External bone-anchoring fixator
First Claim
1. An external fixator for bridging a bone fracture for use with bone pins intended to be inserted in groups into the fracture fragments, said fixator comprising:
- first and second elongated solid planar members formed of a moldable and/or machinable plastics material, said planar members being generally rectangular in shape and cross-section and having a width dimension greater than the thickness dimension, said planar members being arranged in end-to-end relationship in a common plane and each having openings therethrough transverse to its longitudal axis in the direction of the thickness dimension distributed along its length and disposed on a line displaced from one edge of the member by a distance less than half said width dimension for receiving and supporting the pins of a respective one of two groups of pinsseparate means associated with each of said openings for releasably clamping a pin therein comprising a screw extending inwardly from said one edge of the planar member into engagement with the pin, said screw having a head of predetermined shape and size,an elongated lead screw anchored at one end for relative rotation in said first planar member at the end thereof which confronts an end of said second planar member and extending completely through and projecting beyond the other end of said second planar member and threadably engaging a threaded longitudinal bore therein, said lead screw being disposed along an axis parallel to and displaced slightly inwardly from said line of openings and when rotated relative to said second planar member effecting an adjustment in distance between the confronting ends of said first and second planar members whereby to establish a definite extension of the fracture, the projecting end of said lead screw having the same shape and size as the heads of said clamping screws whereby a single tool having an opening of said predetermined shape and size can be used interchangeably to rotate said lead screw to effect said adjustment in distance or to actuate said clamping screws, anda rod secured at one end and in the end of said first planar member which confronts an end of said second planar member and slidably engaging a bore in said second planar member, the axis of which is parallel to and off-set from the axis of said lead screw for normally coacting with said lead screw to maintain said planar members in a common plane.
1 Assignment
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Accused Products
Abstract
A fixator for externally anchoring broken bones including a pair of generally planar members each having a plurality of openings adapted to receive a respective group of bone pins inserted in respective pieces of bone. The pins are clamped to the planar members with respective headed screws, and the members are held in adjustable end-to-end relationship by a lead screw anchored at one end in one of the members and engaging a threaded bore in the other member. In an embodiment useful for the treatment of comminuted displaced fractures of the distal radius and ulna, the said one member consists of two articulated sections arranged for angular and rotational adjustment. The lead screw extends beyond the distal end of the said other member and its free end is of the same shape and size as the heads of the clamping screws, and of other screws provided for locking the planar members in adjusted relative positions, enabling longitudinal adjustment and loosening and tightening of all screws to be done with a single tool, preferably an easily manipulated knurled wheel having an opening corresponding in shape and size to the screw heads.
156 Citations
14 Claims
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1. An external fixator for bridging a bone fracture for use with bone pins intended to be inserted in groups into the fracture fragments, said fixator comprising:
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first and second elongated solid planar members formed of a moldable and/or machinable plastics material, said planar members being generally rectangular in shape and cross-section and having a width dimension greater than the thickness dimension, said planar members being arranged in end-to-end relationship in a common plane and each having openings therethrough transverse to its longitudal axis in the direction of the thickness dimension distributed along its length and disposed on a line displaced from one edge of the member by a distance less than half said width dimension for receiving and supporting the pins of a respective one of two groups of pins separate means associated with each of said openings for releasably clamping a pin therein comprising a screw extending inwardly from said one edge of the planar member into engagement with the pin, said screw having a head of predetermined shape and size, an elongated lead screw anchored at one end for relative rotation in said first planar member at the end thereof which confronts an end of said second planar member and extending completely through and projecting beyond the other end of said second planar member and threadably engaging a threaded longitudinal bore therein, said lead screw being disposed along an axis parallel to and displaced slightly inwardly from said line of openings and when rotated relative to said second planar member effecting an adjustment in distance between the confronting ends of said first and second planar members whereby to establish a definite extension of the fracture, the projecting end of said lead screw having the same shape and size as the heads of said clamping screws whereby a single tool having an opening of said predetermined shape and size can be used interchangeably to rotate said lead screw to effect said adjustment in distance or to actuate said clamping screws, and a rod secured at one end and in the end of said first planar member which confronts an end of said second planar member and slidably engaging a bore in said second planar member, the axis of which is parallel to and off-set from the axis of said lead screw for normally coacting with said lead screw to maintain said planar members in a common plane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification