Screw device for spinal surgery and method for injecting bone cement using same

Abstract

The present invention relates to a screw device for spinal surgery, which can easily prevent a screw from loosening, detaching, or coming out from a vertebra after the screw is press-fit and fixed into a vertebra for surgery, and a method for injecting bone cement using same. That is, the objective of the present invention is to provide a screw device for spinal surgery, which, during spinal surgery for fixing a screw into a vertebra, injects bone cement into the interior of the vertebra through an injection channel formed in the screw, thereby allowing the screw and the bone cement to bond together within the vertebra and thus effectively preventing the screw from loosening or coming out from the vertebra, and a method for injecting bone cement using same.

Description

Screw device for spinal surgery and method for injecting bone cement using the same

[0001] The task (result) of the present invention is a research result of the clinical data-based musculoskeletal human simulation convergence technology support project, which was carried out with financial support from the Ministry of Trade, Industry and Energy and the Korea Institute for Advancement of Technology.

[0002] The present invention relates to a spinal surgery screw device and a bone cement injection method using the same, and more particularly, to a spinal surgery screw device and a bone cement injection method using the same, which can easily prevent a screw from becoming loose and detaching or falling out from a vertebra after a surgery in which the screw is press-fitted into the vertebra.

[0003] In general, when the spine is damaged due to an accident or a degenerative disease progresses due to age, various spinal pains can be caused as the discs and nerves that act as cushions between the vertebral bodies that make up the spine are compressed.

[0004] Accordingly, in cases of mild spinal pain, physical therapy may be used as a treatment method, but in cases of severe pain, surgery is performed to correct the position of the spine by inserting a device to fix the spine or to correct the area that is compressing the nerves so that they are not compressed.

[0005] Instruments used for spinal surgery include various types of fixation devices to fix fractured and deformed areas of the bones, vertebral body prostheses inserted between the vertebrae, and spinal fixation screws inserted and fixed into the corresponding areas of the fractured or damaged vertebrae in patients with spinal and disc problems.

[0006] The attached drawings 1 and 2 are a front view and a cross-sectional view illustrating a conventional spinal fixation device.

[0007] As shown in FIGS. 1 and 2, a conventional spinal fixation device for spinal surgery can be configured to include a screw (1) and a rod (2).

[0008] Accordingly, by press-fitting a pedicle screw (1) into each vertebra of the surgical target and connecting the upper screw (1) and the lower screw (1) with a rod (2), each vertebra can be aligned and corrected to its original position and spacing.

[0009] At this time, the screw (1) must be maintained in a press-fit state inside the spine even after surgery.

[0010] For example, in the case of a patient with a spinal fracture, the spine can be restored to a normal state by interconnecting each vertebra forming the spine with a spinal fixation device including a screw (1) and a rod (2), and for this purpose, the screw (1) must remain firmly fixed to the inside of the vertebra without loosening even after surgery.

[0011] However, there was a problem in that the screw, which was supposed to be permanently fixed, moved along its circumference and became loose and detached from the vertebrae or fell out due to the patient's movements and activities for a long time or due to a decrease in bone density caused by aging of the vertebrae.

[0012] Moreover, if the screw becomes dislodged or removed from the vertebrae, it may cause pain due to contact with the surrounding nerves, or the alignment of the vertebrae's position and spacing may be disrupted, leading to the need for a secondary surgery.

[0013] The present invention has been devised to solve the above-mentioned conventional problems, and the purpose of the present invention is to provide a spinal surgery screw device and a bone cement injection method using the same, which can easily prevent the screw from becoming loose and detached or falling out from the spinal bone by injecting bone cement into the inside of the spinal bone through the injection channel of the screw during surgery to attach a screw to the spinal bone, thereby allowing the screw and bone cement to be combined within the spinal bone.

[0014] In order to achieve the above object, one embodiment of the present invention provides a spinal surgical screw device comprising: a screw having an injection passage formed along a longitudinal direction at an inner central portion with an open upper portion, and a plurality of injection holes formed through a lower peripheral portion communicating with the injection passage, so as to be press-fitted into a vertebra; a head having a structure in which a lower portion is lockably fastened to an upper portion of the screw and a female threaded portion is formed at an inner diameter portion; an adapter having a male threaded portion formed at a lower peripheral portion to be fastened to the female threaded portion of the head, and a guide hole formed through a longitudinal direction at an inner central portion for supplying bone cement to the injection passage of the screw; and a cement injector inserted through the guide hole of the adapter to an inlet of the injection passage of the screw, injecting bone cement into the injection passage of the screw, and pressurizing the injected bone cement to fill the interior of the vertebra through the injection holes of the screw.

[0015] The spinal surgical screw device of the present invention further includes a bone particle pusher that is pushably inserted into the injection channel of the screw through a guide hole of the adapter before injecting bone cement into the injection channel of the screw, and is characterized in that a bone debris discharge hole is formed through the lower end of the screw so that bone debris introduced into the injection channel is discharged to the outside by the pushing force of the bone particle pusher.

[0016] Preferably, the injection hole of the screw is characterized in that it is formed as a streamlined injection hole along the screw thread, or as an elongated injection hole extending a predetermined length along the length of the screw, or as an oblique injection hole arranged diagonally in the direction opposite to the direction in which the screw is inserted into the vertebra.

[0017] In addition, the pitch of the first screw thread formed at the front end of the screw is formed narrower than the pitch of the second screw thread formed at the distal end, so that the first screw thread is fastened to the hard bone portion with high density that forms the exterior of the vertebrae, and at the same time, the second screw thread is fastened to the loose bone portion with low density that forms the interior of the vertebrae.

[0018] In order to achieve the above object, another embodiment of the present invention provides a method for injecting bone cement using a screw device for spinal surgery, comprising: a step of press-fitting a screw into a vertebra, the screw having a structure in which an injection passage with an open upper portion is formed along a longitudinal direction in the inner center and a plurality of injection holes formed through the lower circumference communicating with the injection passage; a step of screw-fitting a male screw portion of an adapter to a female screw portion of a head that is lockably fastened to the upper portion of the screw; a step of inserting a cement injection needle tube of a cement injector through a guide hole formed in the inner center of the adapter to the injection passage entrance of the screw; a step of coupling a cement injection gun to the cement injection needle tube; a step of injecting bone cement from the cement injection gun through the cement injection needle tube into the injection passage of the screw with a predetermined pressure; and a step of discharging the bone cement injected into the injection passage of the screw through the injection holes of the screw to fill the interior of the vertebra.

[0019] The method for injecting bone cement using a spinal surgical screw device of the present invention is characterized by further comprising the steps of: inserting and pushing a bone particle pusher into the injection channel of the screw through a guide hole of the adapter before inserting a cement injection needle tube of the cement injector into the injection channel inlet of the screw; a step of discharging and removing bone debris that has entered the injection channel when the screw is press-fitted into the vertebra through a bone debris discharge hole formed through a lower end of the screw so as to be in communication with the injection channel by the pushing force of the bone particle pusher; and a step of re-inserting and pushing the bone particle pusher into the injection channel of the screw after the bone cement injected into the injection channel of the screw has been discharged through the injection hole of the screw and filled into the interior of the vertebra; so that even the bone cement remaining in the injection channel has been discharged through the bone debris discharge hole and filled into the interior of the vertebra.

[0020] Through the means for solving the above-mentioned problem, the present invention provides the following effects.

[0021] First, a screw is press-fitted into the vertebrae, and then bone cement is injected into the interior of the vertebrae through the injection channel of the screw using a bone cement injection device, so that the screw and bone cement can be combined within the vertebrae, and thus the phenomenon of the screw becoming loose and detaching or falling out from the vertebrae can be completely prevented.

[0022] Second, by completely preventing the screw from being detached or removed from the vertebrae, the screw can be maintained in a firmly fixed state inside the vertebrae, thereby contributing to the patient's normal spinal recovery and preventing secondary surgery due to screw detachment or removal.

[0023] Figures 1 and 2 are a front view and a cross-sectional view showing a conventional spinal fixation device,

[0024] Figure 3 is an exploded perspective view showing a spinal surgical screw device according to the present invention.

[0025] Figures 4 to 9 are cross-sectional views sequentially showing a spinal surgical screw device according to the present invention and a bone cement injection method using the same.

[0026] Figure 10 is a schematic diagram showing various shapes of injection holes formed in a screw among the configurations of a spinal surgical screw device according to the present invention.

[0027] Figure 11 is a schematic diagram showing the screw thread pitch structure of the screw device for spinal surgery according to the present invention.

[0028] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0029] The attached Figure 3 is an exploded perspective view showing a spinal surgery screw device according to the present invention, and Figures 4 to 9 are cross-sectional views sequentially showing a spinal surgery screw device according to the present invention and a bone cement injection method using the same.

[0030] Referring to FIGS. 3 and 4, a screw (10) that is press-fitted into a vertebra is provided with a structure in which an injection passage (11) with an open upper portion is formed along the length direction in the inner center thereof, and a plurality of injection holes (12) that are formed perpendicularly to and communicate with the injection passage (11) are formed through the lower circumference.

[0031] A hollow head (20) for fastening an adapter (30) for injecting bone cement is fastened to the upper portion of the screw (10) in a lockable manner.

[0032] To this end, a fastening jaw (14) is formed protrudingly on the upper circumference of the screw (10), and a locking projection (22) bent inward is formed on the lower portion of the head (20).

[0033] Accordingly, when the head (20) is inserted from the bottom of the screw (10) and pulled upward, the locking projection (22) of the head (20) is caught on the fastening jaw (14) of the screw (10), so that the head (20) is locked and positioned on the top of the screw (10).

[0034] At this time, a female screw portion (21) for fastening an adapter (30) is formed in the inner diameter of the head (20).

[0035] Referring to FIGS. 3 and 5, the adapter (30) has a male screw portion (31) formed on the lower circumference thereof to be fastened to the female screw portion (21) of the head (20), and a guide hole (32) formed along the length direction to supply bone cement to the injection passage (11) of the screw (10) is provided in the inner center.

[0036] Accordingly, by fastening the male screw portion (31) of the adapter (30) to the female screw portion (21) of the head (20), the head (20) can be fixed so as not to move while being pulled, and accordingly, the head (20) and the adapter (30) are fixed in a straight line with respect to the screw (10).

[0037] Referring to FIG. 3, FIG. 7 and FIG. 8, a cement injector (40) is connected through the guide hole (32) of the adapter (30).

[0038] That is, the cement injector (40) may be structured to be inserted into the inlet of the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30), inject bone cement into the injection passage (11) of the screw (10), and pressurize the injected bone cement to fill the interior of the vertebrae through the injection hole (12) of the screw (10).

[0039] Preferably, the cement injector (40) may be composed of a cement injection needle tube (41) inserted into the inlet of the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30), and a cement injection gun (42) connected to the inlet of the cement injection needle tube (41).

[0040] Accordingly, when bone cement is injected at a predetermined pressure from the cement injection gun (42) toward the cement injection needle tube (41), the injected bone cement passes through the injection passage (11) of the screw (10) and is discharged through the injection hole (12) of the screw (10) to fill the interior of the vertebra.

[0041] Meanwhile, when the screw (10) is press-fitted into the vertebra, bone debris may flow into the injection passage (11) through the injection hole (12) of the screw (10), etc., and the injection passage (11) for injecting bone cement may become blocked, and as a result, bone cement may not be properly injected into the injection passage (11) of the screw (10).

[0042] To solve this, the spinal surgical screw device of the present invention is configured to further include a bone particle pusher (50) that is pushably inserted into the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30) before injecting bone cement into the injection passage (11) of the screw (10), as shown in FIGS. 3 and 6.

[0043] At this time, a waste discharge hole (13) is formed through the lower end of the screw (10) to communicate with the injection passage (11) so that the waste introduced into the injection passage (11) is discharged to the outside by the pushing force of the particle pusher (50).

[0044] Accordingly, before injecting bone cement into the injection passage (11) of the screw (10) using the cement injector (40), by repeatedly pushing the particle pusher (50) through the guide hole (32) of the adapter (30) to the injection passage (11) of the screw (10), the bone debris introduced into the injection passage (11) of the screw (10) can be discharged into the interior of the vertebrae through the bone debris discharge hole (13) from the injection passage (11) by the pushing force of the particle pusher (50).

[0045] Accordingly, when bone cement is injected at a predetermined pressure from the cement injection gun (42) toward the cement injection needle tube (41), the injected bone cement flows smoothly along the injection passage (11) of the screw (10) from which the debris has been removed, and is then discharged through the injection hole (12) of the screw (10) to easily fill the interior of the vertebra.

[0046] Meanwhile, in order to vary the amount of bone cement injected by taking into account the patient's spinal bone density, etc., the shape of the injection hole (12) of the screw (10) can be formed in various ways.

[0047] To this end, as shown in Fig. 10, the injection hole (12) of the screw (10) may be formed as a streamlined injection hole (12-1) along the screw thread of the screw (10), or may be formed as a long injection hole (12-2) extended to a predetermined length along the longitudinal direction of the screw (10).

[0048] In addition, in order to prevent debris from flowing into the injection passage (11) of the screw (10) when the screw (10) is press-fitted into the vertebra, the injection hole (12) of the screw (10) may be formed as an oblique injection hole (12-3) arranged diagonally in the direction opposite to the direction in which the screw (10) is inserted into the vertebra.

[0049] Preferably, the pitch of the first screw thread (10-1) formed at the tip end of the screw (10) is formed narrower than the pitch of the second screw thread (10-2) formed at the tip end.

[0050] Accordingly, as illustrated in FIG. 11, the first screw thread (10-1) of the screw (10) can be fastened to the hard bone portion (Cortex bone) with high density forming the exterior of the vertebrae, and at the same time, the second screw thread (10-2) can be fastened to the cancellous bone portion (Cancellous bone) with low density forming the interior of the vertebrae, and accordingly, the screw (10) can be fixed to the vertebrae with strong fastening force.

[0051] Here, the method of injecting bone cement using a spinal surgical screw device having the above-mentioned configuration is examined in order as follows.

[0052] First, as shown in Fig. 4, a screw (10) having a structure in which an injection passage (11) with an open upper portion is formed along the length direction in the inner center as described above, and a plurality of injection holes (12) communicating with the injection passage (11) are formed through the lower circumference is press-fitted into the spine.

[0053] Next, as shown in Fig. 5, the male screw portion (31) of the adapter (30) is screwed into the female screw portion (21) of the head (20) that is lockably fastened to the upper portion of the screw (10).

[0054] Accordingly, by fastening the male screw portion (31) of the adapter (30) to the female screw portion (21) of the head (20), the head (20) can be fixed so as not to move while being pulled, and accordingly, the head (20) and the adapter (30) are fixed in a straight line with respect to the screw (10) so that bone cement can be injected in a constant straight direction.

[0055] Next, as shown in Fig. 6, the above particle pusher (50) is inserted and pushed through the guide hole (32) of the adapter (30) into the injection passage (11) of the screw (10).

[0056] Accordingly, by repeatedly pushing the particle pusher (50) through the guide hole (32) of the adapter (30) to the injection passage (11) of the screw (10), the particle debris introduced into the injection passage (11) of the screw (10) can be removed by being discharged from the injection passage (11) to the inside of the vertebrae through the particle debris discharge hole (13) by the pushing force of the particle pusher (50).

[0057] Next, as shown in Fig. 7, the cement injection needle tube (41) of the cement injector (40) is inserted through the guide hole (32) formed in the inner center of the adapter (30) to the inlet of the injection passage (11) of the screw (10).

[0058] Next, as shown in Fig. 8, a cement injection gun (42) is connected to the inlet of the cement injection needle tube (41).

[0059] Accordingly, when bone cement is injected at a predetermined pressure from the cement injection gun (42) toward the cement injection needle tube (41), the injected bone cement passes through the injection passage (11) of the screw (10) and is discharged through the injection hole (12) of the screw (10) to fill the interior of the vertebra.

[0060] Meanwhile, even if the bone cement injected into the injection passage (11) of the screw (10) is discharged through the injection hole (12) of the screw (10) and filled into the interior of the vertebra, some of the bone cement may remain inside the injection passage (11) of the screw (10) and inside the needle tube (41) for cement injection.

[0061] Accordingly, as shown in FIG. 9, after removing the cement injection gun (42) from the cement injection needle tube (41), the particle pusher (50) is reinserted into the cement injection needle tube (41) and the injection passage (11) of the screw (10) and pushed, so that even the bone cement remaining in the injection passage (11) and the like can be discharged through the bone waste discharge hole (13) of the screw (10) and filled into the interior of the vertebra.

[0062] In this way, as the bone cement filled into the interior of the vertebra spreads around the screw (10), the screw (10) and the bone cement can be firmly bonded to each other, and accordingly, the phenomenon of the screw (10) being loosened and detached or falling out from the vertebra can be completely prevented.

Claims

1. A screw (10) is provided with a structure in which an injection passage (11) with an open upper portion is formed along the length direction in the inner center, and a plurality of injection holes (12) communicating with the injection passage (11) are formed through the lower circumference, and is press-fitted and fastened to the spine; The lower part is provided with a head (20) having a structure in which a female screw part (21) is formed on the inner diameter part and the lower part is lockably connected to the upper part of the screw (10); An adapter (30) having a male screw portion (31) formed on the lower circumference to be fastened to the female screw portion (21) of the head (20), and a guide hole (32) formed along the length direction in the inner center for supplying bone cement to the injection passage (11) of the screw (10); and It is configured to include a cement injector (40) that is inserted into the inlet of the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30), injects bone cement into the injection passage (11) of the screw (10), and pressurizes the injected bone cement to fill the interior of the vertebrae through the injection hole (12) of the screw (10); It further includes a particle pusher (50) that is pushably inserted into the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30) before injecting bone cement into the injection passage (11) of the screw (10); At the lower end of the screw (10), a waste discharge hole (13) is formed through the injection passage (11) so that the waste introduced into the injection passage (11) is discharged to the outside by the pushing force of the particle pusher (50); A spinal surgical screw device characterized in that the pitch of the first screw thread (10-1) formed at the front end of the screw (10) is formed narrower than the pitch of the second screw thread (10-2) formed at the distal end, so that the first screw thread (10-1) is fastened to a hard bone portion with a high density forming the exterior of the vertebrae, and at the same time, the second screw thread (10-2) is fastened to a loose bone portion with a low density forming the interior of the vertebrae.

2. In claim 1, A spinal surgical screw device characterized in that the injection hole (12) of the screw (10) is formed as a streamlined injection hole (12-1) along the screw thread of the screw (10), or as an elongated injection hole (12-2) extended to a predetermined length along the length of the screw (10), or as an oblique injection hole (12-3) arranged diagonally in the direction opposite to the direction in which the screw (10) is inserted into the vertebra.

3. A method for injecting bone cement using the spinal surgical screw device of claim 1, A step of press-fitting a screw (10) into a vertebra, the screw having a structure in which an injection passage (11) with an open upper portion is formed along the length direction in the inner center and a plurality of injection holes (12) communicating with the injection passage (11) are formed through the lower circumference; A step of screwing the male screw portion (31) of the adapter (30) into the female screw portion (21) of the head (20) that is lockably fastened to the upper portion of the screw (10); A step of inserting a cement injection needle tube (41) of a cement injector (40) into the inlet of the injection passage (11) of the screw (10) through the guide hole (32) formed in the inner center of the adapter (30); A step of connecting a cement injection gun (42) to the above cement injection needle tube (41); A step in which bone cement is injected into the injection passage (11) of the screw (10) through the cement injection needle tube (41) from the cement injection gun (42) with a predetermined pressure; and It includes a step in which bone cement injected into the injection passage (11) of the screw (10) is discharged through the injection hole (12) of the screw (10) and filled into the interior of the vertebra; A step of inserting and pushing the particle pusher (50) into the injection passage (11) of the screw (10) through the guide hole (32) of the adapter (30) before inserting the cement injection needle tube (41) of the cement injector (40) into the inlet of the injection passage (11) of the screw (10); A step in which the bone debris introduced into the injection passage (11) when the screw (10) is pressed into the spine is discharged and removed through the bone debris discharge hole (13) formed through the lower end of the screw (10) so as to be connected to the injection passage (11) by the pushing force of the bone particle pusher (50); and A step in which the bone cement injected into the injection passage (11) of the screw (10) is discharged through the injection hole (12) of the screw (10) and filled into the interior of the vertebra, and then the particle pusher (50) is inserted again into the injection passage (11) of the screw (10) and pushed, so that even the bone cement remaining in the injection passage (11) is discharged through the bone waste discharge hole (13) and filled into the interior of the vertebra; A method for injecting bone cement using a spinal surgical screw device, characterized in that it further includes.

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