Spinal correction adjustment systems and methods
View Patent ↗A system provides for lateral translational corrective force(s) and/or derotational corrective force(s) on a spinal column and includes highly adaptive hardware for connecting the system to the spinal column, where the hardware facilitates a more natural range of motion within pre-selected limits and application of such lateral translational and/or derotational corrective force(s). The upper and lower vertebral segments retain freedom of movement while an apical or restricted segment is restricted from relative vertebral movement. A central segment controls primary rod roll while the rod is free to change in pitch, yaw and roll at the upper (superior) and lower (inferior) segments.
1. A coupler for an implantable spinal correction system, the coupler comprising:
a first connector configured for securement to a first stabilizing member;
a second connector configured for securement to at least one of a vertebral anchor or a second stabilizing member;
a first slide member having a central bore and being connected to the first connector;
a second slide member having a central bore and being connected to the second connector and telescopically received within the central bore of the first slide member;
a drive member extending through the central bores of the first and second slide members; and
an actuator coupled with the drive member defining an actuator rotation axis offset from a longitudinal axis of the drive member such that rotation of the actuator about the actuator rotation axis causes rotation of the drive member about its longitudinal axis resulting in relative, longitudinal movement between the first and second slide members along the longitudinal axis of the drive member.
2. The coupler of claim 1 , wherein the drive member and the actuator are configured such that the drive member and the actuator automatically lock relative longitudinal movement between the first and second slide members when the actuator is not under an external rotational force.
3. The coupler of claim 1 , wherein the drive member is a cylindrical member with a threaded exterior surface.
4. The coupler of claim 1 , wherein the drive member has a first end portion and includes a gear at the first end portion and the actuator includes external threads mated with the gear of the drive member.
5. The coupler of claim 1 , wherein the actuator is rotated manually.
6. The coupler of claim 1 , wherein the actuator is rotated with a power source.
7. The coupler of claim 1 , wherein the actuator is rotated non-percutaneously.
8. The coupler of claim 1 , wherein the first connector has a saddle-shaped receptacle for receiving the first stabilizing member that substantially prevents lateral movement of the first stabilizing member and prevents roll of the first stabilizing member with respect to the first connector.
9. The coupler of claim 1 , wherein the first connector is a polyaxial joint for receiving the first stabilizing member that substantially prevents lateral movement of the first stabilizing member and prevents roll of the first stabilizing member while allowing the first stabilizing member to change in pitch, yaw, and axial slide with respect to the first connector.
10. The coupler of claim 1 , wherein the second connector is a polyaxial joint that substantially prevents lateral movement of the second stabilizing member while allowing the second stabilizing member to change in at least roll.
11. The coupler of claim 1 , wherein the second connector is a polyaxial joint that substantially prevents lateral movement of the vertebral anchor while allowing the vertebral anchor to change in pitch, yaw, and roll with respect to the second connector.
12. The coupler of claim 1 , wherein the second connector is configured for securement to the vertebral anchor and the second stabilizing member.
13. The coupler of claim 1 , wherein the second connector has a saddle-shaped receptacle for receiving the second stabilizing member.
14. The coupler of claim 1 , wherein the first slide member includes female threading at the central bore of the first slide member.
15. The coupler of claim 1 , wherein the second slide member includes female threading at the central bore of the second slide member.
16. A system for spinal correction comprising:
a first stabilizing member for extending along a first side of a spine of a patient;
a first stabilizing anchor for being secured at a superior spinal region on the first side of the spine, the first stabilizing anchor receiving the first stabilizing member such that the first stabilizing member is able to change in pitch, yaw, and roll relative to the first stabilizing anchor while being substantially laterally constrained relative to the first stabilizing anchor;
a second stabilizing anchor for being secured at an inferior spinal region on the first side of the spine, the second stabilizing anchor receiving the first stabilizing member such that the first stabilizing member is able to change in pitch, yaw, and roll relative to the second stabilizing anchor while being substantially laterally constrained relative to the second stabilizing anchor;
a second stabilizing member for extending along a second side of a spine of a patient;
a lateral coupler coupling the first and second stabilizing members, the lateral coupler including:
a first connector secured to the first stabilizing member substantially preventing lateral movement of the first stabilizing member and preventing roll of the first stabilizing member with respect to the first connector;
a second connector secured to at least one of a vertebral anchor or the second stabilizing member, the second connector substantially preventing lateral movement of the at least one of the vertebral anchor or the second stabilizing member with respect to the second connector;
a first slide member connected to the first connector;
a second slide member connected to the second connector and telescopically received within the first slide member;
a drive member extending through the first and second slide members; and
an actuator coupled to the drive member and defining an actuator rotation axis offset from a longitudinal axis of the drive member such that rotation of the actuator about the actuator rotation axis causes rotation of the drive member about its longitudinal axis resulting in relative, longitudinal movement between the first and second slide members;
a first vertebral anchor securable to the second side of the spine and including a transverse arm including a terminal end extending away from the second side of the spine toward the first side of the spine; and
an adjustment mechanism securable to the first stabilizing member, the adjustment mechanism secured to the terminal end of the transverse arm of the first vertebral anchor and defining an effective length between the adjustment mechanism and the first vertebral anchor, the adjustment mechanism configured to shorten the effective length to exert a correction force on the first vertebral anchor.
17. The system of claim 16 , wherein the first vertebral anchor includes a receptacle for receiving the second stabilizing member, the receptacle being configured to be selectively locked to the second stabilizing member such that the second stabilizing member is substantially prevented from changing in pitch, yaw, and roll relative to the receptacle and is laterally constrained by the receptacle.
18. The system of claim 16 , wherein the lateral coupler is configured to allow roll of the second stabilizing member.
19. The system of claim 16 , wherein the first vertebral anchor includes a fastener portion configured to provide a polyaxial connection to a vertebral fastener.
20. The system of claim 16 , wherein the drive member and the actuator are configured such that the drive member and the actuator automatically lock relative longitudinal movement between the first and second slide members when the actuator is not under an external rotational force.
21. The system of claim 16 , wherein the first slide member is substantially prevented from axial rotation relative to the second slide member.
22. A method of correcting a spinal defect, comprising:
extending a first stabilizing member along a first side of a spine of a patient;
securing a first stabilizing anchor at a superior spinal region on the first side of the spine and receiving the first stabilizing member with the first stabilizing anchor such that the first stabilizing member is able to change in pitch, yaw, and roll relative to the first stabilizing anchor while being substantially laterally constrained relative to the first stabilizing anchor;
securing a second stabilizing anchor at an inferior spinal region on the first side of the spine and receiving the first stabilizing member with the second stabilizing anchor such that the first stabilizing member is able to change in pitch, yaw, and roll relative to the second stabilizing anchor while being substantially laterally constrained relative to the second stabilizing anchor;
extending a second stabilizing member along a second side of a spine of a patient;
derotating an apical region of the spine;
coupling the first and second stabilizing members with a coupler such that the longitudinal axes of the first and second stabilizing members are substantially prevented from rotating relative to one another;
rotating an actuator of the coupler about an actuator axis offset from a longitudinal axis of the coupler to laterally translate the second stabilizing member toward the first stabilizing member with the first and second stabilizing members substantially prevented from rotating relative to one another such that the apical region is laterally translated; and
locking the laterally translated and derotated position of the apical region of the spine with the coupler such that vertebrae of the inferior and superior regions of the spine relative to the apical region of the spine retain the freedom of relative axial rotation and relative flexure in the anterior-posterior direction and the medial-lateral direction.