To establish the correct volar angle between the proximal radius and a distal fragment of the radius a cortical half pin with a self-threading screw is mounted in a collet. The collet is supported on a pair of members that clamp a volar plate under the collet, the volar plate has a hole in alignment with the half pin that enables the plate to pivot in a plane parallel to the members. The volar plate is tilted to contact the distal fragment and to be joined to the fragment. The half pin is screwed into the proximal radius and the members and collet are removed in order to allow the volar plate to be pressed back against the proximal radius and secured to the radius, thus establishing the correct volar tilt for the distal fragment relative to the proximal position of the radius.
