METHODS AND APPARATUS FOR DETERMINING PIN PLACEMENT DURING HIP SURGERY

• US 20090018546A1
• Filed: 07/10/2008
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Daley, Robert J.
• Granted Patent: US 8,882,780 B2
• Time in Patent Office: Days
• US Class Current: 606/92
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/1742 for the hip
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61B 2017/568 produced with shape and dimensions specific for an individual patient
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides

Abstract

New apparatuses and methods for their design and use are disclosed that can be used to assist a surgeon in placing a guide pin during hip surgery. Specifically, a hip surgery method is disclosed in which an image of a patient'"'"'s femur can be obtained and used to design and prepare a mold that contains an aperture for guiding a drill at the desired location and angle. During surgery the mold can be quickly and accurately positioned on the exposed femur head. Then, a drill bit can be inserted through the aperture and an opening for a pin can be drilled into the femur head. The mold can have a unique contoured surface adapted to fit to the femur head in a single unique position such that the opening is made in a unique desired position. The apparatuses and methods facilitate faster, more accurate surgery and are less invasive.

Claims

1. A method of performing a portion of a hip surgery, the method comprising:

obtaining data indicative of a shape of a femur head;

preparing a mold that defines a first aperture, the mold being shaped to fit on to the femur head based on the obtained data;

positioning the mold on the femur head;

inserting a drill bit through the first aperture; and

drilling an opening into the femur head.

2. The method of claim 1 further comprising, placing a pin into the opening in the femur head.

3. The method of claim 2 further comprising, positioning a central aperture of a resurfacing tool on the pin and removing a portion of the surface of the femur head to form a new surface on a perimeter of the femur head.

4. The method of claim 3, wherein the new surface includes a cylindrical surface.

5. The method of claim 3 further comprising, removing the resurfacing tool and the pin and affixing a surface replacement device onto the femur head.

6. The method of claim 5, wherein the surface replacement device has a portion adopted to match the new surface of the femur head.

7. The method of claim 5, wherein the surface replacement device has a protruding pin adapted to fit within the opening in the femur head.

8. The method of claim 1, wherein the mold defines a second aperture for a positioning pin and the positioning pin is placed through the second aperture into the femur head.

9. The method of claim 1, wherein the mold defines a slot for guiding a cutting device.

10. The method of claim 9, further comprising positioning a cutting device into the slot and cutting into the femur head using the slot as a guide.

11. An apparatus for determining pin placement in a femur head, the apparatus comprising:

a mold formed from data indicative of a shape of the femur head, the mold including a contoured contact surface for contacting the femur head, the mold defining a first aperture.

12. The apparatus of claim 11, wherein the contoured contact surface is adapted to fit on an exposed portion of the femur head in a unique position.

13. The apparatus of claim 11, wherein the contoured contact surface is adapted to fit on an exposed femur head in a unique position such that the first aperture is substantially aligned with an axis in the femur head that is in alignment with a femur neck.

14. The apparatus of claim 11, wherein the mold defines a guide for a cutting device, the guide being aligned with the femur head so as to define an angle and a position for a cut into the femur head.

15. The apparatus of claim 11, further defining a second aperture for positioning a first pin to secure the mold to the femur head.

16. The apparatus of claim 12, further defining a third aperture for positioning a second pin to secure the mold to the femur head.

17. The apparatus of claim 11, wherein the mold is at least partially made of plastic.