Surgical instrument

• US 9,572,590 B2
• Filed: 10/02/2007
• Issued: 02/21/2017
• Est. Priority Date: 10/03/2006
• Status: Active Grant

• Current Assignee: Biomet UK Ltd (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet UK Ltd (Zimmer Biomet Holdings, Inc.)
• Inventors: Singhal, Keshav, Pitkanen, Heikki Vilhelm, Metcalfe, Nick James Theophilius
• Primary Examiner(s): HANNA, SAMUEL SALEEB
• Application Number:
  US12/444,143
• Publication Number:
  US 20100292743A1
• Time in Patent Office: 3,430 Days
• Field of Search: 623/22.11, 623/22.12, 623/22.15, 623/20.36, 623/20.32
• US Class Current: 1/1
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion

Abstract

An instrument (2) for aligning a surgical tool, the instrument (2) comprising, a body portion (4) having a tool guide (90), first and second arms (6), (8) operatively connected to the body portion (4) and adapted to engage a bone, and urging means (10), acting between the body portion (4) and the first and second arms (6), (8), for urging the first and second arms (6), (8) into engagement with a predetermined portion of a bone, thereby clamping the arms (6), (8) onto the bone and aligning the tool guide (90) with the bone.

Claims

1. An instrument for aligning a surgical tool on a femoral head and a femoral neck of a femur, the instrument comprising:

a body portion having a threaded post fixed to the body portion and projecting proximally, along a longitudinal axis, from a proximal surface of the body portion,

a first arm, and a second arm, the first arm and the second arm each pivotably connected to the body portion via a first fork and a second fork, respectively, extending from opposite sides of the post and fixed to the body portion, each of the first and second arms having a distal portion, a proximal portion, and a coupling portion located between the distal and proximal portions, each of the coupling portions being coupled to one of the opposing forks by a pivot pin, wherein the distal portion of each of the first arm and the second arm is curved along a length of the distal portion forming a concave bone facing surface, a distal end of the distal portion of the second arm including a bifurcated tab including two curved jaw elements for engaging the femoral neck, and a distal end of the distal portion of the first arm including a curved jaw for engaging the femoral neck, the proximal portion of each of the first arm and the second arm including a curved cam surface,

the threaded post comprising at least a first bore and a second bore extending therethrough, the first bore having a first longitudinal axis differently aligned from a second longitudinal axis of the second bore, and the first and the second longitudinal axes are differently aligned from the longitudinal axis of the post; and

a nut having a threaded bore configured to threadably engage the post, the nut including a frustoconical engagement surface that tapers outwardly from the threaded bore, the frustoconical engagement surface configured to engage the curved cam surfaces of the proximal portions of the first and second arms and causes the two curved jaw elements and the curved jaw of the first and second arms to engage a predetermined portion of the femoral neck upon threading the nut along the post,

wherein when the first and second arms are clamped on the femoral neck, the first longitudinal axis and the second longitudinal axis converge towards a center portion of the femoral head at a point at a predetermined distance proximate the body portion, the point being located inside the femoral head when the instrument engages the femoral neck.

2. The instrument of claim 1, wherein the curved jaw of the first arm is curved to match a profile of the femoral neck.

3. The instrument of claim 1, wherein the first fork and the second fork each constrains lateral motion of the first arm and the second arm, respectively, towards and away from one another.

4. The instrument of claim 1, wherein longitudinal axes of a third bore and a fourth bore each converge at a different point from the first longitudinal axis and the second longitudinal axis.

5. The instrument of claim 1, wherein the post is configured to allow for drilling an alignment hole into the femoral neck of the femoral head.

6. A surgical instrument for aligning a surgical tool on a femoral head and a femoral neck of a femur, the surgical instrument comprising:

a body portion having opposed forks and an intermediate annular flange having a proximal surface and a distal surface, a threaded post fixed to the body portion and projecting proximally, along a first longitudinal axis, from the proximal surface of the body portion, the post including a plurality of guide bores extending therethrough, at least two of the plurality of guide bores extending through the threaded post along longitudinal axes at different angles relative to each other and to the first longitudinal axis of the threaded post;

a first arm and a second arm each pivotably coupled to one of the opposed forks of the body portion, each of the first and second arms having a distal portion, a proximal portion, and a coupling portion located between the distal and proximal portions, each of the coupling portions being coupled to one of the opposing forks by a pivot pin, wherein the distal portion of each of the first arm and the second arm is curved along a length of the distal portion forming a concave bone facing surface, a distal end of the distal portion of the second arm including a bifurcated tab including two curved jaw elements for engaging the femoral neck, and a distal end of the distal portion of the first arm including a curved jaw for engaging the femoral neck, the proximal portion of each of the first arm and the second arm including a curved cam surface; and

a nut having a threaded bore configured to threadably engage the post, the nut including a frustoconical engagement surface that tapers outwardly from the threaded bore, the frustoconical engagement surface engages the curved cam surfaces of the proximal portions of the first and second arms and configured to urge the curved jaw of the first arm and the two curved jaw elements of the second arm together to contact the femoral neck upon threading the nut along the post,

wherein the at least two of the plurality of guide bores are configured such that when the jaws of the first and second arms are in contact with the femoral neck, the longitudinal axes of the bores are aligned at a predetermined collodiaphyseal angle between the femoral neck and a shaft of the femur, and are aligned at a predetermined anteversion.

7. The surgical instrument of claim 6, wherein motion of the first arm and the second arm is restricted to a first direction in which the distal ends of the first and second arms move towards one another, and a second direction in which the distal ends of the first and second arms move apart.

8. The surgical instrument of claim 6, wherein the axes of the at least two of the plurality of guide bores converge inside the femoral neck bone when the surgical instrument is coupled to the femoral neck.