Osteotomy procedure
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.
1. A computer program product for use in connection with a localization device for removing a wedge from a bone during a surgical procedure so as to achieve a predetermined 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 non-transitory 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 during the surgical procedure;
computer readable program code for determining the pivot location during the surgical procedure using the recorded depth and angle of the first cut; and
computer readable program code for calculating an angle of said second cut during the surgical procedure using (i) the determined pivot location, (ii) said recorded angle of said first cut, and (iii) said predetermined 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 angle of said second cut comprises at least computer readable program code for solving the equation:
β
=
cos
-
1
(
(
PA
PA
′
)
PA
PA
′
)
where β is said angle of said second cut, PA is a vector extending from said pivot location to the second position, and PA′ is a vector extending from said pivot location to the third position.
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 angle of said second cut comprises at least computer readable program code for solving the equation:
β
=
cos
-
1
(
(
PA
PA
′
)
PA
PA
′
)
;
where β is said angle of said second cut, PA is a vector extending from said pivot location to the second position, and PA′ is a vector extending from said pivot location to the third position.
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 cut were commenced at the location of the pointer and ended at the pivot location.