Posterior lumbar interbody fusion device and using method

Abstract

The invention discloses a posterior lumbar interbody fusion device. The posterior lumbar interbody fusion device comprises a fusion device lower body and a fusion device upper body, the fusion devicelower body and the fusion device upper body are separately composed of host materials suitable for bone ingrowth loading in a bracket formed by absorbable medical polymer material 3D printing, the fusion device lower body and the fusion device upper body are coordinated to form a wedge-shaped structure, the wedge-shaped structure can change following intervertebral angles, and a middle ball socketis used as a supporting point to form seesaw effect to adapt to a former convex shape of an intervertebral gap. The invention discloses a using method of the posterior lumbar interbody fusion device.The fusion device cultivated by induction is implanted into the intervertebral gap through posterior; a wedge-shaped angle of the fusion device can perform adaptive change with a certain range following difference of the intervertebral angles; bad stress is reduced, fusion area of the fusion device and an upper vertebra body and a lower vertebra body is increased, and the fusion rate is improved;the fusion device has good biocompatibility, biomechanical property and osteoconduction; and foreign matters cannot be retained in a body after the process of fusion device installation is completed.

Description

technical field [0001] The invention relates to a posterior lumbar intervertebral fusion device and a use method thereof, belonging to the technical field of medical instruments. Background technique [0002] Lumbar interbody fusion is an effective method to rebuild the stability of the spine and correct the abnormal load-bearing mode of the lumbar spine. It is also an effective means to treat spinal diseases such as tuberculosis, infection, deformity, and degenerative diseases. Lumbar interbody fusion can be divided into three types: posterior lumbar interbody fusion, anterior lumbar interbody fusion, and transforaminal bone graft fusion. Posterior lumbar interbody fusion is the earliest and most widely used in China. A broad type of lumbar interbody fusion. [0003] At present, there are various types of intervertebral fusion cages used in posterior lumbar interbody fusion. In terms of materials, titanium alloy, PEEK, carbon fiber reinforced PEEK, tantalum alloy, absorbab...

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Problems solved by technology

[0003] At present, there are various types of intervertebral fusion cages used in posterior lumbar interbody fusion. In terms of materials, titanium alloy, PEEK, carbon fiber reinforced PEEK, tantalum alloy, absorbable polymer, and autologous bone are commonly used. Various materials have their own advantages and disadvantages in application: titanium alloy has high mechanical strength and stable mechanical properties, but its light transmission performance is not good, and it is quite different from the elastic modulus of human bone, so it is easy to cause stress shielding; PEEK is currently the most widely used material. It can well solve the above-mentioned shortcomings of titanium alloy, but at the same time there are problems such as cage loosening, collapse, intervertebral height reduction, non-fusion and so on; carbon fiber reinforced PEEK is to disperse chopped carbon fibers in the PEEK-OPTIMA matrix Compared with PEEK, the elastic modulus of this material is more similar to that of human bone, which can better solve the problem of stress shielding. However, according to previous experience in artificial joints and ligament reconstruction, the carbon fiber tissue structure can separate and cause joint damage. Infection, synovitis, lymphatic spread, and the material is brittle, which can easily cause damage to the fusion device and cause histological reactions; tantalum alloy fusion fusion has good biocompatibility, but tantalum alloy has a certain blocking effect on X-rays , which is not conducive to the observation of bone graft formation after operation; absorbable polymer materials mainly refer to polylactic acid materials, most of which are composite. Low mechanical strength, inherent brittleness makes it easy to rupture during surgery, high concentration of degradation products (such as acids and crystal components) may cause serious tissue reactions, such as infection, osteolysis, etc.; allogeneic / autologous bone, Due to the poor load-bearing capacity of fusion cages made of such materials, the maintenance of intervertebral height and physiological curvature is not ideal, and there are also problems such as long fusion time

[0004] In the actual operation process of the posterior lumbar interbody fusion device in the prior art, due to the influence of the original lumbar facet structure, it is inconvenient to install. There are two ways to deal with the inconvenience of installation: one is the size of the fusion device. It must be controlled within a small size specification, which will result in a limited fusion area between the upper and lower vertebral bodies and the cage, a low fusion rate, and the possibility of subsidence and collapse; the second is to resect the articular process, so that will destroy the original stable structure and increase the potential instability

[0005] In addition to the above problems, the posterior lumbar interbody fusion device in the prior art also has the problem that the angle of the fusion device is relatively fixed, which directly affects the effect of intervertebral fusion

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