US20070162001A1 - Spinous process fixation implant - Google Patents

Abstract

An implantable spinous processes fixation device including a first S-shaped plate having a first surface configured to engage a first lateral surface of a first spinous process and a second surface configured to engage a second lateral surface of a second spinous process and a second S-shaped plate having a first surface configured to engage a second lateral surface of the first spinous process and a second surface configured to engage a first lateral surface of the second spinous process. The first and second S-shaped plates are configured to pivot around an axis perpendicular to the center portions of the first and second S-shaped plates.

Description

CROSS REFERENCE TO RELATED CO-PENDING APPLICATIONS
• This application claims the benefit of U.S. provisional application Ser. No. 60/750,520 filed Dec. 14, 2005 and entitled “SPINOUS PROCESS FIXATION IMPLANT’, the contents of which are expressly incorporated herein by reference.
• This application is also a continuation of U.S. application Ser. No. 11/609,418 filed on Dec. 12, 2006 and entitled SPINOUS PROCESS FIXATION IMPLANT the contents of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
• The present invention relates to a system and a method for spinal stabilization through an implant, and more particularly to spinal stabilization through attachment of the implant to the spinous processes along one or more vertebras.
BACKGROUND OF THE INVENTION
• The human spine comprises individual vertebras30 (segments) that are connected to each other to form aspinal column29, shown inFIG. 1. Referring toFIGS. 1B and 1C, eachvertebra30 has a cylindrical bony body (vertebral body)32, three winglike projections (twotransverse processes33,35 and one spinous process34), left andright facet joints46,lamina47, left andright pedicles48 and a bony arch (neural arch)36. The bodies of thevertebrae32 are stacked one on top of the other and form the strong but flexible spinal column. Theneural arches36 are positioned so that the space they enclose forms a tube, i.e., thespinal canal37. Thespinal canal37 houses and protects the spinal cord and other neural elements. A fluid filled protective membrane, thedura38, covers the contents of the spinal canal. The spinal column is flexible enough to allow the body to twist and bend, but sturdy enough to support and protect the spinal cord and the other neural elements. Thevertebras30 are separated and cushioned by thin pads of tough, resilient fiber known asinter-vertebral discs40. Disorders of the spine occur when one or more of theindividual vertebras30 and/or theinter-vertebral discs40 become abnormal either as a result of disease or injury. In these pathologic circumstances, fusion of adjacent vertebral segments may be tried to restore the function of the spine to normal, achieve stability, protect the neural structures, or to relief the patient of discomfort.
• Several spinal fixation systems exist for stabilizing the spine so that bony fusion is achieved. The majority of these fixation systems utilize rods that attach to screws threaded into the vertebral bodies or thepedicles48, shown inFIG. 3C. In some cases plate fixation systems are also used to fuse two adjacent vertebral segments. This construction usually consists of two longitudinal plates that are each placed laterally to connect two adjacent pedicles of the segments to be fused. This system can be extended along the sides of the spine by connecting two adjacent pedicles at a time similar to the concept of a bicycle chain. Current plate fixation systems are basically designed to function in place of rods with the advantage of allowing intersegmental fixation without the need to contour a long rod across multiple segments. Both the plating systems and the rod systems add bulk along the lateral aspect of the spine limits access to the pars and transverse processes for decortication and placement of bone graft. In order to avoid this limitation many surgeons decorticate before placing the rods, thereby increasing the amount of blood loss and making it more difficult to maintain a clear operative field. Placing rods or plates lateral to the spine leaves the center of the spinal canal that contains the dura, spinal cords and nerves completely exposed. In situations where problems develop at the junction above or below the fused segments necessitating additional fusion, the rod fixation system is difficult to extend to higher or lower levels that need to be fused. Although there are connectors and techniques to lengthen the fixation, they tend to be difficult to use and time consuming.
• Accordingly, there is a need for a spinal stabilization device that does not add bulk to the lateral aspect of the spine and does not limit access to the pars and transverse processes for decortication and placement of bone graft.
SUMMARY OF THE INVENTION
• In general, in one aspect, the invention features an implantable assembly for stabilization of spinous processes including a first S-shaped plate having a first surface configured to engage a first lateral surface of a first spinous process and a second surface configured to engage a second lateral surface of a second spinous process and a second S-shaped plate having a first surface configured to engage a second lateral surface of the first spinous process and a second surface configured to engage a first lateral surface of the second spinous process. The first and second S-shaped plates are configured to pivot around an axis perpendicular to the center portions of the first and second S-shaped plates.
• Implementations of this aspect of the invention may include one or more of the following features. The assembly may further include a post member configured to pass through concentrically aligned through-bore openings formed in the centers of the first and second S-shaped plates. The second S-shaped plate is configured to pivot around the post member and to set first and second pivot angles with the first S-shaped plate, respectively, thereby defining first and second spaces between the first S-shaped plate and the top and bottom portions, respectively. The second S-shaped plate may include top and bottom components configured to pivot around the axis independent of each other. The top and bottom components are configured to pivot around the post member and to set first and second pivot angles with the first S-shaped plate, respectively, thereby defining first and second spaces between the first S-shaped plate and the top and bottom components, respectively. The post member may include a locking element for securing and preventing pivoting of the first and second S-shaped plates. The post member may be an elongated bolt and the locking element may be threads formed at a portion of the bolt, dimensioned to engage inner threads in the first S-shaped plate through-bore, or a nut after the bolt exits the S-shaped plate through-bore. The first and second surfaces of the first and second S-shaped plates may include protrusions configured to engage and frictionally lock the S-shaped plates onto the first and second spinous processes. The protrusions may be teeth, spikes, serrations, rough coatings or ridges. The center portions of the first and second S-shaped plates are dimensioned to fit between the first and second spinous processes and comprise edges sculpted to conform to the shape of the spinous processes. The first and second pivot angles may have values between zero and 180 degrees. The first and second S-shaped plates are pivoted to a horizontal orientation for sidewise insertion of the assembly between the first and second spinous processes. The assembly may be assembled prior to or after being implanted between the first and second spinous processes. The assembly may further include a top locking member configured to lock the first and second S-shaped plates' top ends. The top locking member may be a long bolt configured to be threaded through bolt holes formed through the first S-shaped plate's top end, the first spinous process and the second S-shaped plate's top end. The top locking member may be staples, cables, sutures, pins or screws. The assembly may further include a bottom locking member configured to lock the first and second S-shaped plates' bottom ends. The bottom locking member may be a long bolt configured to be threaded through bolt holes formed through the first S-shaped plate's bottom end, the second spinous process and the second S-shaped plate's bottom end. The bottom locking member may be staples, cables, sutures, pins and screws. The first and second S-shaped plates may be made of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials or combinations thereof. The assembly may further include a center plate configured to pivot around the axis and being dimensioned to fit between the first and second spinous processes and comprising edges sculpted to conform to the shape of the spinous processes. The first and second S-plates may have adjustable lengths.
• In general, in another aspect, the invention features a method for stabilizing spinous processes of a spinal column, including providing a first S-shaped plate and engaging a first surface of the first S-shaped plate with a first lateral surface of a first spinous process and a second surface of the first S-shaped plate with a second lateral surface of a second spinous process and providing a second S-shaped plate and engaging a first surface of the second S-shaped plate with a second lateral surface of the first spinous process and a second surface of the second S-shaped plate with a first lateral surface of the second spinous process. The first and second S-shaped plates are configured to pivot around an axis perpendicular to the center portions of the first and second S-shaped plates.
• Among the advantages of this invention may be one or more of the following. The assembly stabilizes vertebras by attaching plates to the spinous processes of the vertebras. This stabilization device does not add bulk to the lateral aspect of the spine and does not limit access to the pars and transverse processes for decortication and placement of bone graft.
• The details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects and advantages of the invention will be apparent from the following description of the preferred embodiments, the drawings and from the claims
BRIEF DESCRIPTION OF THE DRAWINGS
• Referring to the figures, wherein like numerals represent like parts throughout the several views:
• FIG. 1A is a side view of the human spinal column;
• FIG. 1B is an enlarged view of area A ofFIG. 1A;
• FIG. 1C is an axial cross-sectional view of a lumbar vertebra;
• FIG. 2 is a posterior view of a portion of the spine with a first embodiment of a spinous process fixation implant according to the present invention affixed thereto;
• FIG. 3 is a top view of the spine with the spinous process fixation implant ofFIG. 2 affixed thereto;
• FIG. 4 is a front side view of the spinous process fixation implant ofFIG. 2;
• FIG. 5 is a back side view of the spinous process fixation implant ofFIG. 2;
• FIG. 6 is a right side perspective view of the spinous process fixation implant ofFIG. 2;
• FIG. 7 is partially exploded right side perspective view of the spinous process implant ofFIG. 2;
• FIG. 8 is a left side perspective view of the spinous process fixation implant ofFIG. 2;
• FIG. 9 is a top perspective view of the spinous process fixation implant ofFIG. 2;
• FIG. 10 is an exploded right side perspective view of the spinous process fixation implant ofFIG. 2;
• FIG. 11 is a front side view of theelongated component110 ofFIG. 2;
• FIG. 12 is a back side view of the elongated component ofFIG. 2;
• FIG. 13 is a front side view of the top pivoting component ofFIG. 2;
• FIG. 14 is a front side view of the bottom pivoting component ofFIG. 2;
• FIG. 15 is a front side view of a second embodiment of a spinous process fixation implant according to the present invention, depicting the top and bottom pivoting components in the closed position;
• FIG. 16 is a front side view of the spinous process fixation implant ofFIG. 15 with the top and bottom pivoting components in the open position;
• FIG. 17 is a left side perspective view of the spinous process fixation implant ofFIG. 15, depicting the top and bottom pivoting components in the closed position;
• FIG. 18 is a left side perspective view of the spinous process fixation implant ofFIG. 15, depicting the top and bottom pivoting components in the open position;
• FIG. 19 is an exploded left side view of the spinous process fixation implant ofFIG. 15;
• FIG. 20A is a right side view of theelongated plate component210 ofFIG. 15;
• FIG. 20B is a right side view of thetop pivoting component220 ofFIG. 15;
• FIG. 20C is a right side view of thebottom pivoting component230 ofFIG. 15;
• FIG. 21 is a front side view of a third embodiment of a spinous process fixation implant according to the present invention, depicting front and back pivoting components in the closed position around the spinous processes;
• FIG. 22A depicts insertion of the spinous process fixation implant ofFIG. 21 from the side with front and back pivoting components in the open position;
• FIG. 22B depicts pivoting the front and back pivoting components ofFIG. 21 to close them around the spinous processes;
• FIG. 23 is a front side view of the embodiment of a spinous process fixation implant according ofFIG. 21, depicting front and back pivoting components in the closed position and locked position around the spinous processes;
• FIG. 24 is a front side view of a fourth embodiment of a spinous process fixation implant according to the present invention, depicting front top, front bottom and back pivoting components in the closed position around the spinous processes;
• FIG. 25A is a front side view of the front top pivoting component of the spinous process fixation implant ofFIG. 24;
• FIG. 25B is a front side view of the front bottom pivoting component of the spinous process fixation implant ofFIG. 24;
• FIG. 25C is a front side view of the back pivoting component of the spinous process fixation implant ofFIG. 24;
• FIG. 26 is a front side view of the locking component of the spinous process fixation implant ofFIG. 24;
• FIG. 27 is a front side view of a fifth embodiment of a spinous process fixation implant according to the present invention, depicting front and back pivoting components in the closed and locked position around the spinous processes;
• FIG. 28 depicts cutting and opening paths A and B around superior and inferior adjacent spinous processes;
• FIG. 29 depicts inserting back pivoting component of the spinous process fixation implant ofFIG. 27 along path A ofFIG. 28; and
• FIG. 30 depicts inserting front pivoting component of the spinous process fixation implant ofFIG. 27 along path B ofFIG. 28; and
• FIG. 31 is a front side view of a sixth embodiment of a spinous process fixation implant according to the present invention, depicting a single K-component body.
DETAILED DESCRIPTION OF THE INVENTION
• The present invention relates to a system and a method for a spinous process fixation implant.
• Referring toFIG. 2,FIG. 3, andFIG. 4, a spinousprocess fixation assembly100 stabilizes twoadjacent vertebras92,94 of the human spine by engaging and locking theirspinous processes90aand90b, respectively. Spinousprocess fixation assembly100 includes anelongate plate110 and top and abottom pivoting plates120,130, located opposite toplate110 and configured to form a K-shaped structure together withplate110. Top andbottom pivoting plates120,130 pivot around axis140 (shown inFIG. 6) independent from each other, formingangles162,164 withplate110, respectively. The pivoting motion ofplates120,130 alongdirections144a,144band146a,146b, moves them close to or away from theelongated plate110, as shown inFIG. 4.Elongated plate110 has abody112 and front andback cross plates114,116, extending at right angle to the front of thebody112 and back of thebody112, respectively, as shown inFIG. 10,FIG. 11 andFIG. 12.Body112 has atop end113a, abottom end113b, anouter surface118 and aninner surface117.Axis140 passes throughapertures152 and154 formed in the centers of thecross plates114,116, respectively, as shown inFIG. 11 andFIG. 12.Cross plates114,116 extend between the bottom surface and top surface of the adjacent spinous processes90a,90b, respectively and haveedges115 which are rounded and sculpted to correspond to the geometry of the spinous processes90a,90band lamina around which they will fit once implanted.Cross plates114,116 are substantially flat, parallel to each other and a gap is formed between them sized to hold portions of the top andbottom pivoting plates120,130, as shown inFIG. 7.
• Referring toFIG. 10,FIG. 13 andFIG. 14,top pivoting plate120 has amain body122 with top and bottom ends123a,123b, respectively and inner127 andouter surface128, respectively. Anarm124 extends downward from thebottom end123bof thebody122 and aside plate128 extends at right angle to the back of thebody122. Thearm124 has anaperture126 located at the bottom left corner and extends from the front side to the back side of thearm124. Similarly,bottom pivoting plate130 has amain body132 with top and bottom ends133a,133b, respectively, and inner andouter surfaces137,138 respectively. Anarm134 extends upward form thetop end133aand has anaperture136 at the top left corner, extending from the front side to the back side of thearm134, as shown inFIG. 10, andFIG. 14. Aside plate138 extends at right angle from to the back of thebody132. All edges ofplates110,120,130 are rounded to prevent damage of the adjacent tissue during implantation or spinal movement.Plates110,120,130 are made of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials or combinations thereof.Plates110,120,130 may have adjustable lengths. In oneexample plates110,120,130 have lengths of 30 mm, 15 mm, 15 mm, respectively, and the assembly may have a width between 3 mm to 10 mm.
• Referring toFIG. 7, along bolt180 passes throughapertures152 and154 of thecross plates114,116 of theelongated plate110 and thoughapertures126 and136 formed in the top andbottom pivoting plates120,130, respectively.Bolt180 has ahead181, ashaft183 andthreads184 formed on the end portion of theshaft183.Threads184 engage threads in theaperture154 of theback cross plate116, in order to hold and secure the threecomponents110,120,130, of theassembly100 together. In other embodiments, a nut (not shown) is attached at the end of thebolt180 to hold and secure the threecomponents110,120,130, of theassembly100 together. In other embodiments bolt180 is threaded into the cartilage between the two vertebras to secure the threecomponents110,120,130 together and to attach theassembly100 onto the spine. Theinner surfaces117,127,137 ofplates110,120,130, respectively, haveprotrusions111 that grab and frictionally engage the sides of the spinous processes90a,90b, as shown inFIG. 3,FIG. 11,FIG. 13 andFIG. 14.Protrusions111 may be teeth, serrations, ridges, and other forms of rough surfaces or coatings that produce rough surfaces. The position of pivotingplates120,130 relative to each other and relative toplate110 is locked with aset screw182 passing trough theaperture156 formed in the upper right corner of thefront cross plate114. Tightening of theset screw182 locks the front andback cross plates114,116 to the pivotingplates120 and130. Engaging and locking the spinousprocess fixation assembly100 ontospinous processes90a,90b, prevents thecomponents110,120 and130 from moving sidewise or up and down toward or away from each other during spinal movement.
• The assembled spinousprocess fixation assembly100 is implanted into the patient with the use of instrumentation (not shown) between the two adjacent spinous processes90a,90b, as shown inFIG. 2. Thecross plates114,116 are placed between thespinous processes90a,90bso that thebody112 of theelongated plate110 and the top andbottom pivoting plates120,130 fall on the lateral sides of the spinous processes90a,90b. Onespinous process90alies between the top portion of thebody112 and thetop pivoting plate120, as shown inFIG. 3, and the otherspinous process90blies between the bottom portion of thebody112 and thebottom pivoting plate130, with theirinner surfaces117,127,137 facing the lateral surfaces of the spinous processes90a,90b. On each of theinner surfaces117,127,137 of theplates110,120,130, respectively, theprotrusions111 face toward the lateral surface of the adjacent spinous process. At this point, the top andbottom pivoting plates120,130 are pivoted as necessary to provide the desired fit of the plates to the spinous processes. Thebolt180 is tightened, clamping theprotrusions111 into the surfaces of the spinous processes and locking the three plates relative to each other by engaging the threads of theaperture154. Theprotrusions111 and the threading of the bolt intoaperture154 of theback cross plate116 frictionally secures the spinousprocess fixation assembly100 onto the spinous processes90a,90band helps prevent the device from shifting or slipping.
• Referring toFIG. 15,FIG. 16,FIG. 17,FIG. 18, in a second embodiment of the spinousprocess fixation assembly200, the top andbottom pivoting plates220,230 are designed to pivot past each other and to form any angle with theelongated plate210 between 0 and 180 degrees. In particular,plates220 and230 pivot to a 90 degree angle relative to plate210 and form a sidewise oriented T, shown inFIG. 16 andFIG. 180. Theassembly200 ofFIG. 16, with the pivotingplates220,230 at a 90 degree angle with theplate110, is inserted sidewise between the top and bottom spinous processes90a,90b. Once the assembly is inserted, theplates220 and230 are pivoted upward and downward, respectively, and are placed at angles relative to theplate210 necessary to provide the desired fit of the plates to the spinous processes. Sidewise implantation of theassembly200 has the advantage of reduced trauma in the area between the spinous processes.
• In this embodiment thetop pivoting plate220 has amain body222 with top and bottom ends223a,223b, respectively and inner227 and outer surface228, respectively, shown inFIG. 19,FIG. 20.Main body222 has awidth229 dimensioned to allowplate220 to pivotpast plate230 when placed in thegap219 between the twocross plates214,216 ofplate210. Anarm224 extends downward from thebottom end223bof thebody222. Thearm224 has anaperture226 located at the center of the bottom end of the arm and extends from the front side to the back side of thearm224. A protrudingannulus225 surroundsaperture226 and projects outward form the back side of thearm224.Annulus225 is dimensioned to fit withinaperture254 of theback cross plate216.Aperture226 includes inner threads (not shown) extending from the front to the back side of thearm224. Similarly,bottom pivoting plate230 has amain body232 with top and bottom ends233a,233b, respectively, and inner and outer surfaces237,238 respectively.Main body232 has awidth239 dimensioned to allowplate230 to pivotpast plate220 when placed in thegap219 between the twocross plates214,216 ofplate210. Anarm234 extends upward form thetop end233aand has anaperture236 located at the center of the top end of the arm and extends from the front side to the back side of thearm234, as shown inFIG. 19 andFIG. 20C.
• Elongated plate210,top pivoting plate220 andbottom pivoting plate230 are assembled together, as shown inFIG. 18.Annulus225 is inserted in theaperture254 of theback cross plate216 and theapertures252,236,226 of thefront cross plate214,bottom pivoting plate230 andtop pivoting plate220, respectively, are aligned. Along bolt280 is inserted through the aligned apertures and threaded in the inner threads of theaperture226. The position of pivotingplates220,230 relative to each other and relative toplate210 is locked with aset screw282 passing trough the aperture256 formed in the upper left corner of thefront cross plate214. Tightening of theset screw282 locks the front andback cross plates214,216 to the pivotingplates220 and230. Onceassembly200 is implanted into the patient between the two adjacent spinous processes90a,90b, the assembly is secured and locked in position, according to the process described above.
• Referring toFIG. 21, in a third embodiment the spinousprocess fixation assembly300 includes a front S-shapedplate310 and a mirror image back S-shapedplate320 connected at their centers via abolt380 forming an X-shaped structure. The front S-shapedplate310 pivots relative to a back S-shapedplate320 aroundpivot point340 and thespinous process90aof thetop vertebra92 is frictionally engaged between the upper arms of S-plates310 and320, while thespinous process90bof thebottom vertebra42 is frictionally engaged between the lower arms of S-plates310 and320. Abolt380 is threaded through apertures formed in the centers of the front and back S-plates, as shown inFIG. 21. The inner surfaces of the upper and lower arms of the S-shaped plates are sculpted to fit the shape of the spinous processes and have protrusions that frictionally engage the sides of the spinous processes and together with thebolt380 securely lock theassembly300 between thespinous processes90a,90b.
• Assembly300, with the S-shapedplates310,320 assembled and oriented horizontally, as shown inFIG. 22A, is inserted sidewise between the top and bottom spinous processes90a,90b. Once the assembly is inserted,plates310 and320 are pivoted upward and downward, respectively, as shown inFIG. 22B, and they assume a vertical orientation so that their corresponding inner surfaces surroundspinous processes90a,90b. Sidewise implantation of theassembly300 has the advantage of reduced trauma in the area between the spinous processes.
• Long bolts370 may be added to this embodiment to further anchor theassembly300 on the spinous processes. If they are added, appropriately sized holes must be drilled laterally through the spinous processes prior to placement of the device. Once the device is in place as described above, onelong bolt370 is threaded through a bolt hole on the top end ofplate310, through the drilled hole in thespinous process90a, then out through a bolt hole on top end ofplate320. A secondlong bolt370 may also be threaded through a bolt hole on the bottom end ofplate310, through the drilled hole in thespinous process90b, then out through a bolt hole on the bottom end ofplate320. Tightening ofbolts380 and370 securely locks theassembly300 aroundspinous processes90a,90b.
• In another embodiment of the spinousprocess fixation assembly400, shown inFIG. 24, the front S-shaped plate include atop pivoting component410, shown inFIG. 25A, and abottom pivoting component420, shown inFIG. 25B, forming the top and bottom portions of the S-curve, respectively. The back S-plate430 is formed as one component S-shaped plate with a curvedtop portion432, a bottomcurved portion434 and arounded center438 having an aperture formed in itscenter436, shown inFIG. 25C. Thetop pivoting component410 includes an upward extendingcurved portion412 and a lowerrounded end414 having anaperture416 formed in its center. The bottom pivoting component includes a downward extendingcurved portion422 and an upperrounded end424 having anaperture426 formed in its center. The front and back surfaces of therounded end424, the back surface of therounded end414 and the front surface of therounded center438 haveradial extending grooves425, shown inFIG. 25B andFIG. 25C.Grooves425 define one-degree arcs, thus allowing theplates410,420,430 to rotate relative to each other by one degree steps.Assembly400 further includes ablock440 dimensioned to fit between the adjacent spinous processes90a,90band having top and bottom edges configured to correspond to the geometry of the spinous processes90a,90band lamina around which they will fit once implanted. Different sized blocks are used to accommodate different spacings between adjacentspinous processes90a,90b. The front and back surfaces ofblock440 also includegrooves425 around anaperture446 formed n the center of the block. Thetop pivoting plate410,bottom pivoting plate420, block440 and theback plate430 are arranged so that theircorresponding apertures416,426,446,436 are aligned and a bolt480 is threaded through these apertures. Once theassembly400 is inserted, theplates410 and420 are pivoted upward and downward, respectively, and are placed so as to surround the spinous processes. The inner surfaces of the upper and lower arms of the S-shaped plates are sculpted to fit the shape of the spinous processes and have protrusions that frictionally engage the sides of the spinous processes and together with the bolt480 securely lock theassembly400 between thespinous processes90a,90b.
• Long bolts370 may be also added to this embodiment to further anchor theassembly400 on the spinous processes, as was described above. Alternatively, astaple450 may be placed on the top and bottom open ends of theplates410,420 and430, as shown inFIG. 27. In other embodiments banding, cabling or suturing may be used to attached the ends ofplates410,420 and430 to the spinous processes. The outer surfaces of theplates410,420 and430 may be rounded, as shown inFIG. 24 or straight, a shown in theembodiment500 ofFIG. 27.
• Referring toFIG. 28,FIG. 29 andFIG. 30, the process of implanting the spinous process fixation assembly between two adjacent vertebrae includes the following steps. First an incision is made in the patient's back and paths A and B are opened alongbony planes95 and through ligaments96 between the adjacent spinous processes90a,90b. Path B is mirror image of path A about the centered sagittal plane98. Next, theback component510 of the assembly ofFIG. 27 is inserted along path A, as shown inFIG. 29, and theends513aand513bare attached to the spinous processes90a,90b, respectively. Next, thefront component520 is inserted along path B and abolt580 is threaded through theapertures512,522 formed in the centers of back andfront components510,520, respectively. The front and back components are pivoted around the axis passing through theircentral apertures512,522, so that theirends513a,523a,513b,523bsurround and close around the spinous processes90a,90b. The ends513a,523a, and513b,523bare then attached tospinous processes90a,90b, respectively as shown inFIG. 30. The ends may be attached with any of the above mentioned methods including frictional engagement of protrusions, long bolts, staples, cabling, banding or suturing.Plates510,520 are dimensioned so when assembled,assembly500 has a width535 that covers and protects the spinal cord after laminectomy or facectomy.
• In a sixth embodiment, shown inFIG. 31, spinousprocess fixation assembly600 includes one K-shaped component having anelongated plate610 and twodeformable plates620,630 extending upward and downward, respectively, from thecenter615 of the elongated plate. Atop gap612 is formed between the top portion of theelongated plate610 and the upward extendingplate620. Abottom gap614 is formed between the bottom portion of theelongate plate610 and the downward extendingplate630. The K-shaped assembly is placed between the adjacent spinous processes90a,90b, as shown inFIG. 31, and aplate640 is placed in the center of theassembly600 on topdeformable plates620,630. Abolt680 is threaded through apertures formed in the center ofplate640 and thecenter615 of the K-shaped component, as shown inFIG. 31. Tightening of thebolt680 down applies pressure onto theplate640, which is transferred to the top and bottomdeformable plates620,630.Plates620,630 move closer toplate610 and the widths of the top andbottom gaps612,614 is reduced, resulting in engagingprotrusions111 formed on the inner surfaces ofplates610,620,630 with the spinous processes90a,90band tightening of theplates620,630 and610 around the spinous processes90a,90b. The ends of theplates620,630 may be further attached to the spinous processes with any of the above mentioned methods including long bolts, staples, cabling, banding or suturing.
• Other embodiments are within the scope of the following claims. For example,vertebras92 and94 may be any two vertebras, including lumbar L1-L5, thoracic T1-T12, cervical C1-C7 or the sacrum. Thefixation assembly100 may extend along multiple vertebras. The K shaped structure may be also configured as a mirror image of the structure inFIG. 2, with the pivotingplates120,130 located on the left side and theelongated plate110 located on the right side of theFIG. 2. Theelongated plates110,220 and the top andbottom pivoting plates120,220, and130,230 of the embodiments ofFIG. 4 andFIG. 15, respectively, may have adjustable lengths. Similarly, S-plates310,320 of the embodiment ofFIG. 21 andplates410,420,430 of the embodiment ofFIG. 24 may have adjustable lengths. Similarly, elongatedplate610 anddeformable plates620,630 of the embodiment ofFIG. 31 may have adjustable lengths. Themain bodies122,132 of pivotingplates120,130 may be detached from the corresponding extendingarms124,134.Bodies122,132 may be attached to the extendingarms124,134 via hinges (not shown) which allow them to swing open and close for better placement around the corresponding spinous processes90a,90b.
• Several embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims (49)

1. An implantable assembly for stabilization of spinous processes, comprising:

a first S-shaped plate having a first surface configured to engage a first lateral surface of a first spinous process and a second surface configured to engage a second lateral surface of a second spinous process;

a second S-shaped plate having a first surface configured to engage a second lateral surface of said first spinous process and a second surface configured to engage a first lateral surface of said second spinous process;

wherein said first and second S-shaped plates are configured to pivot around an axis perpendicular to the center portions of said first and second S-shaped plates.

2. The assembly ofclaim 1 further comprising a post member configured to pass through concentrically aligned through-bore openings formed in said centers of said first and second S-shaped plates.

3. The assembly ofclaim 2 wherein said second S-shaped plate comprises top and bottom components configured to pivot around said axis independent of each other.

4. The assembly ofclaim 3 wherein said top and bottom components are configured to pivot around said post member and to set first and second pivot angles with said first S-shaped plate, respectively, thereby defining first and second spaces between said first S-shaped plate and said top and bottom components, respectively.

5. The assembly ofclaim 2 wherein said second S-shaped plate is configured to pivot around said post member and to set first and second pivot angles with said first S-shaped plate, respectively, thereby defining first and second spaces between said first S-shaped plate and said top and bottom portions, respectively.

6. The assembly ofclaim 2 wherein said post member comprises a locking element for securing and preventing pivoting of said first and second S-shaped plates.

7. The assembly ofclaim 6 wherein said post member comprises an elongated bolt and said locking element comprises threads formed at a portion of said bolt, dimensioned to engage inner threads in said first S-shaped plate through-bore.

8. The assembly ofclaim 6 wherein said post member comprises an elongated bolt and said locking element comprises threads formed at a portion of said bolt, dimensioned to engage a nut after the bolt exits said S-shaped plates through-bores.

9. The assembly ofclaim 1 wherein said first and second surfaces of said first and second S-shaped plates comprise protrusions configured to engage and frictionally lock said S-shaped plates onto said first and second spinous processes.

10. The assembly ofclaim 9 wherein said protrusions are selected from a group consisting of teeth, spikes, serrations, rough coatings and ridges.

11. The assembly ofclaim 1, wherein said center portions of said first and second S-shaped plates are dimensioned to fit between said first and second spinous processes and comprise edges sculpted to conform to the shape of said spinous processes.

12. The assembly ofclaim 3, wherein said first and second pivot angles comprise values between zero and 180 degrees.

13. The assembly ofclaim 1 wherein said first and second S-shaped plates are pivoted to a horizontal orientation for sidewise insertion of said assembly between said first and second spinous processes.

14. The assembly ofclaim 1 wherein said assembly is assembled prior to being implanted between said first and second spinous processes.

15. The assembly ofclaim 1 wherein said assembly is assembled after being implanted between said first and second spinous processes.

16. The assembly ofclaim 1 further comprising a top locking member configured to lock said first and second S-shaped plates' top ends.

17. The assembly ofclaim 16 wherein said top locking member comprises a long bolt configured to be threaded through bolt holes formed through said first S-shaped plate's top end, said first spinous process and said second S-shaped plate's top end.

18. The assembly ofclaim 16 wherein said top locking member is selected from a group consisting of staples, cables, sutures, pins and screws.

19. The assembly ofclaim 1 further comprising a bottom locking member configured to lock said first and second S-shaped plates' bottom ends.

20. The assembly ofclaim 19 wherein said bottom locking member comprises a long bolt configured to be threaded through bolt holes formed through said first S-shaped plate's bottom end, said second spinous process and said second S-shaped plate's bottom end.

21. The assembly ofclaim 19 wherein said bottom locking member is selected from a group consisting of staples, cables, sutures, pins and screws.

22. The assembly ofclaim 1 wherein said first and second S-shaped plates comprise material selected from a group consisting of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials and combinations thereof.

23. The assembly ofclaim 1 further comprising a center plate configured to pivot around said axis and being dimensioned to fit between said first and second spinous processes and comprising edges sculpted to conform to the shape of said spinous processes.

24. The assembly ofclaim 1 wherein said first and second S-plates comprise adjustable lengths.

25. A method for stabilizing spinous processes of a spinal column, comprising:

providing a first S-shaped plate and engaging a first surface of said first S-shaped plate with a first lateral surface of a first spinous process and a second surface of said first S-shaped plate with a second lateral surface of a second spinous process;

providing a second S-shaped plate and engaging a first surface of said second S-shaped plate with a second lateral surface of said first spinous process and a second surface of said second S-shaped plate with a first lateral surface of said second spinous process; and

wherein said first and second S-shaped plates are configured to pivot around an axis perpendicular to the center portions of said first and second S-shaped plates.

26. The method ofclaim 25 further comprising securing and preventing pivoting of first and second S-shaped plates after said engaging of said first and second S-shaped plates' surfaces to said lateral surfaces of said first and second spinous processes, respectively.

27. The method ofclaim 25 wherein said engaging comprises engaging protrusions formed in said first and second surfaces of said first and second S-shaped plates, to said lateral surfaces of said first and second spinous processes, respectively.

28. The method ofclaim 27 wherein said protrusions are selected from a group consisting of teeth, spikes, serrations, rough coatings and ridges.

29. The method ofclaim 25 further comprising providing a post member configured to pass through concentrically aligned through-bore openings formed in said centers of said first and second S-shaped plates.

30. The method ofclaim 29 wherein said second S-shaped plate comprises top and bottom components configured to pivot around said axis independent of each other.

31. The method ofclaim 30 wherein said top and bottom components are configured to pivot around said post member and to set first and second pivot angles with said first S-shaped plate, respectively, thereby defining first and second spaces between said first S-shaped plate and said top and bottom components, respectively.

32. The method ofclaim 29 wherein said second S-shaped plate is configured to pivot around said post member and to set first and second pivot angles with said first S-shaped plate, respectively, thereby defining first and second spaces between said first S-shaped plate and said top and bottom portions, respectively.

33. The method ofclaim 29 wherein said post member comprises a locking element for securing and preventing pivoting of said first and second S-shaped plate.

34. The method ofclaim 33 wherein said post member comprises an elongated bolt and said locking element comprises threads formed at a portion of said bolt, dimensioned to engage inner threads in said first S-shaped plate through-bore.

35. The method ofclaim 33 wherein said post member comprises an elongated bolt and said locking element comprises threads formed at a portion of said bolt, dimensioned to engage a nut after the bolt exits said S-shaped plates through-bores.

36. The method ofclaim 25, wherein said center portions of said first and second S-shaped plates are dimensioned to fit between said first and second spinous processes and comprise edges sculpted to conform to the shape of said spinous processes.

37. The method ofclaim 31, wherein said first and second pivot angles comprise values between zero and 180 degrees.

38. The method ofclaim 25 wherein said first and second S-shaped plates are pivoted to a horizontal orientation for sidewise insertion of said method between said first and second spinous processes.

39. The method ofclaim 25 wherein said first and second S-shaped plates are assembled prior to being implanted between said first and second spinous processes.

40. The method ofclaim 25 wherein said first and second S-shaped plates are assembled after being implanted between said first and second spinous processes.

41. The method ofclaim 25 further comprising providing a top locking member configured to lock said first and second S-shaped plates' top ends.

42. The method ofclaim 41 wherein said top locking member comprises a long bolt configured to be threaded through bolt holes formed through said first S-shaped plate's top end, said first spinous process and said second S-shaped plate's top end.

43. The method ofclaim 41 wherein said top locking member is selected from a group consisting of staples, cables, sutures, pins and screws.

44. The method ofclaim 25 further comprising providing a bottom locking member configured to lock said first and second S-shaped plates' bottom ends.

45. The method ofclaim 44 wherein said bottom locking member comprises a long bolt configured to be threaded through bolt holes formed through said first S-shaped plate's bottom end, said second spinous process and said second S-shaped plate's bottom end.

46. The method ofclaim 46 wherein said bottom locking member is selected from a group consisting of staples, cables, sutures, pins and screws.

47. The method ofclaim 25 wherein said first and second S-shaped plates comprise material selected from a group consisting of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials and combinations thereof.

48. The method ofclaim 25 further comprising providing a center plate configured to pivot around said axis and being dimensioned to fit between said first and second spinous processes and comprising edges sculpted to conform to the shape of said spinous processes.

49. The method ofclaim 25 wherein said first and second S-plates comprise adjustable lengths.

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