Systems, devices, and methods for adjusting rotational limits of an orthopedic brace hinge are provided. A hinge stop assembly limits rotational travel of first and second frame members of the hinge. An indexing key of the hinge stop assembly is actuatable in a direction parallel to the axis of rotation of the hinge to lock and unlock the position of the hinge stop assembly relative to the hinge. Actuation of the hinge stop assembly unlocks the indexing key and allows movement of the hinge stop assembly to set a desired limit on the flexion or extension of the brace hinge. Release of the hinge stop assembly locks the indexing key and locks the hinge stop assembly in place.