Porous titanium cervical fusion cage with HA coating and preparation method of fusion cage

Abstract

The invention discloses a porous titanium cervical fusion cage with a hydroxyapatite (HA) coating and a preparation method of the fusion cage. The fusion cage is composed of an entity framework structure and a porous structure, wherein the entity framework structure is filled with the porous structure. The front portion of the fusion cage is of a structure similar to a bullet head, all edges of the fusion cage are covered with entity smooth titanium alloy thin wall, and the risk that in the implanting process, fusion cage edge small beams are subjected to stress concentration, and arm breaking is caused can be reduced. The central part of the rear portion of the fusion cage is of an arc-shaped entity titanium alloy structure with the thickness being 3 mm or above, and a threaded hole and a groove are machined in the arc-shaped entity titanium alloy structure in a second stage machining mode and used for making the fusion cage connected to an implanting handle during an operation. A thread and the groove can provide a connection mode which is firmer and more reliable than a clamping mode, and implanting is conducted conveniently during the operation. The surfaces of all the small beams of the porous structure of the fusion cage are covered with the hydroxyapatite (HA) coating with the thickness being about 100-500 micrometers, and a more excellent early osseointegration effect can be provided.

Description

technical field [0001] The invention belongs to the field of spinal fusion and internal fixation, and in particular relates to a porous titanium cervical fusion device with HA coating and a preparation method thereof. Background technique [0002] Intervertebral disc herniation and cervical instability caused by degenerative cervical spondylosis are common spinal surgery diseases. Those who fail conservative treatment generally require cervical intervertebral fusion. At present, polyether ether ketone (PEEK) material or solid titanium alloy material intervertebral fusion cage is mainly used for cervical intervertebral fusion. However, these traditional intervertebral fusion devices have many limitations in clinical application: PEEK material is a biologically inert material, and the surface of the material is wrapped by a layer of fibrous tissue after implantation in the body, and the bone-material interface is not strong enough, which is prone to loose and lead to fusion f...

AI Technical Summary

Problems solved by technology

However, these traditional intervertebral fusion devices have many limitations in clinical application: PEEK material is a biologically inert material, and the surface of the material is wrapped by a layer of fibrous tissue after implantation in the body, and the bone-material interface is not strong enough, which is prone to fusion failure

[0004] Although there have been a few clinical cases of using 3D printed porous titanium fusion cages for cervical spine fusion, there are still some problems to be solved in the application process: First, due to the limitation of the accuracy of the existing metal 3D printing technology, it is still difficult to use metal 3D printing technology. 3D printing technology directly prepares a precise thread structure. Therefore, unlike solid fusion cages, which are usually fixed by screw connections, the current porous fusion cages are mainly fixed on the connecting handle by clamping and implanted in the body. If the clamping force is too large, it may cause local Stress concentration increases the risk of trabecular fracture, while the clamping force is too small and the fixation is not firm, which brings inconvenience to the operation

Second, in order to ensure a tight fit during the implantation of the fusion cage, it is inevitable that it will collide with the bones of the upper and lower vertebrae, resulting in an increased risk of fracture of the trabecular arm at the edge (especially the front edge) of the fusion cage

Third, although titanium alloy has good biocompatibility, according to existing literature reports, its osseointegration speed in the implanted body is slow, and the early osseointegration effect is not good

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