An implant is disclosed. The implant has a base including an extension arm cavity and a ratchet block cavity that intersects the extension arm cavity, an extension arm that is movably disposed in the extension arm cavity, and a ratchet block that is movably disposed between a first position and a second position in the ratchet block cavity. The ratchet block when disposed in the first position allows movement of the extension arm in an upward direction out of the extension arm cavity and blocks movement of the extension arm in a downward direction into the extension arm cavity. The ratchet block when disposed in the second position allows movement of the extension arm both in the upward direction out of the extension arm cavity and the downward direction into the extension arm cavity.