Abstract: Broadside displacement of sliding patio doors from their building framework for removal from the threshold track upon lifting of the doors in attempts at unauthorized entry is prevented with the use of downwardly-extending leg portions at each side of the door roller wheel assemblies, which leg portions extend downwardly of each side of an upstanding threshold track projection upon which the roller wheels ride. In one embodiment of the invention, the roller wheel assembly leg portions terminate in mutually inwardly-directed hook portions received in slightly spaced relation below rectangular shoulders defined by a rounded head formed along the upper end of the upstanding track projection, thereby preventing removal of the roller wheel assemblies from the threshold track for unauthorized entry.