Apparatus for external fixation of a fractured distal radius with angularly adjustable pin clamping means

Apparatus for external fixation of a plurality of fragments at an end of a bone, wherein the apparatus comprises:

• a housing including an elongated shank mounting portion, a fragment attachment pin array section at a first end of the elongated shank mounting portion having a first array of pin mounting holes, and a lateral fragment mounting section extending parallel to the elongated shank mounting portion and downward from an edge of the fragment attachment pin array section;
• wherein the lateral fragment mounting section includes a first plurality of apertures, an internal mounting surface adjacent each of the apertures, and a threaded surface adjacent each of the apertures;
• a first plurality of bone pins, clamped within the shank mounting portion and extending downward from the shank mounting portion for attachment within a shank portion of the bone;
• a clamping bracket including a clamping plate having a second array of pin mounting holes;
• a second plurality of bone pins, extending through holes within the first array of pin mounting holes and through holes within the second array of pin mounting holes, and extending downward for attachment to fragments within the plurality of fragments;
• at least one clamping screw holding the clamping bracket against the housing so that the second array of holes is misaligned with the first array of holes to hold the second plurality of bone in place within the first array of holes;
• a third plurality of bone pins, clamped within the lateral fragment mounting section and extending laterally for attachment to fragments within the plurality of fragments.
• a first plurality of pin holders held within the housing, wherein each of the pin holders includes a spherical external surface held within the internal mounting surface adjacent an aperture in the first plurality of apertures, a pin mounting hole extending in a straight line through a center of the spherical external surface, and a deformable portion;
• a third plurality of bone pins, each held within the pin mounting hole in a pin holder within the first plurality of pin holders to extend through an aperture in the first plurality of apertures, wherein an angle, relative to the housing, at which each of the bone pins extends through the aperture is varied by pivoting the pin holder within the housing, and
• a plurality of clamping members, wherein each of the clamping members includes a threaded portion engaging a threaded surface adjacent one of the apertures within the housing and a surface engaging the deformable portion of a pin holder within the plurality of pin holders, wherein, as each of the clamping members is rotated in a first direction, an engagement force between the spherically rounded external surface of the pin holder and the internal mounting surface in which the pin holder is held is increased to hold the pin holder in place within the internal mounting surface, while deflection of the deformable portion of the pin mounting hole is increased to hold a bone pin in place within the pin mounting hole, and wherein as each of the clamping members is rotated opposite the first direction, the engagement force between the spherically rounded external surface of the pin holder and the internal mounting surface in which the pin holder is held is decreased to allow movement the pin holder within the internal mounting surface, while deflection of the deformable portion of the pin mounting hole is decreased to release the bone pin to move within the pin mounting hole.