An implant for insertion between a pair of spaced vertebrae has two interfitted parts relatively shiftable along an axis and having outer ends turned axially away from each other and each formed with an axially outwardly directed part-spherical convex surface. Formations such as a screwthread engaged...http://www.google.fr/patents/US8070817?utm_source=gb-gplus-shareBrevet US8070817 - Vertebral implant
