Methods and systems for laterally stabilized constraint of spinous processes
View Patent ↗A spinal implant for limiting flexion of the spine includes a tether structure for encircling adjacent spinal processes. Usually, a pair of compliance members will be provided as part of the tether structure for elastically limiting flexion while permitting an extension. A cross-member is provided between the compliance member or other portions of the tether structure to stabilize the tether structure and prevent misalignment after implantation.
1. A method for restricting flexion in a spine, said method comprising:
positioning an upper strap of a tether structure over an upper spinous process and a lower strap of the tether structure over a lower spinous process,
wherein the spinous processes are on a pair of adjacent vertebrae, and
wherein the upper strap and the lower strap are joined together with a pair of compliance members, and
wherein the compliance members provide a force that resists flexion of the upper and the lower spinous processes; and
mechanically coupling opposed portions of the tether structure with a cross-member that passes through an interspinous space to inhibit circumferential displacement of the tether structure over time,
wherein the cross-member allows extension of the spine to remain substantially unrestricted, and
wherein the cross-member is rigid thereby preventing lateral motion between the opposed portions of the tether structure,
wherein the compliance members are connected with the cross-member, and
wherein one end of the cross-member is fixedly attached to one of the compliance members and another other end is non-fixedly attached to the other compliance member.
2. The method of claim 1 , wherein the cross-member is coupled to one or more of the compliance members during implantation of the upper or the lower tether structure.
3. The method of claim 1 , wherein integrity of the interspinous ligament is not significantly compromised.
4. The method of claim 1 , further comprising:
positioning at least one additional continuous tether structure over a spinous process on another pair of adjacent vertebrae; and
mechanically coupling opposed portions of the at least one additional tether structure through a second interspinous space.
5. The method of claim 1 , wherein the upper and the lower straps are substantially non-distensible.