An external fixation system has a planar ring (102) with an adjustable device (800, 900) having a body (802, 902) releasably mounted on the ring. The adjustable device includes a first member (806, 906) for movement in a direction generally perpendicular to the ring. A second member (808A, 908A) is mounted on the first member for movement in a direction parallel to a side wall of the planar ring. A method for treating a broken bone includes providing an external fixation system and inserting a bone fastener through a first bone piece and affixing the first bone fastener to the ring, then inserting a second bone fastener through a second bone piece and affixing the second bone fastener to the adjustable device. The pieces of bone are realigned, compressed, or distracted by adjusting at least one of the first and second adjustable members.
