CN111419486A - An adjustable self-stress stimulation intervertebral cage - Google Patents

Abstract

The invention discloses an adjustable self-stress stimulating intervertebral fusion cage, comprising an outer sleeve and an inner sleeve; both the outer sleeve and the inner sleeve are open at one end and have an end surface at the other end, and the open end of the outer sleeve is sleeved on At the open end of the inner sleeve, the outer sleeve and the inner sleeve are slidably matched, and the outer sleeve and the inner sleeve are supported by an adjustable elastic support structure; the outer sleeve and the inner sleeve are provided with cross elastic sheets, and the cross The deformation direction of the elastic pieces is the axial direction of the outer sleeve and the inner sleeve, the cross elastic pieces are supported on the inner end surfaces of the outer sleeve and the inner sleeve, and the side walls of the outer sleeve and/or the inner sleeve are provided with bone graft holes. The present invention can provide axial stress and radial stress, which is beneficial to the growth and fusion of bone, and can also provide stress stimulation when the patient is supine.

Description

An adjustable self-stress stimulation intervertebral cage

technical field

The invention relates to the field of medical instruments, in particular to an adjustable self-stress stimulation intervertebral fusion cage.

Background technique

The current cage cannot accurately adjust the stress between the cage and the vertebrae, and cannot achieve stress stimulation when the patient is in a supine position after surgery, which is not conducive to bone graft fusion and rapid recovery; the cage cannot be accurately adjusted according to the intervertebral stress. During the operation, sometimes after the prosthesis is implanted, it is found that the height is not suitable, and it needs to be removed and replaced with another size cage, which increases the cost of disinfection and is ethically controversial.

The current cage needs to be designed in a variety of sizes to adapt to different intervertebral space heights. The production cost is high, the amount of molds is large, the amount of some specifications is small, and the waste is large.

Stress stimulation, the growth and development of human bone tissue and the process of bone disease rehabilitation are constantly undergoing shaping and reconstruction to adapt to the surrounding environment. Only when the bone is constantly adapting to the mechanical environment that bears the stress stimulation caused by the external force, can the bone structure itself be remodeled and shaped to adapt to the changes of the external environment.

The stress adaptability of bone is also known as the functional adaptability of bone. The specific performance is that when the bone needs increase, there is bone formation to increase their ability to complete their functions; when the demand decreases, there is bone resorption, which reduces their ability to complete their functions. It can be seen that the changes of bone growth, development, atrophy and regression are closely related to the stress it bears. Living bone continues to grow, strengthen and resorb, a process called bone remodeling. The goal of bone reconstruction is always to adapt the internal structure and external morphology to changes in its loading environment, and there are two types: surface reconstruction and internal reconstruction. Surface reconstruction refers to the resorption or deposition of bone material on the bone surface, which is a long-term slow process that generally lasts for several months or years; internal reconstruction refers to changes in the mineral content and porosity within the bone tissue. Changes in bone tissue volume density and mass can be accomplished in a very short time. In humans, the time to rebuild a bone injury is relatively short, on the order of weeks.

A study in Russia and the United States showed that spaceflight for more than 10 months would result in a loss of bone mass throughout the body, with a 12% and 8.2% drop in the pelvis and femur, respectively, but the skull, due to redistribution of blood in weightlessness, to the head. Increase in blood flow stress stimulation to compensate for the bone mass of the head, so the bone mass does not decrease significantly.

The stress shielding effect in bone biomechanics, the phenomenon of stress shielding is an important manifestation of the bone remodeling effect. In bone, osteoblasts and osteoclasts in bone tissue regulate bone growth or resorption by sensing mechanical stimuli. When the strain of the bone is lower than 50-100 microstrain and the stress is lower than 1-2MPa, the bone tissue absorbs; when the strain of the bone is higher than 1000-1500 microstrain and the stress is higher than about 20MPa, the bone tissue grows; and When the strain of the bone is further higher than about 3000 microstrain and the stress is higher than about 60 MPa, the bone tissue is damaged.

When stress shielding occurs in the bone tissue, the stress level on the bone tends to be at a low level for a long time, so that the bone tissue gradually absorbs, resulting in osteoporosis at the fracture site, which becomes an important incentive for postoperative refracture.

Wolff's Law: The function of bone is to withstand the mechanical strains of bone tissue during activity, and the ability of bone to adapt to the needs of these functions was recognized a century ago and is known as Wolff's Law (Wolff's Law). Bone strives to achieve an optimal structure, that is, the shape and substance of the bone are regulated by the individual's activity level, so that it is sufficient to bear the mechanical load, but does not increase the burden of metabolic transport.

Bones are living organisms and have their own laws of change. Wolff's law states that the growth of bone is affected by mechanical stimulation and changes its structure. Use it is strong, use it is weak.

At present, various elastic deformation technologies use elastic materials and mechanical design, and use their own gravity to deform under standing and weight-bearing conditions and standing activities, so that "compression micro-deformation" can occur, and fractures can be broken The end or vertebral bone graft part is subjected to more stress stimulation, so as to achieve the effect of stress promoting osteogenesis, fracture healing and intervertebral fusion. "Compression micro-deformation" cannot occur when the patient is lying on his back or in bed, and the average sleep time of adults may be about 8 hours. Because the patient cannot bear weight for a long time, pain and other reasons, the patient may stay in bed for 15 hours or more. , which is not conducive to bone graft fusion and rapid recovery of patients, so the patient remains in bed for a long time after surgery and lacks stress stimulation, and the implant design needs to be improved.

SUMMARY OF THE INVENTION

The present invention aims to provide an adjustable self-stress stimulation intervertebral cage, which can provide adjustable axial stress and radial stress, is beneficial to the growth and fusion of bones, and can also provide stress stimulation when the patient is supine .

To achieve the above object, the present invention adopts the following technical solutions to realize:

The adjustable self-stress stimulation intervertebral cage disclosed by the invention comprises an outer sleeve, an inner sleeve and a deformable structure; the outer sleeve and the inner sleeve are both open at one end and have an end face at the other end, and the outer sleeve The open end of the inner sleeve is sleeved at the open end of the inner sleeve, the outer sleeve and the inner sleeve are slidably matched, and the outer sleeve and the inner sleeve are supported by an adjustable elastic support structure; the deformable structure is located between the outer sleeve and the inner sleeve. In the sleeve, the deformable structure supports the end faces of the outer sleeve and the inner sleeve, and the deformable structure includes axial deformation along the outer sleeve and the inner sleeve; the side walls of the outer sleeve and/or the inner sleeve are provided with implants. Bone hole.

Further, the side walls of the outer sleeve and/or the inner sleeve are provided with through holes, the through holes communicate with the inner cavity of the outer sleeve and/or the inner sleeve, and there are several through holes, several are arranged on the outer circumference of the outer sleeve and/or the inner sleeve.

Further, the end surfaces of the outer sleeve and the inner sleeve are provided with non-locking nails, the non-locking nails are used for fixing the outer sleeve and the inner sleeve, and the non-locking nails are provided with micro-moving devices.

Preferably, the end surfaces of the outer sleeve and the inner sleeve are made of elastic alloy or the end surfaces of the outer sleeve and the inner sleeve are provided with a coating layer or the end surfaces of the outer sleeve and the inner sleeve are porous structures.

Further, the end surfaces of the outer sleeve and the inner sleeve are provided with gaskets.

As a preferred option, the adjustable elastic support structure includes an expansion body and a screw, the expansion body is provided with an axial hole, the diameter of the screw is larger than the diameter of the axial hole, and the expansion body is located in the In the gap between the outer sleeve and the inner sleeve, the expansion body is attached to the side wall of the outer sleeve or the inner sleeve.

As another preferred embodiment, the adjustable elastic support structure includes a screw thread adjustment mechanism.

Preferably, the deformable structure is an elastic deformation mechanism.

Preferably, the elastic deformation mechanism includes a threaded spring, two ends of the threaded spring are respectively connected with elastic sheets, and the two elastic sheets respectively support the inner end surfaces of the outer sleeve and the inner sleeve.

As another preference, the elastic deformation mechanism is a cross elastic sheet, the deformation direction of the cross elastic sheet is the axial direction of the outer sleeve and the inner sleeve, and the cross elastic sheet is supported on the inner end surfaces of the outer sleeve and the inner sleeve.

The beneficial effects of the present invention are as follows:

1. The adjustable elastic support structure can precisely adjust the radial stress of the adjustable self-stressed interbody cage, so that the stress is in an ideal range.

2. The deformable structure can provide axial stress for the adjustable self-stress stimulating interbody cage, so that axial stress can also be generated in the supine position after adjustment. When standing upright, self-gravity will increase the stress, and the stress transmitted by the bone will increase.

3. The adjustable elastic support structure support enables the present invention to match different sizes.

Description of drawings

FIG. 1 is a cross-sectional view of the present invention.

Figure 2 is a front view of the present invention.

FIG. 3 is a partial enlarged view of the adjustable elastic support structure portion.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 2, the present invention includes an outer sleeve 2, an inner sleeve 1 and a deformable structure; both the outer sleeve 2 and the inner sleeve 1 are open at one end and have an end face at the other end, and the outer sleeve 2 has an end face. The open end is sleeved on the open end of the inner sleeve 1, the outer sleeve 2 and the inner sleeve 1 are slidably matched, and the outer sleeve 2 and the inner sleeve 1 are supported by an adjustable elastic support structure 3; The sleeve 1 is provided with a cross elastic piece 4, the deformation direction of the cross elastic piece 4 is the axial direction of the outer sleeve and the inner sleeve, the cross elastic piece 4 is supported on the inner end faces of the outer sleeve and the inner sleeve, and the cross elastic piece 4 can be a pair of It is composed of shrapnel, and can be composed of multiple pairs of shrapnel. Bone graft holes 6 are provided on the side walls of the outer sleeve 2 and/or the inner sleeve 1 . The side wall of the outer sleeve 2 and/or the inner sleeve 1 is provided with a through hole 7, the through hole 7 is communicated with the inner cavity of the outer sleeve 2 and/or the inner sleeve 1, there are several through holes 7, and several are arranged On the outer circumference of the outer sleeve 2 and/or the inner sleeve 1 .

The end surfaces of the outer sleeve 2 and the inner sleeve 1 are made of elastic alloy or the end surfaces of the outer sleeve 2 and the inner sleeve 1 are provided with a coating layer 5 or the end surfaces of the outer sleeve 2 and the inner sleeve 1 are porous structures.

The end surfaces of the outer sleeve 2 and the inner sleeve 1 are provided with non-locking nails, the non-locking nails are used to fix the outer sleeve and the inner sleeve, and the non-locking nails are provided with micro-moving devices. Non-locking nails and micro-moving devices are commonly used structures in the field, so they are not shown in the figures.

As shown in FIG. 3 , the adjustable elastic support structure 3 includes an expansion body 7 and a screw 9 , the expansion body 7 is provided with an axial hole 8 , the diameter of the screw 9 is larger than the diameter of the axial hole 8 , and the expansion body 7 is located in the outer sleeve 2 . In the gap with the inner sleeve 1, the expansion body 7 is attached to the side wall of the outer sleeve 2 or the inner sleeve 1; when in use, insert the screw 9 into the axial hole 8, and adjust the expansion body through the screwing length of the screw 9 9 Expansion.

The adjustable elastic support structure 3 can also adopt the structure of a screw thread adjustment mechanism such as a jack.

Of course, the present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformation should belong to the protection scope of the appended claims of the present invention.

Claims (7)

1. An adjustable self-stress stimulation interbody fusion cage, characterized in that: comprises an outer sleeve and an inner sleeve; the outer sleeve and the inner sleeve are both provided with an opening at one end, the other end of the outer sleeve is provided with an end face, the opening end of the outer sleeve is sleeved at the opening end of the inner sleeve, the outer sleeve and the inner sleeve are in sliding fit, and the outer sleeve and the inner sleeve are supported by an adjustable elastic supporting structure; the outer sleeve and the inner sleeve are internally provided with crossed elastic sheets, the deformation direction of the crossed elastic sheets is the axial direction of the outer sleeve and the inner sleeve, the crossed elastic sheets are supported on the inner end surfaces of the outer sleeve and the inner sleeve, and bone grafting holes are formed in the side walls of the outer sleeve and/or the inner sleeve.

2. The adjustable self-stress stimulating intersomatic cage of claim 1, wherein: the side wall of the outer sleeve and/or the inner sleeve is provided with a plurality of through holes, the through holes are communicated with the inner cavity of the outer sleeve and/or the inner sleeve, and the plurality of through holes are arranged on the periphery of the outer sleeve and/or the inner sleeve.

3. The adjustable self-stress stimulating intersomatic cage of claim 1, wherein: the end surfaces of the outer sleeve and the inner sleeve are provided with non-locking nails, the non-locking nails are used for fixing the outer sleeve and the inner sleeve, and the non-locking nails are provided with micro-motion devices.

4. The adjustable self-stress stimulating intersomatic cage of claim 1, wherein: the end surfaces of the outer sleeve and the inner sleeve are elastic alloy or the end surfaces of the outer sleeve and the inner sleeve are provided with coating layers or the end surfaces of the outer sleeve and the inner sleeve are in porous structures.

5. The adjustable self-stress stimulating intersomatic cage of claim 4, wherein: and gaskets are arranged on the end surfaces of the outer sleeve and the inner sleeve.

6. The adjustable self-stress stimulating intersomatic cage of any of claims 1-5, wherein: the adjustable elastic supporting structure comprises an expansion body and a screw, wherein the expansion body is provided with an axial hole, the diameter of the screw is larger than that of the axial hole, the expansion body is positioned in a gap between the outer sleeve and the inner sleeve, and the expansion body is attached to the side wall of the outer sleeve or the inner sleeve.

7. The adjustable self-stress stimulating intersomatic cage of any of claims 1-5, wherein: the adjustable elastic support structure comprises a screw thread adjusting mechanism.

Images