Software for use with deformity correction
The present disclosure relates to software used in planning the correction of bone deformities preoperatively or postoperatively, and in particular relates to virtually manipulating rings and struts of an external fixation frame in order to plan the steps for making a desired correction to two or more bone portions of a patient. The software can be used prior to surgery, allowing a user to virtually define a bone deformity, and virtually add and manipulate fixation rings and struts to the bone deformity. Based on the virtual manipulations, a correction plan can be generated that describes length adjustments that should be made to the plurality of model struts over a period of time to correct the bone deformity. The software can also be used after surgical fixation of the fixation frame and struts to the deformed bone.
1. A method of generating a correction plan for correcting a deformed bone of a patient comprising the steps of:
prior to generating the correction plan, coupling an external fixation frame to the patient so that a proximal fixation ring is coupled to a proximal fragment of the deformed bone, a distal fixation ring is coupled to a distal fragment of the deformed bone, and a plurality of struts couple the proximal fixation ring to the distal fixation ring;
displaying on a display device a first x-ray image of the deformed bone in a first plane;
overlying a first proximal reference axis with a first central axis of the proximal fragment of the deformed bone in the first x-ray image on the display device so that the first proximal reference axis is substantially aligned with the first central axis of the proximal fragment in the first x-ray image;
overlying a first distal reference axis with a first central axis of the distal fragment of the deformed bone in the first x-ray image on the display device so that the first distal reference axis is substantially aligned with the first central axis of the distal fragment in the first x-ray image;
displaying on the display device a second x-ray image of the deformed bone in a second plane;
overlying a second proximal reference axis with a second central axis of the proximal fragment of the deformed bone in the second x-ray image on the display device so that the second proximal reference axis is substantially aligned with the second central axis of the proximal fragment in the second x-ray image;
overlying a second distal reference axis with a second central axis of the distal fragment of the deformed bone in the second x-ray image on the display device so that the second distal reference axis is substantially aligned with the second central axis of the distal fragment in the second x-ray image;
displaying a model of the proximal fixation ring on the display device;
manipulating the model of the proximal fixation ring so that a position and orientation of the model of the proximal fixation ring corresponds to a position and orientation of the proximal fixation ring coupled to the proximal fragment of the deformed bone; and
generating the correction plan based at least in part on the first and second proximal reference axes, the first and second distal reference axes, and the position and orientation of the model proximal fixation ring,
wherein the first proximal reference axis and the second proximal reference axis are initially presented together as part of a model bone in a non-deformed state which is later deformed by repositioning a distal portion of the model bone relative to a proximal portion of the model bone.
2. The method of claim 1 , wherein the first proximal reference axis is a longitudinal axis of the proximal portion of the model bone in the first plane.
3. The method of claim 2 , wherein the second proximal reference axis is the longitudinal axis of the proximal portion of the model bone in the second plane.
4. The method of claim 1 , wherein the first distal reference axis is a longitudinal axis of the distal portion of the model bone in the first plane.
5. The method of claim 4 , wherein the second distal reference axis is the longitudinal axis of the distal portion of the model bone in the second plane.
6. The method of claim 1 , wherein overlying the first proximal reference axis with the first central axis of the proximal fragment of the deformed bone in the first x-ray image on the display device is performed prior to overlying the second proximal reference axis with the second central axis of the proximal fragment of the deformed bone in the second x-ray image on the display device.
7. The method of claim 1 , wherein overlying the first distal reference axis with the first central axis of the distal fragment of the deformed bone in the first x-ray image on the display device is performed prior to overlying the second distal reference axis with the second central axis of the distal fragment of the deformed bone in the second x-ray image on the display device.
8. The method of claim 1 , wherein the first central axis of the proximal fragment in the first x-ray image on the display device is maintained parallel to a vertical axis of the display device.
9. The method of claim 8 , wherein the second central axis of the proximal fragment in the second x-ray image on the display device is maintained parallel to the vertical axis of the display device.
10. The method of claim 1 , wherein the step of overlying the proximal reference axis with the axis of the proximal fragment of the deformed bone in the first image on the display device so that the proximal reference axis is substantially aligned with the axis of the proximal fragment includes at least one of entering numerical values into an input box and moving a slide-bar corresponding to numerical values.
11. The method of claim 1 , wherein overlying the first proximal reference axis with the first central axis of the proximal fragment of the deformed bone in the first image on the display device includes adjusting at least one of a translation and an angulation of the first proximal reference axis with respect to the first distal reference axis.
12. The method of claim 1 , wherein the step of manipulating the model of the proximal fixation ring further includes changing at least one of the position and orientation of the model of the proximal fixation ring with respect to a model of the deformed bone displayed on the display device.
13. The method of claim 1 , further comprising:
displaying a model of a distal fixation ring on the display device; and
manipulating the model of the distal fixation ring so that a position and orientation of the model of the distal fixation ring corresponds to a position and orientation of the distal fixation ring coupled to the distal fragment of the deformed bone.
14. The method of claim 13 , further comprising:
displaying on the display device a plurality of model struts, each of the model struts having at least one of a size, position, and orientation corresponding to one of the plurality of struts coupling the proximal fixation ring to the distal fixation ring.
15. The method of claim 1 , wherein overlying the first proximal reference axis with the first central axis of the proximal fragment of the deformed bone in the first image on the display device is performed manually by a user via an input device.
16. The method of claim 1 , wherein the first plane of the first x-ray image is an anterior-posterior (“AP”) plane.
17. The method of claim 16 , wherein the second plane of the second x-ray image is a lateral plane.