External fixation apparatus with adjustable pin clamping means and convergent bone pins

Apparatus for external fixation of bone fragments, comprising an integral housing including an elongated portion having a flat surface, a plurality of bone pins;

• and at least three pin mounting structures holding the bone pins to extend outward from the flat surface, wherein:
• the pin mounting structures are spaced apart, extending along a straight line within the elongated portion,
• each of the pin mounting structures comprises a pin holder, including a pin mounting surface holding one of the bone pins and a spherically rounded outer surface;
• a clamping member having a threaded outer surface and a rounded surface engaging the pin holder, a mounting hole formed within the housing, including a spherically rounded inner surface engaging the spherically rounded outer surface of the pin holder, a threaded inner surface, coaxial with the spherically rounded inner surface and the aperture about the central axis, engaging the threaded outer surface of the pin mounting structure, and an aperture extending outward through the housing from the spherically rounded outer surface to the flat surface,
• the spherically rounded inner surface and the aperture are coaxial about a central axis, and wherein the pin mounting structures are arranged so that central axes of the mounting holes are arranged at a plurality of angles relative to the flat surface so that the bone pins are held to converge within a region of convergence substantially shorter than the first distance and spaced apart from the elongated portion, each of the pin holders is rotationally adjustable within the elongated portion to vary a location of a pin within the region of convergence,
• the pin mounting surface within each of the pin holders is formed as a hole extending in a straight line through a center of the spherically rounded surface of the pin mounting structure between first and second ends of the pin mounting structure,
• each of the pin holders additionally comprises a first slot, perpendicular to the pin mounting surface, extending across the pin mounting structure and partially across the pin holder, displaced inward from the first end of the pin mounting structure, a central part extending adjacent the first slot past a center of the spherically rounded outer surface of the holder, and a first deflectable portion extending between the first slot and the first end of the pin mounting structure,
• as each of the clamping members is rotated in a first rotational direction in contact with one of the pin holders, an engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is increased to hold the pin holder in place within the housing, and deflection of the first deflectable portion of the pin holder is increased, moving a portion of the pin mounting hole within the first deflectable portion out of alignment with a portion of the pin mounting hole extending through the central part of the pin holder to hold the bone pin in place within the pin holder, and
• as each of the clamping member is rotated opposite the first rotational direction in contact with one of the pin holders, the engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is decreased to allow rotation of the spherically rounded surface of the pin holder within the internal surface of the housing and wherein the deflection of the first deflectable portion of the pin holder is decreased, returning the portion of the pin mounting hole within the first deflectable portion into alignment with the portion of the pin mounting hole extending through the central part of the pin holder to allow movement of the bone pin within the pin holder.

Apparatus for external fixation of bone fragments, comprising an integral housing including an arcuate portion having an arcuate surface formed as an arcuate cylinder about an arc axis, a plurality of bone pins;

• and at least three pin mounting structures holding the bone pins to extend inward from the arcuate surface, wherein
• the pin mounting structures are spaced apart, extending along an arcuate line on the elongated portion, a clamping member having a threaded outer surface and a rounded surface engaging the pin holder,
• each of the pin mounting structures additionally comprises a pin holder including a pin mounting surface holding one of the bone pins, a spherically rounded outer surface;
• a mounting hole formed within the housing, including a spherically rounded inner surface engaging the spherically rounded outer surface of the pin holder and an aperture extending outward through the housing from the spherically rounded outer surface to the flat surface, and
• the spherically rounded inner surface and the aperture are coaxial about a central axis, and wherein the pin mounting structures are arranged so that central axes of the mounting holes are arranged to extend through the arc axis,
• each of the mounting holes additionally includes a threaded inner surface, coaxial with the spherically rounded inner surface and the aperture about the central axis, engaging the threaded outer surface of the pin mounting structure,
• the pin mounting surface within each of the pin holders is formed as a hole extending in a straight line through a center of the spherically rounded surface of the pin mounting structure between first and second ends of the pin mounting structure,
• each of the pin holders additionally comprises a first slot, perpendicular to the pin mounting surface, extending across the pin mounting structure and partially across the pin holder, displaced inward from the first end of the pin mounting structure, a central part extending adjacent the first slot past a center of the spherically rounded outer surface of the holder, first deflectable portion extending between the first slot and the first end of the pin mounting structure,
• as each of the clamping members is rotated in a first rotational direction in contact with one of the pin holders, an engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is increased to hold the pin holder in place within the housing, and deflection of the first deflectable portion of the pin holder is increased, moving a portion of the pin mounting hole within the first deflectable portion out of alignment with a portion of the pin mounting hole extending through the central part of the pin holder to hold the bone pin in place within the pin holder, and
• as each of the clamping members is rotated opposite the first rotational direction in contact with one of the pin holders, the engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is decreased to allow rotation of the spherically rounded surface of the pin holder within the internal surface of the housing and wherein the deflection of the first deflectable portion of the pin holder is decreased, returning the portion of the pin mounting hole within the first deflectable portion into alignment with the portion of the pin mounting hole extending through the central part of the pin holder to allow movement of the bone pin within the pin holder.

Apparatus for external fixation of bone fragments, comprising an integral housing including an elongated portion having outward-facing and inward-facing surfaces, at least three bone pins, and at least three pin mounting structures, spaced apart along a line extending along the elongated through a first distance, wherein each of the pin mounting structures comprises

• a pin holder including a spherically rounded outer surface, a pin mounting surface holding one of the bone pins and at least one deformable portion, wherein the pin mounting surface within each of the pin holders is formed as a hole extending in a straight line through a center of the spherically rounded surface of the pin mounting structure between first and second ends of the pin mounting structure, wherein each of the pin holders additionally includes a first slot, perpendicular to the pin mounting surface, extending across the pin mounting structure and partially across the pin holder, displaced inward from the first end of the pin mounting structure, and a central part extending adjacent the first slot past a center of the spherically rounded outer surface of the holder, and wherein the at least one deformable portion of each of the pin holders includes a first deformable portion extending between the first slot and the first end of the pin mounting structure,
• a mounting hole formed within the housing, including a spherically rounded inner surface engaging the spherically rounded outer surface of the pin holder and an aperture extending outward through the housing between the spherically rounded outer surface and the inward-facing surface of the housing, a threaded inner surface, coaxial with the spherically rounded inner surface and the aperture about the central axis, wherein the central axis of each of the mounting holes is disposed at an angle different from an angle at which the central axis of each other mounting hole is disposed, so that the bone pins are held to converge within a region of convergence substantially shorter than the first distance and spaced apart from the elongated portion, and wherein each of the pin holders is rotationally adjustable within the elongated portion to vary a location of a pin within the region of convergence,
• a clamping member having a threaded outer surface and a rounded surface engaging the pin holder, wherein engagement between the threaded outer surface of the clamping member and the threaded inner surface of the mounting hole holds the pin holder in place between the rounded surface of the clamping member and the spherically rounded inner surface of the mounting hole, and additionally deflects the at least one deformable portion of the pin holder to hold the bone pin in place within the pin holder, wherein as each of the clamping members is rotated in a first rotational direction in contact with one of the pin holders, an engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is increased to hold the pin holder in place within the housing, and deflection of the first deflectable portion of the pin holder is increased, moving a portion of the pin mounting hole within the first deflectable portion out of alignment with a portion of the pin mounting hole extending through the central part of the pin holder to hold the bone pin in place within the pin holder, and wherein as each of the clamping member is rotated opposite the first rotational direction in contact with one of the pin holders, the engagement force between the spherically rounded surface of the pin holder and the internal mounting surface within the housing is decreased to allow rotation of the spherically rounded surface of the pin holder within the internal surface of the housing and wherein the deflection of the first deflectable portion of the pin holder is decreased, returning the portion of the pin mounting hole within the first deflectable portion into alignment with the portion of the pin mounting hole extending through the central part of the pin holder to allow movement of the bone pin within the pin holder.