Percutaneous access devices and bone anchor assemblies

Abstract

A percutaneous access device includes an inner tube and an outer tube disposed about at least a portion of the inner tube. The outer tube may be sized to span from a skin incision in a patient to a site proximate the spine of the patient. The distal end of the outer tube may be adapted to releasably engage a bone anchor. The inner tube may be adjustable relative to the outer tube between a first position and a second position in which the distal end of the inner tube contacts the bone anchor. A bone anchor assembly includes a bone anchor having a distal bone engaging portion and a receiving member having a recess for receiving a spinal fixation element. The proximal end of the receiving member may have an arcuate groove formed on an exterior surface thereof to facilitate connection of an instrument to the receiving member.

1 .- 46 . (canceled) 
     
     
         47 . A method for implanting a rod implant along a spine of a patient back, the method comprising:
 coupling an elongated guide tool to a head of a bone anchor,   wherein the elongated guide tool comprises an anchor coupling region comprising a first leg spaced apart from a second leg, the first leg comprising an attachment structure projecting radially inward,   wherein the head comprises:
 an outer surface facing radially outward relative to a longitudinal center axis of the head; and 
 a slot extending along at least a portion of the outer surface in a direction perpendicular to the longitudinal center axis of the head, and 
   wherein the coupling comprises causing the first and second legs to be splayed apart as the head is received between the first and second legs followed by the attachment structure being received in the slot; and   employing the elongated guide tool to deliver the rod implant into a channel of the head when an anchoring member of the bone anchor is anchored in a vertebra of the spine, the anchoring member extending distally from the head, the elongated guide tool extending proximally from the head and through a minimally invasive incision in the patient back.   
     
     
         48 . The method of  claim 47 , wherein the coupling further comprises driving the first and second legs distally relative to the head, the head passing proximally between the first and second legs along a longitudinal axis of the elongated guide tool. 
     
     
         49 . The method of  claim 47 , wherein the coupling further comprises proximally axially urging the elongated guide tool relative to the head. 
     
     
         50 . The method of  claim 49 , wherein the proximally axially urging facilitates the attachment structure being received in the slot in a manner that discourages splaying of the first and second legs. 
     
     
         51 . The method of  claim 47 , wherein the bone anchor comprises a bone screw. 
     
     
         52 . The method of  claim 51 , wherein the bone screw comprises a polyaxial bone screw. 
     
     
         53 . The method of  claim 47 , wherein the anchoring member is longitudinally cannulated. 
     
     
         54 . The method of  claim 47 , wherein the slot comprises a recessed overhanging configuration at a proximal boundary of the slot, and the attachment structure comprises a proximally pointing free extent that is received by the recessed overhanging configuration. 
     
     
         55 . The method of  claim 47 , further comprising delivering a threaded closure top into the channel via a route extending along a longitudinal axis of the elongated guide tool, and threading the threaded closure top into the channel to secure the rod implant within the channel. 
     
     
         56 . The method of  claim 55 , wherein the route extending along the longitudinal axis of the elongated guide tool extends along an interior of the elongated guide tool. 
     
     
         57 . The method of  claim 56 , wherein a closure installation tool extends along the route in threading the threaded closure top into the channel. 
     
     
         58 . The method of  claim 47 , further comprising rotating the elongated guide tool relative to the head to disconnect the elongated guide tool from the head once the rod implant is implanted. 
     
     
         59 . The method of  claim 47 , wherein the slot intersects the channel. 
     
     
         60 . The method of  claim 47 , wherein the rod implant minimally invasively enters the patient by causing a first end of the rod implant to lead the rod implant into the elongated guide tool. 
     
     
         61 . A method for implanting a rod implant along a spine of a patient back, the method comprising:
 coupling a tool to a head of a bone anchor,   wherein the tool comprises an anchor coupling region comprising an attachment structure projecting radially inward, wherein the head comprises:
 an outer surface facing radially outward relative to a longitudinal center axis of the head; 
 a slot extending along at least a portion of the outer surface in a direction perpendicular to the longitudinal center axis of the head; 
 a threaded inner surface facing radially inward towards the longitudinal center axis of the head; and 
 a channel extending distally along the longitudinal center axis of the head from a proximal end of the head, and wherein the coupling comprises causing the attachment structure to be received in the slot; 
   delivering the rod implant into the channel of the head when an anchoring member of the bone anchor is anchored in a vertebra of the spine, the anchoring member extending distally from the head; and   with the tool coupled to the head via the attachment structure being received in the slot, threading a threaded closure top into threaded engagement with the threaded inner surface.   
     
     
         62 . The method of  claim 61 , wherein the anchor coupling region further comprises a first leg spaced apart from a second leg, the attachment structure projecting radially inward from the first leg. 
     
     
         63 . The method of  claim 62 , wherein the coupling further comprises driving the first and second legs distally relative to the head, the head passing proximally between the first and second legs along a longitudinal axis of the tool. 
     
     
         64 . The method of  claim 61 , wherein the bone anchor comprises a bone screw. 
     
     
         65 . The method of  claim 64 , wherein the bone screw comprises a polyaxial bone screw. 
     
     
         66 . The method of  claim 61 , wherein the anchoring member is longitudinally cannulated. 
     
     
         67 . The method of  claim 61 , wherein the slot comprises a recessed overhanging configuration at a proximal boundary of the slot, and the attachment structure comprises a proximally pointing free extent that is received by the recessed overhanging configuration. 
     
     
         68 . The method of  claim 61 , further comprising delivering the threaded closure top into the channel via a route extending along a longitudinal axis of the tool, and the threading of the threaded closure top into threaded engagement with the threaded inner surface securing the rod implant within the channel. 
     
     
         69 . The method of  claim 68 , wherein the route extending along the longitudinal axis of the tool extends along an interior of the tool. 
     
     
         70 . The method of  claim 69 , wherein a closure installation tool extends along the route in threading the threaded closure top into the channel. 
     
     
         71 . The method of  claim 61 , wherein the slot intersects the channel. 
     
     
         72 . The method of  claim 61 , wherein delivering the rod implant into the channel of the head comprises employing the tool to deliver the rod implant into the channel with: the anchoring member of the bone anchor anchored in the vertebra of the spine, the anchoring member extending distally from the head; and the tool coupled to the head via the attachment structure being received in the slot, the tool extending proximally from the head and through a minimally invasive incision in the patient back. 
     
     
         73 . The method of  claim 72 , wherein the rod implant minimally invasively enters the patient by causing a first end of the rod implant to lead the rod implant into the tool. 
     
     
         74 . A surgical method for implanting a bone screw having a shank into a spine of a patient, the method comprising:
 a) making a limited surgical opening in soft tissues of a back of the patient over the spine and releasably attaching a bone screw head connected to the shank to a bottom of an elongated guide tool, the elongated guide tool comprising a channel extending upwardly from the bottom toward a top of the elongated guide tool opposite the bottom, the channel opening radially through a wall of the elongated guide tool at least at the bottom of the elongated guide tool via at least one opening in the wall, wherein the channel is configured to removably receive a shaft of a screw driving tool;   b) inserting the shaft of the screw driving tool into the channel of the elongated guide tool such that the shaft of the screw driving tool engages the shank of the bone screw so as to provide a bone screw insertion assembly;   c) anchoring the shank of the bone screw to bone of, the spine through the limited surgical opening in the soft tissues using the bone screw insertion assembly;   d) removing the shaft of the screw driving tool from the channel of the elongated guide tool; and   e) passing an implantable rod along at least one of the at least one opening of the elongated guide tool or the channel of the elongated guide tool and then into a rod receiving channel of the bone screw head.   
     
     
         75 . The surgical method of  claim 74 , further comprising displacing in a direction of the bottom of the elongated guide tool a closure top through the channel of the elongated guide tool and into the rod receiving channel to secure the implantable rod within the rod receiving channel of the bone screw head. 
     
     
         76 . The surgical method of  claim 75 , wherein the closure top is threaded into the rod receiving channel of the bone screw head to secure the implantable rod within the rod receiving channel of the bone screw head. 
     
     
         77 . The surgical method of  claim 74 , wherein step a) comprises distally displacing the bottom of the elongated guide tool over the bone screw head such that at least a portion of the bottom of the elongated guide tool is forced radially outward and then self-biases radially inward such that an engagement feature on the bottom of the elongated guide tool is received in a recess defined in an exterior surface of the bone screw head. 
     
     
         78 . The surgical method of  claim 77 , wherein the at least a portion of the bottom of the elongated guide tool comprises first and second spaced-apart legs, the engagement feature being supported on the first spaced-apart leg, the engagement feature pointing radially inward, the first and second spaced-apart legs being forced radially outward by the bottom of the elongated guide tool being displaced over the bone screw head. 
     
     
         79 . A spinal surgical method comprising:
 a) releasably attaching a head of a bone screw to a distal end of an elongated guide tool comprising:   i) a proximal end opposite the distal end;   ii) a wall extending between the proximal and distal ends; and   iii) an interior passage radially inward the wall and extending along the elongated guide tool, the interior passage terminating at the proximal and distal ends, and the interior passage opening through the wall at least at the distal end via at least one opening in the wall;   b) using a screw driving tool to anchor a shank of the bone screw into bone of a patient spine when:   i) the head is releasably attached to the distal end;   ii) at least a portion of the screw driving tool is located in the interior passage such that the screw driving tool engages the shank; and   iii) the elongated guide tool extends proximally from the head through a limited surgical opening in soft tissue posterior the patient spine, the proximal end being located exterior the patient sufficiently to be manipulated;   c) subsequent to step b), removing the screw driving tool from the interior passage; and   d) subsequent to step c), causing an implantable rod to pass along the interior passage and into a rod receiving channel of the head.   
     
     
         80 . The surgical method of  claim 79 , wherein step d) further comprises causing the implantable rod to pass along at least one of the at least one opening in the wall. 
     
     
         81 . The surgical method of  claim 79 , further comprising distally displacing a closure top through the interior passage and into the rod receiving channel of the head. 
     
     
         82 . The surgical method of  claim 81 , wherein the closure top is threaded into the rod receiving channel to secure the implantable rod within the rod receiving channel. 
     
     
         83 . The surgical method of  claim 79 , wherein step a) comprises distally displacing the distal end over the head such that at least a portion of the distal end is forced radially outward and then self-biases radially inward such that an engagement feature is received in a recess defined in an exterior surface of the head. 
     
     
         84 . The surgical method of  claim 83 , wherein the at least a portion of the distal end comprises first and second spaced-apart legs, the engagement feature being supported on the first spaced-apart leg, the engagement feature pointing radially inward, the first and second spaced-apart legs being forced radially outward by the distal end being displaced over the head.