Granted Patent B2

US 9,855,104 · App. 14/401,715 · Granted Jan 2, 2018

Abstract

Claims (20)

1. A method for identifying a length of a bone screw to be inserted through a bore drilled in a predetermined drilling direction at a predetermined position through a bone, the method comprising:

identifying the predetermined drilling direction and the predetermined position in a first X-ray image of the bone, transferring the identified direction and position to a corresponding bone model, wherein the identification of the predetermined position at the bone includes a measurement of distances between the bore and an outer surface of the imaged bone (i) in an axial direction of the bone and (ii) in a direction perpendicular to the axial direction of the bone, and

determining the length of the bone screw based on the transferred direction and position at the bone model.

2. The method of claim 1 , further comprising the step of determining a diameter of the imaged bone between two opposed outer surfaces of the imaged bone in relation to a reference body visible in the first X-ray image.

3. The method of claim 2 , further comprising the step of determining a diameter of the imaged bone between two opposed outer surfaces of the imaged bone in relation to the reference body in a second X-ray image of the bone, wherein imaging directions of the first X-ray image and the second X-ray image differ from each other.

4. The method of claim 1 , further comprising the step of selecting a bone model from a group of bone models with different sizes and shapes, the selected bone model corresponding to the imaged bone.

5. The method of claim 1 , further comprising the step of adapting the bone model so that the bone model corresponds to the imaged bone.

6. The method of claim 1 , wherein the first X-ray image is generated in a direction being parallel to the drilling direction.

7. The method of claim 1 , wherein the length (L) of the bone screw corresponds to a distance between the outer surfaces of the bone at two ends of the bore.

8. The method of claim 1 , wherein the bone screw is a locking screw adapted to be inserted through a lateral bore of a bone nail.

9. A method for identifying a length of a bone screw to be inserted through a bore drilled in a predetermined drilling direction at a predetermined position through a bone, the method comprising:

taking a first x-ray image of the bone and of a reference body visible in the first x-ray image;

identifying the predetermined drilling direction and the predetermined position in the first X-ray image of the bone, wherein the identification of the predetermined position at the bone includes a measurement of distances between the bore and outer surface of the imaged bone (i) in an axial direction of the bone and (ii) in a direction perpendicular to the axial direction of the bone;

selecting a bone model from a database containing a group of human bone models with different sizes and shapes, the selected bone model being the bone model in the database most closely corresponding to the imaged bone;

transferring the identified direction and position to the selected bone model; and

determining the length of the bone screw based on the transferred direction and position from the bone model.

10. The method of claim 9 , further comprising determining a diameter of the imaged bone between two opposed outer surfaces of the imaged bone in relation to the reference body visible in the first X-ray image.

11. The method of claim 9 , wherein the first X-ray image is generated in a direction being parallel to the drilling direction.

12. The method of claim 9 , wherein the length (L) of the bone screw corresponds to a distance between the outer surfaces of the bone at two ends of the bore.

13. The method of claim 9 , wherein the bone screw is a locking screw adapted to be inserted through a lateral bore of a bone nail.

Assignments (6)