An orthopedic fixator for positioning a first element relative to a second element with precision and with controlled compliance which can be adjusted during the healing process. One embodiment comprises a first frame for attachment to the first element, a second frame attached to the first frame through a plurality of adjustable effective length struts, and a third frame for attachment to the second element, wherein the third frame is compliantly attached to the second frame. A preferred embodiment comprises adjustable length preload elements to apply unidirectional forces between the first and second frames so as preload the adjustable effective length struts and substantially reduce the positional tolerance. An alternative embodiment comprises adjustable spring elements allowing the compliance of the attachment of the third frame to the second frame to be adjusted at various points in the healing process.