Minimally invasive surgical tower access devices and related methods

Abstract

Devices and methods are provided for assisting in spinal stabilization. An access device is provided that includes an outer sleeve, inner sleeve, spring latch and lock nut. The inner sleeve includes compressible grasping elements. The access device can be coupled to a screw head by sliding the outer sleeve relative to the inner sleeve and compressing the grasping elements. The coupled access device and screw can then be delivered to a target location in a patient. After providing two or more access devices, a rod member can be delivered using a rod insertion device. The rod member can serve as a connection between the two screws, and can provide spinal stabilization. An anti-torque device and a persuading device can be used to help ensure that the rod member is placed and secured in a proper location within a patient.

1 . (canceled) 
     
     
         2 . A system for spinal stabilization, comprising:
 an access device comprising a proximal section and a distal section, wherein the proximal section comprises a threaded portion and the distal section is configured to grasp a screw;   an anti-torque device, the anti-torque device including a handle connected to a cannula configured to be placed over the access device; and   a persuader device having a hollow interior and internal threads, wherein the persuader device is configured to be threaded onto the threaded portion of the access device such that the persuader device is in contact with the anti-torque device in use;   wherein the anti-torque device is configured to be forced against a rod member configured to be positioned in the screw by the persuader device in use, wherein the persuader device and the anti-torque device are configured to move distally relative to the access device.   
     
     
         3 . The system of  claim 2 , wherein the access device comprises an inner sleeve and an outer sleeve and relative movement between the inner and outer sleeves causes the distal section of the access device to grasp the screw in use. 
     
     
         4 . The system of  claim 3 , wherein the distal section of the access device comprises two compressible grasping elements configured to grasp the screw. 
     
     
         5 . The system of  claim 4 , wherein the grasping elements comprise one or more longitudinal slits configured to enhance compressibility of the grasping elements. 
     
     
         6 . The system of  claim 5 , wherein each grasping element comprises two longitudinal slits extending from a distal end of the distal section of the access device toward a proximal end such that each grasping element is divided into three sections. 
     
     
         7 . The system of  claim 3 , wherein the outer sleeve is configured to slidably receive the inner sleeve. 
     
     
         8 . The system of  claim 4 , wherein when the inner sleeve is slidably received within the outer sleeve, distal movement of the outer sleeve relative to the elongate sleeve causes compression of the grasping elements. 
     
     
         9 . The system of  claim 3 , comprising a lock nut having internal threads, wherein the lock nut is configured to be threaded onto the threaded portion of the access device to cause relative movement between the inner sleeve and the outer sleeve in use. 
     
     
         10 . The system of  claim 2 , wherein the persuader device includes a handle. 
     
     
         11 . The system of  claim 2 , wherein the cannula includes a side slot for engaging the rod member. 
     
     
         12 . The system of  claim 2 , wherein the persuader device includes rod engaging members. 
     
     
         13 . A method of spinal stabilization, comprising:
 providing an access device comprising an elongate sleeve having a proximal section and a distal section, the proximal section includes a threaded portion, the distal section includes a slot, wherein the slot extends from a distal end toward a proximal end of the elongate sleeve, wherein the slot is configured to allow passage of a rod member therethrough;   grasping a screw with a distal end of the elongate sleeve;   positioning a cannula of an anti-torque device over the access device, wherein a distal end of the cannula includes a side slot for engaging the rod member; and   positioning a persuader device such that internal threads of the persuader device engage the threaded portion of the access device, and such that the persuader device is in contact with the anti-torque device; and   rotating the persuader device relative to the anti-torque device and the access device to apply a downward force on the anti-torque device.   
     
     
         14 . The method of  claim 13 , wherein the access device comprises an outer sleeve and relative movement between the elongate sleeve and the outer sleeve causes the distal section of the access device to grasp the screw. 
     
     
         15 . The method of  claim 14 , comprising placing the cannula of the anti-torque device over the outer sleeve. 
     
     
         16 . The method of  claim 15 , further comprising:
 providing a lock nut having internal threads; and   threading the lock nut onto the threaded portion of the elongate sleeve to cause relative movement between the elongate sleeve and the outer sleeve.   
     
     
         17 . The method of  claim 13 , wherein the persuader device forces a rod member into a desired position with rod engaging members. 
     
     
         18 . The method of  claim 13 , wherein the persuader device includes a handle. 
     
     
         19 . The method of  claim 13 , comprising placing the persuader device within an interior of the elongate sleeve to force the rod member into a seat of a head of the screw.