Disclosed are lockable instrument assemblies for quick and easy configuration of surgical instrumentation. The assemblies are operable between a locked and unlocked position, and generally include an aperture having a shaped profile which receives an adjustment member therein. When the assemblies are placed in a locked assembly configuration, the adjustment member is prevented from rotating or translating within the aperture. When the assemblies are placed in an unlocked assembly configuration, the adjustment member is permitted to rotate or translate within the aperture. Also disclosed are methods of using and making lockable instrument assemblies.