Surgical tether apparatus and methods of use

Abstract

A spinal treatment system includes a constraint device having an upper tether portion, a lower tether portion and a compliance member coupled therebetween. The upper tether portion is coupled with a superior spinous process of a spinal segment in a patient and the lower tether portion is coupled with an inferior spinous process or sacrum of the spinal segment. The length or tension in the constraint device is adjustable so that the construct of the tether portions and the compliance member provides a force resistant to flexion of the spinal segment. The system also includes a first prosthesis coupled with the spinal segment, wherein the constraint device modulates loads borne by the prosthesis or by tissue adjacent thereto.

What is claimed is: 
     
         1 . A system for treating a spinal segment in a patient, the spinal segment having a superior vertebra and an inferior vertebra, said system comprising:
 spinal fusion instrumentation configured to be coupled to the spinal segment; and   a constraint device configured to be implanted in the patient, the constraint device comprising an upper tether portion, a lower tether portion, and a compliance member disposed therebetween,   wherein one of the upper tether portion or the lower tether portion is configured to be coupled to a spinous process of a third vertebra adjacent the spinal segment or to an adjacent sacrum,   wherein the other of the upper tether portion or the lower tether portion is configured to be coupled to a spinous process of the spinal segment or to the spinal fusion instrumentation, and   wherein the constraint device is adjustable to provide an adjustable elastic force resistant to flexion of the spinal segment.   
     
     
         2 . The system of  claim 1 , wherein the spinal fusion instrumentation is configured to facilitate fusion of the spinal segment. 
     
     
         3 . The system of  claim 1 , wherein the spinal fusion instrumentation comprises one or more of a screw, a rod, bone graft material, and fusion hardware. 
     
     
         4 . The system of  claim 1 , wherein the constraint device modulates loads borne by the spinal segment or tissue adjacent thereto. 
     
     
         5 . The system of  claim 1 , wherein the third vertebra is superior to the spinal segment, and wherein the upper tether portion is configured to be disposed about a superior surface of a spinous process on the third vertebra. 
     
     
         6 . The system of  claim 1 , wherein the upper tether portion or the lower tether portion is configured to be disposed through an aperture in an interspinous ligament. 
     
     
         7 . The system of  claim 1 , wherein the third vertebra is inferior to the spinal segment, and wherein the lower tether portion is configured to be disposed about an inferior surface of the spinous process of the third vertebra. 
     
     
         8 . The system of  claim 1 , wherein the upper tether portion or the lower tether portion is configured to be disposed through a gap between a spinous process of the spinal segment and a spinous process of the third vertebra, wherein the gap is created by surgical removal of an interspinous ligament. 
     
     
         9 . The system of  claim 1 , wherein the constraint device is adjustable by adjusting a length or a tension therein to vary the elastic force. 
     
     
         10 . The system of  claim 1 , wherein a space between the superior spinous process and the inferior spinous process remains free of the spinal fusion instrumentation.