A bone fastener includes a fixation portion configured to interface with boney tissue, a connection portion having a longitudinal axis and being configured to interface with an elongated support structure, and a flexible portion disposed between the fixation portion and the connection portion. The flexible portion is configured to permit flexure of the connection portion relative to the fixation portion. The flexible portion has a first set of opposed facing surfaces that mechanically limit the range of flexure in a first direction. It has a second set of opposed facing surfaces that mechanically limit the range of flexure in a second direction. The opposed facing surfaces are substantially transverse to the longitudinal axis.
