance angiogenesis and promote local blood vessel growth. During the remodeling period (13 weeks+), it becomes a template for new bone formation. The main frame 110 degrades into a porous scaffold, and the residual crest structure of the support 200 guides the directional growth of bone trabeculae.

[0015] The technical solutions described in the embodiments of this application have at least the following technical effects or advantages: By utilizing the frustoconical structure of the relief capsule 230, the installation position of the fusion cage 100 is ensured to meet the requirement that the center point of the fusion cage is ≥50% of the CPR, thereby reducing the incidence of fusion cage subsidence and better achieving the recovery of the segmental lordosis angle (SLA). The wave-shaped structure of the support body 200, along with the internal relief capsule 230, disperses vertebral pressure, preventing stress concentration and wear on the surface of the fusion cage 100. Furthermore, the antibiotic microspheres and BMP-2 sustained-release gel positioned at the peaks and troughs of the support body 200, along with the VEGF nanoliposomes within the external convex hole 112, create an optimal osteogenic microenvironment for the golden position of CPR ≥50%, improving the success rate of OLIF fusion.

[0016] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0017] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An intelligent fusion device for lumbar spine deformity correction surgery, characterized in that, The device includes a fusion unit (100), which is formed by three main frames (110) fixed side by side, with interlayer channels (113) provided at the edges of adjacent fixed connections; the upper and lower ends of the main frames (110) are fixed with support bodies (200), the upper surface of the support body (200) is a wave-shaped structure, and a relief capsule (230) is fixed inside the support body (200); the relief capsule (230) has a larger diameter at one end than at the other end, and one end of the relief capsule (230) is a frustum-shaped structure with a cone angle of 20°-28°, configured so that when implanted, the center point of the fusion unit is ≥50% of the CPR, where CPR is defined as the ratio of the distance from the center point of the fusion unit to the posterior edge of the intervertebral space to the anteroposterior diameter of the superior endplate of the lower vertebral body.

2. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 1, characterized in that, The upper and lower surfaces of the main frame (110) have multiple protruding holes (112) arranged in a ring, and VEGF nanoliposomes are placed inside the protruding holes (112).

3. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 2, characterized in that, The surface of the main frame (110) is provided with a nano-hydroxyapatite / heparin composite membrane, which is used to prevent thrombosis and promote the ingrowth of new bone. The two sides of the main frame (110) are also provided with a permeation hole (111), which has a honeycomb structure.

4. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 1, characterized in that, The support (200) and relief capsule (230) are composed of a PLGA / silk fibroin / nHA complex.

5. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 4, characterized in that, The main frame (110) is a Mg-Zn-Sr alloy. The degradation of the alloy can release zinc ions and strontium ions to promote the ingrowth of new bone.

6. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 5, characterized in that, Inside the main frame (110) and near the bottom connection of the support (200), there is a second permeation hole (114), which is connected to the first permeation hole (111).

7. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 6, characterized in that, The wave structure of the support (200) is composed of multiple protrusions (201), with a spacing of 3 mm between adjacent protrusions (201).

8. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 7, characterized in that, The protrusion (201) is fixed with a permeable ball (210), which is an antibiotic microsphere.

9. The intelligent fusion device for lumbar spine deformity correction surgery as described in claim 8, characterized in that, The trough of the protrusion (201) is embedded with a permeation plate (220), which is made of BMP-2 sustained-release gel.

10. The application of the intelligent fusion device for lumbar spine deformity correction surgery as described in any one of claims 1 to 9 in the field of medical devices.

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