A percutaneous and minimally invasive instrument for inserting an interspinous process spacer into a patient is disclosed. The insertion instrument includes a first assembly connected to a handle assembly. The first assembly includes an inner shaft located inside an outer shaft； the inner and outer shafts being configured for relative translational motion with respect to each other to thereby deflect at least one prong formed on one of the inner or outer shafts wherein such deflection causes engagement with a juxtapositioned interspinous spacer. The instrument further includes a driving tool configured for removable insertion into a proximal end of a passageway of the instrument. The driving tool has a distal spacer engaging portion configured to engage that part of the spacer requiring activation for deployment of the spacer from at least one undeployed configuration to at least one deployed configuration and vice versa.
