CN106236333B - Artificial vertebral body fixed by anterior pedicle screw and positioning and installing tool - Google Patents

Abstract

An artificial vertebral body fixed by front pedicle screws and a positioning and installing tool are characterized in that the artificial vertebral body is provided with pedicle screw fixing holes, and the artificial vertebral body can be accurately fixed on the pedicles on two sides by guiding screws, so that strong self-stabilization is realized. The artificial vertebral body can also be fused with a steel plate according to requirements, the upper end and the lower end of the steel plate can exceed the length of the artificial vertebral body, and only the upper end of the steel plate can be longer than the artificial vertebral body. The steel plate extending end can also be provided with a screw hole coaxial with the vertebral pedicle and a screw hole pointing to the vertebral body. In order to ensure that the anterior pedicle screw is safely and accurately placed, a drilling positioning guide plate and a bone cutting guide plate are arranged at the same time. The artificial vertebral body and the mounting tools such as the drilling hole and the bone cutting guide plate are designed and printed by utilizing a 3D printing technology based on medical image data. Safely and quickly can realize the maximization of the fixing strength of the anterior spinal stability operation.

Description

An artificial vertebral body fixed by anterior pedicle screw and a positioning and installation tool

technical field

The invention belongs to the field of medical instruments, in particular to an artificial vertebral body and a positioning and installation tool for anterior pedicle screw fixation.

Background technique

Stable reconstruction surgery is required after cervical spine tumor, tuberculosis, trauma and other lesions are removed. At present, autologous bone or allogeneic bone or artificial bone, or titanium mesh or artificial vertebral body is usually used to support the defect, and then the plate is fixed with locking screw on the lower vertebral body. However, because the vertebral bodies are all cancellous bone and the anterior and posterior diameters are short, only about 15mm screws can be used. Therefore, the fixation strength is weak, and it needs to be fixed with a neck brace for several months. Especially in cases where the screw-fixed vertebral body itself has lesions or has a long reconstructed segment, the fixation effect is weaker, and complications such as spinal displacement, bone nonunion, loosening of plate screws and implants due to fixation failure, and fracture of implants are caused. has happened. For example, cervical vertebral tuberculosis usually occurs in the intervertebral disc and the edges of the upper and lower vertebral bodies. The upper part of the upper vertebral body and the lower part of the lower vertebral body are relatively intact and can be fixed by screws. However, on MRI, the bone is often infiltrated. The cancellous bone of the vertebral body will become more brittle, and it is difficult to obtain stable fixation with only two vertebral body screws. To enhance the fixation force, a total resection of the diseased vertebral body is necessary, so the upper and lower intervertebral discs must be separated. And resection to provide a bone graft bed on which the implanted support is fused, thus increasing the fixed segment, reducing the range of motion of the cervical spine, and making it easier for the degeneration of adjacent segments to occur. For another example, in the case of a long-segment cervical spine tumor, all diseased vertebral bodies and their upper and lower intervertebral discs should be removed. After using titanium mesh or artificial vertebral body support, only two vertebral body screws can be inserted at each end of the steel plate. It cannot be reinforced with screws, so that the span of the steel plate is too long, and the fixing strength is naturally weakened. The above-mentioned problems also exist in the long-segmented cervical vertebrae after anterior fixation with reduced titanium mesh.

In order to solve this problem, in recent years, there has been research on anterior cervical pedicle screw fixation technology, that is, from the front of the vertebral body, the strongest pedicle of the spine is inserted into the screw with more than double the length of the vertebral body screw for fixation. Basic research has shown that its fixation strength is multiplied. However, due to the lack of anatomical landmarks for positioning on the surface of the vertebral body, important structures such as the vertebral artery, spinal cord or nerve root are easily injured during screw placement. In addition, the angle between the screw and the steel plate is large, and the tail end of the locking screw often protrudes above the steel plate. On the top of the esophagus, the top of the back wall of the esophagus hinders the peristalsis generated by esophagus pharyngeal, causing congestion and edema of the back wall of the esophagus, which in turn leads to esophageal fistula. The above complications can lead to life-threatening or high paraplegia and other extremely serious consequences. In addition, because the angle between the axis of the cervical pedicle and the sagittal line of the cervical spine is too large, the tail ends of the two pedicle screws of the same vertebral body will intersect. Therefore, only a few experts at home and abroad have reported clinical cases of anterior cervical pedicle screw fixation, and they are all fixed with a single screw. Thoracic and lumbar spine lesions also have the above problems.

SUMMARY OF THE INVENTION

In order to solve the problem of weak anterior fixation strength of the spine, the present invention designs an artificial vertebral body fixed with anterior pedicle screws, and a surgical tool for auxiliary positioning and installation.

For realizing the purpose of the present invention, the technical scheme adopted in the present invention is:

Use medical image data and 3D printing technology to establish a mathematical model of the diseased spine, according to the disease analysis, make the planning of the lesion resection range on the model, and virtually remove the lesion, and at the same time adjust the position of the restored spine virtually, so that the height and curvature of the spine can be restored. to the best condition that can be corrected intraoperatively. According to the bone defect in this state, an artificial vertebral body to fill the defect and support the spine, or a steel plate to fix the spine is designed. The invention can integrate the artificial vertebral body with the steel plate, and the steel plate is the front wall of the artificial vertebral body. Preferably, both ends of the steel plate may be slightly longer than the artificial vertebral body, or only the upper end may be longer than the artificial vertebral body. There are several screw holes on both ends of the steel plate beyond the artificial vertebral body. Preferably, the screw hole may be coaxial with the pedicle, or may be directed to the vertebral body in an imprecise orientation, or a combination of the two. Preferably, the artificial vertebral body part is also designed with fixed screw holes coaxial with the pedicles of all vertebral bodies to be removed, and all vertebral bodies can be designed with two pedicle screw fixing holes, that is, all vertebral bodies can be designed with two pedicle screw fixing holes. Bilateral anterior pedicle screw fixation can be performed. Therefore, its fixing strength can be maximized.

In order to ensure the excision of the diseased vertebral body and the loss of the original body surface markers, the artificial vertebral body can still be accurately implanted through the pedicle screw fixation hole after the artificial vertebral body is implanted in the bone defect. The present invention also includes using the original bone surface. The fabricated pedicle drilling guide and osteotomy guide. Preferably, the drilling guide plate uses the bone surface that is still dense and smooth during modeling in the operating area as a mask, and makes a protruding drilling guide tube on the long axis extension of each pedicle on the outer surface; on the same vertebral body The bases of the two pedicle guide tubes can intersect, and the inner lumens of the two guide tubes can also intersect. The mask of the osteotomy guide is also made according to the above requirements, and a hollow osteotomy guide window is made on the plane where the osteotomy is planned. Through the drilling guide, the anterior bilateral pedicle drilling can be carried out in advance, and the pedicle screw canal can be opened; the osteotomy guide can be used to remove the lesions in a precise range as planned. After implanting the artificial vertebral body, Exploring the drilled pedicle screw channel through the pedicle screw fixing hole printed on it can verify whether the artificial vertebral body is placed accurately, and place the artificial vertebral body according to the formed pedicle screw channel. Fine-tuning to achieve accurate, safe and fast anterior pedicle screw fixation.

The artificial vertebral body and all guide plates designed by the present invention are manufactured by metal or non-metal 3D printers based on 3D printing technology, and can meet the manufacturing requirements of the design. In particular, the implant can be printed into a biomimetic bone trabecular structure with dense porous edges, which can effectively prevent its subsidence and facilitate its fusion with the host bone.

The installation of the present invention can also be carried out with the aid of navigation and robotics.

The beneficial effect of the present invention is that the individualized artificial vertebral body with the self-stabilizing mechanism maximization can be precisely customized, and the maximum fixation strength of the anterior spinal lesion resection, stability reconstruction operation can be realized safely, quickly and accurately. At the same time, it can achieve friendly fusion and long-term stability of implants and human tissue.

Description of drawings

Fig. 1 is the rear side schematic diagram of adding screw according to the present invention;

Fig. 2 is the front side schematic diagram of the present invention;

3 is a schematic diagram of a positioning drilling guide plate of the present invention;

Fig. 4 is the schematic diagram of the osteotomy guide plate of the present invention;

In the picture:

1. Vertebral body; 2. Plate; 3. Screw hole; 4. Pedicle screw fixation hole; 5. Pedicle screw; 6. Vertebral screw; 7. Drill guide plate; 8. Guide tube; 9 . Osteotomy guide mask.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

The artificial vertebral body of the present invention may be a winged columnar body composed of a vertebral body 1 and a steel plate 2, or a simple columnar body. The vertebral body 1 is in the shape of a hollow barrel and is used to fill autologous or allogeneic, xenogeneic or artificial bone. The shape of the vertebral body 1 can be flexibly set according to the shape of the resected diseased vertebral body and its adjacent vertebral bodies. For example, its cross-section can be circular, oval, rectangular, trapezoidal, and the like.

Preferably, the artificial vertebral body in the form of a winged columnar body is composed of a steel plate 2 that is closely attached to the front wall of the vertebral body 1 and is integrated with it, so as to thicken the front wall. The length of the plate 2 is greater than the length of the vertebral body 1. It can be a double-winged column with both ends exceeding the edge of the vertebral body 1; it can also be a single-winged column with the upper end exceeding the vertebral body 1 and the lower end being flush with the vertebral body 1. The parts of the two ends of the steel plate 2 beyond the vertebral body 1 are respectively provided with a number of screw holes 3 for traversing the screws to fix the steel plate 2 on the vertebral body or the pedicle of the vertebral body 1 supported by the vertebral body 1 .

Preferably, the screw holes 3 at both ends of the steel plate 2 can be divided into pedicle screw holes and vertebral body screw holes, the pedicle screw holes are coaxial with the corresponding pedicles, and the pedicle screws 5 pass through the holes. Pass through the longitudinal axis of the pedicle and fix it on it; the axis of the vertebral body screw hole points to the rear of the vertebral body, and the vertebral body screw 6 is screwed into the vertebral body through this hole.

Preferably, the lengths of the vertebral body 1 and the steel plate 2 are determined according to the number of vertebrae to be excised and reconstructed and whether the entire vertebral body is excised or not. There are pedicle screw fixing holes 4 on the axis of the pedicle, which run through the front and rear walls of the vertebral body 1; Shen. In order to avoid the collision of the pedicle screws 5 on both sides, the thicker hole at the end of the fixation hole 4 should be deepened so that the pedicle screws 5 can sink into the thickened anterior wall of the vertebral body 1 .

The pedicle screw and the vertebral body screw of the present invention are both composed of a screw body with threads and a screw head part with a larger diameter than the screw body to generate a compression mechanism and prevent the screw from sinking. The screw head is short and the shape of the screw head only allows its After screwing into the screw holes, it should be flush with the steel plate 2, or slightly higher than the surface of the steel plate 2 and must be smooth and slightly convex. The combination of the screw hole 3 and the screw can be a common screw structure that can rotate and yaw, or a locking structure.

The invention also includes a pedicle drilling guide plate and an osteotomy guide plate made by using the original bone surface. Preferably, the drill guide mask 7 is the drill guide mask 7 whose surface is still dense and smooth during modeling in the operating area, and the inner surface of the drill guide mask 7 matches the outer surface of the attached bony structure. , the drilling guide mask 7 cannot move in any direction after being pressed and stuck on the bone surface. Drilling guide tubes 8 coupled with the drilling guide mask 7 are made on the outer surface of the drilling guide mask 7 along the extension line of the long axis of each pedicle. The guide tube 8 can constrain the drill bit only along its longitudinal direction The axis advances, that is, it can only advance along the longitudinal axis of the pedicle, so as to accurately open the pedicle screw channel; the bases of the two pedicle drilling guide tubes 8 on the same vertebral body can intersect, and the tube walls can be fused with each other , whose internal lumens may also intersect.

The osteotomy guide mask 9 of the osteotomy guide is also made according to the above requirements, and a hollow osteotomy guide window is made on the plane where the osteotomy is planned, and the edge of the window is the osteotomy guide surface 10 .

Through the drilling guide, the anterior bilateral pedicle drilling can be performed in advance, and the pedicle screw canal can be opened; the osteotomy guide can be used to perform accurate lesion removal according to the plan. After the artificial vertebral body is implanted in the defect after the lesion is removed, the drilled pedicle screw canal can be explored through the pedicle screw fixing hole 5 printed on it, so as to verify whether the artificial vertebral body is placed accurately and according to The preformed pedicle screw can fine-tune the placement of the artificial vertebral body, so as to achieve accurate, safe and fast anterior pedicle screw fixation.

Claims (10)

1. An artificial vertebral body fixed by an anterior pedicle screw and a positioning and installation tool, used for the reconstruction of cervical intervertebral disc and its upper cervical vertebra lower and lower cervical vertebra upper defects, the artificial vertebral body is the use of medical image data and 3D printing. The technology establishes a mathematical model of the diseased spine. According to the disease analysis, the planning of the lesion resection range is made on the model, and the lesions are virtually removed. At the same time, the position of the spine is adjusted and restored virtually, so that the height and curvature of the spine can be restored to the maximum that can be corrected during the operation. The artificial vertebral body is a hollow columnar body, which corresponds to the bilateral pedicles of the replaced cervical vertebrae. The image data collected by each specific patient is modeled and manufactured with a 3D printing process. Individualized, pedicle screw fixation holes that are coaxial with the pedicle through the anterior and posterior walls can be fixed with anterior pedicle screws. On the pedicle of the cervical vertebra where the vertebral body to be excised is located; and there is a bone defect formed under the virtual resection of the lesion and the virtual adjustment of the restored spine position, so that the spine height and curvature can be restored to the best state that can be corrected during surgery. The positioning drilling guide device for assisting the opening of the pedicle screw channel and the osteotomy guide device for assisting the precise resection of the diseased vertebral body are individually designed according to specific conditions. 2. a kind of artificial vertebral body fixed with anterior pedicle screw as claimed in claim 1 and the positioning and installation tool, it is characterized in that the artificial vertebral body section of hollow column is circular, oval, rectangle or trapezoid; each The pedicle screw fixation holes are all single-stage stepped tubes, which are used to accommodate the pedicle screw head and prevent the pedicle screw from sinking. To make the pedicle screw sink in the anterior wall of the vertebral body; screw the pedicle screw through the pedicle screw fixation hole to fix the artificial vertebral body on the pedicle. 3. a kind of artificial vertebral body fixed with anterior pedicle screw as claimed in claim 1 and the positioning and installation tool, it is characterized in that described artificial vertebral body is a winged columnar body synthesized by vertebral body and steel plate, and the steel plate is tightened. It is attached to the front wall of the vertebral body and integrated with it to thicken the front wall. 4. a kind of artificial vertebral body and positioning installation tool for anterior pedicle screw fixation as claimed in claim 3, it is characterized in that the length of described steel plate is greater than the length of vertebral body, and the shape of described steel plate is that both ends exceed the vertebral body. A two-winged columnar edge at the edge, or a single-winged columnar shape with the upper end extending beyond the vertebral body and the lower end being flush with the vertebral body. 5. a kind of artificial vertebral body fixed with anterior pedicle screw as claimed in claim 3 and the positioning installation tool, it is characterized in that the part of the two ends of the steel plate beyond the vertebral body is each provided with several screw holes, in order to traverse the screw , the steel plate is fixed on the cervical vertebral body supported by the vertebral body. 6. The artificial vertebral body and the positioning and installation tool for anterior pedicle screw fixation as claimed in claim 1, characterized in that the pedicle screw and the vertebral body screw are composed of a threaded screw body and a larger diameter than the screw body. It is composed of the part of the nail head that is large to generate a compression mechanism and prevent the screw from sinking. The nail head is short and the shape of the nail head only allows it to be flush with the steel plate after being screwed into the screw hole, or slightly higher than the surface of the steel plate and must be smooth and slightly convex The combination of the screw hole and the screw is a common screw structure that can rotate and yaw. 7. The artificial vertebral body and the positioning and installation tool for anterior pedicle screw fixation as claimed in claim 1, characterized in that the pedicle screw and the vertebral body screw are composed of a threaded screw body and a larger diameter than the screw body. It is composed of the part of the nail head that is large to generate a compression mechanism and prevent the screw from sinking. The nail head is short and the shape of the nail head only allows it to be flush with the steel plate after being screwed into the screw hole, or slightly higher than the surface of the steel plate and must be smooth and slightly convex shape; the combination of the screw hole and the screw is a locking structure. 8. An artificial vertebral body and a positioning and installation tool for anterior pedicle screw fixation as claimed in claim 1, characterized in that the drilling guide device is based on the dense and smooth surface of the bone surface during modeling in the operating area. Drilling guide mask, the inner surface of the mask is consistent with the outer surface of the attached bony structure, and the mask cannot be micro-moved in any direction after being pressed and stuck on the bone surface; the outer surface of the mask is along each vertebra. The extension line of the long axis of the arch root is used to make a drilling guide tube coupled with the mask, and the guide tube can constrain the drill bit to only advance along its longitudinal axis. 9. The artificial vertebral body and the positioning and installation tool for anterior pedicle screw fixation as claimed in claim 1, characterized in that the osteotomy guiding device is based on the dense and smooth bone surface during modeling in the operating area. Osteotomy guide mask, the inner surface of the mask is consistent with the outer surface of the attached bony structure, and the mask cannot be slightly moved in any direction after being pressed and stuck on the bone surface; a hollowed-out surface is made on the plane of the planned osteotomy Osteotomy guide window, the edge of the window is the osteotomy guide surface. 10 . The artificial vertebral body and the positioning and installation tool for anterior pedicle screw fixation according to claim 1 , wherein the artificial vertebral body is a bionic trabecular bone structure. 11 .

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