Anchors to secure a rod to a vertebral member. The anchors may include a fastener with a distal end adapted to be connected to the vertebral member and a proximal end. A receiver may be operatively connected to the proximal end of the fastener. The receiver may include a channel sized to receive the rod. The receiver may further include at least one convex section that extends inward towards a longitudinal axis of the rod. The receiver may be formed in a unitary one-piece construction. The anchor may also include a securing member that connects to the receiver and may include a lower edge that extends into the channel and may contact the rod.