KR20060094733A - Apparatus and method for transdermal placement of lumbar pedicle screws and connecting rods - Google Patents

Abstract

 A minimally invasive method for stabilizing adjacent fusion vertebrae is achieved with an instrument that is configured to connect pedicles of adjacent vertebrae to each other and includes a plurality of pedicle screws. The screw head of each pedicle screw is configured to receive a connecting rod, with the connecting rod and the pedicle screw receiving it aligned vertically.

Pedicle, lumbar vertebra, union, connecting rod

Description

 DEVICE AND METHOD FOR PERCUTANEOUS PLACEMENT OF LUMBAR PEDICLE SCREWS AND CONNECTING RODS}

 1 is a side view of a mechanical device system of the prior art;

FIG. 2 is an exploded view of the screws of the mechanism device system shown in FIG. 1. FIG.

3 is a side view of the device according to the invention.

4 is an isometric view of the screw of the present invention configured to be introduced subcutaneously into the pedicle of the vertebrae.

5 illustrates one embodiment of a guide system configured to position a plurality of instruments associated with adjacent screws in a desired position.

6 is a front view of the guidance system of FIG. 5 showing a combination of an awl and an inner dilator and an outer dilator;

7 is an isometric view of a tissue cutting instrument constructed in accordance with the present invention.

8 is a front view of a rod holder system constructed in accordance with the present invention in which the connecting rod is in a first position engaged with the interior of the rod holder;

9 is a cross-sectional view of the rod holder system of FIG. 7 showing the initial stage of movement of the rod toward its final position.

10 is an isometric view of one embodiment of a rod holder system configured to determine the final position of a connecting rod at which the rear end of the connecting rod is received by the second screw.

11 is an isometric view of another embodiment of a rod holder system.

12 is a side view of the rod guide system for determining the final position of the connecting rod;

13 is an isometric view of a placement system for setting the desired trajectory of the guidance system relative to the position of entry into the pedicle to be interconnected.

FIG. 14 is a plan view of a combination of an inner frame and a cradle frame of the placement device shown in FIG. 13; FIG.

FIG. 15 is a front view of the placement apparatus shown in FIG. 13. FIG.

FIG. 16 shows one embodiment of an outer frame of the positioning system shown in FIG. 13. FIG.

17-21 illustrate various embodiments of a track structure provided in the outer frame of FIGS. 13 and 15 for engaging the inner frame of the placement system.

FIG. 22 is an isometric view of one embodiment of the cradle of the placement system shown in FIG. 13. FIG.

FIG. 23 illustrates another embodiment of a cradle of the placement system of FIG. 13.

 The present invention relates to an instrument device system for use in a spinal fusion procedure and a method of operating the same. In particular, the present invention relates to a mechanical device system for subcutaneously securing pedicles of adjacent fusion vertebrae to each other and to a minimally invasive posterior approach for interlocking pedicles.

 Over the past decades, the value of pedicle screw stabilization to enhance lumbar fusion procedures has been clearly demonstrated. Many systems have been introduced to achieve this, and there are now a number of systems for the placement of screws and connecting rods or plate systems as one of the components of the traditional lumbar fusion procedure. Most of these systems require a "open way" procedure that involves extensive incision of the skin, extensive detachment or takedown of the paraspinal muscles, and exposure of bone elements. This includes serious and complex surgical interventions through large incisions of muscle tissue around the spine. As a result, traditional lumbar fusion procedures involve severe pathological symptoms, including blood loss, increased anesthesia time and subsequent complications, and increased risk of infection. In addition, severe postoperative pain occurs very often in patients, resulting in longer hospital stays, which adds significant cost to current systems.

In one of the procedures developed to overcome the shortcomings of traditional fusion procedures, unique endoscopy equipment is used. Such equipment can be very expensive, and this procedure can only be used in some medical facilities. Another undesirable consequence of this endoscopic procedure is its complexity, which requires not only a significant amount of experience for the medical staff to properly position the screws with this equipment, but also requires highly trained technicians.

U.S. Patent No. 6,443,953 discloses a more commonly performed procedure, which is configured to secure the pedicle of the vertebral body to be fused together, inserting a plurality of screws into the pedicle and connecting the screw heads of these screws to the connecting rods. It is associated with a system comprising crosslinking. As shown in FIGS. 1 and 2, such procedures require an incision in the upper part of the perivertebral tissue of the lower thoracic region located below the bottom of the screw 22. Then, as indicated by arrow A, the connecting rod 14 is passed through the hole 18 in the screw head 12 in a direction parallel to the spine, and the screw head 12 is first covered with the cap 20 and the nut ( 16) on its cap 20 to secure the connecting rod 14 in place. In connection with the procedure there is a possibility of soft tissue damage as the connecting rod 14 moves through the soft tissue. In addition, in this procedure the screws must be precisely aligned, in particular the respective holes 18 of adjacent screw heads 12 must be precisely aligned with respect to the connecting rods 14 as well as with respect to each other. Thus, this procedure places additional demands on the practitioner, increases the overall surgical time, and consequently adds health risks to the patient.

Another problem associated with the above-described system is the problem of passing a bone screw into the pedicle of the lumbar spine, in which case, using only intraoperative imaging and surface anatomy, the bone can be maximized and damage to structures surrounding the pedicle such as nerve roots The screws must be able to be secured inside the pedicle in a way that minimizes the risk.

  Therefore, there is a need for an instrument system and method of use that minimizes soft tissue damage, reduces overall surgical time, optimizes the guidance of the connecting rods towards the screws, and simplifies the positioning of the connecting rods and screws.

This object is achieved by the system of the present invention configured to act to bridge adjacent screws after the connecting rods are first introduced to one of the screws from above rather than laterally as in the prior art.

One aspect of the invention relates to a new method of joining fusion vertebrae to one another, in which the tip of the connecting rod is pivotally coupled to one of a plurality of screws inserted into the pedicle of the fusion vertebra. In order to complete the interconnection of the vertebrae, the method further pivots the connecting rod about its leading end so that the trailing end of the connecting rod engages an adjacent screw attached to the pedicle of the other vertebrae.

Unlike the known prior art methods in which the connecting rod is introduced up and down of the screw and guided through the soft tissue in a direction parallel to the spine, the system of the present invention allows the surgeon to guide the connecting rod in the vertical direction towards one of the screws. To be. Thus, one of the advantages of the present invention is that penetration of soft tissue occurs locally, with the result that the cut soft tissue is only minimally damaged.

Another aspect of the invention is directed to a guide system for placing screws in a subcutaneous interconnected pedicle. According to the configuration of the guide system of the present invention, the practitioner is able to guide and position the screw such that the engagement and movement of the connecting rod is made in a simple and reliable manner between the primary position and the final position. Thus, the time consuming and burdensome alignment procedure, including moving the connecting rod through the hole in the screw head, is greatly simplified. As a result, the safety of the method of the present invention is improved.

According to another aspect of the invention, the system of the present invention is provided with a rod holder system configured to cooperate with a guide system in such a way that the connecting rod is pivotally engaged with one of the screws. The rod holder system is also configured to move the connecting rod to the final position where the screws are connected to each other.

According to another aspect, the system of the present invention further comprises an identification system configured to make a reference mark on the interconnected pedicle using multiple imaging techniques. According to another aspect of the present invention, the system of the present invention includes a placement system for directing and automatically positioning the screw placement mechanism to a desired position. This positioning system is configured such that a guide providing a desired trajectory to the screw and the screw positioning mechanism can move in three mutually orthogonal planes with respect to the reference mark. Thus, the practitioner can set the position of the guide with high precision relative to the point of entry into the identified pedicle.

According to another aspect of the present invention, there is provided an orthopedic / neurosurgery kit comprising a combination of instruments used during the execution of the method of the present invention. The kit provides the practitioner with an assembly of guides, screws, and screw placement mechanisms associated with the method of the present invention to the practitioner, greatly simplifying the surgical procedure and reducing its cost.

Accordingly, one object of the present invention is to provide a minimally invasive surgical procedure for connecting vertebrae to each other while avoiding tissue damage associated with the procedure.

It is a further object of the present invention to provide a positioning system for positioning various instruments associated with guiding and positioning the pedicle screw and rod system of the system of the present invention.

It is a further object of the present invention to provide a system for the identification of reference marks associated with the placement of the screw / rod system.

It is another object of the present invention to introduce a tissue cutting assembly configured to cooperate with the guide system and to cut the soft tissue between the screw heads to create a tube containing the connecting rod.

The foregoing and other objects, features and advantages will become more apparent from the following detailed description of the preferred embodiments and the accompanying drawings.

 As shown in Figures 3 and 4, the method of the present invention is carried out to connect the vertebrae to be fused together, by guiding the connecting rod 66 in alignment with the longitudinal axis AA of the screw 54 subcutaneously. After engaging the connecting rod 66 with the screw, the connecting rod 66 is pivoted to bridge the adjacent screw 54. Thus, one of the adjacent screws 54 advances toward the pedicle of one of the vertebrae to be fused along the path formed thereon, and then the connecting rod 66 passes through the path and the screw head 60 of the screw 54. ) Is automatically aligned and engaged.

The system 55 of the present invention, configured to help the practitioner implement the method of the present invention, includes a tip 70 of the connecting rod 66 after the pedicle is positioned relative to each other in addition to the screw 54 and the connecting rod 66; 4) and a nut 78 that secures the rear end 72. For vertical movement of the connecting rod 66, the screw head 60 is at the leading end of the connecting rod 66 at the primary position of the connecting rod 66 where the connecting rod 66 and the shank 56 of the second screw 54 are aligned. Should be configured to receive 70 from above. Accordingly, the screw head 60 is formed with a peripheral wall to form a central opening dimensioned to accommodate the tip 70 of the connecting rod 66 at the primary position of the connecting rod 66. However, only by introducing the tip 70 of the connecting rod 66 into the screw head 60, while the connecting rod 66 is pivoting toward the adjacent screw 54, the freezing rod 66 is screw head 60. Insufficient to prevent movement in In order to reliably engage the tip 70 of the connecting rod 66 with the screw head 60 of the first screw 54, slots and recesses are formed in the peripheral wall of the screw head 60. As shown in FIG. 4, two recesses 64 formed in each segment of the circumferential wall are aligned with each other, and are dimensioned to accommodate the pins 68 provided at the tip 70 of the connecting rod 66. It is. These recesses 64 and the pins 68 are configured to allow the connecting rod 66 to rotate about its front end 70. At this time, the front end 70 of the connecting rod 66 is screwed during rotation. It is held detained between the slots 62 aligned at the head 60. In this way, the tip 70 of the connecting rod 66 is received from above and has at least one slot 62 and a pair of recesses 64 dimensioned to allow the connecting rod 66 to rotate. Screw head 60 is very important for the successful implementation of the method of the present invention.

As an alternative, the tip 70 of the connecting rod 66 can be permanently attached to the screw head 60. According to this configuration of the screw 54, a pin 68 is formed incorporating the screw head 60, and the tip 70 is permanently and pivotally mounted to the pin 68.

In the final position as shown by the broken line in FIG. 3, the rear end 72 of the connecting rod 66 engages the screw head 60 of the adjacent screw 54 inserted into the pedicle of the second vertebra of the vertebrae to be fused. . As will be described later, the rear end 72 of the connecting rod 66 moves along the arc path toward the slot 62 and passes through the slot 62 and is disposed within the screw head 60 of the adjacent screw 54. In order for the connecting rod 66 and the adjacent screw 54 to engage in this way, the slots 62 formed in the screw head 60 of the particular screw and the adjacent screw 54 form some spatial relationship with each other. It must be located. In one particular position, the slots 54 of the screw head 60 of the screw 54 receiving the rear end 72 of the connecting rod 66 and the screw 54 coupled to the tip 70 are connected to the connecting rod 66. ) Can be aligned if they are straight. Alternatively, if the connecting rod 66 is bent, the slots 62 of adjacent screws 54 can be positioned at a desired angular position with respect to each other. One reason why the connecting rod 66 can be bent is to connect adjacent screws 54 introduced into the pedicle that can extend at different angles as is known in the art. The curved connecting rod is also useful for maintaining the lumbar lordosis. To accommodate the curved connecting rod, each screw 54 has a rotating component, such as a ratcheting or hinged mechanism, but has a ball-in-socket joint 58 as shown in FIGS. 3 and 4. In the embodiment of the rotary component shown, it is preferred that the ball be formed on the shank 56. The screw head 60 of the screw 54 is engaged with the ball by the socket surrounding the ball in the ball-in-socket joint 58. In the configuration shown, the socket forms the bottom or bottom of the screw head 60. This mechanism allows the screw head 60 to rotate in a significant range, ultimately adjusting the path of the connecting rod. As an alternative, a ball may be provided at the bottom of the screw head 60 and a socket may be located at the top of the shank 56.

5 and 6 show a guide system configured to move the screw 54 into the pedicle of the vertebrae to be fused and to set a desired position between the screw disposition mechanisms associated with the adjacent screw 54. The system includes a pair of tubular sheaths 81 positioned to align with the entry point of the screw 54 into the pedicle. This shell 81 further installs a screw placement mechanism comprising a plurality of inner dilators 86 and an outer dilator 80 that form a path of the screws 54 from the skin to the entry point of the screws into the pedicle to be fused. It serves as a guide for.

There may be one problem with this installation procedure. Adjacent screws 54 must be connected to each other by connecting rods 66, which are moved to their final position with the outer dilator 80 still fixed to the pedicle for the reasons described below. As a result, the connecting rod 66 must extend through the outer dilator 80 in its final position, for this reason and a slit 82 is formed in the outer dilator 80 for other reasons described below. Therefore, the position of the slit 82 must be determined so that the connecting rod 66 can penetrate the slit 82 before connecting the screws 54 to each other in the final position. For positioning of these slits 82, the tubular sheaths 81 must be placed in a constant spatial relationship with each other.

By varying the length of the retractable arm 84 having a foldable structure or a mechanism for converting rotational motion into linear motion, the sheath 81 can be appropriately disposed on the fusion pedicle. After determining the location of the sheath 81, a screw placement mechanism comprising an medial dilator 86 and an lateral dilator 80 is successively introduced over each sheath 81 and allowed to stay in each pedicle. The lateral dilator 80 is provided with two or three small fixation pegs to maintain the position in contact with the bone at the point of entry into the pedicle as needed during surgery. The retractable arm 84 allows each successive dilator to be introduced in only one position, in which a slit 82 of the dilator that grows over the opposite end of the arm 84. The diameters of the dilators that are sequentially inserted and gradually larger are different from each other so that the tissue enters the plane between the two dilators while allowing the relative movement of the dilators 80, 86 by allowing the inner diameter of each successive dilator to approach the outer diameter of the preceding dilator. Prevent it. When the path extended by the sequentially introduced dilator slightly exceeds the outer diameter of the screw head 60, the outer shell 81 and all inner dilators 86 are removed, which stays in the pedicle and slit Make sure 82 is aligned.

Another configuration of the guiding system includes the sheath 81 and the retractable arm 84, providing the desired initial position of the sheath 81 relative to the pedicle. However, in this configuration, the retractable arm is detachably attached to the outer shell 81, and is separated after the desired position of the outer shell is set. In order to maintain this desired position corresponding to the aligned position of the slit 82 of the outer dilator 80, the outer surface of the sheath 81 has a guide surface 93. This guide surface 93 has a complementary shape mating with the guide surface 91 and is formed in the inner dilator 86 and the outer dilator 80 which are sequentially introduced. Thus, the lateral dilators 80 staying in adjacent pedicles are placed relative to each other only in one location characterized by the spatial relationship between the slits 82 being aligned. Guide surfaces 91 and 93 may be formed along a portion of the length of the shell and dilator, and various transverse sections may be provided, including circular or polygonal protrusions and indentations of complementary shapes.

In order to prevent soft tissue from infiltrating between the inner dilator 86 and the lateral dilator 80, which are sequentially installed, these dilators include a movable panel 83 that exposes the slit 82 after the dilator stays in the pedicle. Can be formed. For the reasons described above, the sheath 81, the dilators 80 and 86, and the awl 87 (FIG. 6), excluding the tip, are radiation permeable, such as hard plastic, carbon fiber, or any other material that can firmly provide a pathway. It is preferably made of a material. The tips of these instruments in contact with the pedicle should be tracked to prevent damage to the pedicle, and therefore made of radiopaque material, depending on the quality of whether the tip is reusable or disposable.

The tip of each dilator 80 and 86 is relatively sharply configured to cut the subcutaneous tissue through the skin along the path towards the pedicle. The tip of the awl 87, designed to cut the pedicle and insert the screw 54, is much sharper than the tip of the dilator and can be formed into a pyramid, cone or circle. Although not essential, it is advantageous to install the awl 87 before the dilator. However, this order helps to avoid the possibility of damage by the sharp tip of the dilator if the initial placement is incorrect. It is also helpful to keep the starting awl sharp unless it is exposed to the thick fibrous tissue that must be cut to create a path from the skin to the pedicle entry point. The cannulated screw 54 can be guided to be placed over the pin by cannulating the awl 87 guided using a hand or standard operating room mallet and passing the orthopedic pin through the pedicle. As with the dilators 86 and 80, the tip of the auger 87 is made of radiopaque material to assist the surgeon in tracking the advancement of the auger during surgery. This tip may be configured for single use or to be reused to preserve sharpness.

After incision of the cortex of the pedicle to be joined, the awl 87 is removed from the lateral dilator 80 to allow further instrumentation (not shown), such as a drill, to pass through. Like other instruments guided through the outer dilator 80, the drill is configured such that "wobble" in the outer dilator 80 is minimized. Peck installed in the expander is a mechanism to reduce such fluctuations. One configuration of the drill according to the present invention is a guide surface in the dimensions and shape mated with the guide surface 91 (FIG. 6) of the outer dilator 80. In addition, although the drill tip widens the initial incision due to the awl 87, the diameter is still small to prevent damage to the pedicle. After removal of the drill, the drill can be cannulated, such as auger 87, to allow the guide wire to remain in the tube, and the tip of the drill is made of a radiopaque material to track the position of the drill relative to the vertebral vertebrae.

At this point, the screws 54 are sequentially introduced into adjacent pedicles of the fusion vertebrae located on one side of the spine, and when the entire procedure is repeated, the other pair of screws 54 on the pedicles located on the opposite side of the spine. Introduce. The unique structure of the screw 54 allows the connecting rod 66 to be introduced perpendicular to the screw head 60, which allows the system to perform transdermal placement of the screw and connecting rod in accordance with the method of the present invention. Shows. The order of arrangement of the screws is not critical, but it is preferable to introduce the screws 54 (FIG. 3) formed in the head 60 with recesses 64 pivotally engaged with the tip 70 of the connecting rod 66. The screw 54 penetrating the pedicle and vertebral body is preferably made of titanium, but the method of the present invention may be practiced using any other material, including stainless steel, other metals, or bioabsorbable materials. The dimensions of the screw 54 are not limited to uniform sizes with respect to both diameter and length. The inner diameter of the screw may increase in size from the tip of the shank 56 of the screw 54 (FIG. 3) to the screw head 60 to maximize the bone and minimize the risk of screw breakage. The tip, helix and pitch of the screw are configured such that the screw 54 can pass into the pedicle and vertebral body without the need for complete drilling or tapping along the path and trajectory through the pedicle and vertebral body.

After the screw 54 is placed subcutaneously in the pedicle, the practitioner needs to percutaneously cut the tissue between the screw heads 60 positioned subcutaneously to form a tube to receive the connecting rod 66. Referring to FIG. 7, the tissue cutting device 26 has a cylindrical body 28 configured to slide through the outer dilator 80 like other instruments. The blade 34 pivots between a resting position retracted from the cylindrical body 28 and a cutting position extending through the slit 82 of the adjacent outer dilator 80. For safety reasons, in the rest position the blade must be fully retracted into the cylinder 28 and recessed at 30. Thus, the blade 34 can move only when the recess 30 and the slit 82 of the outer dilator 80 are aligned. Such alignment position provides guide surfaces 91 (FIG. 6) mated with each other on opposite surfaces of the cylindrical body 28 and the outer dilator 80 so that the cylindrical body 28 moves through the outer dilator 80. Can be set automatically by defining the alignment position.

The structure for pivoting the blade 34 includes a mechanism for converting the linear motion of the blade-driven rod 32 into the pivotal motion of the blade 34. As shown in FIG. 7, the downward pivoting action of the blade 34 occurs during the upstroke of the drive rod 32. Specifically, the distal end 36 of the drive rod 32 is recessed to form two identical arms which are bridged by the pins 38, which pins 38 serve as points for the blades 34. A portion of the blade 34 is rotatably mounted to the pin 38 between the arms. In order to realize the pivoting movement of the blade 34, the distal end of the cylindrical body 28 is provided with another fin 42 which bridges the bottom of the recess 30 and is separated from the fin 38 so that the blade 34 ) Extends perpendicular to the cylinder 28 at the cutting position. The blade 34 has a short slot 40 and provides a cam face for the pin 42 passing through the slot 40. In operation, when the push rod 32 is lifted, the blade first linearly moves upward because the pin 38 couples the blade 34 and the actuating rod 32. As the pins 42 begin to squeeze against the surface of the slot 40, the linear motion of the blades is converted into rotational motion so that the blades 34 attached to the distal end 36 of the frozen rod 32 are still upwards. The torque is generated by linear movement. The combination of the linear force generated from the connecting rod 32 and the torque generated from the pin 42 causes the blade 34 to pivot, which is the slit of the outer dilator 80 where the blade 34 is adjacent in the cutting position. 82 extends horizontally to end. According to one configuration of the blade 34, the opposite edges of the blades are all cutting edges capable of cutting in both directions of the blade. The connecting rod 32 is disposed eccentric with respect to the axis of symmetry of the cylinder 28 so that the blade can be completely received in the cylinder 28 in the rest position.

According to another embodiment of the tissue cutting mechanism 26, the blade 34 pivots to the cutting position during the downward stroke of the drive rod 32. As shown by dashed lines in FIG. 7, the slot 40 of the blade 34 is defined between the two edges and extends not parallel to the longitudinal axis of the drive rod 32 in the resting position of the blade. The distal end of the drive rod 32 is divided into two arms and attached to each other so that the pins connecting these arms extend through the slots. Thus, during the downward stroke of the connecting rod 32 its distal end first slides along the slot without interfering with movement. Once the connecting rod 32 has moved and the plane in which the slot extends is converged, the blade is pin 38. Start to rotate to the cutting position around. This structure is largely similar to the structure described above, but is more efficient since most of the tissue is cut in response to the downward linear force, and the connecting rod 32 does not have to be eccentrically disposed. In order to allow the tube to form properly between the screw heads 60, the tissue cutting device 86 may be installed in the adjacent outer dilator 80, and the entire procedure may be repeated. Although the tissue cutting device 26 is shown with a mechanical structure, any of the cutting devices using heat, laser, and ultrasound may be used.

After forming the tube, the connecting rod 66 is attached to the screw head 60 of one of the screws 54 with the rod holder system 100 as shown in FIGS. 8 and 9. The rod holder system 100 includes a sleeve 104 which is guided to slide through the outer dilator 80, which has a slit 82 in which the recess 102 formed in the sleeve is provided in the outer dilator 80. Is configured to occupy an aligned position matching. In this aligned position and only in this position the connecting rod 66 can move to the final position connecting the adjacent screws 54 to each other. In order to ensure such an aligned position between the recess 102 and the slit 82, the guide surface 93 mating to the opposing face of the outer dilator 80 and the sleeve 104 as described in connection with FIG. 6. Can be formed. Of course, without the guide surface, the sleeve 104 can be manually rotated relative to the outer dilator.

The importance of the rod holder 100 is to 1) engage the tip 70 with the screw head 60 when the screw 54 has separate parts, and 2) allow the connecting rod 66 to bridge the adjacent screw head. It is to initiate the movement of the connecting rod in the desired direction. The engagement between the connecting rod 66 and the screw head 60 is achieved by detachably fixing the rear end 72 of the connecting rod 66 into the rod holder 100. The sleeve 104 may include a number of holding systems, such as chucks, spring loaded ball mechanisms, or simple O-rings, which are made of a friction material and provided on the inner side of the sleeve. As shown in FIGS. 8 and 9, in the case of the spring loaded ball mechanism, the balls 108 and 110 holding the rear end 72 of the connecting rod 66 retreat laterally in response to the external force exerted by the surgeon. The connecting rod 66 can be moved. Likewise, the O-ring is configured to grip the connecting rod 66 until an external force is applied. In the case where the chuck is provided, the rod holder 100 has a rotary driver to bring the engaging surfaces of the chuck toward and away from each other. The screw head 60 (FIG. 3) is pre-rotated to a position where the pin 68 of the connecting rod 66 automatically extends through and engages the recess 64 formed in the screw head 60. Alternatively, an additional guide member may be provided on the inner side of the outer dilator so that the screw head 60 slides through the outer dilator 80 only in one position where the slot 62 is automatically aligned with the slit 82 of the dilator. You can do it. Such a structure is advantageous for screw configurations in which the tip 70 of the connecting rod 66 is permanently attached to the screw head 60.

The generation of external forces directed in a straight line alone is insufficient to pivot the connecting rod 66 between the primary and final positions. Torque is applied to the rear end 72 of the connecting rod 66 so that the connecting rod 66 pivots about its tip 70. The structure that converts the thrust generated from the push rod 116 to the rotation of the connecting rod 66 includes a rear end 72 of the connecting rod 66 configured in a specific manner, and the push rod 116 facing each other in the rod holder 100. Of the distal end 108. Specifically, as shown in FIG. 9 these ends are complementarily inclined, causing the push rod 116 to apply the required torque in the required direction towards the adjacent dilator. As such, after the tip 70 is coupled to the screw head 60, the push rod 116 is driven to apply torque to the rear end 72 of the connecting rod 66, thereby connecting the connecting rod 66 to the tip 70 thereof. Rotate to the center to move to the final position.

The torque applied to the connecting rod 66 is often insufficient to move the connecting rod 66 to the screw head of the adjacent screw 54. In addition, a tube formed between adjacent screws 54 may not be perfectly shaped and dimensioned to accommodate the connecting rod 66 sufficiently. In order to ensure that the connecting rod 66 is fully received in the tube and the connecting rod 66 is positioned in the final position where the rear end 72 remains in the screw head of the adjacent screw 54, the present invention provides a rod guide tool as shown in FIGS. Provide 120. A key specification of the rod guide tool 120 is an arm 128 that can engage with the rear end 72 of the connecting rod 66 and guide it into each threaded head 60 of the screw 54. One embodiment according to the invention of this tool as shown in FIG. 10 includes a housing 122 provided with a spring loaded arm 128 to move between a resting position and a deployed position. In the deployed position of the arm 128, the arm 128 receives the rod as the arm 128 is fully aligned with the slot 82 of the dilator 80 while the housing 122 is moving downward through the dilator 80. Extend substantially parallel to the tube. The free end 130 of the arm is paddle shaped (not shown) configured to press against the rear end 72 of the connecting rod 66 and move it into the screw head 60 when the housing 122 is lifted upwards. Can be equipped. Like the rest of the mechanism that can be guided through the outer dilator 80, the housing 122 mate with the guide surface of the outer dilator 80 to guide the arm 128 with the slit 82 of the dilator 80. It may be provided.

In another embodiment of the rod guide tool 120 as shown in FIG. 11, an arm carrier 124 formed as a single piece with an L-shaped distal end 130 acting as an arm 128 is provided with a housing 120. ) Can be provided. The arm 128 is driven by the downward movement of the arm carrier 124 in the housing 122.

The above-described methods and systems of the present invention are for connecting at least one pair of pedicles of the vertebrae to be fused together by placing an appropriate reference mark on the skin to be aligned at the point of entry into the pedicle. The identification procedure in the process of the present invention identifies the pedicle to which the reference marks are to be made using X-ray imaging, fluorescence, ultrasound, and computer guided techniques. Specifically, this procedure involves preparing a sterile, transparent plastic sheet that is contoured to the profile of the lumbar spine, for example when viewed from the fore and aft projection of the spinal image (hereinafter referred to as A-P). The sheet also has an ellipse to identify the pedicle from an A-P tilt of approximately 30 degrees. These contours are thin lines contained in the material of the transparent sheet and are made of radiopaque material, and also appear black to the naked eye so that they can be easily distinguished when in contact with the patient's skin. A sterile adhesive is provided on the edge of this transparent sheet, and this adhesive can be exposed and fixed when a position is set suitably.

A sterile sheet with a reference mark in it is placed on the skin of the patient's lumbar spine and A-P degrees are obtained. In the A-P diagram, the seat can be moved until the profile matches the lateral shape of the lumbar spine. If available, appropriate software can be written to use various video guidance systems in this manner, but the recommendation is to some extent to use radiographic imaging.

If the profile of the lumbar spine matches the contour of the reference, the reference sheet can be further moved out of the skin to introduce a photographic component, such as a fluorescent camera, at an A-P degree of approximately 30 degrees. It has been suggested that this is the most accurate picture to observe the pedicle. The system can be further refined with several adjustments, including a simple system for measuring pedicle angles in preoperative studies. This consists of placing the compass-like transparent material in relation to the pre-axial axial image and measuring the angle of the pedicle when the pedicle enters the vertebral body. It is generally accepted that this angle is approximately 5 degrees at L3, 10 degrees at L4, 15 degrees at L5 and 20 degrees at S1. Under this generally accepted assumption, most practitioners will accept a reference mark with an ellipse placed so that this projection set of angles is identified when a 30 degree A-P is used. However, if an unusual angle appears on a particular pedicle, a self-supporting ellipse with an adhesive on one side can also be used. Imaging techniques, including X-rays, fluorescence, computer guidance, and ultrasound imaging techniques, require that the instruments of the system of the present invention, as shown in FIGS. 3 to 24, be radiation transmissive to prevent observation of subcutaneous structures. However, in order to properly position dilators 80 and 86, augers 67, screws 54 and other necessary instruments relative to the pedicle to be interconnected, their tips located near the pedicle are easily viewed with a fluoroscope. It should be identifiable. For example, the importance of the tip of the dilator 80 and the fact that only the tip is a metal is reflected in the fact that this tip is easily visible in imaging during the incision of the tissue between the skin and the pedicle introduction point. An identification reflector or other instrument device may be provided on the object to be photographed so that it can be used with any of the currently available "image guided" systems.

By identifying the fiducial marker, the practitioner may use a “hand free” approach, in which the incision of the skin above the entry point into the pedicle based on the area identified by the fiducial marker is followed by an enlargement through the incision. Introduce. However, the manual introduction of the dilator in this manner is insufficient to accurately transfer the mechanism associated with the screw 54 because the surgeon may not be able to select the optimal trajectory. To overcome this drawback, the system of the present invention further comprises a positioning system or assembly shown in FIGS. 13-23 to assist the practitioner in setting the desired trajectory of the tissue incision instrument. As shown in FIG. 13, the placement system 140 allows the hollow guide 148, through which one of the dilator or sheath 81 will subsequently pass, to be aligned with the reference mark and positioned at the desired angle with respect to the pedicle. . Thus, the instrument is moved to the pedicle along the optimally set screw path through the interior of the hollow guide 148.

As shown in FIGS. 13 and 15, the placement system 140 includes a rectangular outer frame 142 provided with a track 150 and extending along the spine, and an inner frame 144 that can move along the track; And cradle 146 with a guide 148 that can be manipulated to move across the spine. According to one configuration of the outer frame 142, the outer frame has a transparent base, the bottom of which is attached to the transparent sheet with reference marks by means of a small through blade or pin inserted into the outer layer of the adhesive or skin. Temporarily attached. According to another configuration as shown in FIG. 16, the outer frame 142 is connected to the side of the operation table and has two connector stand-holders 152 which are manipulated to set the height of the placement system 140 as desired. Is mounted on. By operating the fixing mechanism 154, the outer frame 142 can be fixed in any position. As an alternative to the integral outer foundation with a recess formed in the center, the outer frame may have two half foundations 156 each provided with a track 150. By providing the two-piece base in the outer frame 152 in this way, there is no need to form a central recess in the base 156 to receive the guide 148.

The inner frame 144 of the placement system 140 allows the hollow guide to adjust along the spine as the hollow guide 148 slides along the track 150 of the outer frame 142. The bottom of the inner frame 144 has guide surfaces 151 (FIGS. 3, 13 and 22), which guide surfaces extend complementarily with the tracks 150 of the outer frame 142, and these frames extend from each other. Let them slide Various cross-sections of the track 150, one of T, U, V, C, or L shapes, may require a surface complementary to the surface of the inner frame 144. For example, as shown in FIG. 17, the track 150 is inverted T-shaped with a trapezoidal bottom. 18 shows a T-shaped recess provided with two undercuts 152 formed in the upper portion of the track 150. As shown in FIG. 19, the track 150 is inverted T-shaped and the bottom of the track 150 of FIG. 20 is C-shaped. FIG. 21 illustrates a shape in which two side surfaces 160 of track 150 extend inwardly from opposing walls of track 150 and terminate at a distance from each other to form a two level rectangular compartment 162.

Finally, FIGS. 15, 22 and 23 show two variations of the cradle 146 mounted on the inner frame 144 to move the hollow guide 148 under control in a direction orthogonal to the longitudinal dimension of the spine. An example is shown. In general, as shown in FIG. 15, the inner frame 144 may accommodate the base of the cradle 146, and the grays 146 may be inward and outward and up and down with the outer frame 142, not shown. To move the guide 148. Referring to FIG. 22, the guide rail 166 provided in the inner frame 144 has a slide 168 that is polygonal or circular in cross section and can be manipulated to move along the guide rail 166. In order to move the guide portion 148 in the angular direction, the slide 168 is provided with an arc element 170 rigidly attached to the hollow guide portion 148, and the hollow guide portion 148 has an inner frame 144. It is mounted so that it can turn around. The desired angle of the hollow guide 148 derived from the preoperative study by examining the angle the pedicle makes with the vertebral body is set when the mark 182 on the slide 168 coincides with the desired calibration mark on the scale 172. Can be.

Another configuration of the cradle 146 as shown in FIG. 23 includes a pair of arced elements 174 provided with recesses 188, which elements are guides 148 mounted to the crossbars 186. Define paths that can slide along recess 188 and are aligned with each other. The crossbar has at least one fastening nut 176 provided with a mark 184, which mark 184 is desired for the guide portion 148 when aligned with each mark on the scale 180 corresponding to the selected angle. Indicative of the angular position, the guide 148 is fixed in this position by tightening the nut 176 relative to the guide 174. As a result of the placement system 140, the hollow guide 148 sets the trajectory entering the pedicle, specifically the trajectory entering the elliptic reference mark indicating the entry point into the pedicle. This trajectory setting allows the screw 54 to pass through the pedicle in the safest manner while minimizing the risk for important pedicle periphery structures, particularly neuromuscular and vesicles. In addition, the placement system 140 allows the screw to be fully positioned in the pedicle, reducing the chance of the screw breaking or coming off.

The foregoing is not limiting and is merely illustrative of preferred embodiments. For example, a combination of the aforementioned instruments may constitute a kit for spinal surgery. Those skilled in the art can make modifications within the scope and spirit of the disclosure as defined in the appended claims.

 The present invention provides an instrument device system and a method of operating the same for use in a spinal fusion procedure. In particular, the present invention provides a mechanical device system for subcutaneous fixation of pedicles of adjacent fusion vertebrae to each other and a minimally invasive posterior approach for interlocking pedicles.

Claims (50)

 A method for interconnecting at least vertebrae of a patient's spine, Percutaneously disposing a screw into each of the pedicles of the at least two vertebrae; Engaging the leading end of the connecting rod with the first pedicle screw of the first vertebra; And Pivoting the connecting rod about the leading end such that the rear end of the connecting rod is coupled with the first pedicle screw of the second vertebra, thereby connecting the first screws of the first and second vertebrae to each other. Characterized in that the method.  The method of claim 1, further comprising forming a tube configured in the shape and dimensions to receive the connecting rod and extending between the first screws of the first and second vertebrae, the tube forming step being mechanical , Thermal, laser and ultrasonic techniques.  3. The method of claim 2, further comprising securing the leading and trailing ends of the connecting rods to the first screws of the first and second vertebra respectively.  The method of claim 1, Disposing a second screw at a distance from the first screw within each vertebra of the first and second vertebrae and causing the first and second screws to laterally fall away from the spine, Coupling the tip of another connecting rod to a second pedicle of the first vertebra, and Pivoting the other connecting rod about its leading end such that the rear end of the other connecting rod is engaged with the second pedicle screw of the second vertebra, thereby connecting the second screws of the first and second vertebrae to each other. And further comprising a step.  In the method of stabilizing the spine of a patient, Identifying and indicating a reference mark corresponding to each entry point of at least two vertebrae of the spine into each pedicle; Respectively guiding screws through each entry point of the at least two vertebrae to each pedicle; Engaging the distal end of the connecting rod with the first screw at a primary position of the connecting rod with the connecting rod aligned with the first screw of the first vertebra; And Moving the connecting rod about its tip to engage the rear end of the connecting rod with the second screw of the second vertebra at the final position of the connecting rod.  6. The method of claim 5, wherein each of the screws is placed transdermally within the vertebrae of the first and second vertebrae on the same side of the length of the spine.  6. The transdermal placement of the screw of claim 5 wherein Adjusting the hollow guides in the inner and outer planes and the upper and lower planes of the spine such that the adjusted hollow guides are aligned with respect to each of the vertebrae, and Moving the adjusted hollow guide by an awl to form a small incision in each vertebra.  8. The method of claim 7, further comprising percutaneously guiding at least one dilator through the hollow guide to provide a path between each reference mark and entry point to the pedicle prior to moving the awl, and the spine of the spine. Moving said awl through said at least one dilator toward a diameter.  The method of claim 5, wherein the identification of the reference mark, Providing a sterile transparent sheet of radiopaque material having a radiopaque reference contour of the profile of the spine and a radiopaque reference ellipse contour of the pedicles; Photographing the spine by X-ray, fluorescent, ultrasound or computer guided techniques to obtain a view of the pedicles of at least two vertebrae of the patient; And Moving the sterile transparent sheet of radioactive material from the patient's back such that the profile and the reference contour of the pedicles coincide with the views obtained for the pedicles.  The method of claim 8, Sequentially move at least one additional medial dilator through the at least one medial dilator into the at least two pedicles and move the lateral dilator over the at least one additional medial dilator to Gradually expanding the path in each vicinity of the at least two pedicles to the inner diameter of the lateral dilator slightly exceeding the outer diameter, and Removing the medial dilators from each of the at least two pedicles to secure a passageway within the lateral dilators.  12. The method of claim 10, further comprising positioning the outer dilators such that slits formed in each of the outer dilators are aligned with respect to one another and face each other.  12. The method of claim 11, wherein the tissue cutting device is guided through at least one of the outer dilators to a cutting position at which the blades of the tissue cutting device are aligned with each slit of at least one of the dilators, and wherein the blades are at least one And percutaneously moving through the slit of the dilator and other dilators to drive the tissue cutting mechanism such that a subcutaneous tube is formed between the first and second screws connected to each other by the connecting rods. How to.  The method of claim 12, Guiding the connecting rod through the at least one outer dilator such that the tip of the connecting rod pivotably engages the first screw, and Applying an external force to the rear end of the engaging rod to pivot the connecting rod about its rear end, wherein the connecting rod extends along the tube and the rear end extends through each slit of the other outer dilator so that the second spine And engaging the light screw.  13. The method of claim 12, further comprising guiding first and second nuts through the outer dilators to fix the connecting rods inside the first and second pedicle screws, respectively.  6. The method of claim 5, wherein the pin is provided at the tip of the connecting rod and extends in a direction perpendicular to its longitudinal axis through the pair of aligned recesses formed in the screw head of the first screw to guide the connecting rod. 1 pivotally mounting the screw.  An apparatus for interconnecting at least two pedicles, First and second screws disposed subcutaneously in each of the at least two pedicles; And And a connecting rod mounted to the first screw and pivoting about the second screw to engage the second screw to secure the first and second screws with respect to each other.  17. The method of claim 16, wherein each of the first and second screws is an axis extending between the distal end and the proximal end, a screw head positioned parallel to the proximal end of the axis, and positioned between and proximal to the screw head of the axis. And a rotating element connected to the shaft and the screw head to move and rotate relative to each other.  18. The screw head of claim 17 wherein the screw heads of the first and second screws have peripheral walls defining first and second openings, and the tip of the connecting rod received in the openings of the first screws pivotably thereof. Coupled to a screw head to cause the connecting rod to rotate between a primary position in which the connecting rod and the axis of the first screw are aligned and a final position in which the opening of the screw head of the second screw receives the rear end of the connecting rod. Device.  19. The circumferential wall of the screw head of the first screw has at least one slot configured to have a dimension slightly larger than the outer diameter of the tip of the connecting rod, the slot having two aligned recesses. And these recesses are configured to rotatably receive pins fixed at a leading end of the connecting rod at regular intervals from the at least one slot and extending perpendicularly thereto.  20. The method of claim 19, wherein the screw head of the second screw is provided with at least one slot, the slot is aligned with at least one slot of the screw head of the first screw, the connecting rod in the final position of the connecting rod And configured to receive the rear end.  19. The method of claim 18, further comprising a plurality of nuts received in each of the openings of the screw heads of the first and second screws, each of the screw heads and each of the nuts being movable and rotatable by the nut and the screw head. And forming formations which engage each other to be fixed relative to one another.  21. A device according to claim 20, wherein the rear end of the connecting rod is inclined such that when the external force is applied, the connecting rod pivots about its tip towards the second screw and reaches its final position.  21. The system of claim 20, further comprising a guide system for placing each screw in each pedicle, the guide system including an inner and outer dilator with a gradual increase in inner diameter, wherein the outer dilator is above the inner dilator. And guided to extend the subcutaneous path to each pedicle for each of the first and second screws.  24. The apparatus of claim 23, wherein the inner dilator and outer dilator are each made of a radiopaque material, each having a distal region of a radiopaque material, the outer dilator having a slit aligned with a slit of the screw head, respectively. And the slit passes through the connecting rod at its final position.  25. The apparatus of claim 24, wherein the outer dilator and the inner dilator each have a guide surface that causes the outer dilator to slide over the aircraft inner dilator so that the slits formed in the outer dilator are aligned with each other and the connecting rod is in a final position. And move to.  27. The apparatus of claim 25, wherein the lateral dilators each have panels that can move along the lateral dilators after the lateral dilators are attached to the pedicle to expose each slit.  25. The method of claim 24, further comprising two envelopes that are crosslinked by a contractile arm, the contractive arm acting to position each of the two envelopes relative to the pedicle, wherein the two envelopes are lateral And each slit formed in the dilator is configured to receive each outer dilator in a position aligned with respect to each other.  24. The system of claim 23, further comprising a placement system including a hollow guide for guiding the medial dilator and the lateral dilator through a pedicle, wherein the placement system is along and perpendicular to the spine. To move in the horizontal direction.  The system of claim 23, wherein the placement system is Tracks extending along the vertebrae, spaced apart and arranged outside the back of the patient, An inner frame mounted to move on the spaced tracks, and And a cradle coupled to the guide tube, the cradle moving along an arc path orthogonal to the spine such that the guide tube reaches a desired position aligned with the pedicle.  29. The apparatus of claim 28, wherein the inner frame has an engagement surface configured in a shape complementary to the track of T, U, V, C or L shapes.  30. The cradle of claim 29, wherein the cradle comprises two arc guides, the arc guides being coupled to the guides such that a carriage is movably mounted to move the guides to a desired position, wherein the guides are radiation transparent. And at least one end ring made of a material and made of a radiation opaque material and mounted to at least the distal end of the guide.  A plurality of screws configured to be transdermally disposed inside each of the at least two pedicles to be connected to each other; And At least one connecting rod, wherein a leading end of the connecting rod is engaged with a first screw such that the connecting rod is aligned with the first screw and the final position at which the connecting rod bridges the first and second screws. Spinal surgery kit, characterized in that the connecting rod is pivoting.  33. The screw of claim 32, wherein the first and second screws are provided with an outer helix configured such that each stem has a pitch that widens from its distal tip to the proximal upper end and maintains bone gain, wherein the screw has a respective pedicle A spinal surgery kit, characterized in that each configured to move into the pedicle without fully tapping or drilling.  34. The connecting rod of claim 33 wherein the first and second screws have a screw head and a rotating component, respectively, wherein the rotating component is located between and coupled to the top of the stem and the screw head, and at the end of the connecting rod. And providing a relative rotational movement between the screw head and the stem configured to receive the spine.  35. A spinal surgery kit according to claim 34, wherein the distal end of the connecting rod is permanently coupled to the screw head of the first screw.  35. The method of claim 34, wherein the screw head of the first screw has a pair of aligned recesses, the recesses releasably receiving a pin provided at the tip of the connecting rod, A spinal surgery kit, characterized in that configured to provide rotational movement between the screw heads.  35. The method of claim 34, wherein the connecting rods are straight or curved, and the screw heads of the first and second screws are rotatable relative to each other after placing the screws in the pedicle to receive the leading and trailing ends of the connecting rods. Spinal surgery kit, characterized in that the adjustable.  35. A spine according to claim 34, wherein the rotating component comprises a joint ball assembly, the assembly having a socket for receiving a ball formed at the top of the stem of each screw and a ball formed at the bottom of the screw head. Surgical Kit.  35. A spinal surgery kit according to claim 34, wherein the rotating component comprises a hinged mechanism or a ratcheting mechanism.  33. The apparatus of claim 32, further comprising a plurality of progressively widening expanders, including at least one outer dilator and an inner dilator associated with an adjacently located screw and another screw, wherein the inner diameter of the at least one outer dilator is Slightly larger than each outer diameter, the dilators each have a sharp distal tip to provide a progressively widening subcutaneous path toward each pedicle and detachably attached to each pedicle. .  41. A spinal surgery kit according to claim 40, wherein the dilators are each made of a radiopaque material comprising hard plastic or carbon fiber, the distal tip being a radiopaque metal material.  42. The method of claim 41, further comprising at least one awl, the awl having an outer diameter smaller than the inner diameter of the inner dilator, the incision of each pedicle with a pyramidal or rounded distal tip made of a radiopaque material. Spinal surgery kit, characterized in that the action.  43. A spinal surgery kit according to claim 42, wherein the at least one awl is cannulated to have a passageway for an orthopedic pin, the body of the auger extending from the distal tip and made of a radiopaque material. .  41. The method of claim 40, further comprising a drill configured to be introduced through the at least one outer dilator, wherein the drill serves to create a tube in each pedicle and is provided with a drill tip made of a radiopaque material. Spinal surgery kit characterized in that.  45. The drill of claim 44, wherein the drill tip taps each pedicle while creating a tube in each pedicle, and provides a passage to the guide wire remaining in the tube after removing the drill. Spinal surgery kit, characterized in that the cannulated.  41. The rod of claim 40 further comprising a rod holder configured to be inserted into the at least one outer dilator associated with one of the screws configured to receive the tip of the connecting rod, the rod holder being detachably fitted with a rear end of the connecting rod. And a push rod that acts to apply a torque to the rear end of the connecting rod to bite and move the connecting rod to a final position where the rear end is received by another screw.  47. The screw of claim 46, wherein the rear end of the connecting rod and the opposite end of the push rod are complementary to each other in an inclined shape such that the connecting rod pivots when one torque is applied to the rear end when torque is applied to the rear end. Spinal surgery kit, characterized in that the cross-linking.  47. The device of claim 46, further comprising a rod guide tool insertable through the at least one outer dilator and detachably attachable to another screw, the rod guide tool having a pivoting arm, The pivot arm is between a deployment position in which the pivot arm extends toward another screw and a resting position in which the pivot arm engages the rear end of the connecting rod and guides the rear end into the other screw as the pivot arm moves from the deployment position. Spinal surgery kit, characterized in that configured to move in.  41. The apparatus of claim 40, further comprising a tissue cutting mechanism capable of inserting into the at least one outer dilator associated with a screw, the tissue cutting mechanism having a two-edged cutting blade, the blade at least A spinal surgery kit, characterized in that the tube extends through a recess formed in one outer dilator to form a tube in the tissue located between one screw and the other to receive the connecting rod in its final position.  Dilators capable of transdermal movement and recessed; And A tissue cutting device capable of moving through the dilator, the tissue cutting device being provided with a blade, the blade having a deployment position in which the blade extends through a recess of the dilator and the blade retreating into the dilator And pivot between the resting position, and configured to cut tissue while moving in both directions between the deployed position and the resting position.

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