CN111449745A - A three-column fixation-based intravertebral expansion device, implant sleeve and implant method - Google Patents

Abstract

The invention discloses a vertebral body internal expansion device based on three-column fixation, an implantation sleeve and an implantation method.A slender implant body (1) with a hollow middle part and a screw (2) with a hollow inner part form an integrated or separated expansion device, the implantation sleeve (3) comprises an outer sleeve (31) and an inner rod (32), the inner rod (32) can move in the outer sleeve (31), an external thread (321) is arranged at one end of the inner rod (32), the integrated vertebral body internal expansion device or the separated vertebral body internal expansion device is implanted into a target area in a vertebral body through an established working channel (4) through the implantation sleeve (3), the front and near end distance of the implant body (1) is shortened through the acting force between the outer sleeve (31) and the inner rod (32), the middle part of the implant body (1) is expanded, a certain supporting force is achieved, and immediate mechanical support in an operation is realized. And the implant (1) and the screw (2) are used for realizing three-column fixation, so that the stability of the expansion device in the vertebral body is further enhanced.

Description

A three-column fixation-based intravertebral expansion device, implant sleeve and implant method

technical field

The invention belongs to the technical field of medical devices, and in particular relates to an intravertebral expansion device based on three-column fixation, an implantation sleeve and an implantation method.

Background technique

Osteoporosis is an age-related disease. By 2020, the number of people aged 60 and over will exceed the number of people under five for the first time. There are currently 841 million people aged 60 and over worldwide, and it is expected to reach 2 billion by 2050. Osteoporosis and its related complications have become a major disease threatening the health of the elderly. Of these, about 39% of women over the age of 65 have osteoporotic vertebral compression fractures.

The most widely used treatments are percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP), both of which aim to infuse the fractured vertebral body with methyl methacrylate. Polymethyl methacrylate (PMMA) bone cement can restore the height of the vertebral body as much as possible, achieve anterior and central column fixation, reshape the stability of the spine, and use the thermal effect of bone cement to damage peripheral nerve pain transmission, so as to achieve effective relief. As the number of cases has increased, clinicians have come to realize that the vertebral body height restored during PKP may be temporary, as partial or even complete vertebral body collapse usually occurs after balloon deflation. Intraoperative bone cement injection is prone to bone cement leakage if too much. However, postoperative complications such as bone cement displacement and vertebral body refracture are caused by poor cross-linking between the bone cement and the cancellous bone or a significant difference between the stiffness of the bone cement and the vertebral body. It brings additional pain to patients and increases medical expenses.

等,在术中无须球囊即可恢复椎体高度的椎体增强系统。虽然尚未广泛推广进入临床，但已取得一定的效果。这也提示我们如何维持术中复位后的椎体高度、提高固定稳定性，减少内植物与松质之间的刚度差异，从而提高手术的疗效仍是当前脊柱外科亟待解决的问题。Some companies have successively launched a variety of products based on different structures, such as: Vertebral Body Stenting

Etc., a vertebral augmentation system that can restore vertebral height without a balloon during surgery. Although it has not been widely promoted into clinical practice, certain effects have been achieved. This also suggests that how to maintain the height of the vertebral body after intraoperative reduction, improve the stability of fixation, and reduce the stiffness difference between the implant and cancellous tissue, thereby improving the efficacy of the operation is still an urgent problem to be solved in current spine surgery.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems and deficiencies in the prior art, the present invention provides an intravertebral expansion device, an implantation sleeve and an implantation method based on three-column fixation, the purpose of which is to construct a device that can be opened instantly during surgery, An intravertebral expansion device and implantation method that maintains the height of the vertebral body, the elastic modulus is lower than that of bone cement, and provides ideal stability based on the three-column fixation theory. In order to further improve the curative effect of osteoporotic vertebral fractures through a simple and easy way.

Specifically, the following design structures and design schemes are adopted:

An intravertebral expansion device based on three-column fixation, comprising an elongated implant body (1) hollowed out in the middle and a screw (2) hollow inside, and a distal port of the implant body (1) is provided with a first An internal thread (11), the proximal port of the implant (1) and the head of the screw (2) are integrally connected.

Preferably, the implant (1) and the screw (2) can also be of a separate assembly type, by providing a thread in the proximal port of the implant (1) to match the thread on the head of the screw (2). of the second internal thread (12).

Preferably, the middle part of the implant body (1) is a mesh structure, which intersects to form holes of different shapes, and the middle part of the implant body (1) is expanded by reducing the distance between the distal end and the proximal end of the implant body (1). , the elongated implant (1) is expanded into a mesh-shaped implant (1) with a certain supporting force.

Preferably, the threads from the head of the screw (2) to the outer side of the tail are sparse in front and dense in the back, and the tail of the screw (2) is provided with an inner hexagonal lace hole (21).

Preferably, the inner diameter of the distal port of the implant (1) is equal to the inner diameter of the screw (2).

An intravertebral implant sleeve based on three-column fixation, the implant sleeve (3) comprises an outer sleeve (31) and an inner rod (32), and the inner rod (32) can move in the outer sleeve (31) , and one end of the inner rod (32) is provided with an external thread (321).

Preferably, the external thread (321) is adapted to the first internal thread (11).

A method for intravertebral implantation based on three-column fixation, comprising the following steps,

Step 1, establishing a working channel (4) to the fracture area through a channel of bilateral or unilateral pedicles (6);

Step 2, using an implant sleeve (3) to implant an integrated intravertebral expansion device of a suitable size or a separate and assembled intravertebral expansion device into the vertebral body (5) through the established working channel (4). In the target area, the inner rod (32) of the implant sleeve (3) is connected to the distal end of the implant body (1), and the outer sleeve (31) of the implant sleeve (3) is connected to the proximal end of the implant body (1). or connect with the tail of the screw (2), then hold the outer sleeve (31) still, while the inner rod (32) is pulled toward the proximal end of the implant (1), and the middle of the implant (1) is pulled out. Carry out expansion.

Step 3: Withdraw the implant sleeve. For the separate and assembled expansion device, it is also necessary to insert a guide wire along the working channel (4), and guide the head of the screw (2) to the implant (1) through the guide wire. A second thread (12) in the end connects.

Step 4: Finally, inject bone cement as needed.

The working principle of the present invention is as follows:

In the present invention, the implant (1) and the screw (2) are made into an integrated intravertebral expansion device or a separate and assembled intravertebral expansion device, and an implant sleeve (3) is used to attach the implant (1). ) and the screw (2) are implanted into the target area in the vertebral body (5), and the implant (1) is stretched and expanded through the outer sleeve (31) and the inner rod (32) of the implanted sleeve (3) to support the vertebral body (5); the spine is divided into the anterior column (anterior half of the vertebral body), the middle column (the posterior half of the vertebral body), and the posterior column (pedicle), of which the implant (1) and the front part of the screw (2) is used to support the anterior column and the middle column, that is, to achieve the stability of the vertebral body (5) fixation, and the rear half of the screw (3) is used to hold the posterior column, that is, to achieve the pedicle (6) fixation stability, so as to achieve three-column fixation.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention is simple and easy to implement. Compared with the commonly used PKP/PVP operation, it can immediately restore and maintain the vertebral body height during the operation, and based on the three-column fixed intravertebral expansion device, with the help of the holding force of the pedicle, it can be Further improving the stability of the fixation can reduce the incidence of surgical failure caused by the loosening and displacement of the implant.

2. The present invention adopts titanium alloy material, which provides a certain vertebral body support force after expansion, and the elastic modulus is lower than that of traditional PMMA bone cement. It provides conditions for the application of bone cement with biological activity such as calcium sulfate or magnesium sulfate, but insufficient mechanical strength. In this way, the risk of damage caused by the heating of PMMA polymerization can be avoided, and the incidence of PMMA poisoning can also be reduced. It can also reduce the high elastic modulus of PMMA and the incidence of vertebral refracture caused by stress concentration.

Description of drawings

FIG. 1 is a schematic structural diagram of an integrated expansion device of the present invention;

2 is a cross-sectional view of the integrated expansion device of the present invention;

3 is a schematic structural diagram of the integrated expansion device of the present invention after expansion;

4 is a schematic structural diagram of a separate expansion device of the present invention;

5 is a cross-sectional view of a separate expansion device of the present invention;

FIG. 6 is a schematic structural diagram of the detachable expansion device of the present invention after expansion;

Fig. 7 is the structural representation of the hexagonal lace hole of the screw of the present invention;

8 is a schematic structural diagram of an implanted sleeve of the present invention;

Fig. 9 is the use state diagram of the integrated expansion device and the implantation sleeve of the present invention;

Fig. 10 is a use state diagram of the separated expansion device and the implanted sleeve according to the present invention;

11 is a state diagram of the integrated expansion device of the present invention when the implant screw is implanted as a whole and an outer sleeve is added;

12 is a state diagram of the integrated expansion device of the present invention when it is screwed into the inner rod;

Fig. 13 is a state diagram of the expansion after implantation of the integrated expansion device of the present invention;

14 is a state diagram of the integrated expansion device of the present invention after implantation;

Fig. 15 is a state diagram of the present invention when the separable expansion device is implanted into the implant and the outer sleeve is added;

Fig. 16 is a state diagram of the separate expansion device of the present invention when it is screwed into the inner rod;

FIG. 17 is a state diagram of the expansion state of the separable expansion device of the present invention after implantation;

Fig. 18 is a state diagram of the detachable expansion device of the present invention screwed into a screw;

Figure 19 is a state diagram of the separated expansion device of the present invention after implantation;

Reference number: 1—implant; 11—first internal thread; 12—second internal thread; 2—screw; 21—hexagonal lace hole; 3—implantation sleeve; 31—outer sleeve; 32—inner Rod; 4—working channel; 5—vertebral body; 6—pedicle.

Detailed ways

The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

The specific implementation is as follows:

Example 1

As shown in Figures 1-7 of the description, a three-column fixation-based intravertebral expansion device includes an elongated implant 1 hollowed out in the middle and a hollow screw 2. The distal port of the implant 1 A first internal thread 11 is provided, and the proximal port of the implant 1 is connected with the head of the screw 2 in one piece.

Further, as shown in the accompanying drawings 4-6 of the description, the implant 1 and the screw 2 can also be of a separate assembly type, by providing a thread in the proximal port of the implant 1 to match the thread on the head of the screw 2 The second internal thread 12.

Further, the middle part of the implant body 1 is a mesh structure, which crosses to form holes of different shapes, and by reducing the distance between the distal end and the proximal end of the implant body 1, the middle part of the implant body 1 expands, as shown in FIG. 3 and FIG. 6 in the description. As shown, the elongated implant 1 is expanded into a mesh-shaped implant 1 having a supporting force.

Further, the threads from the head of the screw 2 to the outside of the tail are sparse in front and dense in the back. As shown in FIG. 7 in the specification, the tail of the screw 2 is provided with a hexagonal inner hexagonal lace hole 21 to facilitate the insertion of the guide wire.

Further, the inner diameter of the distal port of the implant 1 is equal to the inner diameter of the screw 2 .

Example 2

As shown in FIG. 8 of the description, an intravertebral implant sleeve based on three-column fixation, the implant sleeve 3 includes an outer sleeve 31 and an inner rod 32, and the inner rod 32 can move in the outer sleeve 31, and One end of the inner rod 32 is provided with an external thread 321 .

Further, the external thread 321 is adapted to the first internal thread 11 .

Implementation 3

A method for implanting an integrated expansion device in a vertebral body based on three-column fixation, comprising the following steps:

Step 1, establish a working channel 4 to the fracture area through the 6 channels of bilateral or unilateral pedicles;

Step 2, as shown in the accompanying drawings 11-14 of the description, an integrated intravertebral expansion device of a suitable size is implanted into the target area in the vertebral body 5 through the established working channel 4 by using the implant sleeve 3, and the implant body 1 And the front half of the screw 2 supports the vertebral body 5, and the back half of the screw 2 holds the pedicle 6; Pass through and pass through the implant body 1, connect with the first inner thread 11 of the distal end of the implant body 1 through the external thread 321, the outer sleeve 31 of the implant sleeve 3 is connected with the tail of the screw 2, and then hold the The outer sleeve 31 does not move, as shown in FIG. 13 of the specification, while the inner rod 32 is pulled toward the proximal end of the implant body 1, the middle part of the implant body 1 is stretched and expanded, and the vertebral body 5 is supported, wherein the The screw 2 with a slightly longer length is selected, and the tail of the screw 2 is passed out of the pedicle 6, which is convenient for the secondary operation to locate the implantation position.

Step 3, as shown in FIG. 14 in the description, withdraw the implant sleeve 3, withdraw the outer sleeve 31, and simultaneously unscrew the inner rod 32.

Step 4: Finally, inject bone cement as needed.

Example 4

A method for implanting a separable expansion device in a vertebral body based on three-column fixation, comprising the following steps:

Step 1, establish a working channel 4 to the fracture area through the 6 channels of bilateral or unilateral pedicles;

Step 2, as shown in the accompanying drawings 15-19 of the description, use the implant sleeve 3 to implant a suitable size of the separable intravertebral expansion device into the target area in the vertebral body 5 through the established working channel 4, as shown in the accompanying drawings of the description. As shown in 16, screw into the inner rod 32 of the implant sleeve 3, the inner rod 32 is screwed in from the proximal end of the implant 1 to the distal end of the implant 1, and is connected to the distal end of the implant 1 through the external thread 321. The first internal thread 11 is connected, the outer sleeve 31 of the implant sleeve 3 is connected to the proximal end of the implant body 2, and then the outer sleeve 31 is held still, as shown in FIG. 17 of the specification, and the inner rod 32 is implanted Pull the proximal end of the body 1, expand and expand the middle part of the implant body 1, support the vertebral body 5, the first half of the implant body 1 and the screw 2 support the vertebral body 5, and the second half of the screw 2 holds the vertebral body 5 bow root 6;

Step 3, withdraw the implantation sleeve 3, withdraw the outer sleeve 31, and screw out the inner rod 32 at the same time, then insert a guide wire along the working channel 4, and screw in the screw 2 through the guide wire, as shown in Figure 18 of the specification. As shown, the head of the screw 2 is connected with the second internal thread 12 at the proximal end of the implant 1, so that the screw 2 is fully connected with the proximal end of the implant 1, and the screw 2 with a slightly longer length can be selected. The tail is exposed on the surface of the lamina outside the pedicle 6, which is convenient for the second surgery to determine the position of the first implant.

Step 4: Finally, inject bone cement as needed.

The protection scope of the present invention is not limited to the above-mentioned embodiments, and the above-mentioned embodiments are only to help explain and illustrate the present invention, rather than to limit the protection scope of the present invention, as long as the design is the same as the design of the present invention or as long as it is an equivalent replacement All fall within the scope of the claimed protection of the present invention.

Claims (8)

1. The utility model provides an expansion device in centrum based on three post are fixed, includes the slender type implant (1) of middle fretwork and inside hollow screw (2), its characterized in that: a first internal thread (11) is arranged in a far end port of the implant body (1), and a near end port of the implant body (1) is connected with the head of the screw (2) into a whole.

2. The intravertebral dilation device based on three post fixation according to claim 1 wherein: the implant (1) and the screw (2) can also be assembled separately by providing a second internal thread (12) in the proximal end of the implant (1) that is adapted to the thread of the head of the screw (2).

3. The intravertebral dilation device based on three post fixation according to claim 1 wherein: the middle part of the implant body (1) is of a net-shaped structure, holes with different shapes are formed in a crossed mode, the middle part of the implant body (1) is expanded by reducing the distance between the far end and the near end of the implant body (1), and the slender implant body (1) is expanded into the net-shaped implant body (1) with supporting force.

4. The intravertebral dilation device based on three post fixation according to claim 1 wherein: the threads from the head of the screw (2) to the outer side of the tail of the screw are sparse in front and dense in back, and an inner hexagonal flower side hole (21) is formed in the tail of the screw (2).

5. The intravertebral dilation device based on three post fixation according to claim 1 wherein: the inner diameter of the distal end port of the implant (1) is equal to the inner diameter of the screw (2).

6. An intravertebral implantation sleeve based on three-column fixation is characterized in that: the implantation sleeve (3) comprises an outer sleeve (31) and an inner rod (32), wherein the inner rod (32) can move in the outer sleeve (31), and one end of the inner rod (32) is provided with an external thread (321).

7. The three-column fixation based intrabody implantation cannula as claimed in claim 1 or 6, wherein: the external thread (321) is matched with the first internal thread (11).

8. A centrum implantation method based on three-column fixation is characterized in that: comprises the following steps of (a) carrying out,

step one, establishing a working channel (4) to a fracture area through a bilateral or unilateral pedicle (6) channel;

step two, implanting the integrated intravertebral expansion device or the split-assembly type intravertebral expansion device with a proper size into a target region in a vertebral body by using an implantation sleeve (3) through an established working channel (4), connecting an inner rod (32) of the implantation sleeve (3) with the far end of the implant (1), connecting an outer sleeve (31) of the implantation sleeve (3) with the near end of the implant (1) or the tail part of a screw (2), then fixing the outer sleeve (31), drawing the inner rod (32) towards the near end of the implant (1), and expanding the middle part of the implant (1).

And step three, withdrawing the implantation sleeve (3), and for the assembled expansion device, arranging a guide wire along the working channel (4), and connecting the head of the screw (2) with a second thread (12) in the proximal end of the implant body (1) through guide of the guide wire.

And step four, finally injecting bone cement according to the requirement.

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