A stylus assembly (10) is adapted to be attached to a surgical jig (50). The stylus assembly (10) comprises a body (12) having first and second arms (22, 24) with a space (32) therebetween for receiving a portion of the surgical jig, a stylus (16) adjustably mounted relative to the body (12), and a locking member (20), In use, actuation of the locking member (20) from an unlocked to a locked position enables locking of the body (12) to the surgical jig (50) and locking of the stylus (16) relative to the body (12).