Minimally invasive combined type absorbable interbody cage

Abstract

The invention discloses a minimally invasive combined type absorbable interbody cage. The interbody cage is formed by sequentially overlapping a top cap, a top plate, middle plates and a bottom plate which are crescent-shaped, wherein the contact surfaces of every two adjacent plates of the top cap, the top plate, the middle plates and the bottom are provided with an arc boss and an arc groove respectively which has the same bending direction as that of the crescent-shaped outlines, the arc boss is inserted into the arc groove along the arc direction and is in slide fit with the arc groove; and the top cap is made of a polymeric material capable of being absorbed by a vertebral end plate, and the upper surface of the top cap is adaptive with the natural camber of the vertebral end plate, and the lower surface of the bottom plate is matched with the natural camber of the vertebral end plate. By overlapping different quantity of the middle plates, the minimally invasive combined type absorbable interbody cage meets different acantha interbody expanded heights and has small operational wounds; the crescent-shaped interbody cage does not need bilateral imbedding, can be imbedded conveniently and more stably; and the absorbable polymeric material can be gradually degraded and absorbed, reduce stress block to implanted bone and promote the implanted bone to fuse better.

Description

technical field [0001] The invention relates to a medical device, in particular to a minimally invasive combined absorbable intervertebral fusion device. Background technique [0002] Intervertebral fusion cages are widely used in posterior lumbar operations, and can also be used in cervical and thoracic operations. They are mainly made of metal materials such as titanium alloys. The titanium alloy intervertebral fusion cage restores the physiological curvature and height of the lumbar spine by expanding the vertebral body through its external structure. Due to the limited contact surface between the intervertebral fusion cage and the vertebral body, the stress is concentrated, and the upper and lower vertebral endplates are easily damaged, which often leads to collapse of the vertebral body, narrowing of the intervertebral space, and malunion. The titanium alloy intervertebral fusion cage has sufficient strength, but its upper and lower sides are vertebral cancellous bone,...

AI Technical Summary

Problems solved by technology

The titanium alloy intervertebral fusion cage has sufficient strength, but its upper and lower sides are vertebral cancellous bone, and the elastic modulus of the two is inconsistent. The vertebral cancellous bone is partially absorbed due to pressure, and the height of the postoperative intervertebral space is partially lost. ; Permanent implantation of the stent may cause electrolysis and foreign body stimulation reactions, resulting in complications related to the intervertebral fusion device; metal implants cannot be absorbed by the human vertebral body, so there is stress shielding, which can lead to bone fusion Delay or even non-convergence

Moreover, the existing intervertebral fusion devices are all inseparable integral structures, and the height of the fusion device cannot be adjusted, so it cannot adapt to different intervertebral distraction heights, which often increases the surgical trauma and increases the pain of the patient; at the same time, the existing intervertebral fusion Most of the devices have a square structure, which is inconvenient to place, occupies a large space, and the amount of bone graft is less, which is not conducive to bone graft fusion; the stability of unilateral placement is poor, and bilateral placement increases the amount of surgery

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