An external fixation system comprising: first and second planar at least part-circular ring elements, the first ring element having a circumferential track extending along the part-circular circumference thereof a plurality of struts each having a first and second end, the first end of each strut coupled to the first ring by a first connector and the second end of each strut coupled to a second ring by a second connector, the first connector including a spherical joint the second connector non-rotatably coupled to the second ring, the strut second end being coupled to the second connector by a U-joint shuttles mounted on the track of the first ring for movement there along with one shuttle coupled to each strut and means for controlling the angular position of each strut second end and means for controlling the position of each shuttle along the circumferential track on the first ring.