(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0085813 A1
`Spitler et al.
`(43) Pub. Date:
`Apr. 21, 2005
`
`US 20050085813A1
`
`(54) SYSTEM AND METHOD FOR STABILIZING
`OF INTERNAL STRUCTURES
`
`(52) US. Cl. .............................................................. .. 606/61
`
`(75) Inventors: James Spitler, Frisco, TX (US); Scott
`Schorer, Longmont, CO (US)
`
`(57)
`
`ABSTRACT
`
`Correspondence Address:
`DALLAS OFFICE OF FULBRIGHT &
`JAWORSKI L.L.P.
`2200 ROSS AVENUE
`SUITE 2800
`DALLAS, TX 75201-2784 (US)
`
`(73) Assignee: Innovative Spinal Technologies, Plano,
`TX
`
`(21) Appl. No.:
`
`10/690,211
`
`(22) Filed:
`
`Oct. 21, 2003
`
`Publication Classi?cation
`
`(51) Int. Cl? ................................................... .. A61B 17/58
`
`There is shoWn a system and method for reducing the
`dif?culty in percutaneous placement of a spine stabilization
`brace by coupling the brace to a pedicle screW in a single
`assembly. The brace-screw assembly is delivered along With
`an anchor extension through a cannula for anchoring in the
`vertebrae pedicle. The anchor extension becomes a cannula
`for Working on the brace from the exterior of the patient, as
`constructed With a slot opening along tWo sides. Once the
`screW portion of the brace-screw assembly is locked in place
`With respect to the ?rst vertebra, the proximal end of the
`brace is beloW the skin line. The brace is then repositioned
`so that the proximal end leaves the cannula through one slot
`and is captured by a corresponding slot positioned in a
`second cannula coupled to a second anchor. Once captured,
`the proximal end of the brace is guided by the second
`cannula to a receptacle positioned in the second vertebra.
`
`1
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`Patent Application Publication Apr. 21, 2005 Sheet 1 0f 14
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`5
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`Patent Application Publication Apr. 21, 2005 Sheet 5 0f 14
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`US 2005/0085813 A1
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`FIG. 5A
`
`FIG. 6A
`
`V \,J/
`
`f41
`
`f42
`
`FIG. 4
`<>/\
`
`402
`
`/41,42
`
`6
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`

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`Patent Application Publication Apr. 21, 2005 Sheet 6 0f 14
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`US 2005/0085813 A1
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`FIG. 5B
`
`L '
`
`1
`
`FIG. 63
`
`L |
`
`7
`
`

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`Patent Application Publication Apr. 21, 2005 Sheet 7 0f 14
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`US 2005/0085813 A1
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`F1G.5C
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`8
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`

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`Patent Application Publication Apr. 21, 2005 Sheet 8 0f 14
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`US 2005/0085813 A1
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`FIG. 6C
`
`42
`
`1'
`'
`‘J
`W606
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`‘/~604
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`ii”; i
`“in I
`F I
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`7
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`66 M
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`9
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`Patent Application Publication Apr. 21, 2005 Sheet 9 0f 14
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`US 2005/0085813 A1
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`FIG. 7A
`
`FIG. 8A
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`10
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`

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`Patent Application Publication Apr. 21, 2005 Sheet 10 0f 14
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`US 2005/0085813 A1
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`FIG. 8B
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`75
`FIG.
`
`11
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`Patent Application Publication Apr. 21, 2005 Sheet 11 0f 14
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`US 2005/0085813 A1
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`FIG. 8C
`
`FIG.
`
`12
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`

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`Patent Application Publication Apr. 21, 2005 Sheet 12 0f 14
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`US 2005/0085813 A1
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`Y
`I
`
`92
`
`FIG. 9
`
`593 @
`
`X
`
`94
`
`95
`
`FIG. 1 O
`
`v / / 52
`/
`220
`
`92
`
`13
`
`

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`Patent Application Publication Apr. 21, 2005 Sheet 13 0f 14
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`US 2005/0085813 A1
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`FIG. ]2A
`
`1207
`
`4/1200
`‘,1203
`
`H IL
`
`14
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`

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`Patent Application Publication Apr. 21, 2005 Sheet 14 0f 14
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`US 2005/0085813 A1
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`FIG. ]2B
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`1204
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`15
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`US 2005/0085813 A1
`
`Apr. 21, 2005
`
`SYSTEM AND METHOD FOR STABILIZING OF
`INTERNAL STRUCTURES
`
`TECHNICAL FIELD
`
`[0001] This invention relates to bony structure stabiliZa
`tion systems and more particularly to systems and methods
`for percutaneously inserting a pedicle screW stabilization
`device.
`
`BACKGROUND OF THE INVENTION
`
`[0002] The human spine provides a vast array of func
`tions, many of Which are mechanical in nature. The spine is
`constructed to alloW nerves from the brain to pass to various
`portions of the middle and loWer body. These nerves,
`typically called the spinal cord, are located in a region Within
`the spine called the neuro canal. Various nerve bundles
`emerge from the spine at different locations along the lateral
`length of the spine. In a healthy spine, these nerves are
`protected from damage and/or undue pressure thereon, by
`the structure of the spine itself.
`
`[0003] The spine has a complex curvature made up of a
`plurality (24 in all) of individual vertebrae separated by
`intervertebral discs. These discs hold the vertebrae together
`in a ?exible manner so as to alloW a relative movement
`betWeen the vertebrae from front to back and from side to
`side. This movement then alloWs the body to bend forWard
`and back and to tWist from side to side. Throughout this
`movement, When the spine is operating properly the nerves
`are maintained clear of the hard structure of the spine and the
`body remains pain free.
`
`[0004] Over time, or because of accidents, the interverte
`bral discs loose height, become cracked, dehydrated, or are
`simply jarred out of position. The result being that the disc
`space height is reduced leading to compression of the nerve
`bundles causing pain and in some cases damage to the
`nerves.
`
`[0005] Currently, there are many systems and methods at
`the disposal of a physician for reducing, or eliminating, the
`pain by minimiZing the stress on the nerve bundles. In some
`instances, the existing disk is removed and an arti?cial disk
`is substituted therefore. In other instances, tWo or more
`vertebrae are fused together to prevent relative movement
`betWeen the fused discs.
`
`[0006] Often there is required a system and method for
`maintaining proper space for the nerve bundles that emerge
`from the spine at a certain location. In some cases a cage or
`bone graft is placed in the disc space to preserve height and
`to cause fusion of the vertebral level. As an aid in stabiliZing
`the vertebrae, one or more rods or braces are placed betWeen
`the fused vertebrae With the purpose of the braces being to
`support the vertebrae, usually along the posterior of the
`spine While fusion takes place. These braces are often held
`in place by anchors Which are ?tted into the pedicle region
`of the vertebrae. One type of anchor is a pedicle screW, and
`such screWs come in a variety of lengths, diameters, and
`thread types.
`[0007] One problem When connecting the braces to the
`anchors is to position the braces in place as quickly as
`possible and Without doing more damage to the surrounding
`tissue and muscle of the patient as is absolutely necessary.
`For that reason, procedures have been developed that alloW
`
`the physician to secure the anchors in the bony portion of the
`spine and to then connect the brace betWeen the anchors.
`Techniques have been developed to alloW the surgeon to
`perform this procedure in a minimally invasive manner,
`utiliZing a percutaneous method.
`
`[0008] In one such procedure, a ?rst pedicle screW is
`inserted in a ?rst vertebra to be stabiliZed. This screW is
`inserted using a tube, or cannula, extending through the
`patient’s skin to the pedicle portion of the vertebrae. A
`second pedicle screW is inserted through a second cannula
`into the second vertebrae to be stabiliZed. Under current
`practice, the physician then must Work the brace, or other
`supporting device, so that each brace end is positioned
`properly With respect to the preplaced pedicle screWs. In
`order to properly position the brace ends ?uoroscope pic
`tures are taken as the brace is Worked into position. It is
`dif?cult for the physician to knoW the exact orientation of
`the brace and even to knoW for certain When the brace ends
`have been properly positioned. US. Pat. No. 6,530,929
`shoWs one instrument for positioning a stabiliZation brace
`betWeen tWo preplaced anchors.
`
`[0009] Another problem With both of the approaches dis
`cussed above, is that the braces must be made signi?cantly
`longer than the distance betWeen the pedicle screWs to alloW
`for proper attachment of the brace ends to the screWs.
`Placement of the brace is sensitive to anchor alignment since
`the adjustment establishes the trajectory of the brace. If this
`trajectory is not established properly, the brace Would have
`to pass through tissue, and, or bone that should not be
`touched. Also, the brace must enter a separate incision in the
`back of the patient. In addition to these, the learning curve
`for manipulation the insertion device of the ’929 patent is
`greater than What should be required.
`
`[0010] Another, more recent, approach has been to insert
`the cannulas over the respective pedicle areas of the verte
`brae to be stabiliZed and then measure the distance betWeen
`the cannulas. This measurement is then used to select, or cut,
`a rod, adding a bit to the dimension to ensure that the rod can
`be rigidly af?xed to each anchor. In addition, each rod must
`be bent a certain amount (or a pre-bent rod utiliZed) to re?ect
`the curvature of the spine. Once the proper rod dimension
`and shape is obtained each end of the rod is positioned in a
`separate one of the cannulas and the rod is Worked doWn
`Ward toWard the anchors passing through a separation of
`muscle and tissue from the skin line to the pedicle site. This
`placement of the rod is facilitated by a long handheld gripper
`Which must then be manipulated to position the rod ends
`over the respective anchors so as to be captured by set
`screWs in the tops of the respective anchors. Proper posi
`tioning of the rod ends is dif?cult, and requires repeated use
`of ?uoroscopy to insure that the rod is fully seated and in a
`correct position.
`
`BRIEF SUMMARY OF THE INVENTION
`
`[0011] In one embodiment, there is shoWn a system and
`method for reducing the difficulty in percutaneous place
`ment of a spine stabiliZation brace by coupling the brace to
`a pedicle screW in a single assembly. The brace-screW
`assembly is delivered along With an anchor extension
`through a cannula for anchoring in the vertebrae pedicle.
`The anchor extension, Which becomes a cannula for Working
`on the brace from the exterior of the patient, is constructed
`
`16
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`US 2005/0085813 A1
`
`Apr. 21, 2005
`
`With partial slot openings along tWo sides. Once the screw
`portion of the brace-screW assembly is locked in place With
`respect to the ?rst vertebrae, the proximal end of the brace
`is beloW the skin line. The brace is then repositioned so that
`the proximal end leaves the cannula through one slot and is
`captured by a corresponding slot positioned in a second
`cannula coupled to a second anchor. Once captured, the
`proximal end of the brace is guided by the second cannula
`to a receptacle positioned in the second vertebrae. In one
`embodiment, the distal end of the brace is designed to adjust
`about the head of the ?rst anchor and is further designed to
`alloW for polyaxial as Well as lateral movement, thereby
`adjusting for relative distances and angles betWeen verte
`brae.
`[0012] The foregoing has outlined rather broadly the fea
`tures and technical advantages of the present invention in
`order that the detailed description of the invention that
`folloWs may be better understood. Additional features and
`advantages of the invention Will be described hereinafter
`Which form the subject of the Claims of the invention. It
`should be appreciated that the conception and speci?c
`embodiment disclosed may be readily utiliZed as a basis for
`modifying or designing other structures for carrying out the
`same purposes of the present invention. It should also be
`realiZed that such equivalent constructions do not depart
`from the invention as set forth in the appended Claims. The
`novel features Which are believed to be characteristic of the
`invention, both as to its organiZation and method of opera
`tion, together With further objects and advantages Will be
`better understood from the folloWing description When con
`sidered in connection With the accompanying ?gures. It is to
`be expressly understood, hoWever, that each of the ?gures is
`provided for the purpose of illustration and description only
`and is not intended as a de?nition of the limits of the present
`invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0013] FIG. 1 is a sketch of the human spine shoWing a
`pair of cannulas positioned With respect to tWo vertebrae;
`
`[0014] FIGS. 2A-2F shoW a cut-aWay vieW shoWing
`different stages of the installation of the stabiliZation device;
`
`[0015] FIG. 3A shoWs a side vieW of tWo vertebrae;
`
`[0016] FIG. 3B shoWs a top vieW of a single vertebrae;
`
`[0017] FIG. 4 shoWs an embodiment of a slated cannula;
`
`[0018] FIG. 5A shoWs a brace-anchor assembly Within a
`cannula;
`[0019] FIG. 5B is a cross-section vieW taken through line
`5B-5B of FIG. 5A;
`
`[0020] FIG. 5C is a cross-section vieW taken through line
`5C-5C of FIG. 5A;
`
`[0021] FIG. 6A shoWs the receiving cannula attached to a
`receiving anchor;
`[0022] FIG. 6B is a cross-section vieW taken through line
`6B-6B of FIG. 6A;
`
`[0023] FIG. 6C is a cross-section vieW taken through line
`6C-6C of FIG. 6A;
`[0024] FIG. 7A shoWs the brace-anchor assembly of FIG.
`5A With the brace in a brace-doWn (rotated) position;
`
`[0025] FIG. 7B is a cross-section vieW taken through line
`7B-7B of FIG. 7A;
`
`[0026] FIG. 7C is a cross-section vieW taken through line
`7C-7C of FIG. 7A;
`
`[0027] FIG. 8A shoWs the receiving cannula of FIG. 6A
`having captured a brace from an adjacent cannula;
`
`[0028] FIG. 8B is a cross-section vieW taken through line
`8B-8B of FIG. 8A;
`
`[0029] FIG. 8C is a cross-section vieW taken through line
`8C-8C of FIG. 8A;
`
`FIG. 9 shoWs an embodiment of a hinged brace;
`
`[0030]
`[0031] FIG. 10 shoWs an embodiment of a pair of anchors
`each ?rmly attached to a brace;
`
`[0032] FIG. 10 illustrates one embodiment of a screW
`driver applying force to a brace; and
`
`[0033] FIGS. 12A and 12B illustrate one embodiment of
`a tool for positioning the brace.
`
`DETAILED DESCRIPTION
`
`[0034] Turning noW to FIG. 1, there is shoWn a sketch of
`human spine 10 shoWing a pair of tubes, or cannulas 41 and
`42 extending through skin 101 into vertebrae L5 and L4.
`Cannula 41 is positioned over the pedicle of vertebrae L5 (as
`Will be discussed), and cannula 42 is positioned over the
`pedicle of vertebrae L4. This procedure is being illustrated
`With respect to vertebrae L4 and L5 but could be performed
`With respect to any vertebrae or With respect to any bony
`portions of the body (human or animal) Where a brace is to
`be placed betWeen tWo points. The distance D is variable as
`desired. The sketch of FIG. 1, as are the sketches shoWn in
`other ?gures, are not to scale and are shoWn for illustration
`purposes With angles selected for clarity of explanation and
`not necessarily selected to be anatomically correct.
`
`[0035] The procedure to insert the brace betWeen verte
`brae L5 and L4 is as folloWs: The surgeon identi?es the
`desired vertebral levels and pedicle positions via standard
`techniques. Once the target vertebrae are identi?ed, a small
`incision 102 is made through skin 101 and a tracking needle
`(or other device) is inserted to pinpoint exactly Where each
`anchor is to be placed. A ?uoroscope, or other x-ray tech
`nique, is used to properly position the tracking needle. Once
`the proper position is located, guide Wire (K Wire) 22 (FIG.
`2A) is positioned With its distal end against the pedicle, in
`this case pedicle 37-1 of vertebrae L5. A guide Wire 23 may
`be similarly positioned With its distal end against pedicle
`37-1 of vertebrae L4, as shoWn in FIG. 2A. The surgeon
`then slides a series of continuing larger siZed dilators 12,
`12a, 12b, 12c doWn Wire 22, and slides a series of continuing
`larger siZed dilators 13, 13a, 13b, 13c doWn Wire 23 as
`shoWn in FIG. 2B.
`
`[0036] Approximately four or ?ve dilators are used until a
`diameter suitable for passing the pedicle screW and its
`extensions is achieved. A tap is sent doWn over the K Wire
`to tap a hole into the pedicle in preparation for receiving the
`anchor, Which in this case is a pedicle screW. This tap Will
`usually be a siZe slightly smaller than the pedicle screW
`thread siZe selected for that patient and that level.
`
`17
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`
`Apr. 21, 2005
`
`[0037] After the hole is tapped and the K Wire and the
`inner dilators, such as dilators 13, 13a, 13b, are removed, the
`surgeon is ready to introduce the anchor into the vertebrae.
`As shoWn in FIG. 2C, prior to inserting the anchor, brace 90
`is attached to screW 51 to form a brace-screW assembly. This
`assembly is then positioned at the distal end of cannula 41
`and a screWdriver or Wrench (1101 shoWn in FIG. 11) is
`inserted into cannula 41 and attached to the proximal end 91
`of brace 90. The entire assembly is then inserted into dilator
`13C. The screWdriver engages With proximal end 91 of
`brace 90 so as to alloW the surgeon to screW pedicle screW
`51 into the pre-tapped hole in vertebrae L5. Pressure on the
`screWdriver forces the screW to be in-line With the brace,
`Which, in turn, is in-line With the screWdriver. The screW
`driver can be removeably attached to end 91 of brace 90 by
`engaging, for example, ?at 94 (shoWn in FIG. 11) and/or
`hole 95 (shoWn in FIG. 9).
`
`[0038] This same procedure Would be repeated for each
`additional level, in this case level L4, except that screW 61
`has assembly 62 af?xed thereto. Assembly 62 is adapted to
`receive proximal end 91 of brace 90 as Will be more fully
`described herein.
`
`[0039] For a single level the above procedure is typically
`performed ?rst on one side of both vertebral levels and then
`on the other side. When ?nished, four pedicle screWs are
`inserted, holding tWo braces positioned laterally With respect
`to the center of the spine.
`
`[0040] Once both screWs are in place in vertebrae L5 and
`L4, dilators 12C and 13C are removed and, the surgeon
`slides a blunt dissection tool into incision 102 (FIG. 1) and
`gently parts the muscle bundle beloW the skin betWeen
`vertebrae L4 and L5. Alternatively, the blunt dissection tool
`could go doWn the second cannula and, starting at the
`bottom of the second cannula 41, Work open the muscle
`bundle betWeen the cannula Working upWard as far as is
`necessary. Using this procedure, the muscles (and other
`tissue), only need be separated to a point Where the brace 90
`must pass. Thus, the separation need not go to the skin level.
`This reduces trauma even further.
`
`[0041] Once an opening in the muscles has been devel
`oped betWeen cannulas 41 and 42, brace 90 is then posi
`tioned, by pivoting, as shoWn in FIG. 2D, by sliding a tool
`(for example, tool 1200, FIG. 12A) doWn cannula 41 to
`engage proximal end 91 of brace 90. The tool could have a
`force ?t With end 91 or as shoWn in FIG. 12A, can have
`handle 1201 and trigger control 1204 for controlling remov
`able attachment With brace 90. One or more Wires 1205,
`1206 and 1207 extending inside tool portions 1202, 1203,
`can be controlled by triggers 1204 and 1208 so that spring
`loaded grips (not shoWn) controlled by Wire 1202 can mate
`With hole 95 (shoWn in FIG. 9). Trigger 1208 can control
`Wire 1205 to releasably grip end 91 of brace 90. Once
`portion 1203 is mated With end 91 of brace 90 the surgeon
`can pull the tool slightly outWard to disengage brace end 92
`from screW 51. The surgeon can then operate Wires 1206 and
`1207, via trigger 1204, or otherWise, Which Wires pull on one
`side of tool portion 1203 to bend tool portion 1203, as shoWn
`in FIG. 12B. This bending forces brace end 91 out of
`cannula 41 (through opening 402 thereof) and through the
`prepared muscle opening and into opening 402 of cannula
`42. Once Within cannula 42, tool end 1203, under control of
`the surgeon, manipulates brace end 91 doWn cannula 42 and
`
`into a mating relationship With screW 61. Once this mating
`relationship is achieved, (as Will be discussed) tool end 1203
`is released from brace end 91, under control of Wire 1205
`and tool 1200 is removed from both cannulas. Wires 1206
`and 1207 are used on opposite sides of tool 1200 under
`control of trigger 1208 to control bending and unbending of
`tool portion 1203. Note that only temporary locking mecha
`nism and/or tool bending mechanism, including pneumatic
`and hydraulic can be used, if desired.
`
`[0042] Slots 402 of the respective cannulas are positioned
`fully under the skin line 101 of the patient. Brace 90 can
`have any shape desired. It can be ?at, oval or rod shaped and
`the cross-section need not be constant in shape or diameter.
`
`[0043] The surgeon receives positive feedback (a sensory
`event), either by feel (for example, a snap action) or by
`sound (for example, a click), or both When brace 90 is
`properly mated With assembly 62. If desired, one or both of
`assembly 52 or 62 mounted to the respective pedicle screWs
`51 and 61 can be angularity adjusted (as Will be discussed)
`to accommodate the patient’s body structure. The polyaxial
`nature of assemblies 52 and 62 With respect to the anchors
`alloWs for such adjustments Which are necessary for a
`variety of reasons, one of Which is that the angulation
`betWeen adjacent vertebral pedicles varies.
`
`[0044] As shoWn in FIG. 2E, after all angular and lateral
`adjustments are made, set scres 220, or other locking
`devices, are introduced doWn cannulas 41 and 42 to lock
`each end of brace 90 to its respective pedicle screW.
`
`[0045] As shoWn in FIG. 2F, once the proximal end of
`brace 90 is snapped in place to screW 61 and set screWs 220
`are tightened, cannulas 41 and 42 can be removed and the
`incision closed. As discussed, this procedure Would then be
`repeated on the opposite side of spinous process 33.
`
`[0046] FIG. 3A is a lateral vieW of tWo vertebrae seg
`ments and L5 and L4. Nerve roots 32 are shoWn coming out
`from spinal cord 301. The nerve roots become compressed
`When vertebrae L4 collapses doWn upon vertebrae L5 When
`disc 31 becomes reduced in siZe due to injury, a dehydration
`or otherWise. Spinous processes 33 form a portion of the
`posterior of the vertebral bodies.
`
`[0047] FIG. 3B is a top vieW of vertebrae L4 and is similar
`to other lumbar levels. A Vertebra L4 includes vertebral
`body 36, spinous process 33, neuro canal 34, and transverse
`processes 35. The pedicle region, such as pedicle 37, is the
`bony area bridged roughly betWeen outer Wall 38 and neuro
`frame 34. Areas 37-1 and 37-2 are the target areas for the
`pedicle screWs, as discussed above.
`
`[0048] FIG. 4 shoWs cannulas 41 and 42 Which could be
`identical, if desired. Cannula 41 includes opening 401 to
`alloW for lateral adjustment of the distal end of brace 90. On
`cannula 42, opening 402 can be adjusted doWnWard from
`that of cannula 41 (because of the arc of brace 90) so as to
`more precisely capture and retain proximal end 91 of brace
`90. Also, as Will be seen, the opening 402 on cannula 42 can
`be adopted to receive the shape of end 91 of brace 90, and
`loWer opening 401 eliminated, if desired.
`
`[0049] FIG. 5A shoWs pedicle screW 51, and brace rod
`adjustment assembly 52. Assembly 52 acts as a hinge for
`brace 90 positioned Within cannula 41. ScreW portion 51 is
`extended out from the base of the connection in an in-line
`
`18
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`Apr. 21, 2005
`
`orientation With brace 90. By the application of torque to
`proximal end 91 of brace 90 by a screwdriver (or Wrench),
`as discussed above, and or as shoWn in FIG. 11, screW 51
`can be turned so that it can be screWed into the bone as
`desired. Note that assembly 52 has tWo openings 520 and
`521 Which, as Will be seen, alloW brace 90 to pivot.
`
`[0050] ScreW 51 is connected to assembly 52 as Will be
`described herein. This combination is attached to the distal
`end of cannula (extension) 41 by, for example, constructing
`?exible ?ngers at the distal end of cannula 41 and construct
`ing on the inside of these ?ngers protrusions in the form, for
`example, of small pyramids. These pyramids then ?t into a
`tight mating relationship With mating structures constructed
`on the parity of assembly 52. When it is desired to release
`cannula 41 from assembly 52, upWard pressure and perhaps
`a tap is applied to the ring at the proximal end of cannula 41.
`That upWard force causes the ?ngers to ?y outWard. Thereby
`releasing the above-described mated structures. This same
`arrangement is used to assemble and release cannula 42
`from assembly 62 (FIG. 6A)
`[0051] FIG. 5B is a cross-section taken through line
`5B-5B of FIG. 5A and shoWs screW 51 attached to brace 90
`via assembly 52. Brace 90 is shoWn curved to approximate
`the spinal curvature. The length of brace 90 is selected to
`shoW the distance betWeen the respective anchors. For the
`L5-L4 level this distance is approximately 35 mm to 45 mm.
`
`[0052] FIG. 5C shoWs screW 51 having neck 53 and head
`54. ScreW 51 also has recess area 55 designed for mating
`With end 92 of brace 90. This mating call be a slot or other
`?at con?guration or any means of connecting tWo structures
`together so that force (in this embodiment the force is
`torque) can be delivered from one to another. Brace 90 Will,
`When desired, lift upWard so as to unmate end 92 from ?at
`55 so that brace 90 can then pivot With respect to assembly
`52. Bearings 501 positioned in slots 93 of brace 90 facilitate
`such pivoting. Slots 93 serve to limit the in-line and lateral
`distance brace 90 can move. Bearings 501 also serve as a
`pivot point for brace 90 and to prevent brace 90 from
`turning.
`[0053] Assembly 52 alloWs brace 90 to move from the
`in-line position to a rotated position While also accommo
`dating the lateral motion of brace 90. This lateral motion
`accommodates different lateral distances betWeen anchors.
`Assembly 52 can be constructed in different Ways and from
`different materials as desired, for example, as shoWn in US.
`Pat. No. 5,672,176 hereby incorporated by reference herein.
`When brace 90 is repositioned to approximately a 90° angle
`and a set screW (not shoWn) is in place Within threads 506,
`pressure is applied doWnWard on the side of brace 90. This
`action, in turn, applies pressure on clamp 502, forcing Wedge
`503 against head 54 of screW 51. This then locks the
`polyaxial mechanism in place and prevents brace 90 from
`further movement With respect to screW 51. This clamping
`action also maintains the relative angular position betWeen
`brace 90 and screW 51. Spring band 505 snaps betWeen a
`groove in clamp 502 and a groove in shell 504 holding
`assembly 52 together. Note that assembly 52 can be separate
`from screW 51 as shoWn or can be constructed integral
`thereto. Also note that the polyaxial motion described is not
`necessary and can be eliminated, if desired.
`
`end 91 is captured Within slot 402, end 91 passes doWn
`inside cannula 42 crrying brace 90 doWn slot 403 toWard
`assembly 62. Slot 620 in assembly 62 alloWs brace 90 to
`enter assembly 62.
`
`[0055] FIG. 6B is a cross-section taken along lines 6B-6B
`of FIG. 6A, and shoWs assembly 62 With receptacle 66.
`Receptacle 66 is designed, in one embodiment, to snap
`together With end of brace 90. This snap-action provides
`positive feed back to the surgeon, either by feel or audibly,
`or both. This tactile (or audible) feed back is caused, for
`example by end 91 passing into receptacle 66. In one
`embodiment, a force ?t could be achieved betWeen end 91
`and receptacle by making the inner circumference of the
`outer rim of receptacle 66 smaller than the diameter of end
`91. Mating can be facilitated by cutting small grooves or
`slots in receptacle 66 to alloW receptacle 66 to expand
`around end 91 for a locking ?t. This expansion occurs as end
`91 enters into receptacle 66. As the mating occurs, end 92 of
`brace 90 (FIG. 7A) is free to move laterally With respect to
`anchor 51 since brace 90 is held in place (as discussed
`above) by bearings 501 riding in slots 93 (FIG. 7C).
`[0056] FIG. 6C shoWs an expanded vieW of assembly 62
`mounted to head 64 of screW 61. Receptacle 65 accepts a
`Wrench or screW driver from the surgeon for inserting screW
`61 into the bone and is accessible through the base of
`receptacle 66. Clamp 602 acts on Wedge 603 to apply force
`on head 64 of screW 61. Until tightened fully by a set screW
`positioned Within threads 505, assembly 62 is free to rotate
`polyaxially around head 64 of anchor 61. This polyaxial
`movement can, if desired, be eliminated.
`[0057] FIG. 7A shoWs the brace/screW assembly With
`brace 90 repositioned approximately 90° With respect to
`screW 51. ScreW 51 Would be embedded in a bony structure
`(or other hard structure), not shoWn in FIG. 7A. In a
`particular application, the exact rotation Will depend upon
`many factors, including the angle betWeen anchors and the
`angle the respective anchors make With respect to the bone
`in Which they are imbedded.
`
`[0058] FIG. 7B sloWs a cross-section taken along line
`7B-7B of FIG. 7A. As shoWn, brace 90 is rotated approxi
`mately 90° With respect to assembly 52. End 92 of brace 90
`has been disengaged from mating structure 55 on head 54 of
`screW 51. In FIG. 7B, set screW 220 is shoWn about to press
`doWn on brace 90 to compress brace 90 to screW head 54,
`as previously discussed.
`
`[0059] FIG. 7C is a cross-section taken through line
`7C-7C of FIG. 7A and again shoWs brace 90 rotated 90°
`With respect to screW 51. Lateral movement of brace 90 (in
`and out of the page in FIG. 7C and left and right in FIG. 7B)
`is facilitated by berings 501 riding in grooves 93 of brace 90
`and acting both as a fulcrum and as lateral limitation. All
`such movement is inhibited When set screW 220 presses
`doWn on brace 90. Wing 511 on clamp 503 prevents clamp
`503 from upWard movement.
`
`[0060] FIG. 8A shoWs the receptacle/screW assembly With
`brace 90 positioned in its capture mode With respect to
`assembly 62. Assembly 62 is, in turn, mounted on head 64
`of screW 61. ScreW 61 Would be embedded in a second bony
`structure (on other hard structure) not shoWn in FIG. 8A.
`
`[0054] FIG. 6A shoWs cannula 42 having slot 403, With
`opening 402 positioned to receive end 91 of brace 90. Once
`
`[0061] FIG. 8B shoWs a cross-section taken along line
`8B-8B of FIG. 8A. End 91 of brace 90 is captured by
`
`19
`
`

`
`US 2005/0085813 A1
`
`Apr. 21, 2005
`
`receptacle 66. Set screw 220 is shown applying downward
`pressure on brace 90 in order to lock brace 90 to screw head
`64 as previously discussed. The inner geometry of receptacle
`66 is keyed to match the proximal end of brace 90.
`
`[0062] FIG. 8C shows a cross-section taken along line
`SC-SC of FIG 8A. End 91 of brace is shown mated with
`receptacle 66 and locked tight by set screw 220. Once set
`screw 220 presses down on brace 90, hinge assembly 62
`clamps against head 64 of screw 61 to prevent further
`movement of brace 90 with respect to screw 61. Area 610 is
`created in assembly 62 such that receptacle 66 can expand
`as brace end 91 passes into the receptacle. Wing 611 on
`wedge 603 prevents wedge 603 from moving upward.
`[0063] FIG. 9 shows one embodiment of brace 90 with
`distal end 92 and proximal end 91. Slot 93 is longer than
`actually necessary to allow for lateral movement of brace 90
`during the seating process so as to allow for different
`distances between anchors. As discussed, distal end 92 can
`have any shape required for mating with head 54 of screw
`51 for the purpose of force transfer. Also note that proximal
`end 91 has a ball (or partial ball) shape for capture by slot
`402 of cannula 42. End 91 can have any shape, provided
`such shape is adapted for capture by cannula 42.
`[0064] FIG. 10 shows a single level brace system 1000
`having brace 90 with its distal end 92 clamped tightly with
`respect to screw 51 (a ?rst anchor) and its proximal end 91
`clamped tightly with respect to screw 61 (a second anchor).
`Each of these anchors is ?rmly supported in a respective
`bony structure (not shown in FIG. 10) of a patient. Note that
`brace 90 is slightly curved to, at least partially, adjust for the
`spine curvature. Also note that the respective anchors are not
`necessarily parallel to each other but each has assumed an
`angle necessary for proper placement in the pedicle (or other
`bony area) of the respective vertebra. While the brace has
`been shown with respect to the L4 and L5 vertebrae, the
`system, method, and device discussed herein are not so
`limited and can be used between any bony or other hard
`portions that must be supported, including single level or
`multilevel.
`
`[0065] For bracing two or more levels, one option is to
`skip one or more vertebral levels onto the anchor, another
`option is to use a “pass-through” anchor assembly on the
`skipped vertebral level(s). The pass-through assembly can
`be adapted for locking to the brace on the