For this reason screw fit safety gates are the best choice for restricting the top opening of a stairway, where the risk of the stair gate becoming unsecured would be greatest. The screw fit safety gates come with a wall mounting kit and will need to be screwed directly into the wall or a solid surface, but this means that these safety gates do not come loose easily. 

The advantage of choosing screw fit stair gates is that you can walk easily through the entire width and area of the opening without the inconvenience of having a sill or bar along the base that could pose a possible trip hazard. Also some screw fit stair gates have a quick release system that removes the entire safety gate when you want it out of your way.