Spinal correction tensioning system

A vertebral column correction system comprising:

• a connection member;
• a first vertebral anchor and a second vertebral anchor, each vertebral anchor comprising:
• a threaded shank comprising a proximal shank portion and a distal shank portion configured to engage bone;
• a head including two open sides, the head comprising:
• a distal head portion coupleable to the proximal shank portion;
• a proximal head portion open at a proximal end;
• a concave channel at the distal head portion, the concave channel configured to receive the connection member therethrough;
• an interior head portion extending between the proximal head portion and the distal head portion to, together with the two open sides, substantially form a U shape;
• and
• a locking member receivable within the interior head portion to partially enclose the two open sides, the locking member to secure the connection member between the locking member and the concave channel;
• an engaging member receivable in the interior head portion to retain the locking member within the head portion;
• and
• a single tensioning member couplable to a proximal end of the connection member;
• wherein the connection member is extendable through the open sides of the head;
• and
• wherein the securing member is threadable into the threaded bore and is extendable into the locking member, the securing member to retain the connection member between the locking member and the concave channel without applying a clamping force onto the connection member, allowing longitudinal movement of the connection member within the aperture.

A vertebral anchor system comprising:

• a threaded shank comprising a proximal shank portion and a distal shank portion configured to engage bone;
• a head including two open sides to substantially form a U shape, the head comprising:
• a distal head portion coupleable to the proximal shank portion;
• a proximal head portion open at a proximal end;
• a concave channel at the distal head portion;
• the concave channel configured to receive a connection member therethrough;
• and
• a threaded bore extending between the proximal head portion and the distal head portion;
• a locking member receivable within the threaded bore adjacent the concave channel to partially enclose the two open sides;
• the locking member to secure the connection member between the locking member and the concave channel, wherein the locking member is convex at a distal locking portion to create, together with the concave channel, an aperture to receive the connection member therethrough;
• and
• a securing member threadably engageable with the threaded bore to retain the locking member within the head portion, the securing member extendable into the locking member to retain the connection member without applying a clamping force onto the connection member, allowing longitudinal movement of the connection member within the aperture.