A locking apparatus for use with a head fixation device allows for a stabilizing fixture, such as a rocker arm having a pair of skull pins, to be selectively secured so that the stabilizing fixture can be adjustably rotated to a desired position. In some version the locking apparatus includes a connector that is retained within an opening in a portion of the head fixation device. The connector can translate within the opening and is restricted from rotation. The translating of the connector permits the connector to engage an arch member that retains the stabilizing fixture. The engagement of the connector and arch member is accomplished, in some versions, by way of matching axial oriented toothed portions or starburst features. In some versions the teeth on the starburst features include a chamfer surface.
