Spinal Anchor Assemblies Having Extended Receivers

Abstract

There are provided systems ( 40 ) and methods for positioning a connecting member ( 100 ) adjacent the spinal column that include one or more anchor assemblies ( 45 ) having an anchor ( 120 ) engageable to bony structure and an extended receiver ( 50 ) having a guide portion ( 54 ) and an implantation portion ( 52 ). A connecting member ( 100 ) is movable along the guide portion ( 54 ) from a location outside the patient to the implantation portion ( 52 ) in the patient, where the connecting member ( 100 ) is secured to the anchor assembly ( 45 ) with an engaging member ( 90 ). The guide portion ( 54 ) is formed as a single unit with but separable from the implantation portion ( 52 ) to provide a modified low-profile anchor assembly ( 45 ) after implantation of the connecting member ( 100 ).

1 . A spinal surgical system, comprising:
 a connecting member including an elongated body having a length sized to extend between at least two vertebrae; and   an anchor assembly including a distal anchor engageable to bony structure and an extended receiver extending proximally from and pivotally coupled to said anchor, said extended receiver including a distal implantation portion adjacent said anchor sized and shaped to receive said connecting member therein, said extended receiver further including a proximal guide portion including a pair of removable arms extending along a central axis, said arms extending proximally from and formed as a single unit with a respective one of a pair of opposite side members of said implantation portion, said arms defining a channel extending therebetween from said implantation portion through proximal ends of said pair of arms, said channel including a thread profile along only a distal portion of said arms, and said channel being sized and shaped to receive said connecting member through said proximal end opening thereof in a transverse orientation to said central axis.   
     
     
         2 . The system of  claim 1 , wherein each of said arms is joined to said respective side member with a break-off region having a wall thickness reduced comparatively to an adjacent wall thickness of said respective arm and said respective side member. 
     
     
         3 . The system of  claim 1 , wherein each of said side members defines an internal thread profile along said implantation portion and each of said arms defines an internal thread profile adjacent a distal end thereof that forms an extension of the thread profile of said side members. 
     
     
         4 . The system of  claim 3 , wherein each of said arms is joined to said respective side member at a break-off region between said internal thread profile of said side members and said internal thread profile of said arms. 
     
     
         5 . The system of  claim 1 , wherein said anchor includes a head pivotally captured in said implantation portion of said extended receiver, said anchor further including a shaft extending through a distal opening through said implantation portion for engaging the bony structure. 
     
     
         6 . The system of  claim 5 , further comprising a crown positioned about said head of said anchor in said implantation portion. 
     
     
         7 . The system of  claim 6 , further comprising a second anchor assembly including a second distal anchor engageable to a second vertebra and a second extended receiver extending proximally from and pivotal relative to said second anchor, said second extended receiver including a distal implantation portion adjacent said second anchor sized and shaped to receive said connecting member therein, said second extended receiver further including a proximal guide portion including a pair of removable arms extending along a central axis proximally from and formed as a single unit with a respective one of a pair of opposite side members of said implantation portion, said arms defining a channel extending therebetween from said implantation portion through proximal ends of said pair of arms, said channel being sized and shaped to receive said connecting member through said proximal end opening thereof in a transverse orientation to said central axis. 
     
     
         8 . The system of  claim 7 , wherein, for each of said extended receivers, each of said side members defines an internal thread profile along said implantation portion and each of said arms of said respective extended receiver defines an internal thread profile adjacent a distal end thereof that forms an extension of the thread profile of said side members, and further comprising:
 first and second engaging members positionable in a respective one of said extended receivers to secure said connecting member in said implantation portion thereof, each of said engaging members including an externally threaded portion threadingly engageable with said internal thread profiles along said arms and said side members of said respective extended receiver.   
     
     
         9 . The system of  claim 7 , wherein said connecting member includes a length sized to extend between at least three vertebrae and further comprising a third anchor assembly including a third distal anchor engageable to a third vertebra and a third extended receiver extending proximally from and pivotal relative to said third anchor, said third extended receiver including a distal implantation portion adjacent said third anchor sized and shaped to receive said connecting member therein, said third extended receiver further including a proximal guide portion including a pair of removable arms extending along a central axis proximally from and formed as a single unit with a respective one of a pair of opposite side members of said implantation portion, said arms defining a channel extending therebetween from said implantation portion through proximal ends of said pair of arms, said channel being sized and shaped to receive said connecting member through said proximal end opening thereof in a transverse orientation to said central axis. 
     
     
         10 . The system of  claim 1 , wherein each of said arms includes a length extending from said respective side member that is at least 30 millimeters. 
     
     
         11 - 22 . (canceled)