Percutaneous registration apparatus and method for use in computer-assisted surgical navigation

Abstract

An apparatus and procedures for percutaneous placement of surgical implants and instruments such as, for example, screws, rods, wires and plates into various body parts using image guided surgery. The invention includes an apparatus for use with a surgical navigation system, an attaching device rigidly connected to a body part, such as the spinous process of a vertebrae, with an identification superstructure rigidly but removably connected to the attaching device. This identification superstructure, for example, is a reference arc and fiducial array which accomplishes the function of identifying the location of the superstructure, and, therefore, the body part to which it is fixed, during imaging by CAT scan or MRI, and later during medical procedures.

What is claimed is: 
     
       1. An apparatus for facilitating percutaneous placement of surgical instruments into the spine, adapted for use with a surgical navigation system employing an energy-detecting array in communication with a surgical navigation computer to track positions of instruments in three dimensional space relative to a known reference point, said apparatus comprising:
 a connector adapted to be rigidly attached to a portion of the spine;   at least one central post connected to said connector;   a position identification structure rigidly and removably connected to said central post at a predetermined position on said central post and adapted to be reconnected at the same said predetermined position, said identification structure being further adapted to allow a patient to be scanned with the structure connected to the central post, said structure including an assembly for communicating positioning information with respect to said assembly to the energy detecting array and surgical navigation computer; and   a connector assembly for said reconnecting of said structure substantially to said predetermined position on said central post.   
     
     
       2. The apparatus of  claim 1 , wherein the connector is a clamp having teeth adapted for biting into a spinous process. 
     
     
       3. The apparatus of  claim 1 , wherein the connector includes an elongated fixture with a central axis and a threaded end adapted to be inserted into the spinous process and a substantially rigid wire connected to the fixture with the central axis of the wire adapted to be implanted into the spinous process at an angle to elongated fixture to prevent the fixture from rotating. 
     
     
       4. The apparatus of  claim 1 , wherein said assembly for communication positioning information is a substantially H-shaped frame. 
     
     
       5. The apparatus of  claim 1 , wherein said assembly for communicating positioning information is a substantially W-shaped frame. 
     
     
       6. The apparatus of  claim 1 , wherein said assembly for communicating positioning information is a substantially U-shaped frame. 
     
     
       7. The apparatus of  claim 1 , wherein said assembly for communicating positioning information is a substantially X-shaped frame. 
     
     
       8. The apparatus of  claim 1 , wherein said assembly for communicating positioning information comprises:
 a fiducial array for registering the location of a spinal element with rigidly connected fiducials; and   a reference arc for signaling the position of a spinal element, said arc further comprising rigidly connected emitters.   
     
     
       9. The apparatus of  claim 1 , wherein said reference point is on the spine. 
     
     
       10. A method for monitoring the location of an instrument, surgical implant and various portions of the body, to be operated on, using a surgical navigation system with a surgical navigation computer and a digitizer array for monitoring the location of instruments in three-dimensional space relative to a known reference point, said method comprising the steps of:
 attaching a fixture having a central post to a portion of the spine;   removably attaching an identification structure including a fiducial array and a reference arc to said central post;   providing a scanned three-dimensional image of a patient including said fiducial array rigidly attached to said central post of said fixture, said fixture being rigidly attached to the patient to identify the position of said fixture and said fiducial array on the scanned image;   using an image-guided system, by touching an image guided surgical pointer to one or more fiducials on the fiducial array to register the location of a spinal element fixed to said array; and   emitting a signal from said reference arc to indicate changes in position of the spinal element during a surgical procedure.   
     
     
       11. The method of  claim 10 , further comprising:
 performing a surgical procedure percutaneously on a patient using an instrument and implant locatable relative to the spinal element and said structure in known positions identified in the surgical navigation system.   
     
     
       12. The method of  claim 10 , further comprising:
 inserting a threaded fixture having a substantially rigid wire into a spinal element; and   touching an image guided pointer to said threaded fixture and wire to positively register the location of said fixture and wire in a surgical navigation computer.   
     
     
       13. The method of  claim 10 , further comprising:
 implanting imageable devices into spinal elements to identify the location of the spinal elements in the surgical navigation computer.   
     
     
       14. The method of  claim 10 , further comprising:
 implanting imageable devices into a plurality of spinal elements; and   manipulating the patient's spine by viewing the location of the implanted devices, as communicated to the surgical navigation computer by touching an instrument with a tracking emitter to said implanted imageable devices to align the actual position of the spinal elements with the previously scanned image.   
     
     
       15. The method of  claim 10  further comprising:
 percutaneously implanting screws into spinal elements; and 
 locating the position of said screws using image guided surgical navigation techniques.  
 
     
     
       16. The method of  claim 15  further comprising:
 manipulating the orientation of the screw heads percutaneously using a head-positioning probe for communicating location containing an emitter, said probe communicating to the surgical navigation computer the orientation of the screw heads; and 
 using a head positioning tool for manipulating implants having an end portion that mates with the heads of the screws and rotating the screws to receive a connecting implant. 
 
     
     
       17. The method of  claim 16  further comprising:
 tracking the location and position of the connecting implant by means of an instrument affixed to the implant having emitters capable of communicating orientation and location to the surgical navigation computer. 
 
     
     
       18. A system for use in performing the percutaneous placement of surgical implants and instruments into the spine using image guided surgery and a surgical navigation computer and energy detecting array, said system comprising:
 means for attaching a fixture to a portion of the spine;   means for communicating position information to the surgical navigation computer and energy detecting array said means rigidly and removably connected to said means for attaching a fixture;   means for providing location information of said spinal portion to the surgical navigation system adapted to be connected to spinal elements;   means for indicating screw-head position said means electrically connected to the surgical navigation system and adapted to mate with the head of a screw implanted in one or more of said spinal elements.   
     
     
       19. The system of  claim 18  further comprising:
 an elongated implant adapted to be inserted into said implanted screws; 
 means for indicating the position of said elongated implant electrically connected to the surgical navigation system and adapted to mate with the elongated implant. 
 
     
     
       20. The system of  claim 18 , wherein said implanted screws have heads and the elongated implant is a rod adapted to be guided through holes in said implanted screw heads.  
     
     
       21. A method of registering a physical space defined relative to a subject to an image space of the subject, comprising:
 connecting an attaching device to the subject;   connecting at least one of a fiducial portion or a reference portion to the connected attaching device with a connector in a geometric orientation and location;   acquiring image data of the subject and the connected at least one fiducial portion or reference portion that is connected to the subject in the geometric orientation and location;   removing the connected at least one fiducial portion or reference portion from the connected at least one clamp or screw after acquiring the image data; and   registering the physical space of the subject to the image space of the acquired image data, including:
 reattaching at least one of the fiducial portion or the reference portion to the connected attaching device in the geometric orientation and location as during the acquiring the image data, and 
 determining a location of a registration portion of the connected at least one fiducial portion or reference portion. 
   
     
     
       22. The method of claim 21, further comprising:
 attaching the reference portion to the connected attaching device after acquiring the image data of the subject.   
     
     
       23. The method of claim 21, wherein determining the location of the registration portion of the fiducial portion includes determining a location of at least one divot on the fiducial portion. 
     
     
       24. The method of claim 23, further comprising:
 folding the fiducial portion to reduce a volume encompassed by the fiducial portion.   
     
     
       25. The method of claim 23, further comprising:
 removing the fiducial portion subsequent to the registering the subject space to the image space and maintaining registration of the subject space to the image space with the attached reference portion.   
     
     
       26. The method of claim 23, wherein determining a location of at least one divot on the fiducial portion includes tracking an instrument to touch the at least one divot. 
     
     
       27. The method of claim 21, wherein connecting the attaching device to the subject includes fixing a clamp to the subject by moving a first arm and a second arm towards one another to compress a structure of the subject between the first arm and the second arm to hold the clamp relative to the structure. 
     
     
       28. A method of registering a physical space defined relative to a subject to an image space of the subject, comprising:
 connecting a device to the subject;   connecting at least a portion of a super-structure to the connected device with a connector;   acquiring image data of the subject and the connected at least a portion of the super-structure connected to the device that is connected to the subject;   removing the connected at least a portion of the super-structure from the connected device after acquiring the image data; and   registering the physical space of the subject to the image space of the acquired image data, including:
 re-connecting the at least the portion of the super-structure to the connected device in a same geometric orientation and location as during the acquiring the image data, and 
 determining a location of a registration portion of the re-connected at least a portion of the super-structure. 
   
     
     
       29. The method of claim 28, wherein connecting the device to the subject includes fixing at least one of a clamp or a screw to a structure of the subject. 
     
     
       30. The method of claim 28, wherein connecting at least the portion of the super-structure to the connected device includes connecting at least one of a fiducial portion or a reference arc to the fixed device with a connector to the device. 
     
     
       31. The method of claim 28, wherein connecting the device to the subject includes fixing the device to a structure of the subject. 
     
     
       32. The method of claim 31, wherein connecting at least the portion of the super-structure to the device includes connecting a reference portion to the connected device after acquiring the image data of the subject. 
     
     
       33. The method of claim 28, wherein determining the location of the registration portion of the re-connected at least a portion of the super-structure includes determining a location of a plurality of divots on the at least a portion of the super-structure. 
     
     
       34. The method of claim 33, wherein re-connecting the at least the portion of the super-structure includes re-connecting at least a fiducial portion that defines the plurality of divots. 
     
     
       35. The method of claim 34, further comprising:
 folding the fiducial portion to reduce a volume encompassed by the fiducial portion.   
     
     
       36. The method of claim 34, further comprising:
 removing the fiducial portion subsequent to the registering the physical space to the image space and maintaining registration of the physical space to the image space via the re-connected at least a portion of the super-structure.   
     
     
       37. The method of claim 36, wherein re-connecting the at least the portion of the super-structure includes connecting at least a reference portion;
 wherein maintaining registration of the physical space to the image space includes tracking the connected reference portion.   
     
     
       38. The method of claim 28, wherein connecting the device to the subject includes connecting a clamp to a structure of the subject by at least moving a first arm towards a second arm to compress the structure between the first arm and the second arm to hold the clamp relative to the structure. 
     
     
       39. A system for registering a physical space defined relative to a subject to an image space of the subject, comprising:
 a device operable to be connected to the subject; and   at least one of a reference portion operable to be detachably connected to the device or a fiducial portion operable to be detachably connected to the device;   wherein the reference portion is operable to determine a location of the subject and the fiducial portion is operable to be registered relative to an image of the subject.   
     
     
       40. The system of claim 39, further comprising:
 a member extending and detachable from the device.   
     
     
       41. The system of claim 40, wherein the device includes a screw operable to be driven into the subject;
 wherein the member is detachable from the screw.   
     
     
       42. The system of claim 40, wherein the device includes a clamp operable to compress a structure of the subject between a first arm and a second arm;
 wherein the member is detachable from the clamp.   
     
     
       43. The apparatus of claim 40, further comprising:
 a connector to interconnect the at least one of the reference portion or the fiducial portion to the member;   wherein the member extends from a first end to a second end, wherein one of the first end or the second end of the member is operable to be connected to the device;   wherein the connector is connected near the second end;   wherein the connector is operable to interconnect the reference portion and the member.   
     
     
       44. The apparatus of claim 43, wherein the connector includes a shaped interface such that the reference portion and the member can be separated and placed back in the same geometric orientation and location. 
     
     
       45. The apparatus of claim 39, wherein the fiducial portion includes a plurality of divots operable to be registered to increase accuracy when compared to a single registration divot.