A spinous process plate fixation assembly is provided that has a pin plate including a first central aperture and a pin plate interior surface. The assembly has a lock plate including a second central aperture and a lock plate interior surface opposingly facing the pin plate interior surface. The interior surfaces have a pluralities of spikes extending therefrom. A pin receptacle is disposed within the pin plate and is configured to receive a lock pin. A pivoting lock mechanism is disposed within the lock plate. A connector shaft extends from the pin plate to the lock plate and passes through the first central aperture and the second central aperture. The connector shaft includes a pin side configured to receive the lock pin, and a lock side opposite the shaft side, the lock side configured to operatively engage the pivoting lock mechanism so as to secure the plates and the shaft.
