Minimally Invasive Bone Broach

• US 20100094295A1
• Filed: 12/15/2009
• Published: 04/15/2010
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Original Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Inventors: Schnieders, Barry, Daniels, David W., Jones, Michael C.
• Granted Patent: US 8,562,609 B2
• Time in Patent Office: Days
• US Class Current: 606/79
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1668 for the upper femur A61B17/164 takes precedence
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61F 2002/4658 for measuring dimensions, e.g. length

Abstract

A broaching system is disclosed for creating a cavity in a bone. The cavity has a cross section which has a generally triangular profile having a first side generally parallel with an axis of the bone and a second side forming an acute angle with the first side. The cavity is contiguous with a pre-existing conical cavity in the bone. The apparatus comprises as shaft and a broach. The shaft has a longitudinal axis. The broach is mounted to the shaft and has a first cutting side mounted at the acute angle relative to the longitudinal axis of the shaft. The first cutting side is formed to include teeth. The shaft and broach are configured so that when the longitudinal axis of the shaft is advanced into the bone along the axis of the bone, the teeth of the broach form the triangular cavity. A method for cutting a triangular cavity in bone is also described. The method comprises a providing a shaft step, an incising step and a cutting step. The provided shaft is configured to be movable relative to the bone to be prepared and includes a broach coupled thereto to dispose a cutting surface of the broach at an acute angle relative to the shaft. The shaft and broach have a width defined by the distance between the shaft and the outer most portion of the cutting surface. The incising step includes incising the patient adjacent the bone to be prepared to form an incision having a length approximating the width of shaft and broach. The cutting step includes cutting the cavity by driving the broach by moving the shaft relative to the bone.

Claims

1. Apparatus for creating a cavity in a bone, said cavity (i) having a cross section which has a generally triangular profile having a first side generally parallel with an axis of the bone and a second side forming an acute angle with the first side, and (ii) being contiguous with a pre-existing conical cavity in the bone, said apparatus comprising:

a shaft having a longitudinal axis;

a broach mounted to the shaft and having a first cutting side mounted at the acute angle relative to the longitudinal axis of the shaft the first cutting side being formed to include teeth; and

wherein the shaft and broach are configured so that when the longitudinal axis of the shaft is advanced into the bone along the axis of the bone, the teeth of the broach form the triangular cavity.

2. The device of claim 1 wherein shaft includes a proximal end and a distal end and the broach is mounted adjacent the distal end and further comprising a head coupled to the proximal end of the shaft.

3. The device of claim 2 wherein the shaft includes a proximal portion and a distal portion and wherein the proximal portion has a larger cross section perpendicular to the longitudinal axis than the corresponding cross section of the distal portion and the corresponding cross section of the distal portion is sized to be received in a cavity reamed about the longitudinal axis of the bone.

4. The device of claim 3 wherein the distal portion of the shaft is formed to include witness marks which when registered with an indicator after advancing the shaft facilitate selection of an appropriately sized prosthesis component.

5. The device of claim 4 wherein the broach includes oppositely facing spaced apart triangular shaped side walls between which the first cutting side extends.

6. The device of claim 5 distal shaft portion is removably attached to the proximal shaft portion.

7. The device of claim 4 and further comprising a broach shell for registering the apparatus with the pre-existing conical cavity, the broach shell having a longitudinal axis, an external surface a portion of which engages the wall of the pre-existing conical cavity, and a shell configured to receive the shaft and allowing the shaft to move along the longitudinal axis.

8. The device of claim 7 and wherein the proximal end of the broach shell acts as the indicators for indicating the longitudinal location of the broach relative to the broach shell.

9. Apparatus for creating a cavity in a bone for receiving a prosthesis which has a conical portion and a projection of a generally triangular profile, said apparatus comprising:

a shell comprising a conical portion which defines a longitudinal axis and a shaft-receiving cavity for receiving a shaft;

a shaft configured to be received in the shaft-receiving cavity and being movable with respect to the shell along the longitudinal axis when so received, said shaft being configured to carry a broach having a cutting surface disposed at an acute angle relative to the longitudinal axis, and

a broach having a generally triangular profile and including oppositely facing spaced apart triangular shaped side walls between which the cutting surface extends, the broach being mounted to the shaft.

10. The apparatus of claim 9 wherein the shell includes a longitudinal slot communicating with the shaft receiving cavity through a wall of the shell and the shaft is formed to include a plate formed symmetrically about a plane including the longitudinal axis and configured to be received in the slot for longitudinal movement relative to the slot when the shaft is received in the shaft-receiving cavity, the longitudinal slot and the plate cooperating to inhibit rotation of the shaft about the longitudinal axis.

11. The apparatus of claim 9 and further comprising a driver component coupled to the shaft.

12. The apparatus of claim 11 wherein driver component is removably coupled to the shaft and further comprising:

a second shaft configured to be received by the shaft-receiving cavity and being movable with respect to the shell along the longitudinal axis when so received, said shaft being configured to carry a broach having a cutting surface disposed at an acute angle relative to the longitudinal axis, the second shaft being configured to be removably coupled to the driver component, and

a second broach having a generally triangular profile and including oppositely facing spaced apart triangular shaped side walls between which the cutting surface extends, the side walls being spaced apart by a displacement greater than the displacement between the side walls of the first broach, the second broach being mounted to the shaft.

13. The apparatus of claim 12 and further comprising a second shell comprising a conical portion which defines a longitudinal axis and a shaft-receiving cavity for receiving the first or second shaft wherein the conical portion of the second shell is larger than the conical portion of the first shell.

14. The apparatus of claim 13 and further comprising a first pilot stem configured for removable coupling to the first or second shell and having a diameter sized to be received in a cavity formed in the intramedullary canal of the bone along the axis of a bone with a reamer having a first diameter, and a second pilot stem configured for removable coupling to the first or second shell and having a diameter sized to be received in a cavity formed in the intramedullary canal of the bone along the axis of a bone with a reamer having a second diameter smaller than the first diameter.

15. The apparatus of claim 14 wherein the first and second shell each include a longitudinal slot communicating with the shaft receiving cavity through a wall of the shell and the first and second shaft are each formed to include a plate formed symmetrically about a plane including the longitudinal axis and configured to be received in the slot for longitudinal movement relative to the slot when the shaft is received in the shaft-receiving cavity of the first or second shell, the longitudinal slot and the plate cooperating to inhibit rotation of the shaft about the longitudinal axis.

16. The apparatus of claim 15 wherein the first and second shell each include a longitudinal channel communicating with the shaft receiving cavity through a wall of the shell and communicating with the longitudinal slot, the longitudinal channel being formed to allow the first and second broach to travel uninhibited therein as the first and second shaft are advanced distally within the shaft receiving cavity.