Bone anchor assemblies are disclosed herein that include one or more features for indicating the relative positioning of the receiver member and the shank, or for selectively maintaining the receiver member and the shank in a fixed relative position. For example, the head of the shank can include a surface feature that interacts with a drag ring to provide tactile or audible feedback when the shank is positioned at a particular orientation with respect to the receiver member. By way of further example, the head of the shank and a compression cap disposed in the receiver member can each include engagement features that cooperate to allow for selective locking of the orientation of the shank with respect to the receiver member.
