Six axis external fixator strut
AssigneeSmith & Nephew, Inc.
InventorsHarold S. Taylor, J. Charles Taylor
Life of this patent
Estimating the term…
Abstract
An orthopedic fixation device in which two or more translation members are secured to adjacent tissue segments for reorientation relative to each other. The device includes telescopically adjustable struts that can be secured to base members by connectors that permit movement of the struts relative to the base members. Rotation of the struts is possible about three axes that intersect at a single coincident point of universal rotation.
Claims24
In combination with an orthopaedic external fixator having proximal and distal base members that can be manipulated relative to each other to position a first tissue segment relative to a second tissue segment, an adjustable strut comprising:
- a telescopic body with a proximal end and a distal end;
- a pair of connectors, one rotatably attaching the proximal end of the strut to the proximal base member and one rotatably attaching the distal end of the body to the distal base member, each of said connectors comprising:
- a) a first pivot member joined to the adjacent end of the body;
- b) a second pivot member pivotally joined to the first pivot member;
- and
- c) a third pivot member pivotally joined to the second pivot member and pivotally joined to the adjacent base member;
- wherein the first pivot member is pivotable relative to the second pivot member about a first rotational axis;
- wherein the second pivot member is pivotable relative to the third pivot member about a second rotational axis that is orthogonal to the first rotational axis;
- wherein the third pivot member is pivotable relative to the adjacent base member about a third rotational axis that is orthogonal to the second rotational axis;
- and
- wherein the first, second and third rotational axes all substantially intersect at a single coincident point of universal rotation thereby permitting the body to rotate in three dimensions relative to the adjacent base member without translating relative to the adjacent base member.
In combination with an orthopaedic external fixator having proximal and distal base members that can be manipulated translated relative to each other to position a first tissue segment relative to a second tissue segment, a telescopically adjustable strut comprising:
- a cylindrical shaft with a hollow axial center;
- an externally threaded rod that extends into the axial center of the shaft;
- an internally threaded adjustment nut that mates with the external threads of the rod;
- and,
- a detent means for maintaining the rotational position of the adjustment nut relative to the shaft;
- wherein the adjustment nut is rotatably attached to an end of the shaft through which the rod extends;
- wherein rotational axis of the rod is fixed relative to the shaft, whereby rotation of the nut relative to the rod will cause the rod to translate about the axis of the shaft;
- and,
- wherein the detent means engages at least once for each revolution of the adjustment nut relative the shaft.
In combination with an orthopaedic external fixator having proximal and distal base members that can be manipulated relative to each other to position a first tissue segment relative to a second tissue segment, a telescopically adjustable strut comprising:
- a cylindrical shaft with a hollow axial center;
- an externally threaded rod that extends into the axial center of the shaft;
- an internally threaded adjustment nut that is rotatably attached to an end of shaft and mates with the external threads of the rod whereby rotation of the nut relative to the rod will cause the rod to translate about the axis of the shaft;
- a pair of connectors, one rotatably attaching the proximal end of the strut to the proximal base member and one rotatably attaching the distal end of the strut to the distal base member;
- and,
- means for rotating the strut relative to that base member about three rotational axes that substantially intersect at a single coincident point of universal rotation thereby permitting the strut to rotate in three dimensions relative to the adjacent base member without translating relative to the adjacent base member.
Dependencies are inferred from the claim text.