NZ767376B2 - Acetabular reamer handle and method of reaming an acetabulum - Google Patents

Abstract

acetabular reamer handle including a hollow shaft (20) having a distal end (32) and wall with pair of holes (55) extending therethrough; a neck part (6) having a longitudinal axis (46); a driveline (40) extending through the shaft and the neck part; and a locking mechanism. A distally located head part (42) of the driveline is mounted for rotation about the longitudinal axis of the neck part and is connectable to a reamer (not shown). The distal end of the shaft (32) and a proximal end of the neck part (62) are pivotally attached to allow the shaft to be tilted relative to the longitudinal axis. The locking mechanism includes an engagement member (50) having a ring-shaped engagement surface (51) at the distal end of the locking mechanism, a spring (80) mounted proximally with respect to the engagement member, a handle (52) at the proximal end of the locking mechanism, and a pair of arms (54) extending from the proximal end to the distal end of the locking mechanism. The engagement member and spring are mounted inside the hollow shaft, the engagement member being slidably mounted and configured to protrude from the distal end of the hollow shaft to urge the engagement surface against the proximal end of the neck part to resist tilting of the shaft relative to the longitudinal axis of the neck part. The pair of arms extend through a respective hole of the pair of holes (55) in the hollow shaft at the proximal end of the locking mechanism so that the handle is mounted outside the hollow shaft. The proximal end of the neck part includes a surface (8) for engagement with the engagement surface of the engagement member, the neck part surface contained in a plane oriented at a non-zero angle less than 90° with respect to the longitudinal axis of the neck part. Allowing the neck of the reamer handle to be tilted during surgery allows a surgeon a better view for determining the depth to which the acetabulum has been reamed, without having to remove the reamer and reamer handle from the acetabulum or disconnect the reamer handle from the reamer.

Claims (10)

1. An acetabular reamer handle comprising: a hollow shaft having a distal end and a wall with pair of holes extending therethrough; a hollow neck part having a longitudinal axis; a driveline extending through the shaft and the neck part, wherein a distally located head part of the driveline is mounted for rotation about the longitudinal axis of the neck part and is connectable to an acetabular reamer, and wherein the distal end of the shaft and a proximal end of the neck part are pivotally attached to allow the shaft to be tilted relative to the longitudinal axis of the neck part; and a locking mechanism having a proximal and distal end, the locking mechanism comprising: an engagement member having an engagement surface located at the distal end of the locking mechanism, wherein the engagement surface is positioned at the distal end of the hollow shaft and is ring-shaped and substantially perimetric to a longitudinal axis of the hollow shaft at the distal end of the shaft, wherein the engagement member is slidably mounted inside the hollow shaft and is configured to protrude from the distal end of the hollow shaft to urge the engagement surface against the proximal end of the neck part; a spring mounted proximally with respect to the engagement member, the spring being mounted inside the hollow shaft; a handle mounted at the proximal end of the locking mechanism, the handle being mounted outside the hollow shaft; a pair of arms extending from the proximal end to the distal end of the locking mechanism such that the pair of arms are substantially parallel to the distal end of the hollow shaft, the pair of arms being mounted to the engagement member at the distal end of the locking mechanism and the handle at the proximal end of the locking mechanism, and the pair of arms extending through a respective hole of the pair of holes in the hollow shaft at the proximal end of the locking mechanism so that the handle is mounted outside the hollow shaft; and wherein the engagement member moveable distally to urge the engagement surface against the proximal end of the neck part to resist said tilting of the shaft relative to the longitudinal axis of the neck part, wherein the proximal end of the neck part includes a surface for engagement with the engagement surface of the engagement member, wherein said surface of the proximal end of the neck part is contained in a plane and said plane is oriented at a non-zero angle with respect to the longitudinal axis of the neck part, where < 90 .

2. The acetabular reamer handle of claim 1, wherein the engagement member is resiliently biased distally to urge the engagement surface against the proximal end of the neck part.

3. The acetabular reamer handle of claim 2, wherein the spring comprises a helical spring further mounted coaxially with respect to the distal end of the hollow shaft.

4. The acetabular reamer handle of claim 1, wherein the handle is configured for manually retracting the engagement member in a proximal direction to release the engagement surface from the proximal end of the neck part.

5. The acetabular reamer handle of claim 1, comprising one or more locking members extending from the engagement surface to be received within one or more corresponding openings in the proximal end of the neck part for locking the engagement surface against the proximal end of the neck part to resist said tilting of the shaft relative to the longitudinal axis of the neck part.

6. The acetabular reamer handle of claim 1, wherein the acetabular reamer handle is an offset acetabular reamer handle in which the hollow shaft includes a proximal shaft section and a distal shaft section, in which the shaft has a bend located at an interface between the proximal shaft section and the distal shaft section.

7. The acetabular reamer handle of claim 6, wherein the proximal shaft section and the distal shaft section are rigidly formed whereby the angle between the longitudinal axis of the distal shaft section and a longitudinal axis of the proximal shaft section is fixed.

8. A surgical kit comprising the acetabular reamer handle of claim 1 and one or more differently sized acetabular reamers connectable to the head part of the acetabular reamer handle.

9. The acetabular reamer handle of claim 1, substantially as herein described with reference to any embodiment disclosed.

10. The surgical kit of claim 8, substantially as herein described with reference to any embodiment disclosed.