An interspinous spacer system includes a core having a shape configured to fit in an interspinous space between adjacent spinous processes. A plurality of extending forks extends from the core and has shaped configured to extend along vertical sides of the spinous processes. A first fork of the plurality of forks is moveable relative to the core from a non-use position to an in-use position. The first fork is located on a first side of the core in the in-use position and has a first inner side defining an opening for receiving a first spinous process of the spinous processes. The first fork is substantially non-flexible. A second fork is located on the first side of the core and has a second inner side defining an opening for receiving the first spinous process of the spinous processes. The second fork is immovable relative to the core. The first fork avoids protruding from the core such that the first fork bounds the opening in the non-use position to allow the core to be inserted into the interspinous space.