Clamping patella drill guide

1. A patella drill guide for use in preparing a resected patellar bone surface to receive a prosthetic patellar implant, the patella drill guide comprising:

a handle having a proximal end, a distal end, a longitudinal axis extending between the proximal and distal ends, a top surface, a bottom surface and an aperture extending between the top and bottom surfaces;

a base portion extending from the handle to a free distal end having a flat patella bone-facing surface, and a trial articulation surface opposite and spaced from the flat patella bone-facing surface, the trial articulation surface having a curved contour;

an independent bone-gripping portion assembled with the base portion at the free distal end;

a plurality of spaced drill guide bores extending from the trial articulation surface through the base portion to and through the flat patella bone-facing surface;

a cantilever spring member having one end fixed to the handle and an opposite free distal end aligned with the flat patella bone-facing surface;

a bone-gripping member at the free distal end of the cantilever spring member and having a portion extending outward from the cantilever spring member toward the flat patella bone-facing surface of the base portion; and

a deflector engaging a portion of the cantilever spring member between the two ends of the cantilever spring and extending through the aperture in the handle;

wherein:

the cantilever spring member has a relaxed position wherein there is a first distance between the bone-gripping member of the cantilever spring member and the flat patella bone-facing surface of the base portion;

the cantilever spring member has a deflected position wherein the bone-gripping member of the cantilever spring member is spaced a second distance away from the flat patella bone-facing surface of the base portion;

the second distance is greater than the first distance; and

activation of the deflector moves the bone-gripping member of the cantilever spring member from the relaxed position to the deflected position.

2. The patella drill guide of claim 1 wherein when the patella drill guide is configured to be mounted on a patella, and the patella drill guide is rotatable with respect to the patella about an axis extending through the bone-gripping member and the base portion when mounted on a patella.

3. The patella drill guide of claim 2 wherein the axis of rotation is substantially perpendicular to the plane of the flat patella bone-facing surface and substantially parallel to the central longitudinal axis of the drill guide bore.

4. The patella drill guide of claim 1 wherein the bone-gripping component assembled with the base portion is rotatable with respect to the base portion.

5. The patella drill guide of claim 4 wherein the bone-gripping component on the base portion comprises a plurality of spikes.

6. The patella drill guide of claim 5 wherein the bone-gripping member at the free end of the cantilever spring member comprises a plurality of spikes.

7. The patella drill guide of claim 1 wherein the trial articulation surface and the flat patella bone-facing surface comprise discrete components assembled to define a combination patella drill guide and trial.

8. The patella drill guide of claim 1 wherein:

the bone-gripping member at the free end of the cantilever spring member comprises a pedestal and a plurality of spikes extending outward from the pedestal; and

the cantilever spring member is pivatably connected to the bone-gripping member so that the handle, the free end of the base portion and the cantilever spring member are pivotable with respect to the bone-gripping member.

9. The patella drill guide of claim 1 wherein the first distance is greater than zero.

10. The patella drill guide of claim 1 wherein the first distance is zero.