MXPA97003631A - Hooks of subjection of lamina segment - Google Patents

The present invention relates to a spinal fixation system with clamping hooks for attaching to a vertebra, which includes a cranial side, a sacrum side, a lamina and a spinal process with a first and second lateral sides, the fixation system spinal with clamping hooks is characterized in that it comprises: a superior single spinal fixation system for attachment to the lamina under the spinal ophphysis on the cranial side of the vertebra, the upper spinal fixation system has first and second upper arms extending from the upper fixation system to extend outward from the lamina; a lower inferior fixation system for attachment to the lamina under the spinal process on the sacrum vertebrae side, the inferior fixation system has a first lower limb extending outward from the lower fixation system for extending from the lamina on the first lateral side of the apical process, and a second arm extending outward from the lower fixation system to extend from the lamina on the second lateral side of the spinal process, a first and second means for attaching the superior fixation system to the inferior fixation system, the first means connection between the first arms of the upper and lower fixation systems of the first lateral side of the spinal process, and the second joining means extends between the second arms of the upper and lower fixation systems on the second lateral side of the spinous process

SEGMENTED SHEATH CLAMP HOOKS FIELD OF THE INVENTION This invention relates to a spinal fixation system that can be implanted for the surgical treatment of spinal disorders. More specifically, it is related to a restraint system which reduces damage to the vertebrae of the spinal cord when installed.

BACKGROUND OF THE INVENTION Various types of disorders of the spinal column are known to include scoliosis (abnormal lateral curvature of the spinal cord), quiposis (abnormal backward curvature of the spinal cord, excessive lordosis) (abnormal forward bend of the spine), spondylolisthesis (forward displacement of a lumbar vertebra) and other disorders, such as ruptured or deflected discs, broken or fractured vertebrae, and the like. Patients who suffer from such conditions often experience extreme and debilitating pain.

A technique known as spinal fixation uses surgical transplants which immobilize REF: 24789 mechanically areas of the spinal cord and help the final fusion of the treated vertebrae. Such techniques have been used effectively to treat the conditions described in the foregoing and, in most cases, to alleviate the pain experienced by the patient. A spinal fixation technique includes the immobilization of the spinal cord through the use of a pair of attached rods; the spinal cord that run generally parallel to the spinal cord. When practicing this technique, both screws must first be attached to the pedicles of the appropriate vertebrae or to the sacrum and act as fixation points for the rods attached to the spinal cord. The screws attached to the bone are usually placed in groups of two per vertebra, one in each pedicle on both sides of the spinal process. Staple mounts join the rods attached to the spinal cord with the screws. The rods attached to the spinal cord are usually curved based on the user to obtain the desired curvature of the spinal column. Examples of such spinal fixation devices can be found in U.S. Pat. Nos. 4,653,481 and 5,030,220, which are incorporated herein by reference. These types of systems are very stable but require the implant of screws in each of the vertebrae on the area to be treated. Also, since the pedicles of the vertebrae above L2 are very small, only small screws can be used. To stabilize the implanted system sufficiently, a vertebra above and a vertebra below the area to be treated is often used to implant screws attached to the pedicles. Other fixation systems use hooks which attach to a vertebra a rod attached to the spinal cord for reduction or compression. The hook systems which are currently in use are attached to the vertebral sheet (such as that described in US Pat. No. 5,005,562) or to the transverse spinal process (such as that described in US Pat. No. 4,269,178) of the vertebrae. . These types of positions for joining the hooks place a load on part of the vertebra which leads to the possibility of damage to the vertebrae and failure of the system during its use. It is desirable that a fixation device be provided which not only reduces the need to implant screws in the pedicles inside the vertebrae but also connects with the strong sections of the vertebrae and thus reduces the damage of the vertebrae after the vertebrae. installation of the fixing system. Preferably, the attachment point of such fixation device is to the lamina or to the intersection of the lamina and the spinal process of the vertebra in the area of the spinal cord that is to be treated. This area has demonstrated the strongest bone structure of the vertebra.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a spinal fixation hook fastening system which is attached to the region of the lamina of a vertebra to which it is to be attached. The fastening hook system comprises a lower hook attached to the lamina on the sacral side of the vertebra, and an upper hook attached to the lamina on the side of the skull of a vertebra. Means are provided for attaching the lower hook to the upper hook to thereby attach the lower and upper hooks to the vertebrae and to attach the lower and upper hooks to the pins attached to the spinal cord. The rods attached to the spinal cord, which are attached to the system of clamping hooks, are placed along the central line of the spinal cord, on both sides of the spinal process of the vertebra.

BRIEF DESCRIPTION OF THE DRAWINGS The features, aspects, and advantages of the invention will be more fully understood when considered with respect to the following detailed description, appended claims and accompanying drawings, in which: Figure 1 is a perspective view, looking towards down the spinal cord, towards the sacrum, of a first embodiment of the present invention; Figure 2 is an exploded perspective view of the components of the first embodiment of the present invention; Figure 3 is a front plan view of a lower hook of the first embodiment of the present invention; Figure 4 is a top plan view, taken along lines 4-4 of Figure 3; Figure 5 is a side plan view taken along lines 5-5 of Figure 3; Figure 6 is a front plan view of an upper hook of the first embodiment of the present invention; Figure 7 is a side plan view taken along lines 7-7 of Figure 6; Figure 8 is a side view, partially in section, of the upper and lower hooks of Figures 11 to 13, as shown oriented when assembled; Figure 9 is a side view of 45 ° towards the sacrum, of a second embodiment of the present invention attached to a vertebra; Figure 10 is an exploded perspective view of the components of the second embodiment of the present invention, to fit the right side of the spinal cord; Figure 11 is a perspective view of an upper hook of the second embodiment of the present invention; Figure 12 is a front plan view of a lower hook of the second embodiment; Figure 13 is a side plan view taken along lines 13-13 of Figure 12; Fig. 14 is a side view of a staple bolt; Fig. 15 is a side view of a manual "T" nut wrench for use in the present invention; Figure 16 is a side view of an impeller for use in the present invention; Figure 17 is a bottom view of an impeller taken along line 17-17 of Figure 16; and Figure 18 is a bottom view of an impeller taken along line 18-18 of Figure 16.

DETAILED DESCRIPTION The present invention relates to a hook connector for a spinal lamina / apophysis, for use in spinal cord rods (rods connected to the bone) attached to a vertebra to treat various spinal disorders. When the components of the present invention are attached to the area of the spinal cord to be treated, the rods are located close to the spinous spinal process of the vertebra, ie, along the central line of the vertebra. In Figures 1 to 7 an embodiment of the present invention is illustrated. Figure 1 illustrates the combined clamping hook system attached to a vertebra of the spinal cord. The fastening hook system (see Figure 2) is constituted by a lower hook 10 which is attached to the sacral side of the vertebra (see Figure 1). An upper hook 30 is attached to the upper side of the vertebra opposite the lower side and is attached to the lower hook by hexagonal bolts 50. Hexagonal bolts, when installed, they are fixed in place by fixing washers 70. The C-90 spacers that fit over the main diameter of the hexagonal bolts 50 are used to separate the lower hook from the upper hook and prevent pressing and damaging the vertebrae when the system is tightened down in the final assembly. These components connect the hook system to the spinous spinal plate / spinous process region of the vertebrae. The hook system is also attached to points along the length of a pair of spinal cord rods 92, for example at one end of the rods (see Figure 1) by holding the upper staples 100 to the lower hook with bolts. 120 of staple. Other points along the length of the spinal cord rods (rods in contact with the bone) can then be attached to other vertebrae by conventional clamping systems such as those described in U.S. Patent No. 5,030,220 or by hook systems of additional fastening as that of the present invention. The components of the hook system are described in detail below. The lower hook 10, as illustrated in Figures 3 to 5, is constituted by a three-arm member. The first arm 12, when viewed from its front face (see Figure 3), generally has an inverted triangular shape which includes a hook 14 at its vertebra. When installed, the hook is placed on the underside of the vertebra. The face 16 of the first arm abuts against the spinal process of the vertebra, as illustrated in Fig. 1. At the upper end of the first arm (the base of the triangle) and extending out of the first arm on opposite sides, they are at second and third arms 18. The upper part of the first arm 12, the base of the triangle, is recessed 22 to provide a space for the end of the spinal process when the lower hook is installed. The second and third arms are mirror images of one another and extend from the first arm at an angle of approximately 20 ° with respect to the horizontal center line and tos the center line of the first arm. At the junctions of the second and third arms with the first arm are threaded openings 20 or holes extending through the lower hook, perpendicular to the arms to receive the hexagonal bolts 50 for attaching the lower hook to the upper hook. The generally cylindrical portions of the lower hook form the threaded opening 20 which extends outly from the body of the lower hook in the same direction as the hook 14 (Figure 2). The extended portions of the lower hook around the threaded openings 20 provide clearance between the lower hook and the upper hook, when the hook-and-hook assembly is installed, and extends on opposite sides of the spinal process. When viewed from the top, the lower hook generally has an oval shape with the second and third arm forming the ends of the oval, and the first arm in the center of the oval (figure 4). On one side of the lower hook and in the middle part of the oval, above the hook 14 and between the openings 20, there is a slot 29 to provide a space for the spinal process. At each end of the oval, that is, at each end of the second and third arms, opposite the ends attached to the first arm, are openings 24 threaded to receive the staple pins 120 (see FIGS. 2 and 14) and upper staples 100 of FIG. union to the lower hook. Between the openings 20 and the openings 24 are semi-openings 26 which extend through the upper surface from the second and third arms to receive the spinal cord rods 92. The half-openings include indentations, indicated with the number 28, to coincide and hold the indentations which run along the length of the linear support rods. They are also provided 100 upper staples for use in the present invention for attaching the spinal cord rods to the lower hook. The upper staple openings coincide with the half-openings 26 of the lower hook to define apertures or openings for receiving spindles 92 of the spinal cord. The staple bolts 120 are used to attach the upper clamp to the lower hook to securely hold the rods. The upper staples comprise a generally cylindrical body (see Figure 2) with an opening 110 through the center of the cylinder. The internal diameter of the opening 110 is stepped. A lower section 102 of the opening has a diameter such that when the staple bolt is attached to the upper clamp, the staggered section 122 of the upper clip fits securely against the lower section 102. The staple pin 120 loads its face 123 from the edge against the projection of the loading face 103 in the upper staple 100. An upper section 104 is larger in diameter than the diameter of the lower section and is dimensioned so that it can receive the head 126 of the staple bolt. The upper clips also each include an arm 106, projecting from the cylindrical body, of the upper clip, in which the half-opening 108 is located. The half-opening is indented, as indicated by the number 112, to coincide and hold to the indented stem.

When assembled, the indented surfaces of the half-openings of the two staples and the half-openings of the lower hook are in mutually opposite relationship and form the receiving openings of the rod in which the closed rods are firmly clamped. The staple pins 120 (see Figure 102) are used to hold the lower hook and the upper staples together and to ensure a firm hold on the rod. The staple bolts 120 have a threaded section 124 that matches the threaded opening 24 of the lower hook. Between the head 126 of the staple bolt and the threaded section 124 is a middle section 122 adjusted, without threading, in which the diameter of the clamping bolt is intermediate that of the head and the threaded shaft, and is dimensioned so that the The middle section of the staple bolt will fit in the staggered region 102 of the upper staple. The taper 122 provides resistance to the upper clip and inhibits the break. At the upper end of the staple bolt is a head 126 of larger diameter. The larger diameter portion is dimensioned so that it adjusts by sliding in the staggered region 104 of the upper staple and the face 123 abuts the face 103 to thereby hold the upper staple and the lower hook securely on the rod. spinal cord when the staple bolt is screwed into place. The stepped interior of the upper staple allows the distribution of the force conferred by the staple bolt on the upper staple over a relatively larger area of the upper staple. The upper face 128 of the staple bolt includes four radial notches 130, spaced at equal distances from each other. The notches are aligned with the teeth of an impeller so that the surgeon can more easily hold the staple bolt and the top cover with the lower hook. An impeller and a "T" handle are illustrated in Figures 15 to 18. The handle 150 is constituted by an axis 152. At a first end of the shaft is the handle 154 which is perpendicular to the axis. At the second end of the shaft is a union site 156 with a square shape. On one side of the attachment site is a spring loaded ball retainer 158. The attachment site 156 of the handle 150 fits on the impeller 160. The impeller comprises an axis 162. At a first end of the shaft is a recess 164 with a square shape to coincide with the square shape 156 of attachment of the handle. Located on opposite sides of the square are recesses 164 that match the spring-loaded ball retainer 158 to secure the impeller to the handle. Located within the recess 164 are bevels or chamfers 167 which allow depression of the spring-loaded ball retainer 158. The spring-loaded ball retainer is trapped in the indentations 165 to fix the impeller to the handle. At the second end of the impeller are four teeth 166 to coincide with the radial notches 130 in the staple pin 120. When used, the handle fits on the impeller and the driver teeth match the radial notches of the staple pins 120. The handle is then rotated to tighten or loosen the staple bolts, as required. The upper hook comprises a member which has a generally inverted triangular-shaped member with an open center when viewed from its front face (see FIGS. 1 and 6). In the upper part of the upper hook, at the two corners of the base of the triangle, there are openings or holes 32 for receiving the hexagonal bolts 50 and in this way attaching the upper hook to the lower hook and for extracting the hooks together on the vertebrae. When viewed from the side (see Figure 7), the upper hook generally has a rectangular shape with a "cutout" section 34 at the bottom, or the third corner of the triangle. The section of the cut-out forms the hook 36 to join the upper hook with a vertebra. In an embodiment of the present invention, blind openings or recesses 38 adjacent to each other are placed in the front face portion of the triangle of the openings 32 (see FIGS. 6 and 7). The upper hook is attached to the lower hook by the hexagonal bolts 50. The hexagonal bolts include a threaded section 52 and a head 54 (figure 2). Included around the side surface of the head 54 are the four recesses 156, spaced apart equidistantly from each other around the perimeter of the head. The fastening assembly comprises a lock washer 70 that is provided to hold each hex bolt in place when the fastener hook assembly is installed. The fixing washer comprises at least two tongues 72 and 74. When used, one of the tongues 72 deforms inside the blind opening 38 on the upper hook. The hex bolt 50 is threaded into the opening 32 and tightened and the remaining tab 74 deforms against one of the hexagonal surfaces 54 on the head of the bolt 50. When the tongue 72 deforms against the hexagonal part fixed to the bolt in place and prevents it from loosening after installation. In some cases, openings 56 are used to additionally wire and stabilize and assist in the installation of the fastening system. In use, the lower hook is placed on one side of the vertebra adjacent to the area of the spinal cord that is to be treated. Subsequently, the upper hook places in confronting relation with the lower hook on the other side of the vertebra (see Figure 1), C-shaped spacers 90 are installed between the opening faces 20 of the lower hook and 32 of the upper hook. The size of the C-spacers may vary as needed to correct the distance between the upper and lower hooks and for it to fit around the sheet of the vertebrae to be treated. The hexagonal bolts 50 are threaded through the openings 32, the spacers C and into the threaded openings 20 and screwed into place to thereby attach the lower and upper hooks to the vertebra. The tongues 74 are deformed in the blind openings 38 in the upper hook and the tabs 72 are deformed in one of the fins 54 or hexagonal flat parts of the head of the hexagon bolt to prevent rotation and prevent the hex bolt from loosening after its installation. The spinal cord rods 92 are placed in the half-openings 26 of the lower hook and the staple pins 120, and subsequently threaded through the openings 110 of the upper staple within the threaded opening 24 of the lower hook, using an impeller, which is illustrated in figures 15 to 18 and as described in the foregoing. The teeth of the impeller are made to coincide with the notches of the staple bolt and the impeller is then used to tighten the staple bolt inside the upper clamp, in order to fix the spinal cord stem to the lower hook. The staple pin, when tightened, is contained completely within the section 104 of the upper staple, which leaves a small portion of the upper edge of the wall 114 of the upper staple exposed. After the staple bolt is in place, the exposed portion of the wall 114 is clamped at a point along its periphery which corresponds to one of the radial grooves. This clamping ensures that the staple bolt is firmly fixed in place and that unwanted rotation of the staple bolt is inhibited once the system is installed. In the case where some adjustment is necessary and therefore some removal of the staple bolt, the fastener can be easily removed by using the impeller to remove the staple bolt, when the staple bolt is unscrewed to release the staple higher. After the required adjustments have been made, the screw and staple assembly is fixed in place as described above. The other ends of the spinal cord rods 92 can then be attached to conventional staples, for example, such as those described in U.S. Patent Nos. 4,653,481 and 5,030,220, or to another fastening hook assembly which are placed on the opposite side of the attachment site of the described fastening hook of the area of the spinal cord that is to be treated. The attachment of the spinal cord rods in this way stabilizes the region of the spinal cord that is to be treated. In figures 8 to 13 another embodiment of the present invention is illustrated. This embodiment of the invention allows the surgeon to hold only one side of the spinal cord (unilateral union) when damage to the spinal process occurs as a result of surgery or the initial damage or condition. The clamping hook system (see Figure 10, staples are shown to fit the right side of the spinal cord; the components to adjust the left side of the spinal cord are mirror images of these components) of this other modality is similar to that described above, except that two sets of components are installed in one vertebra, one on each side of the vertebra. spinal process, without covering the spinal process. Since the components of this embodiment of the present invention are similar to those of the embodiment described above, similar part numbers are used for similar parts.

This other embodiment of the present invention comprises a lower hook 10 which is attached to one side of the vertebral sheet, on one side of the spinal process. An upper hook 30 is attached to the lamina of the vertebra opposite the lower hook, and on the same side of the spinal process and is attached to the lower hook by the hexagonal bolt 50. The hex bolt, when installed, is fixed in place by the fixing washer 70. The C 90 spacer that fits over the larger diameter of the hex bolt is used to separate the lower hook from the upper hook to prevent pressure and damage to the blade when the system is installed. These components connect the hook system to the region of the lamina of the vertebra. The hook system also attaches to a point along the length of spinal cord shank 92, such as that which is at one end of the spinal cord stem (see Figure 9), by clamping the upper staple 100. to the lower hook with the staple pin 120. Then another point can be joined along the length of the spinal cord stem, for example at the other end, to another vertebra by conventional clamping systems or by fastening systems with clamping hooks according to the present invention. The components of this embodiment of the hook-and-loop system are described in detail below. The lower hook 10, as illustrated in Figures 12 and 13, is an L-shaped element when viewed from its front face (see Figure 12). An arm 12 of the "L" includes a hook 14 at its end that is configured to hold the region of the lamina of a vertebra on the sacral side of the vertebra. The hook 14 illustrated in FIG. 12 is for holding the region of the vertebrae lamina to the right of the spinal cord, as illustrated in FIG. 9 looking down the spinal cord, toward the sacrum. A second lower hook, identical to the lower hook 10, shown in Figure 10, except that it is a mirror image, is attached to the left side of the spinal cord, as illustrated in Figure 9. When installed, the hook is fixed on the underside of the sheet. The face 16 of the "L" of the previous hook 14 abuts the edge of the vertebrae sheet as illustrated in Figure 9. On the other arm 18 of the "L" there is a threaded opening 24 for receiving the pin. 120 of staple and to join the upper staple 100 with the lower hook (figure 10). Adjacent and extending perpendicular to the opening 24 through the upper surface of the lower hook 10 is located a half-opening 26 for receiving the spinal cord shank 92. The half-opening includes indentations, which are shown with the number 28, to coincide and hold the rod which includes the indentations along its length. In the joint or articulation of the arms of the "L" and extending generally parallel to the half-opening 26 is the opening 20 threaded to receive the hexagonal bolt 50 and join the lower hook with the upper hook. When the upper hook 30 (see FIG. 11) is installed, it coincides with the lower hook described above by the region of the lamina of a vertebra on the cranial side of the vertebra (see FIGS. 8 and 9). A second upper hook is used, which is identical, except that it is an image in the mirror, to coincide with the lower hook placed on the other side of the spinal cord. The upper hook comprises a member with an opening 32 extending through the upper part of the upper hook, for receiving a hexagonal bolt 50 and in this way attaching the upper hook to the lower hook, and to the vertebrae. A blind or recessed opening 38 is in the surface of the upper hook, adjacent to the opening of the orifice 32. Extending away from the section of the upper hook, which includes the hole 32 is the hook 36. The hook 36 projects from the body of the upper hook in a direction opposite to the surface containing the recess 38. The section which includes the hook, is deflected from the hole, so that the lower part of the hook is held in a horizontal position when the hole is not directly above the hook, but is diverted to one side. To join the right side of the vertebra (see Figure 9), the hole 32 is offset to the right in relation to the hook. To join the left side of the vertebra (see Figure 9), the hole 32 is offset to the left in relation to the hook. This deviation allows the upper hook to be placed on the lamina of the vertebra but avoid contact with the spinal process. The upper hook is attached to the lower hook by the hex bolt 50 as described above for the first embodiment. When used, a lower hook is placed on one side of the lamina and on one side of the spinal process. The upper hook is then placed in a confronting relationship with the lower hook on the other side of the lamina and on the same side of the spinal process, as illustrated in Figure 9. A 90 C separator is installed (which is not shown in Figure 8) between the face of the hole 20 of the lower hook and the face of the opening or hole 32 of the upper hook. The size of the separator C may vary as needed to establish a correct distance of the lower and upper hooks so that it fits around the sheet to be treated. The hexagonal bolt 50 is threaded through the opening 32, the spacer in C and is threaded in the opening 20 and screwed in place so that the lower and upper hooks are fixed to the vertebra. A spinal cord stem is placed in the middle opening of the lower hook and the staple pin 120 is then threaded through the hole 110 in the upper clamp and threaded in the opening 24 of the lower hook, as is written in the above for the first modality. Subsequently, the spinal assembly process is repeated to join the second mounting of the clamping hook with the other side of the spinal process, in the same vertebra. The components of the fastening hook of the present invention are preferably manufactured from an alloy capable of resisting corrosion when installed in a human body. It has been found that 316 stainless steel, which has been electropolished and passivated to resist corrosion, works well. Other metal alloys such as titanium alloys can also be used. The present invention is not limited to the specific designs shown, which are illustrative only. Various and numerous different arrangements may be considered by one skilled in the art without departing from the spirit and scope of this invention. The scope of the invention is defined by the following claims. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following: