| abstract |
A spinal stabilization system may comprise: na collar having a proximal end, a distal end and a recess configured for receiving a spinal rod, the collar having internal threading; na bone anchor having a proximal head and a distal bone engaging portion, the head configured to be received within the collar; nan outer member having proximal and distal ends and a lumen extending therebetween; nan inner member configured to be disposed at least partially within the lumen of the outer member, the inner member having proximal and distal ends and a lumen extending therebetween, the distal end being configured to releasably engage the collar, wherein the distal end of the inner member is configured to be held in contact with the collar when the inner and outer members are connected to each other and connected to the collar; and na connection mechanism configured to threadingly connect the inner member to the outer member, wherein the connection mechanism includes external threading on the inner member; nwherein the lumen of the inner member and the lumen of the outer member are sized to pass a threaded closure mechanism configured to threadingly engage the internal threading of the collar therethrough, and wherein the inner and outer members are configured such that after the inner and outer members are engaged to the collar, the closure mechanism is configured to be inserted through the inner member and threadingly engaged with the collar. |