US 5,728,095 A · Method of using an orthopaedic fixation device

Abstract

An external fixator for positioning a first element or the like relative to a second element or the like. The external fixator includes a first base for mounting to the first element; a second base for mounting to the second element; a plurality of adjustable effective length struts; connector structure for rotatably attaching the first ends of a first pair of struts relative to one another and relative to the first base; connector structure for rotatably attaching the first ends of a second pair of struts relative to one another and relative to the first base; connector structure for rotatably attaching the first ends of a third pair of struts relative to one another and relative to the first base; connector structure for rotatably attaching the second ends of the first pair of struts relative to one another and relative to the second base; connector structure for rotatably attaching the second ends of the second pair of struts relative to one another and relative to the second base member; and connector structure for rotatably attaching the second ends of the third pair of struts relative to one another and relative to the second base member. A unique method of using an external fixation device to reposition a first bone segment relative to a second bone segment is claimed herein. The unique method of using the external fixation device of the current invention includes attaching said first base member to said first bone segment, attaching said second base member to said second bone segment, and adjusting the effective length of at least one of the struts, thereby repositioning said first bone segment relative to said second bone segment.

Claims49

Dependent claims

A method of using an external fixation device to reposition a first tissue segment to a predetermined position relative to a second tissue segment, whereby the external fixation device includes a first base member, a second base member, and at least six adjustable-length struts interconnecting said first and second base members through a plurality of connectors, wherein the method comprises the steps of:

(A) attaching said first base member to said first tissue segment;
(B) attaching said second base member to said second tissue segment;
(C) calculating new effective lengths for each of said struts that are required to reposition said first tissue segment to said predetermined position, wherein said calculation includes the steps of:
1) using a mathematical correlation of the relative positions of said first tissue segment, said second tissue segment, and said device to determine new connector locations required to reposition the first tissue segment to said predetermined position;
and
2) determining said new effective lengths of said struts based on said new connector locations;
and
(D) adjusting the effective lengths of said struts to said new effective lengths.

5 more elements

A method of using an external fixation device to correct a deformity in a tissue having a first tissue segment and a second tissue segment with a deformity site therebetween, whereby the external fixation device includes:

(1) a first base member having a first effective diameter,
(2) a second base member having a second effective diameter,
(3) a plurality of adjustable-length struts interconnecting said first and second base members with each strut initially having a neutral length that is the same,
(4) a first attachment mechanism associated with the first base member, and
(5) a second attachment mechanism associated with the second base member,
whereby the device has a centerline extending from an effective center of the first base member to an effective center of the second base member;
wherein the method comprises:
(A) determining the following measurements of the first tissue segment relative to the second tissue segment:
(1) deformity anterior-posterior displacement,
(2) deformity lateral-medial displacement,
(3) axial displacement,
(4) anterior-posterior angulation,
(5) lateral-medial angulation,
(6) axial rotation;
(B) determining an origin at the deformity site that will act as a convenient reference point;
(C) predetermining an appropriate location on said first tissue segment for attachment of the first base member to the first tissue segment, said location being characterized by
(1) the vertical distance from the first base member to the origin,
(2) the horizontal displacement of the origin from the centerline of the device, whereby the horizontal displacement consists of am eccentric anterior-posterior displacement and an eccentric lateral-medial displacement, and
(3) a predetermined orientation of the device and the amount said second tissue segment is rotated about its axis from its correct position;
(D) calculating a new effective length of each strut that is required to configure the device to mimic the deformity;
(E) adjusting the effective length of each strut to said new effective length;
(F) attaching the first attachment mechanism to the first tissue segment at the predetermined appropriate location, and attaching the second attachment mechanism to the second tissue segment;
(G) adjusting the effective length of each strut to said initial neutral length, and thereby substantially correcting the deformity.

20 more elements

(1) a first base member having a first effective diameter,
(2) a second base member having a second effective diameter,
(3) a plurality of adjustable-length struts interconnecting said first and second base members with each strut initially having a neutral length that is the same,
(4) a first attachment mechanism associated with the first base member, and
(5) a second attachment mechanism associated with the second base member, whereby the device has a centerline extending from an effective center of the first base member to an effective center of the second base member;
wherein the method comprises:
(A) attaching the first attachment mechanism to the first tissue segment, and attaching the second attachment mechanism to the second tissue segment;
(B) determining the following measurements of the first tissue segment relative to the second tissue segment:
(1) deformity anterior-posterior displacement,
(2) deformity lateral-medial displacement,
(3) axial displacement,
(4) anterior-posterior angulation,
(5) lateral-medial angulation,
(6) axial rotation;
(c) determining an origin at the deformity site that will act as a convenient reference point;
(D) characterizing the location of the first tissue segment relative to the first base member in terms of
(1) the vertical distance from the first base member to the origin,
(2) the horizontal displacement of the origin from the centerline of the device, whereby the horizontal displacement consists of an eccentric anterior-posterior displacement and an eccentric lateral-medial displacement, and
(3) a predetermined orientation of the device and the amount the second tissue segment is rotated about its axis from its correct position;
(E) calculating new effective lengths for each strut that is required to configure the device to mirror the deformity;
(F) adjusting each strut to its new effective length to configure the device to mirror the deformity, and thereby substantially correcting the deformity.

18 more elements

A method of using an external fixation device to correct a deformity in a bone having a first bone segment and a second bone segment with a deformity site therebetween, whereby the external fixation device includes:

(1) a first base member having a first effective diameter,
(2) a second base member having a second effective diameter,
(3) a plurality of adjustable-length struts interconnecting said first and second base members through a plurality of connectors, wherein each strut initially has a neutral length that is the same,
(4) a first attachment mechanism associated with the first base member, and
(5) a second attachment mechanism associated with the second base member, whereby the device has a centerline extending from an effective center of the first base member to an effective center of the second base member;
wherein the method comprises:
(A) determining the following measurements of the first bone segment relative to the second bone segment:
(1) deformity anterior-posterior displacement,
(2) deformity lateral-medial displacement,
(3) axial displacement,
(4) anterior-posterior angulation,
(5) lateral-medial angulation,
(6) axial rotation;
(B) determining an origin at the deformity site that will act as a convenient reference point;
(C) characterizing the location or anticipated location of said first bone segment relative to said device in terms of
(1) the vertical distance from the first base member to the origin,
(2) the horizontal displacement of the origin from the centerline of the device, whereby the horizontal displacement consists of an eccentric anterior-posterior displacement and an eccentric lateral-medial displacement, and
(3) a predetermined orientation of the device and the amount the second bone segment is rotated about its axis from its correct position;
(D) calculating new effective lengths for each strut by
(1) determining new connector locations from a general deformity equation that includes the rotational matrix given by the formula:
##EQU25## and (2) determining the new lengths of the adjustable struts that interconnect the connectors if said connectors were positioned at said new connector locations;
and
(E) adjusting the length said struts to said new effective lengths.

20 more elements

Dependencies are inferred from the claim text.

Method of using an orthopaedic fixation device

Life of this patent

Method of using an orthopaedic fixation device

Life of this patent

Abstract

Claims49