An expandable spinal implant is disclosed. The implant includes a plurality of ribs which are deformable between first and second states. In the first state, the ribs present a generally cylindrical implant. In the expanded second state, the ribs are arced outwardly to define a generally spherical implant....http://www.google.fr/patents/US5059193?utm_source=gb-gplus-shareBrevet US5059193 - Expandable spinal implant and surgical method
