Abstract:
Insertion instruments and a main body assembly and a universal wing to be inserted are provided, along with methods of using these instruments for the insertion of the spinal implants in patients to relieve the symptoms of, for example, spinal stenosis, injuries, and degenerative diseases of the spine. The instruments are simply designed and can be disassembled, making cleaning and sterilization easy and convenient. The instruments are designed to engage with and disengage from spinal implants easily, and use of the instrument in spinal implant surgery can be carried out with minimal surgical intervention and does not require general anesthesia. The main body assembly and the universal wing are designed to conveniently be secured to the insertion instruments.

Description:
RELATED CASES 
     This application claims priority to U.S. Provisional Application No. 60/220,022, filed on Jul. 21, 2000, entitled SPINAL IMPLANTS, INSERTION INSTRUMENTS, AND METHODS OF USE, and is a continuation-in-part of U.S. patent application Ser. No. 09/473,173, filed on Dec. 28, 1999 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,235,030, which is a continuation of U.S. patent application Ser. No. 09/179,570, filed on Oct. 27, 1998 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,048,342 which is a continuation-in-part of U.S. patent application Ser. No. 09/474,037, filed on Dec. 28, 1999 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,190,387, which is a division of U.S. patent application Ser. No. 09/175,645, filed on Oct. 20, 1998 and entitled SPINE DISTRACTION IMPLANT, now U.S. Pat. No. 6,068,630, which is a continuation-in-part of U.S. patent application Ser. No. 09/200,266, filed on Nov. 25, 1998 and entitled SPINE DISTRACTION IMPLANT AND METHOD, now U.S. Pat. No. 6,183,471, which is a continuation of U.S. patent application Ser. No. 09/139,333, filed on Aug. 25, 1998 and entitled SPINE DISTRACTION IMPLANT AND METHOD, now U.S. Pat. No. 5,876,404, which is a continuation of U.S. patent application Ser. No. 08/958,281, filed on Oct. 27, 1997 and entitled SPINE DISTRACTION IMPLANT AND METHOD, now U.S. Pat. No. 5,860,977, which is a continuation-in-part of U.S. patent application Ser. No. 09/361,510, filed on Jul. 27, 1999, now U.S. Pat. No. 6,379,335, which is a continuation of U.S. patent application Ser. No. 09/124,203, filed on Jul. 28, 1998, now U.S. Pat. No. 6,090,112, which is a continuation of U.S. patent application Ser. No. 08/778,093, filed on Jan. 2, 1997, now U.S. Pat. No. 5,836,948. All of the above applications and patents are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to instruments used for the insertion of spinal implants during spinal surgery and to the spinal implants. 
     2. Background of the Invention 
     As the present society ages, it is anticipated that there will be an increase in adverse spinal conditions which are characteristic of older people. By way of example, with aging comes increases in spinal stenosis (including but not limited to central canal and lateral stenosis), the thickening of the bones which make up the spinal column and facet arthropathy. Spinal stenosis is characterized by a reduction in the available space for the passage of blood vessels and nerves. Pain associated with such stenosis can be relieved by medication and/or surgery. Of course, it is desirable to eliminate the need for major surgery for all individuals and in particular for the elderly. 
     Accordingly, there needs to be developed procedures and implants for alleviating such and other spine related conditions, which are minimally invasive, which can be tolerated by the elderly and for that matter any individual, and which can be performed preferably on an outpatient basis. 
     SUMMARY OF THE INVENTION 
     In general aspects, this invention is directed toward apparatus and methods for relieving pain associated with the spine. Inventive spinal implants can be inserted using inventive instruments between spinous processes using inventive methods to keep adjacent vertebrae at a desired separation. 
     In one series of embodiments of the invention, an implant can have a main body assembly which comprises a tissue expander, a spacer, and a main body that includes a wing. Using an embodiment of an instrument of the invention, the spacer is placed between dorsal spinous processes of adjacent vertebrae. The main body assembly has a main body wing which can be positioned on one side of adjacent dorsal spinous processes. A second, universal wing of the invention can be attached to the main body assembly and can be positioned on the other side of the adjacent dorsal spinous processes using another instrument of this invention. Upon insertion, the spacer separates the adjacent spinous processes, thereby reducing the symptoms of spinal stenosis and/or other symptoms associated with the spine. In other embodiments of the inventive spinal implant, the spacer between the wings is rotatable and can provide for placement of the implant between spinous processes. 
     This invention includes instruments and methods for the insertion of inventive spinal implants into the spine of a surgical patient. An insertion instrument generally has a handle for grasping and another portion which engages a portion of a spinal implant. An implant can be engaged by the insertion instrument and then can be positioned relative to adjacent vertebrae of a patient. Instruments can be desirably made of biologically inert materials, such as stainless steel, and can be designed simply, so that the component parts of the instruments can be separated easily from one another for cleaning and sterilization between uses. 
     In certain embodiments of the instruments of this invention, spring-actuated locking mechanisms and one or more alignment pins can unite with alignment points of the inventive implant and can hold portions of the implant. When alignment pins are present, it can be desirable to orient the longitudinal axis of the pins across the axis of the locking mechanism. When engaged by the locking mechanism and alignment pins, the implants can be held firmly in relationship to the insertion instrument, making positioning of the implant easy and convenient. When the implant is positioned and secured in place, the locking mechanism can be easily disengaged from the implant, leaving the implant in place in the spine. 
     In other embodiments of this invention, an insertion instrument can have a driver for engaging a fastener of a universal wing with a main body assembly, via a threaded fastener or other suitable means. When provided together, insertion instruments and implant devices can improve the efficiency of spinal surgery to relieve pain associated with spinal stenosis and other degenerative and traumatic injuries to the spine. 
     Insertion of spinal implants can be generally accomplished using three instruments of this invention, one to determine the correct size of an implant to be used and to distract the spinous processes, one to insert a main body assembly, and another to install a universal wing. After a surgical field is prepared, an incision or access port is made in the back of the patient. The intraspinous space is accessed, and specially designed trial implant instruments can be used to determine the correct size of a spinal implant to be inserted and to distract the spinous processes. Generally, the smallest trial implant is inserted between the spinous processes. If the smallest trial implant is too loose in the interspinous space, the next largest size is tried. The process continues until the correct size of implant is determined. This process can also be used, as desired, to distract apart the adjacent spinous process to a desired separation. Once the correct size of the implant is selected, a main body insertion instrument can be used to hold a main body assembly and a main body wing in position relative to the spinous processes of adjacent vertebrae. The main body assembly is urged into the intraspinous space, preferably near the vertebral body. Another instrument of this invention can be used to attach a universal wing to the main body assembly. The two wings assist in maintaining the spacer in place between the spinous processes. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention will be described with respect to particular embodiments thereof. Other objects, features, and advantages of the invention will become apparent with reference to the specification, claims and drawings in which: 
         FIG. 1  depicts an exterior view of a main body insertion instrument of one embodiment of this invention for inserting an implant body into the spine of a patient. 
         FIG. 2  depicts a schematic, sectional, longitudinal view of a main body insertion instrument as depicted in FIG.  1 . 
         FIGS. 3   a - 3   c  depict schematic views of an insertion tip of the main body insertion instrument of one embodiment of this invention as shown in  FIGS. 1 and 2 . More particularly,  FIGS. 3   a - 3   c  depict the following. 
         FIG. 3   a  depicts a side view of the insertion tip of a main body insertion instrument of one embodiment of this invention with a locking pin and spacer engagement pin spacer in the extended position. 
         FIG. 3   b  depicts the insertion tip as shown in  FIG. 3   a  with a locking pin and spacer engagement pin spacer in a retracted position. 
         FIG. 3   c  depicts a top view of the insertion tip of the main body insertion instrument of one embodiment of this invention with the locking pin and engagement pin spacer in a retracted position. 
         FIG. 4   a  depicts an embodiment of a main body assembly of a spinal implant of the invention used with a main body insertion instrument of this invention. 
         FIG. 4   b  depicts an embodiment of a main body insertion instrument of this invention and an embodiment of a main body assembly of the invention as shown in  FIG. 4   a , showing the points of engagement between the assembly and the instrument. 
         FIG. 4   c  depicts an embodiment of a main body assembly of the invention and an embodiment of a main body insertion instrument of the invention, both depicted in  FIG. 4   b , engaged with one another. 
         FIG. 5  depicts an exterior view of an embodiment of a wing insertion instrument of the invention. 
         FIG. 6  depicts a schematic, sectioned, longitudinal view of the embodiment of a wing insertion instrument of the invention as shown in FIG.  6 . 
         FIG. 7   a  depicts an end view of an embodiment of an insertion tip of a wing insertion instrument of the invention are depicted in  FIGS. 5 and 6 . 
         FIG. 7   b  depicts a top view of an embodiment of an insertion tip of a wing insertion instrument of the invention as depicted in  FIG. 7   a  with a driver in a distal position. 
         FIG. 7   c  depicts a top view of the embodiment of the insertion tip of a wing insertion instrument of the invention as depicted in  FIGS. 7   a  and  7   b  with the driver in a proximal position. 
         FIG. 8   a  depicts a side view of an embodiment of a universal wing of the invention which is implantable with a wing insertion instrument of the invention. 
         FIG. 8   b  depicts an end view of an embodiment of a universal wing of the invention are depicted in  FIG. 8   a  without an attachment bolt. 
         FIG. 8   c  depicts the embodiment of an embodiment of the universal wing of the invention as shown in  FIG. 8   b  with an attachment bolt. 
         FIGS. 9   a - 9   c  depict an embodiment of an insertion tip of a wing insertion instrument of the invention as shown in  FIGS. 6 and 7 , and an embodiment of a universal wing of the invention. More particularly,  FIGS. 9   a - 9   c  depict the following. 
         FIG. 9   a  is a side view showing the relationships of an embodiment a universal wing of the invention and an embodiment of a wing insertion instrument of the invention, showing the points of engagement. 
         FIG. 9   b  is a side view of the embodiment of the universal wing and the wing insertion instrument of the invention depicted in  FIG. 9   a  after engagement. 
         FIG. 9   c  is a top view of the embodiment of a universal wing and a wing insertion instrument of the invention as depicted in  FIG. 9   b.    
         FIGS. 10   a - 10   d  depict trial implantation and distraction instruments of the invention. 
         FIGS. 11   a  and  11   b  depict the insertion of a main body assembly of the invention into the spine of a patient. More particularly,  FIGS. 11   a  and  11   b  depict the following. 
         FIG. 11   a  depicts a lateral view of a spine, and an embodiment of a main body insertion instrument of the invention engaged with an embodiment of a main body assembly of the invention positioned between spinous processes of adjacent vertebrae of a patient. 
         FIG. 11   b  depicts a dorsal view of a spine of a patient depicting an embodiment of a main body assembly of the invention inserted between spinal processes of adjacent vertebrae. 
         FIG. 12  depicts a lateral view of a spine with an embodiment of a main body assembly of the invention inserted between spinous processes of adjacent vertebrae and a wing implant insertion instrument of the invention engaged with an embodiment of a universal wing of the invention, showing the points of attachment between the embodiment of the main body assembly and the universal wing of the invention. 
         FIG. 13  depicts a dorsal view of a spine with an embodiment of a main body assembly of the invention inserted between spinous processes of adjacent vertebrae, and showing the insertion of an embodiment of a universal wing of the invention and its attachment to the embodiment of main body assembly of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     This invention includes instruments and methods for inserting spinal implants in the vertebral columns of patients and to spinal implants themselves. In one embodiment, instruments are provided for inserting a main body assembly between spinous processes of adjacent vertebrae. These instruments, termed herein “main body insertion instruments” generally comprise an elongated body portion having a handle at one end, an insertion shaft and an insertion tip. The insertion tip engages with the main body assembly and holds the assembly in fixed relation to the instrument. The surgeon prepares the site for implantation, and uses the instrument to urge the assembly between spinous processes of adjacent vertebrae. 
     In other embodiments of this invention, different instruments can be used to insert universal wings on to the main body assembly of the spinal implant. These other instruments are termed herein “wing insertion instruments.” A wing insertion instrument generally comprises a handle, an insertion shaft and an insertion tip. The insertion tip of a wing insertion instrument engages with the universal wing and holds it fixed relative to the instrument. The surgeon then grasps the handle portion of the instrument and uses it to urge the wing implant portion into proximity with a main body assembly which has been inserted between spinous processes of the spine. 
     I. Main Body Insertion Instrument 
     Main body insertion instrument of this invention is illustrated, by way of example only, in  FIGS. 1-3 .  FIG. 1  depicts an exterior view of a main body insertion instrument  100  of this invention having a handle  10 , an insertion shaft  20  and an insertion tip  30 . Handle  10  can be made of any suitable material, such as by way of example only, Gray ULTEM™, a polyetherimide resin. Insertion shaft  20  can be made of any suitable, strong material, such as  304  stainless steel. Insertion shaft  20  has a central bore extending through its length. The proximal end of insertion shaft  20  is adapted to fit within the distal end of handle  10 , and can be held in place with a set screw, made of, by way of example only, 304 or 455 stainless steel. A main body insertion tip  30  is attached to the distal end of the insertion shaft. Insertion tip  30  can be made of, by way of example only, 17-4 stainless steel. A bore extends longitudinally through the insertion tip  30  and is contiguous with the bore through the insertion shaft  20 . An insertion rod  40 , having a distal end with a spacer engagement pin and a locking pin, extends through the length of the bore in insertion shaft  20 . Insertion rod  40  extends into the handle  10  of the main body insertion instrument  100 . On one side of handle  10 , insertion knob  110 , having a raised portion  112 , is for manipulation of a locking pin and spacer engagement pin in insertion tip  30 . The insertion knob  110  can be made of, by way of example only, 304 stainless steel. The stainless steel components of the instruments of this invention can desirably meet ASTM Standard F899-95: Standard Specifications for Stainless Steel Billet, Bar, and Wire for Surgical Instruments. 
       FIG. 2  depicts a longitudinal cross-sectional view of a main body insertion instrument  100  as depicted in  FIG. 1 , and shows details of this embodiment of the invention. Handle  10  has an insertion knob groove  105  on a lateral surface, within which insertion knob  110  is provided. Insertion knob  110  and groove  105  are sized so that insertion knob  110  can move in a proximal/distal path along the handle  10 . Insertion knob  10  has said raised portion  112  used for applying force to move insertion knob  10  proximally and distally along handle  10 . Insertion knob  110  is attached to rod  111 , which is located within cavity  121  of the cavity  121 . When placed within cavity  121 , the rod  111  engages spring  125 , which is located within an interior space  124  of handle  10 . Spring  125  is urged against insertion rod  40 . The spring  125  provides a force that urges rod  111  and also rod  40  toward the distal portion of the instrument  100 . Spring  125  is compressed by manual movement of insertion knob  110  in a proximal direction, acting via rod  111 . Because insertion rod  40  is engaged with rod  111 , insertion rod  40  is drawn proximally by proximal movement of insertion knob  110 . When manual force on insertion knob  110  is relaxed, as for example, after alignment of a main body implant in relation to insertion tip  30 , spring  125  urges rod  111 , insertion rod  40  and insertion knob  110  in a distal direction. As insertion rod  40  is urged distally, locking pin  155  and spacer engagement pin  157  are urged toward the distal end of insertion instrument  100  as well, where pins  155 ,  157  can engage the main body assembly of the spinal implant. 
       FIG. 2  depicts insertion shaft  20  having a proximal end that is adapted to fit within the distal portion of handle  10 . When so placed, set screw  130  engages with insertion shaft  20  to keep insertion shaft  20  engaged in handle  10 . Set screw  130  can be made of any convenient material, such as, by way of example only, stainless steel. It can be especially desirable for set screws  120  and  130  to be completely removable from handle  10 , to provide open access to the interior of handle  10  for cleaning and sterilization. 
     Insertion tip  30  is adapted to fit onto the distal end of insertion shaft  20 , by way of example only, with an interference fit.  FIG. 2  depicts such an interference fit engagement of insertion tip  30  with the distal end of insertion shaft  20 . However, other ways of attaching insertion tip  30  to insertion shaft  20  are contemplated and are considered to be part of this invention. 
       FIG. 2  depicts components of insertion tip  30 , which include a proximal portion  145 , which can act as a position stop for spacer engagement pin  157 . Spacer engagement pin  157  protrudes laterally from the portion of the insertion rod  40 , and is adapted to engage a spacer engagement hole of a main body assembly. When so engaged, spacer engagement pin  157  can position a spacer relative to the remainder of the main body wing and tissue expander, making insertion of the implant between spinous processes convenient. At the distal end of insertion rod  40 , locking pin  155  is positioned to engage a hole in the main body assembly. Thus, when so engaged, locking pin  155  and spacer engagement pin  157  can hold the main body, tissue expander and spacer in position relative to one another for convenient insertion. At the distal end of the insertion tip  30 , portion  147 , having a flat medial surface  165 , can support the main body. In some embodiments, one or more alignment pins  160  can be provided to engage with a main body to provide additional support during surgery. 
     In general, the construction of main body insertion instrument  100  desirably is sufficiently robust to provide firm support of the main body assembly during surgery. For example, in certain situations, it can be desirable for the surgeon to exert relatively large forces on the main body assembly to urge the tissue expander between spinous processes. Generally, the connective tissue, including ligaments, can be strong and tough, tending to resist stretching. However, during surgery using the spinal implants and insertion instruments of this invention, it maybe desirable to deflect, distract and/or stretch the ligaments to permit passage and proper location of spinal implants. In these situations, the instruments are strong and rigid. 
     It also can be desirable for the surfaces to be smooth and have relatively simple geometrical shape. Simple shape and relatively open construction can provide for easy access to the interior of the parts of the instrument, and can permit easy and convenient cleaning and sterilization. 
       FIGS. 3   a - 3   c  depict the insertion tip  30  of main body implant insertion instrument  100  in additional detail.  FIG. 3   a  depicts a side view of insertion tip  30  fitted into the distal end of insertion shaft  20 . Bore  150  of insertion shaft  20  is shown in dashed lines. Locking pin  155  of insertion rod  40  is shown in the distal-most extension, as urged by spring  125  of FIG.  2 . Portion  147  is shown having aligmnent pin  160  with an axis aligned substantially perpendicularly to the plane of portion  147 . Spacer engagement pin or catch  157  is shown above locking pin  155 . At its distal-most extension, locking pin  155  crosses the axis of alignment pin  160 . When alignment pin  160  and spacer engagement pin  157  have engaged their respective portions of a main body assembly, the assembly can be firmly held by the insertion tip  30 . 
       FIG. 3   b  depicts an insertion tip as shown in  FIG. 3   a  in which the insertion rod  40  has been moved to a proximal position. In the embodiment depicted in  FIG. 3   b , locking pin  155  and spacer engagement pin  157  have been retracted sufficiently to be proximal to surface  156  of insertion tip  30 . When so positioned, the main body assembly can be disengaged from insertion tip  30  and the instrument can be withdrawn from the patient&#39;s body, leaving the main body assembly in place. 
       FIG. 3   c  depicts a top view of insertion tip  30 . Insertion rod  40  is shown in the retracted position, with locking pin  155  and spacer engagement pin  157  being located proximally to surface  156  of insertion tip  30 . Two alignment pins  160  are shown. When engaged with a main body assembly, flat surfaces  156  and  165 , alignment pins  160 , and locking pin  155  and spacer engagement pin  157  of the instrument  100  can hold the main body assembly firmly to the insertion instrument. 
       FIGS. 4   a - 4   c  depict the method of engagement of a main body insertion instrument of the invention with a main body assembly of the invention. 
       FIG. 4   a  depicts a main body assembly  400  of the invention for use with the instrument  100  of this invention. Main body assembly  400  has a main body wing  401  having a cephalad wing member  402  and a caudal wing member  402   a . Cephalad wing member  402 , after insertion, is aligned toward the head of the subject along the right side of a dorsal spinous process. Member  402   a  is also positioned along the side of a spinous process. Main body wing  401  also can have one or more holes  403  adapted to receive alignment pins  160  of main body insertion instrument  100 . Main body wing  401  also has locking pin hole  404  adapted to receive locking pin  155  of main body insertion instrument  100 . Main body wing  401  is attached to spacer  405 , which has spacer engagement hole  406  adapted to receive spacer engagement pin  157  of insertion instrument  100 . On the other end of spacer  405 , tissue expander  407  is shown, having a threaded hole  408  adapted to receive a bolt of a universal wing implant (described below). Tissue expander  407  has a tapered left end to ease insertion of the main body assembly between spinous processes. 
       FIG. 4   b  depicts a lateral view showing the points of engagement between a main body assembly and main body insertion instrument. Insertion rod  40  of insertion instrument is shown in a retracted, or proximal position. Locking pin  155  and spacer engagement pin  157  are shown aligned proximally to plane  156  of insertion tip  30 . Spacer engagement pin  157  is adapted to engage with spacer engagement hole  406 , locking pin  155  is adapted to engage with locking pin hole  404 , and alignment pin  160  is adapted to engage with alignment hole  403 . 
       FIG. 4   c  depicts main body insertion instrument engaged with main body assembly. While insertion rod  40 , locking pin  155  and spacer engagement pin  157  are in the retracted position, a main body assembly has been positioned with alignment pin  160  received into alignment pin hole  403 . Thereafter, insertion rod  40  has been urged distally by the spring  125  of  FIG. 2 , thereby engaging locking pin  155  with locking pin hole  404  and spacer engagement pin  157  with spacer engagement hole  406 . The engagement of spacer engagement pin  157  with spacer  405  keeps spacer  405  from rotating about its axis, and thereby keeps the spacer  405  in position relative to the tissue expander  407  and to the main body implant insertion instrument  100 . 
     A wing insertion instrument of this invention is depicted in  FIGS. 5-7 .  FIG. 5  depicts an exterior, lateral view of a wing insertion instrument  500 , having a handle  10 , and insertion shaft  20 , an insertion tip  30  and a driver knob  50 . As with the main body insertion instrument  100  depicted in  FIGS. 1 and 2 , on a lateral surface, insertion knob  110 , having raised portion  112  is provided to actuate a locking mechanism at the distal end of the instrument. 
       FIG. 5  depicts a cross-sectional longitudinal view through the wing insertion instrument  500  of this invention. Handle  10  has an insertion knob groove  505  on a lateral surface, within which insertion knob  110  is provided. Insertion knob  110  and groove  505  are sized so that insertion knob  110  can move in a proximal/distal path along the handle  10 . Insertion knob  110  has a raised portion  112  used for applying force to move insertion knob  110  proximally and distally along handle  10 . Insertion knob  110  is attached to rod  511 , which is located within interior space  521  of the handle  10 . Rod  511  engages insertion-rod  541  by way of set screw  520  which is accessible through hole  515 . Hole  515  is desirably of sufficient size to permit complete removal of set screw  520  from the instrument, permitting insertion knob  110  to be removed from handle  10  and the instrument to be cleaned and sterilized. 
     Insertion shaft  540  has a proximal end that fits within the distal portion of the bore of handle  10 . Set screw  530  is inserted through hole  535 , and engages insertion shaft  540  with handle  10 . It is desirable for hole  535  to be of sufficient size for set screw  530  to be completely removed, permitting cleaning and sterilization of the component parts of instrument  500 . 
     Insertion rod  541  extends through the full length of the bore of instrument  500 , and has a proximal portion sized to accommodate spring  525 . When installed in handle  10 , insertion rod  541  compresses spring  525 . The distal end of spring  525  is held in place by handle end cap  501 , which, along with handle  10  can be made of, by way of example, Gray ULTEM™. Handle end cap  501  is engaged with handle  10  by means of threads. Thus, for disassembly, handle end cap  501  can be disengaged from handle  10 , and spring  525  and insertion rod  541  can be removed from the proximal end of handle  10 . When assembled, rod  511  and insertion knob  110  are urged by spring  525  in a distal direction. The distal motion is stopped when insertion knob  110  or rod  511  reach the distal wall of space  521 . Spring  525  is further compressed by manual movement of insertion knob  110  in a proximal direction, acting via insertion rod  511 . Because insertion rod  541  is engaged with rod  511 , insertion rod  541  is drawn proximally by proximal movement of insertion knob  110 . When manual force on insertion knob  110  is relaxed, as for example, after alignment of a universal wing in relation to insertion tip  30 , spring  525  urges insertion rod  541  and insertion knob  110  in a distal direction. As insertion rod  541  is urged distally, driver  555  is urged toward the distal end of insertion instrument  500  as well. 
     Driver knob  502  is provided at the proximal end of instrument  500 . Driver knob  502  can be made of, by way of example, Gray ULTEM™. Driver knob  502  has a bore into which the proximal most extension of insertion rod  541  is placed. Insertion rod  541  is held within driver knob  502  by means of set screw  504  within hole  503 . It can be desirable for hole  503  to be sufficiently large so that set screw  504  can be completely removed from driver knob  502  for cleaning and sterilization. Insertion rod  541  desirably is free to rotate about its longitudinal axis, so that when driver knob  504  is rotated, driver  555  is rotated. 
     In summary and referring to  FIGS. 2 and 6 , set screws  120 ,  130  of main body insertion instrument  100 , and set screws  520 ,  530 , and  504  of universal wing insertion instrument  500  can be removed using a hex screw driver, having a hexagonal driver head made of, by way of example,  455  stainless steel. Such removal can be used to disassemble the instruments  100  and  500  for cleaning. 
       FIGS. 7   a - 7   c  depict details of insertion tip  30  of wing insertion instrument  500  of this invention.  FIG. 7   a  is an end-view of the distal end of insertion tip  30 , showing driver  555 , alignment pins  560 , and surfaces  547  and  565 . An edge of universal wing  800  can abut surface  547  to provide support during the insertion of universal wing  800 . A surface of universal wing  800  can abut surface  565  to provide additional support of universal wing  800 . 
       FIG. 7   b  depicts a bottom view of insertion tip  30  of wing insertion instrument  500 . Insertion rod  541  is depicted in a distal position, within insertion shaft  540 . Driver  555  is shown extending into space  567  of insertion tip  30 .  FIG. 7   c  depicts a bottom view of the insertion tip  30  as shown in  FIG. 7   b  with the driver  555  and insertion rod  541  in a proximal position, with the distal-most end of driver  555  retracted from the space  567 . In this position, mounting ring  816  of  FIG. 8  (below) of a universal wing can be received in space  567 . 
       FIGS. 8   a - 8   c  depict a universal wing  800  of the invention for use with the wing insertion instrument  500  of the invention.  FIG. 8   a  is a lateral view of universal wing  800 , having caudad portion  801  and cephalad portion  802 . Alignment holes  806  are adapted to receive alignment pins  560  of wing insertion instrument  500 . Although two alignment holes  806  are depicted, additional or fewer alignment holes can be provided. Between caudad portion  801  and cephalad portion  802 , mounting ring  816  is provided having an oblong bore therethrough to receive shaft  814  of bolt  812 . Bolt  812  has a proximal end with a recess  813  adapted to receive driver  555  of instrument  500 . The distal end of bolt  812  is threaded to engage with hole  408  of a tissue expander  407  depicted in  FIGS. 4   a - 4   c . The oblong bore has partial threads that allow a bolt to be screwed through the bore with the smooth shaft of the bolt then trapped in the bore. 
       FIG. 8   b  is a side view of universal wing  800  without bolt  812 , depicting mounting ring  816  with oblong bore  817  therethrough. Alignment holes  806  are shown as dashed lines.  FIG. 8   c  depicts a similar view of universal with  800  with bolt  812  provided. Hex recess  813 , adapted to receive driver  555  of instrument  500  is shown. Hole  817  is oblong to provide a choice of positions of bolt  812  within bore  817 . By providing a choice of bolt positions, the surgeon can install universal wing with a desired spacing between universal wing  800  and main body wing  401 . 
       FIGS. 9   a - 9   c  depict the relationships between wing insertion instrument  500  of this invention and the universal wing  800  of the invention.  FIG. 9   a  depicts a lateral view of the insertion tip  30 , with driver  555  in space  567  and alignment pin  560 . Insertion rod  541  is shown within insertion shaft  540 . Also depicted is universal wing  800 , having bolt  812  with recess  813 , mounting ring  816 , alignment hole  806 , and caudad wing portion  801 . The axes of driver  555  and alignment pin  560 , which in this embodiment cross each other and can be substantially perpendicular if desired, are shown in relation to recess  813  and alignment hole  806 , respectively. 
       FIG. 9   b  depicts a lateral view of insertion tip  30  engaged with universal wing  800 . Driver  555  is received by recess  813  in bolt  812  and alignment pin  560  is received by alignment hole  806 . Bolt  812  is received within recess  567  of insertion tip  30 , and when insertion shaft  541  is rotated, bolt  812  can rotate. 
       FIG. 9   c  depicts a bottom view of insertion tip  30  and universal wing  800 , engaged as in  FIG. 9   b . Cephalad portion  802  and caudad portion  801  of the universal wing are shown engaged by alignment pins  560  received through alignment holes  806 . Edge  807  of wing  800  is shown abutted against surface  547  of insertion tip  30 . 
     Spinal implant surgery can be carried out by using specially designed instruments to determine the correct size of an implant to be used and to predistract the spinous process. The instruments incorporating trial implants comprise a handle, made of a convenient material, for example, Gray ULTEM™,  FIGS. 10   a - 10   d  depict four embodiments of trial implant instruments of the invention.  FIGS. 10   a - 10   d  depict instruments  1000 ,  1001 ,  1002 , and  1003  of this invention, each having handle  1006  and insertion shaft  1007 . The instruments differ in the size of the trail implant for each. Trial implant  1010  is the smallest, implant  1011 ,  1012 , and  1013  become progressively larger, corresponding to instruments  1000 ,  1001 ,  1002  and  1003 , respectively. These trial implants in the embodiment are cylindrical in shape with diameters of 6 mm, 8 mm, 10 mm, and 12 mm, respectively. The trial implants have a lead-in nose, guide, or tissue expander that is cone shaped. Other shapes such as elliptical shapes, oval shapes, and egg-shapes are within the scope of the invention. Further, the nose can be of other shapes such as pyramid shaped. In use, these trial implant instruments are used one after the other to size the implant location and to progressively distract the implant location in preparation for insertion of the implant, which is left in the patient. 
     IV. Methods of Insertion of Spinal Implants 
     To use the instruments of this invention to insert spinal implants of the invention, a patient is placed, desirably in a lateral decubitus position with maximum flexion of the lumbar spine. Lateral decubitus position permits easy orientation of the main body assembly during surgery. Generally, the implant can be inserted between the spinous processes from the bottom or right side of the spinous processes to the top or left side of the spinous processes. Such orientation permits easy visualization of the main body assembly when the universal wing is attached. The wings should be oriented properly, with cephalad portions  402  and  802  oriented in a cephalad direction, and caudad portions  402   a  and  801  oriented in a caudal direction. The field is prepared for sterile surgery, and local anesthesia of the area is provided. Once the entry point is determined, local anaesthetic is applied to the skin and the underlying musculature. 
     To insert a spinal implant in one affected vertebral area for a single level implant process, a midline incision about 1.5 inches long is made at the entry point, exposing the supraspinous ligament overlying the spinous processes at the symptomatic level. The fascia may be incised on either side of the spinous processes and supraspinous ligament. The paraspinous musculature can be elevated laterally from both sides of the midline. The supraspinous ligament is desirably preserved. The interspinous ligament may be separated to permit insertion of main body assembly  400 . 
     To insert spinal implants in adjacent portions of the spine for a double level implant process, a midline incision about 3 inches long is made at the entry point, exposing the supraspinous ligament overlying the spinous processes at the appropriate segments. The fascia is incised if necessary on either side of the spinous processes and supraspinous ligament. The paraspinous musculature can be elevated laterally from both sides of the midline. 
     The first implant  400  can be inserted at the inferior level, and the second implant  400  of the same or different size, can be inserted at the superior, adjacent level after the first implant has been completely secured. If the supraspinous ligament is compromised during the procedure, it can be desirable to suture the excision in the ligament closed after insertion of the spinal implant. 
     Before installing the spinal implant  400 , the intraspinous space is prepared using trial implants. Generally, the surgeon can first select the smallest trial implant, for example, trial implant  1000 . The trial implant  1000  is urged between the spinous processes of the patient, and if little resistance is encountered, the surgeon can select a larger sized trial implant, such as trial implant  1001 . If insufficient resistance is encountered, the surgeon can use progressively larger trial implants to distract the spinous process. When the correct trial implant is found, the spinal implant  400  is then chosen for insertion. Additionally, the surgeon may choose to use a trial implant instrument that is larger than the implant to be used in order to further distract the spinous process to make the insertion of the implant easier. 
     To insert the main body assembly, a surgeon or assistant engages such assembly with main body insertion instrument  100  of this invention. The leading edge of tissue expander  407  of the main body assembly is advanced through the interspinous ligament. If significant resistance is encountered during the insertion of the implant, the next smallest size main body assembly can be used. Once the correct sized implant has been selected, the main body implant is inserted as shown in  FIGS. 11   a  and  11   b.    
       FIG. 11   a  depicts a right lateral view of a portion of a spine of a patient. L4 and L5 refer to lumbar vertebrae 4 and 5, respectively. For purposes of illustration only, these lumbar segments are depicted. However, any spinal segments can be the sites of insertion of the implants by use of the instruments of this invention. L4-5D refers to the intravertebral disk. L4D and L5D refer to the dorsal spinous processes of L4 and L5, respectively. Main body insertion instrument  100  having insertion tip  30  attached to main body assembly  400  is shown in position. Cephalad portion  402  and caudad portion  402   a  of a main body wing are shown. It can be desirable to urge main body assembly  400  ventrally within intraspinous space  1005 . 
       FIG. 11   b  depicts a dorsal view of an inserted main body assembly  400 . Spacer  405  is shown between dorsal spinous processes L4D and L5D. Main body wing  401  is shown near the right lateral surfaces of spinous processes L4D and L5D. 
       FIG. 12  depicts a left lateral view of the L4-L5 area of a patient. The main body assembly  400  has been inserted, and the tissue expander  407  is shown, urged ventrally in intraspinous space  1005 . Main body wing portions  402  and  402   a  are shown in dashed lines, being located behind (i.e., the right of) the spinous process L4D and L5D, respectively. Threaded hole  408  in tissue expander  407  is shown, and axis (dashed lines) is shown to depict the insertion of threaded portion  815  of bolt  812  of universal wing  800 . Insertion tip  30  of wing insertion instrument  500  is shown, with a universal wing engaged  800 , as depicted in  FIGS. 9   b  and  9   c . The engaged wing is shown from the top view, in contrast to the view of  FIG. 9   c , which is from the bottom. While grasping main body insertion instrument  100 , the surgeon inserts the universal wing with wing insertion instrument  500 . When the universal wing is brought into the correct position relative to the main body assembly, bolt  812  can be inserted into hole  408  of the tissue expander  407 , and by rotation of the driver knob  50  of  FIG. 5  in a clockwise direction, driver  555  can rotate bolt  812  thereby engaging threads of the threaded end  815  with the threads of hole  408 . Alternatively, if the threaded portions  815  of bolt  812  and hole  408  have left-handed threads, then driver knob  50  should be rotated in a counter-clockwise direction to engage bolt  812  with threaded hole  408 . Before tightening bolt  812 , it can be desirable to urge universal wing  800  medially or closer to main body wing  401  to provide a desired degree of support of spinous processes L1D and L2D. Once in the proper position, bolt  812  can be tightened, and the insertion instrument  100  and  500  are removed, the incisions sutured and closed. 
       FIG. 13  depicts a dorsal view of the spine of a patient, depicting an installed main body assembly  400  with universal wing  800  attached thereto. Universal wing portion  802  is shown oriented in the cephalad direction, as is main body wing portion  402 . Caudad wing portions  801  and  402   a  are shown oriented in the caudal direction. Wing element  400 ,  402   a  are shown near the right lateral surface of the spinous process. Universal wing  800  is shown placed near the left lateral surfaces of the spinous process. Adjustment of the spacing between universal wing  800  and the spinous process is accomplished by urging the wing medially before tightening bolt  812  in oblong mounting ring  817 . 
     INDUSTRIAL APPLICABILITY 
     Accordingly, it is evident that the insertion instruments, implants and methods disclosed can be said to relieve pain associated with the spine. 
     The above descriptions are for illustrative purposes and are not intended to be limiting to the scope of the invention. It is contemplated that instruments having locking pins and alignment pins can have other configurations. Further, the implant can have other configurations. It is also contemplated that the additional methods of using the instruments with the implants described as well as with other implants are possible, and all such embodiments are considered to be within the scope of this invention.