Alignment system with longitudinal support features

1. A method of exerting a force on a spine, the method comprising:

securing a first rod anchor on a first side of a spine to a first vertebra and securing a second rod anchor on the first side of the spine to a second vertebra;

receiving a first portion of a first rod in the first rod anchor and a second portion of the first rod in the second rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation, the first and second portions being able to change in pitch and yaw at the first and second rod anchors, respectively, in response to movement of the spine during a correction;

locating a first stop feature along the first rod at a first position adjacent the first rod anchor and a second stop feature along the first rod at a second position adjacent the second rod anchor;

imposing a first force on the first rod with the first and second stop features; and

transferring the first force to the first side of the spine.

2. The method of claim 1 , further comprising:

securing a third rod anchor on a second side of a spine to a vertebra and a fourth rod anchor on the second side of the spine to a vertebra;

receiving a first portion of a second rod in the third rod anchor and a second portion of the second rod in the fourth rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation during the correction;

locating a third stop feature along the second rod at a first position adjacent the third rod anchor and a fourth stop feature along the second rod at a second position adjacent the fourth rod anchor;

imposing a second force on the second rod with the third and fourth stop features; and

transferring the second force to the second side of the spine.

3. The method of claim 1 , wherein the first and second forces impose a compressive force on at least one of the first and second rods, respectively.

4. The method of claim 1 , wherein the first force imposes a compressive force on the first rod, distracting the first side of the spine, and the second force imposes a tensile force on the second rod, compressing the second side of the spine.

5. The method of claim 1 , wherein the first and second forces impose tensile forces on the first and second rods, respectively, and compress the first and second side of the spine, also respectively.

6. The method of claim 1 , wherein the first and second portions are able to change in pitch and yaw at the third and fourth rod anchors, respectively, in response to movement of the spine during the correction.

7. A method of exerting a distraction force on a spine, the method comprising:

securing a first rod anchor on a first side of the spine to a first vertebra and a second rod anchor on the first side of the spine to a second vertebra;

receiving a first portion of a rod in the first rod anchor and a second portion of the rod in the second rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation, the first and second portions being able to change in pitch and yaw at the first and second rod anchors, respectively, in response to movement of the spine during a correction;

locating a first stop feature along the rod at a first position adjacent the first rod anchor and a second stop feature along the rod at a second position adjacent the second rod anchor; and

imposing a compressive force on the rod with the first and second stop features.

8. The method of claim 7 , further comprising distracting the first side of the spine.

9. A method of preparing two sides of a spine for a correction, the method comprising:

securing a first rod anchor on a first side of a spine to a first vertebra and a second rod anchor on the first side of the spine to a second vertebra;

receiving a first portion of a first rod in the first rod anchor and a second portion of the first rod in the second rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation, the first and second portions being able to change in pitch and yaw at the first and second rod anchors, respectively, in response to movement of the spine during the correction;

securing a third rod anchor on a second side of the spine to a vertebra independent of the vertebrae to which any rod anchors on the first side of the spine are secured;

securing a fourth rod anchor on the second side of the spine to a vertebra independent of the vertebrae to which any rod anchors on the first side of the spine are secured;

receiving a first portion of a second rod in the third rod anchor and a second portion of the second rod in the fourth rod anchor such that the first portion is substantially constrained against lateral translation during the correction and the second portion is substantially constrained against lateral translation during the correction;

locating a first stop feature along the first rod at a first position adjacent the first rod anchor and a second stop feature along the first rod at a second position adjacent the second rod anchor; and

adjusting an effective length of the first rod to cause the first and second stop features to contact the first and second rod anchors, respectively, and impose a compressive force on the first rod.

10. A method of preparing two sides of a spine for a correction, the method comprising:

securing a first rod anchor on a first side of a spine to a first vertebra and a second rod anchor on the first side of the spine to a second vertebra;

receiving a first portion of a first rod in the first rod anchor and a second portion of the first rod in the second rod anchor such that the first portion is substantially constrained against lateral translation and the second portion is substantially constrained against lateral translation, the first and second portions being able to change in pitch and yaw at the first and second rod anchors, respectively, in response to movement of the spine during the correction;

securing a third rod anchor on a second side of the spine to a vertebra independent of the vertebrae to which any rod anchors on the first side of the spine are secured;

securing a fourth rod anchor on the second side of the spine to a vertebra independent of the vertebrae to which any rod anchors on the first side of the spine are secured;

receiving a first portion of a second rod in the third rod anchor and a second portion of the second rod in the fourth rod anchor such that the first portion is substantially constrained against lateral translation during the correction and the second portion is substantially constrained against lateral translation during the correction;

locating a first stop feature along the first rod at a first position adjacent the first rod anchor and a second stop feature along the first rod at a second position adjacent the second rod anchor; and

imposing a first force on the first rod with the first and second stop features.

11. The method of claim 10 , further comprising transferring the first force to the first side of the spine.

12. The method of claim 10 , wherein the first force imposes a tensile force on the first rod and compresses the first side of the spine.

13. The method of claim 10 , wherein the first force imposes a compressive force on the first rod and distracts the first side of the spine.

14. The method of claim 13 , wherein distracting the first side of the spine causes the spine to translate laterally in a medial direction.

15. The method of claim 13 , wherein distracting the first side of the spine causes the spine to translate laterally in one of an anterior and a posterior direction.

16. The method of claim 13 , wherein distracting the first side of the spine causes the spine to take on a more natural curvature.