Various embodiments described herein provide interspinous process spacing devices and related systems and methods. In one embodiment, surgical instrument system for implanting an interspinous process spacing device includes a first arm having a proximal end, an elongated central portion, and a distal end, wherein the distal end includes a first engagement element configured for releasably engaging a first attachment side of an interspinous process spacing device. The system also includes a second arm having a proximal end, an elongated central portion, and a distal end, wherein the distal end includes a second engagement element configured for releasably engaging a second attachment side of the interspinous process spacing device. The first arm and the second arm are removably attachable to one another via attachment elements and are configured for aligning a spacer of the first attachment side and a spacer opening of the second attachment side.