Harrington Arthritis Research Center

Orthotic Limited Partnership

Mark Phillips

James B Koeneman

Thomas M Hansen

Allan M Weinstein

A unilateral external fixation device comprises a distal frame and a proximal frame interconnected by a hinge formed of mating, partially spherical-shaped surfaces which permits relative movement of the distal frame and proximal frame. Each of the frames includes one or more pin clamps which mount half pins inserted with the proximal or distal segments of a fractured bone to immobilize the bone segments and permit reduction of the fracture. The focal point of the partially spherical-shaped surfaces of the hinge is positioned in direct alignment with the fracture, preferably in a vertical plane passing through the fracture transverse to the longitudinal axis of the bone, so that manipulation of one or both of the distal and proximal frames permits a relatively slight and precise movement of the bone segments connected thereto by the half pins to ensure proper reduction of the fracture.

Unilateral external fixation device

A pin clamp particularly adapted for use in an external skeletal fixation device to clamp pins inserted in the distal segment and/or proximal segment of a fractured bone for positioning and immobilizing the bone segments to reduce the fracture. The pin clamp employs a wedge lock construction including a block having a tapered, hollow interior which receives a wedge element having opposed, tapered sidewalls connected to a slotted top wall. The pins are inserted between the sidewalls of the wedge element into the slot, and are clamped therebetween as the wedge element is moved into the block. A screw carried by the block threads into a bore in the top wall of the wedge element to move the wedge element in and out of the block. Both the block and wedge element are formed of a composite material and the sidewalls of the wedge element which contact the pins are preferably coated with a grit material having a high coefficient of friction.

Pin clamp

A unilateral external fixation device for closed reduction of simple or comminuted long bone fractures includes a frame formed of composite materials which mounts a proximal carriage at one end and a distal carriage at the other end. The proximal carriage is adapted to mount half pins inserted in the proximal segment, and is supported on the frame by support arms which are movable with respect to the frame for adjusting the position of the proximal segment. The distal carriage includes a clamping member adapted to mount half pins inserted in the distal segment, which is pivotal about the fracture to permit precise adjustment of the distal segment for alignment with the proximal segment. A fragment support, mounted to one of the side rails of the support arm for the proximal carriage, is adapted to clamp a half pin inserted within a central fragment positioned between the proximal and distal segments of a comminuted fracture.

Growing community of inventors

Mesa, AZ, United States of America

Mark Phillips