The present invention is an interspinous process implant with a selectably expandable spacer that can be placed between adjacent spinous processes....http://www.google.es/patents/US7306628?utm_source=gb-gplus-sharePatente US7306628 - Interspinous process apparatus and method with a selectably expandable spacer
Interspinous process apparatus and method with a selectably expandable spacer
