Dynamic inter-spinous process spacer

A dynamic spacer for insertion between the superior and inferior spinous processes of adjacent vertebra, comprising:

• a body portion having a first side member and a second side member and defining a void there between, said first side member and said second side member joined by a bridging member at a first end of said body portion;
• at least one anchor member extending from said body portion for engaging said superior spinous process or said inferior spinous process when said body portion is situated between said adjacent vertebra;
• a first operative panel pivotably engaged to said first side member and said second side member to form an upper surface of said body portion, said first operative panel rotatable between a first, stowed position and a second, deployed position and having a protrusion extending therefrom into said void and adapted to engage said bridging member when said first operative panel is fully in said deployed position;
• a second operative panel pivotably engaged to said first side member and said second side member to form an lower surface of said body portion, said first operative panel rotatable between a first, stowed position and a second, deployed position and having a protrusion extending therefrom into said void and adapted to engage said bridging member when said second operative panel is fully in said deployed position;
• an expandable member disposed within said void and having a port for receiving a fluid at a first end and having a second end proximal to said first and second operative panels, said second end adapted to be enlarged upon receipt of said fluid via said port
• whereby engagement of said enlarged second end of said expandable member causes each of said first and second operative panels to rotate from said stowed position toward said deployed position and thereby increase the height of said body portion to distract said adjacent vertebra.