Osteotomy saw/file, cutting guide and method

• US 5,147,364 A
• Filed: 03/01/1990
• Issued: 09/15/1992
• Est. Priority Date: 08/20/1981
• Status: Expired due to Fees

• Current Assignee: Ohio Medical Instrument Co., Inc.
• Original Assignee: Ohio Medical Instrument Co., Inc.
• Inventors: Comparetto, John E.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): Owens, Kerry
• Application Number:
  US07/486,815
• Time in Patent Office: 929 Days
• Field of Search: 29/78, 30/144, 30/166.3, 606/86, 606/87, 606/79, 606/80, 606/82, 606/84, 606/85
• US Class Current: 606/85
• 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

Abstract

A method and apparatus for performing arcuate osteotomies wherein a wedge-shaped correction is filed rather than sawed from the bone. A combined saw and file for use in the method has a curved blade with teeth along a longitudinal edge for making an arcuate cut in the direction perpendicular to the edge, and file teeth on one or both of its curved faces for filing out the correction. The effective width of the the blade determines the tip width of the correction; the thickness of the blade determines the width of the arcuate kerf; and the radius of curvature of the blade determines the radius of the arcuate cut. Also disclosed is cutting guide for guiding a saw/file or other cutting implement to make the arcuate cut and the correction.

Claims

1. An osteotomy saw/file comprising:

a semicircularly curved blade of uniform thickness having first and second faces on opposite sides thereof and first and second longitudinal edges between said faces,

at least one of said faces comprising a file having teeth for filing a kerf in a bone in a direction transverse to said face,

said first edge having teeth formed thereon for cutting edgewise through a bone to make an arcuate cut having a curvature corresponding to that of said blade, and

a shank for engagement by a drive motor to apply reciprocating motion to said blade,

the described configuration of said blade thereby enabling an arcuate osteotomy including both a correction cut and an arcuate cut to be performed without removing the blade from a bone, the blade filing a correction cut as a kerf when the blade is advanced in a bone in a direction transverse to said one face and sawing an arcuate cut when advanced circumferentially in a bone along the circumference of said blade.

2. An osteotomy saw/file in accordance with claim 1 wherein,

said blade has a semi-circular cross sectional shape, said first face being concave and said second face being convex.

3. An osteotomy saw/file in accordance with claim 2 wherein said first face is concave and comprises said file.

4. An osteotomy saw/file in accordance with claim 2 wherein said second face is convex and comprises said file.

5. An osteotomy saw/file in accordance with claim 1 wherein said shank is elongated and has an axis parallel to said first edge.

6. An osteotomy saw/file in accordance with claim 1 wherein said shank is centered with respect to said first and second edges.

7. An osteotomy file for filing a transversely tapered correction in a bone,

said file having a blade with first and second faces on opposite sides thereof,

said faces being angulated to one another,

each said face comprising a film having teeth for filing a bone,

the angulation of said faces defining a taper for filing a correction in an osteotomy

said blade having no taper in its longitudinal direction thereby being adapted to cut on both said faces simultaneously, to form a correction slot which is tapered transversely but not longitudinally.

8. An osteotomy instrument comprising a bone file and a guide for controlling the path of filing movement of said file in a bone,

said file comprising,

a blade having first and second faces on opposite sides thereof and first and second longitudinal edges between said faces,

at least one of said faces having teeth for filing a kerf in a direction transverse to said face when reciprocated, and

a shank for engagement by drive means to apply reciprocating motion to said blade;

said guide comprising, means mountable to a bone to guide said file for filing a kerf in the form of a slot of uniform width and extending in a direction transverse to said one face.

9. An osteotomy instrument comprising a bone file and a guide for controlling the path of filing movement of said file in a bone,

said file comprising,

a blade having first and second faces on opposite sides thereof and first and second longitudinal edges between said faces,

at least one of said faces having teeth for filing a kerf in a direction transverse to said face when reciprocated, and

a shank for engagement by drive means to apply reciprocating motion to said blade;

said guide comprising, means mountable to a bone to guide said file for filing a kerf extending in a direction transverse to said one face,

a slide mounted for movement along and guided by said arm,

said slide having means for holding said blade perpendicular to said slide while said file is reciprocated,

said file filing a kerf in said bone when said slide is moved along said arm as said file is reciprocated.

10. An osteotomy instrument in accordance with claim 9 wherein said arm has a slot and said slide is slidable along and guided by said slot.

11. An osteotomy instrument in accordance with claim 9 further including means for adjusting the angle of said blade with respect to said slide, thereby to change the width of said kerf.

12. An osteotomy instrument in accordance with claim 9 further wherein said arm has pivot means securable to a bone, said arm being swingable about said pivot means.

13. An osteotomy instrument in accordance with claim 12 wherein at least one of said longitudinal edges of said file has teeth formed thereon for cutting a kerf edgewise through a bone when said file is reciprocated and said arm is swung about said pivot means.

14. Apparatus for performing arcuate osteotomies comprising a cutting guide and a bone cutting implement,

said cutting guide comprising,

an arm,

a pivot pin extending from said arm and securable into a bone, said arm being swingable about said pivot pin,

a slide mounted for guided movement along said arm,

means on said slide for holding said cutting implement for cutting a kerf perpendicular to said arm,

said slide being movable inwardly and outwardly along said arm to guide said cutting implement,

said arm also presenting a stop which arrests inward movement of said slide so that when said arm is rotated about said pin, said cutting implement is moved along an arc of constant radius.

15. The apparatus of claim 14 wherein said guide further includes means for limiting the extent of rotation of said arm about said pivot pin, thereby to guide said cutting implement to form a tapered correction by moving said slide along said arm along first and second angular paths corresponding to the limits of rotation of said arm about said pivot pin.

16. The apparatus of claim 14 wherein said rotation limiting means is a transverse slot in said arm and a stop extending through said slot and into a bone,

said arm being swingable about said pivot pin between angular positions at which said stop arrests the opposite ends of said slot.

17. The apparatus of claim 14 wherein said cutter is a file.

18. The apparatus of claim 14 wherein said cutter is a rotary burr.

19. The apparatus of claim 14 wherein said cutter is a reciprocating saw.

20. In the method of performing an arcuate osteotomy wherein an arcuate cut is made with a cutting implement across part of the width of a bone and a tapered correction is cut across the rest of the width of the bone, thereby severing the bone into two segments which can be rotated about the arcuate cut to close the correction and thereby straighten the bone,

the improvement comprising,

mounting a cutting guide for rotation about a pivot pin fixed to said bone, said guide presenting a guide track which extends outwardly from said pivot,

moving a rotary burr cutter along said guide track to cut one side of said correction,

swinging said guide about said pivot to a second angular position corresponding to a desired taper for the correction, and

moving said rotary burr cutter along said guide track to cut a second side of said correction.

21. The improvement of claim 20 wherein said rotary burr cutter is held at a given position along said guide track as said guide is swung about said pivot pin thereby to cut said arcuate cut.

22. In a method of performing an arcuate osteotomy wherein an arcuate cut is sawn across part of the width of a bone and a correction extends across the rest of the width of the bone to an opposite side thereby severing the bone into two segments, and wherein the segments are then rotated about said arcuate cut and set in a desired new alignment,

the improvement comprising,

making said correction by filing a wedge-shaped kerf which extends between said arcuate cut and said opposite side of the bone.

23. The improvement of claim 22 wherein said correction is made by filing said kerf with a curved blade having a file cut on a curved face thereof.

24. The improvement of claim 22 wherein said correction is filed inwardly from said opposite side of the bone,

said correction being made with a blade having a concave face with a file cut thereon.

25. The improvement of claim 22 wherein said arcuate cut is made by cutting with an edge of a curved blade, and

said correction is cut by filing with a curved face of said blade.

26. The improvement of claim 25 wherein said blade is moved in a direction transverse to said curved face to file said correction.

27. The improvement of claim 25 wherein said correction is made before said arcuate cut, by filing it with a semicircularly curved blade having a file on a concave face thereof, and

said arcuate cut is made from said correction.

28. The improvement of claim 23 wherein the path of said blade is guided by a guide fixed to said bone,

said arcuate cut is made by swinging said guide around a pin fixed to said bone, said blade moving along a semicircular path,

said blade having a radius of curvature equal to the radius of curvature of said path.

29. The improvement of claim 28 further wherein said blade is moved along a transverse path defined by said guide to make said correction.

30. The improvement of claim 29 wherein said guide is swung between angular movement limiting stops to guide said blade to cut a wedge-shaped correction.

31. The improvement of claim 22 wherein said kerf is wider than said arcuate cut.