Osteotomy Procedure

• US 20070053568A1
• Filed: 09/13/2006
• Published: 03/08/2007
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Original Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Inventors: Pinzuti, Jean-Baptiste, Leitner, Francois
• Granted Patent: US 8,147,494 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 17/142 with reciprocating saw blades, e.g. with cutting edges at the distal end of the saw blades
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/152 for removing a wedge-shaped piece of bone
• CPC Class Codes: A61B 17/1703 using imaging means, e.g. by X-rays
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

An osteotomy resection procedure for removing a wedge from a bone utilizing a localization device. The localization device being used to track reference points associated with the bone, track surgical instruments, perform calculations to determine a resection angle for the wedge, and assist a surgeon in performing the procedure.

Claims

1. A computer program product for use in connection with a localization device for removing a wedge from a bone so as to achieve a desired correction angle between joints at opposing ends of said bone, said edge being formed by first and second cuts in the bone that intersect at a pivot location, said computer program product comprising:

computer readable program code embodied in a computer readable medium, the computer readable program code comprising at least;

computer readable program code for recording a depth and angle of said first cut observed by the localization device and determining the pivot location therefrom;

computer readable program code for calculating an angle of said second cut as a function of the pivot location, said recorded angle of said first cut, and said desired correction angle.

2. The computer program product of claim 1, wherein said localization device provides information identifying a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone prior to removing the wedge and wherein, after removing the wedge, said second end of said bone is relocated to a third position such that the desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position.

3. The product of claim 2, wherein said computer readable program code for calculating said resection angle comprises at least computer readable program code for solving the equation:

$\mathrm{\beta <br><br>}={\cos }^{-1}<br><br>\left(\frac{\left(\mathrm{PA}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{PA}}^{\mathrm{\prime <br><br>}}\right)}{<br><br>\mathrm{PA}<br><br><br><br><br><br>{\mathrm{PA}}^{\mathrm{\prime <br><br>}}<br><br>}\right)$

where β

is said resection angle, PA is a vector extending from said pivot point to the second position, and PA′

is a vector extending from said pivot point to the third position, wherein said pivot point is supplied by the localization device.

4. The product of claim 2, wherein said computer readable program code further comprises at least:

computer readable program code for determining;

A′

=K+KA cos(α

)+KA^ortho sin(α

);

where A′

is the third position, K is the first position, KA is a vector extending from the first position to the second position, KA^ortho is a vector of equal magnitude and orthogonal to KA, and α

is the desired correction angle.

5. The product of claim 4, wherein said computer readable program code for calculating said resection angle comprises at least computer readable program code for solving the equation:

$\mathrm{\beta <br><br>}={\cos }^{-1}<br><br>\left(\frac{\left(\mathrm{PA}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{PA}}^{\mathrm{\prime <br><br>}}\right)}{<br><br>\mathrm{PA}<br><br><br><br><br><br>{\mathrm{PA}}^{\mathrm{\prime <br><br>}}<br><br>}\right);<br><br>$

where β

is said resection angle, PA is a vector extending from said pivot point to the second position, and PA′

is a vector extending from said pivot point to the 4third position, wherein said pivot point is supplied by said localization device. the desired correction angle when the wedge is removed from the bone.

6. The computer program product of claim 2, wherein the computer readable program code for recording a depth and angle of the first cut comprises:

computer readable code for determining an axis of said bone using the localization device; and

computer readable code for guiding a cutting jig for making the first cut relative to the bone using the localization device.

7. The computer program product of claim 6, wherein the computer readable program code for recording the angle and depth of the first cut further comprises:

computer readable code for generating a display showing the axis and the position of the cutting jig relative to the axis

8. The computer program product of claim 7, further comprising:

computer readable code for tracking a pointer relative to the bone; and

computer readable code for generating a display showing the wedge angle that would result if the second resection cut were commenced at the location of the pointer and ended at the pivot location.