Artificial cervical intervertebral disc based on bending section with reversed U-shaped structure having like-trapezoidal section

Abstract

The invention provides an artificial cervical intervertebral disc based on a bending section with a reversed U-shaped structure having a like-trapezoidal section. The artificial cervical intervertebral disc comprises an artificial cervical intervertebral disc body which is prepared from titanium alloy. The artificial cervical intervertebral disc is characterized in that bending sections connected to an upper end plate and a lower end plate of the artificial cervical intervertebral disc body are of reversed U-shaped structures having the like-trapezoidal sections; the physiological curvature of the upper end plate and the lower end plate protruding towards of the artificial cervical intervertebral disc body is 3 to 6 degrees; the front ends of the upper end plate and the lower end plate are fixed through bolts; the front edges of the upper end plate and the lower end plate have arc-shaped appearances similar to human vertebration; two rows of reversed teeth for stopping backing are respectively arranged in the outer surfaces of the upper end plate and the lower end plate; the elasticity modulus of the artificial cervical intervertebral disc body is 45 to 110GPa, and the yield strength is more than 620MPa. The artificial cervical intervertebral disc meets the requirements on long service life and fatigue resistance; the mobility of operated sections of a patient can be more than 50% of that of normal human body.

Description

technical field [0001] The invention relates to an artificial cervical intervertebral disc, in particular to an artificial cervical intervertebral disc with an omega-shaped structure with a trapezoidal cross-section based on a curved section. Background technique [0002] Artificial cervical disc replacement can decompress the spinal cord and keep it stable while ensuring the physiological activity of the surgical segment, which is more in line with the biomechanical characteristics of cervical spine activities. [0003] Although the Z-Brace dynamic fusion device uses a Z-shaped elastic connecting rod, which can move slightly, and has several rows of inverted teeth on the upper and lower sides of the end surface to achieve the purpose of cooperating with the normal intervertebral disc of the patient, there are still The following main deficiencies: First, the range of motion of the Z-Brace dynamic fusion device is only 10% to 30% for forward flexion, lateral flexion, and t...

AI Technical Summary

Problems solved by technology

[0003]Z-Brace dynamic fusion device, although this solution uses a Z-shaped elastic connecting rod, which can be moved slightly, and there are several rows of inverted teeth on the upper and lower sides of the end surface and other measures To achieve the purpose of cooperating with the normal intervertebral disc of the patient, but there are still the following main shortcomings: First, the Z-Brace dynamic fusion cage has only 10% to 30% of the range of motion for forward flexion, lateral flexion, and twisting, and only 10% for backward flexion. 20% to 40%; the second is that the stability of the Z-Brace dynamic fusion device is too dependent on the anti-recession teeth, and there are no bolts to ensure the upper and lower stability of the intervertebral disc and the prosthesis when it is immediately fixed with the patient's normal intervertebral disc

[0004] Chinese patent application 200620112142 discloses the "shrapnel-type artificial intervertebral disc", although the scheme uses a horseshoe-shaped shrapnel, and measures such as a plurality of barbs are respectively arranged on the upper and lower sides of the shrapnel to achieve the purpose of cooperating with the patient's normal intervertebral disc. However, there are still the following major deficiencies: first, from the perspective of biophysics, it cannot well meet the normal physiological curvature of C5-C6 lordosis, which is 3-6°; second, it lacks precision design for the curvature and height means, so that the implanted prosthesis cannot restore and maintain the height of the intervertebral space and maintain the stability of the segment; the third is that the segmental mobility after the implantation of the existing integrated shrapnel type artificial cervical intervertebral disc is the same as that of the normal cervical segmental motion. There is a large difference in the degree of cervical vertebrae, and the motor function of the normal cervical segment cannot be well restored.

[0005] Chinese patent application 201310223928.1 discloses "an integrated artificial cervical intervertebral disc prosthesis with high mobility", Chinese patent application 201310217563.1 discloses "an Ω-shaped artificial cervical intervertebral disc implant prosthesis with herringbone bidirectional anti-retraction teeth ", Chinese patent application 201310217243.6 discloses "an Ω-shaped artificial cervical intervertebral disc implant prosthesis with diamond-shaped two-way anti-retraction teeth", and Chinese patent application 200920211398 discloses "a dynamic stabilization implant device for medical orthopedic cervical intervertebral space", although These schemes all adopt the Ω-shaped non-contact elastic structure with rectangular support for the curved section, and symmetrically set anti-retraction teeth on the outer surface of the upper and lower end plates to achieve the purpose of cooperating with the normal intervertebral disc of the patient, but there are still the following deficiencies: First, the lateral flexion range of motion of the existing integrated artificial cervical intervertebral disc implant is only 30% to 60%, and the torsional range of motion is only 10% to 40%. The stability performance is too dependent on the anti-recession teeth, and there are no bolts to ensure the up and down stability of the intervertebral disc and the prosthesis when it is immediately fixed with the patient's normal intervertebral disc

[0006] United States Patent 7794465B2 discloses an "artificial cervical disc and its related implantation equipment and methods" (United States Patent 7794465B2 "Artificial spinal discs and associated implantation instruments and methods"), although the solution uses a ball-and-socket joint connection combination The mode of flexion and extension, lateral bending and axial torsion can all meet the requirements of the range of motion of various functions of the human body, and the outer surface of the upper and lower end plates has two rows of inverted teeth and bolts to achieve the purpose of cooperating with the normal intervertebral disc of the patient, but there are still the following Disadvantages: First, the structure is cumbersome and the operation is relatively complicated, which can easily cause heterotopic ossification; second, when the ball-socket of the prosthesis moves, it is easy to produce wear particles and cause inflammation; third, the front edge of the artificial cervical intervertebral disc and the end surface of the bolt hole It is the same curved surface, without considering the specificity of the human body, and it is easy to compress nerves and vascular tissues, so the spacing should be set; Fourth, when the prosthesis ball-socket moves, due to the lack of elastic structure support, it relies too much on the two rows of high and long teeth, which increases the difficulty of surgery and The patient suffers from pain and easily compresses the nerve, causing complications

[0007] To sum up, although fusion cages and integrated artificial cervical intervertebral discs have different materials and shapes, these prostheses generally have the following disadvantages: the range of motion of the prosthesis in flexion, torsion, and lateral flexion is difficult to reach 60% of the normal range of motion of the human body , the autonomous fusion rate is high, and it is difficult to meet the needs of normal human movement; at the same time, when the patient's normal intervertebral disc is immediately fixed, there are no bolts to ensure the up and down stability of the intervertebral disc and the prosthesis

Common prostheses with multi-body structures generally have the following disadvantages: cumbersome structure, relatively complicated surgery, and easy to cause heterotopic ossification; poor fatigue and wear resistance, fatigue fracture, and fatigue wear can easily lead to wear particles on the prosthesis, which is prone to Cause aseptic bone resorption, leading to failure of prosthetic replacement, prone to postoperative complications

Images