Claims
- 1. A method for the determination of reduction parameters for the subsequent adjustment of a reduction device to reduce the fragments of a fractured bone, comprising the steps of:
A) comparing the contour of a first bone on a first side of a patient's body with respect to a corresponding second bone on the opposite side of the patient's body, wherein the first bone is a non-fractured bone and the second bone is a fractured bone; B) determining the positions of a first set of at least three non-collinear points on the first bone, and establishing a three-dimensional coordinate system with respect to the body of the patient; C) determining the positions of a second set of at least three non-collinear points on the second bone within the coordinate system, wherein the second set of points corresponds to the first set of points; D) establishing a plane of symmetry by dividing vectors between each point of the first set and its corresponding point of the second set in two parts, and defining central points of the vectors which define at least three points of the plane of symmetry within the coordinate system; E) generating a mirror image of the first bone symmetrically to the plane of symmetry by determining the positions of a third set of at least three non-collinear points on the first bone at each section corresponding to a fragment of the second bone and by forming the mirror image of the first bone by determining the positions of a fourth set of at least three non-collinear points that are symmetrical to the third set of points with respect to the plane of symmetry; F) determining the positions of a fifth set of at least three non-collinear points on the second bone at each fragment section, wherein the fifth set of points corresponds to the third set of points on the first bone; and G) determining the reduction parameters by comparing the different positions of the fifth set of points on the second bone with the positions of the fourth set of points within the mirror image.
- 2. The method claim 1, wherein the second set of points includes at least three points situated on a proximal fragment of the bone
- 3. The method claim 1, wherein determining the position of the first and second set of points is performed by means of touching the points on the surface of the bones with the tip of a pointer which is provided with at least three markers whose position is determinable within a three-dimensional coordinate system by means of an optical position measurement device and respective data management via a computer.
- 4. The method claim 3, wherein the first set of points and second set of points are defined by means of fiducial markers pre-operatively implanted.
- 5. The method claim 1, wherein the determination of the position of the first or second set of points is performed by fastening at least one reference bar to the bone through at least two screws or pins and determining a third point with an adjustable pin.
- 6. A device for the determination of reduction parameters of a fractured bone according to the method of claim 1, comprising:
a cylindric or prismatic reference bar having a longitudinal axis; at least two clamps displaceable on the reference bar in the direction of the longitudinal axis and fastenable to the reference bar; at least two screws or pins with axes loosenable and fixable transversely to the reference bar within the clamps, and the screws are screwable into the bone for attaching the reference bar to the bone; and at least one adjustable clamp to loosenably fasten a pin tip to a desired point on the surface of the bone.
- 7. The device of claim 6, wherein the adjustable clamp is configured such that the tip is displaceable with three degrees of freedom.
- 8. The device of claim 7, wherein the adjustable clamp comprises a socket slidable on the reference bar in the direction of the longitudinal axis, a post extending from the socket and having a central axis, and a support slidable on the post in the direction of the central axis.
- 9. The device of claim 8, wherein the central axis is arranged perpendicularly to the longitudinal axis and to the axes of the screws.
- 10. The device of claim 8, wherein the support defines a bore hole for accepting the pin, wherein the bore hole has an axis extending perpendicular to the central axis and perpendicular to the longitudinal axis.
- 11. The device of claim 6, wherein at least one pin is an articulated pin.
- 12. The device of claim 11, wherein the articulated pin has a threaded end to be introduced into the bone.
- 13. The device of claim 11, wherein the articulated pin has a turning knuckle with one degree of freedom.
- 14. The device of claim 13, wherein the articulated pin is provided with a ball joint.
- 15. The device of claim 11, wherein the articulation of the articulated pin is loosenably fastenable.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of the U.S. national stage designation of copending International Patent Application PCT/CH99/00538, filed Nov. 15, 1999, the entire content of which is expressly incorporated herein by reference thereto.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/CH99/00538 |
Nov 1999 |
US |
Child |
10144849 |
May 2002 |
US |