Methods and apparatus for deploying spinous process constraints

Abstract

A surgical tool for deploying an implant includes an elongate outer shaft having a proximal end, a distal end and a central channel therebetween. An elongate inner shaft is at least partially slidably received in the central channel and an actuator mechanism is operatively coupled with either the outer or inner shaft. The tool also includes a piercing element that is coupled with the outer shaft and releasably coupled with the implant.

1 . A surgical tool for deploying an implant, said tool comprising:
 an elongate outer shaft having a proximal end, a distal end and a central channel therebetween;   an elongate inner shaft at least partially slidably received in the central channel;   an actuator mechanism operatively coupled with either the outer or inner shaft; and   a leader releasably coupled with the outer shaft, the leader coupled with the implant and adapted to pass through tissue.   
     
     
         2 . A tool as in  claim 1 , wherein the tissue comprises an interspinous ligament disposed between adjacent spinous processes. 
     
     
         3 . A tool as in  claim 1 , wherein the actuator mechanism comprises a rotatable knob. 
     
     
         4 . A tool as in  claim 1 , wherein the actuator mechanism comprises an indicator for indicating the position of the outer shaft relative to the inner shaft. 
     
     
         5 . A tool as in  claim 4 , wherein the indicator provides audible, tactile or visual feedback to an operator. 
     
     
         6 . A tool as in  claim 1 , wherein the outer shaft comprises an aperture disposed near the distal end thereof and the inner shaft comprises an aperture near a distal end thereof, the outer shaft aperture at least partially aligned with the inner shaft aperture so as to slidably receive the leader in both apertures. 
     
     
         7 . A tool as in  claim 1 , wherein the inner shaft comprises a key feature for receiving the leader only when the leader has a predetermined orientation relative to the inner shaft. 
     
     
         8 . A tool as in  claim 1 , further comprising a handle coupled with the outer shaft near the distal end thereof. 
     
     
         9 . A tool as in  claim 8 , wherein the handle comprises a T-shaped grip. 
     
     
         10 . A tool as in  claim 1 , wherein the leader comprises a piercing element. 
     
     
         11 . A tool as in  claim 1 , wherein the leader comprises a coupling mechanism for releasably holding the implant. 
     
     
         12 . A tool as in  claim 1 , wherein the leader comprises an arcuate tip. 
     
     
         13 . A tool as in  claim 1 , wherein the leader is releasably coupled with the implant. 
     
     
         14 . A tool as in  claim 1 , wherein the implant is severable from the leader. 
     
     
         15 . A tool as in  claim 11 , wherein the coupling mechanism comprises a closable loop. 
     
     
         16 . A tool as in  claim 15 , wherein the closable loop comprises a movable collar adapted to close the loop. 
     
     
         17 . A tool as in  claim 11 , wherein the coupling mechanism comprises a filament having loops on opposite ends thereof. 
     
     
         18 . A tool as in  claim 11 , wherein the coupling mechanism comprises a filament slidably threaded through the leader, the filament having first and second ends knotted together to form a closed loop. 
     
     
         19 . A tool as in  claim 11 , wherein the coupling mechanism comprises a radiopaque filament. 
     
     
         20 . A tool as in  claim 11 , wherein the coupling mechanism comprises an open end sized to receive a portion of the implant. 
     
     
         21 . A tool as in  claim 1 , wherein the leader has a sharp piercing tip and a flat shoulder adapted to distend an initial puncture created by the sharp piercing tip. 
     
     
         22 . A surgical system comprising:
 a spinous process constraint device having a tether structure and a compliance member, the tether structure adapted to be coupled to adjacent spinous processes or a spinous process and a sacrum, wherein the spinous process constraint device provides a force resistant to flexion of a spinal segment;   a leader coupled with the spinous process constraint device, the leader having a distal piercing tip adapted to pass through tissue without resulting in trauma to adjacent tissue, wherein the tissue is disposed either between the two adjacent spinous processes, or between the spinous process and the sacrum, or the tissue comprises the spinous process or the sacrum, and wherein the piercing tip is adapted to be distinguished from the tissue and the adjacent tissue by tactile sensation; and   a tool for deploying the spinous process constraint, the tool comprising an elongate outer shaft having a proximal end, a distal end, and a central channel therebetween, an elongate inner shaft at least partially slidably received in the central channel, and an actuator mechanism operatively coupled with either the outer or inner shaft, wherein the leader is releasably coupled with the outer shaft.   
     
     
         23 . The system of  claim 22 , wherein the distal piercing tip is further adapted to create an aperture in the tissue, the aperture sized to receive the tether structure. 
     
     
         24 . The system of  claim 22 , wherein the distal piercing tip is shaped to preferentially pierce the tissue in a single direction. 
     
     
         25 . The system of  claim 22 , wherein the distal piercing tip comprises a tapered shoulder region adapted to expand the channel as the piercing tip passes therethrough. 
     
     
         26 . The system of  claim 22 , wherein the distal piercing tip comprises an arcuate tip. 
     
     
         27 . The system of  claim 22 , wherein the leader comprises a woven textile tube having an open end and a rigid tip, wherein the open end is sized to receive a portion of the tether structure. 
     
     
         28 . The system of  claim 27 , wherein the rigid tip comprises a tapered shoulder region adapted to expand the channel as the piercing tip passes therethrough. 
     
     
         29 . The system of  claim 22 , wherein the leader is releasably coupled with the spinous process constraint device. 
     
     
         30 . The system of  claim 22 , wherein the leader is severable with the spinous process constraint device. 
     
     
         31 . The system of  claim 22 , wherein the leader comprises a coupling mechanism for releasably holding the spinous process constraint device. 
     
     
         32 . The system of  claim 31 , wherein the coupling mechanism comprises a closeable loop. 
     
     
         33 . The system of  claim 32 , wherein the closeable loop comprises a movable collar adapted to close the loop. 
     
     
         34 . The system of  claim 31 , wherein the coupling mechanism comprises a filament having loops on opposite ends thereof. 
     
     
         35 . The system of  claim 31 , wherein the coupling mechanism comprises a filament slidably threaded through the leader, the filament having first and second ends knotted together to form a closed loop. 
     
     
         36 . The system of  claim 31 , wherein the coupling mechanism comprises a radiopaque filament. 
     
     
         37 . The system of  claim 31 , wherein the spinous process constraint device comprises radiopaque markers for verifying the position of the device when placed in a patient. 
     
     
         38 . The system of  claim 22 , further comprising:
 a handle detachable from the leader; and   a keyway element disposed on the handle or the leader, the keyway element adapted to permit coupling of the leader with the handle in a single orientation.