Interspinsous implants and methods

Abstract

The present invention provides spinous process implant and associated methods. In one aspect of the invention the implant limits the maximum spacing between the spinous processes. In another aspect of the invention, a spacer has at least one transverse opening to facilitate tissue in-growth. In another aspect of the invention, an implant includes a spacer and separate extensions engageable with the spacer. The spacer is provided in a variety of lengths and superior to inferior surface spacings. In another aspect of the invention, an implant includes a spacer and a cerclage element offset from the midline of the spacer in use so that the spacer defines a fulcrum and the cerclage element is operative to impart a moment to the vertebrae about the spacer. In another aspect of the invention, instrumentation for inserting the implant is provided. In other aspects of the invention, methods for treating spine disease are provided.

We claim: 
     
         1 . An implant for placement between spinous processes of adjacent vertebrae of a spine, the implant comprising:
 a spacer with a first end, a second end, and a longitudinal axis extending from the first end to the second end, the spacer having a sidewall generally parallel to the longitudinal axis and having superior and inferior surfaces operable to abut the spinous processes and maintain the spinous processes in spaced apart relationship, the superior and inferior surfaces being spaced apart a distance corresponding to a predetermined minimum spacing between the spinouses process; and   a first extension projecting from the spacer transverse to the longitudinal axis to lie generally alongside the spinous processes of adjacent vertebrae, the first extension being engageable with the spinous processes to limit the maximum spacing between the spinous processes.