Steerable spine implant insertion device and method

Abstract

A method to insert a spinal implant into a vertebral space, the method including the steps of: grasping the implant with a distal end of an implant insertion tool; holding a proximal end of the implant insertion tool and inserting the implant toward the vertebral space; and manipulating the proximal end to apply a yaw movement to the implant while the implant is attached to the tool and in the vertebral space.

What is claimed is: 
     
         1 . A method comprising:
 inserting an implant between portions of bone, wherein the implant locked at a first angle relative to a shaft of the instrument;   loosening the implant relative to the shaft;   turning the shaft to pivot the implant relative to the shaft;   sensing a predetermined angular position of the implant relative to the shaft as the shaft is turned, and releasing the implant from the instrument so that the implant is in position between the bone.   
     
     
         2 . The method of  claim 1  wherein the predetermined angular position is sensed as a ridge on the implant slides across a groove on a cam surface of the instrument. 
     
     
         3 . The method of  claim 1  wherein turning the shaft rotates gears fixed to the shaft across a geared surface on the implant. 
     
     
         4 . The method of  claim 3  wherein turning the geared shaft pivots the implant. 
     
     
         5 . The method of  claim 2  wherein a cam surface is slanted and the movement of the opposing cam across the cam surface pivots the implant. 
     
     
         6 . A spinal insertion tool comprising:
 an elongated shaft including a proximal end region and a distal end region, wherein the distal end region includes a coupling adapted to be reversibly connected to a spinal implant and the proximal end region is connected to a handle, and   an elongated sleeve including a proximal end region and a distal end region, wherein the sleeve is coaxial to and encircles the elongated shaft, and the distal end region of the sleeve includes legs configured to engage the spinal implant, and   a knob engaging threads on the proximal end region of the shaft, wherein the knob moves helically about the shaft towards the distal end region of the shaft so as to bind against the proximal end region of the sleeve and thereby advance the legs of the sleeve and moves helically about the shaft towards the handle so as to release the proximal end region of the sleeve and allow the sleeve to slide axially over the shaft.   
     
     
         7 . The spinal insertion tool of  claim 6  wherein the legs are adjacent the coupling on the shaft while advanced and the legs are retracted away from the coupling while the sleeve is axially moved towards the proximal end region. 
     
     
         8 . The spinal insertion tool of  claim 6  wherein the legs are on opposite sides of the shaft. 
     
     
         9 . The spinal insertion tool of  claim 6  wherein the coupling is a threaded end of the shaft. 
     
     
         10 . A method to surgically insert a spinal implant between vertebra in a mammalian patient using an insertion tool including a sleeve and shaft within the sleeve and coaxial to the sleeve, the method comprising:
 releasably attaching a pivotable coupling in the spinal implant to shaft coupling at a distal portion of the shaft;   advancing a distal end of the sleeve to engage the spinal implant while the distal portion of the shaft is attached to the pivotable coupling in the spinal implant;   inserting the spinal implant between the vertebra while the pivotable coupling in the spinal implant is attached to the shaft coupling and the distal portion of the sleeve engages the spinal implant;   positioning the spinal implant between the vertebra, including pivoting the spinal implant about the shaft coupling such that the spinal implant makes a yaw movement with respect to the pivotable coupling, and   after making the yaw movement, releasing the distal portion from the shaft from the spinal implant and removing the insertion tool from the patient while the spinal implant remains between the vertebra.   
     
     
         11 . The method as in  claim 10  wherein advancing the distal end of the sleeve to engage the spinal implant locks the implant at a first angle relative to the shaft. 
     
     
         12 . An assembly of a spinal implant and an insertion tool to insert the spinal implant between vertebras wherein
 the insertion tool comprising:
 a shaft assembly including a hollow tube concentric with a rod; 
 a distal portion of the rod including a coupling for releasably attaching to the spinal implant; 
 a distal portion of the hollow tube including legs adapted to engage the spinal implant, and 
 a proximal region of the shaft assembly including a knob engaging threads on the rod, wherein the knob moves helically to bind against the distal potion of the hollow tube and to retract to allow the tube to slide axially over the shaft, and 
   the spinal implant comprising:
 a pivoting pin within a housing on the implant, the pivoting pin adapted to couple to the coupling of the distal portion of the rod, and 
 a surface of the implant adjacent the pivoting pin configured to engage the legs of the hollow tube. 
   
     
     
         13 . The assembly in  claim 12  wherein the surface of the implant includes surfaces on opposite sides of the pivoting pin. 
     
     
         14 . The assembly in  claim 12  wherein the pivoting pin includes an aperture configured to receive the distal portion of the rod. 
     
     
         15 . The assembly in  claim 14  wherein the cam aperture includes threads configured to engage threads on the distal portion of the rod. 
     
     
         16 . The assembly as in  claim 12  where the spinal implant includes an upper surface and a lower surface each adapted to engage one of the vertebras.