Rotary surgical cutting tool and related accessories

1 . A high-speed surgical bur assembly configured to cut tissue and to be coupled to a surgical handpiece assembly, the high-speed surgical bur assembly comprising:

a nose tube defining a lumen extending between proximal and distal ends of the nose tube, the nose tube having a proximal portion extending along an axis, the proximal portion of the nose tube having an outer surface defining a recess for receiving a biasing member of the surgical handpiece assembly to constrain a depth of the nose tube relative to the surgical handpiece assembly, and the nose tube comprising a projection disposed proximal to the recess, the projection configured to constrain a radial orientation of the nose tube relative to the surgical handpiece assembly to prevent relative rotation between the nose tube and the surgical handpiece assembly;

a driveshaft at least partially disposed within the lumen of the nose tube and configured to rotate relative to the nose tube, the driveshaft having a drive portion at a proximal region of the driveshaft for engaging a rotatable drive chuck of the surgical handpiece assembly, and the driveshaft having a retention portion distal to the drive portion;

a proximal bushing disposed at least partially within the lumen of the nose tube, the proximal bushing surrounding a portion of the drive shaft and being sized smaller than the retention portion to prevent movement of the driveshaft in a distal direction relative to the nose tube;

a cutting tool coupled to a distal region of the driveshaft opposite the drive portion, the cutting tool configured to rotate with the driveshaft relative to the nose tube in response to rotation of the rotatable drive chuck of the surgical handpiece assembly; and

a distal bushing coupled to a distal region of the nose tube and extending distally outside the nose tube, the distal bushing surrounding a portion of the driveshaft proximal the cutting tool and being sized smaller than the cutting tool to prevent movement of the driveshaft in a proximal direction relative to the nose tube;

wherein the proximal and distal bushings axially constrain the driveshaft to the nose tube such that movement of the driveshaft relative to the nose tube in proximal and distal directions is prevented; and

wherein the driveshaft further comprises an alignment portion proximal the drive portion of the driveshaft, the alignment portion configured to align the drive portion of the driveshaft with the rotatable drive chuck of the surgical handpiece assembly and permit engagement between the drive portion of the driveshaft and the rotatable drive chuck, and wherein the alignment portion defines a notch extending distally from the proximal end such that the notch is formed at the proximal end of the driveshaft for mitigating contact between the alignment portion of the driveshaft and the rotatable drive chuck during engagement of the alignment portion with the rotatable drive chuck.

2 . The high-speed surgical bur assembly of claim 1 , wherein the projection of the proximal portion of the nose tube extends proximally and generally parallel to the axis.

3 . The high-speed surgical bur assembly of claim 1 , wherein a proximal end of the projection of the proximal portion of the nose tube comprises a rounded surface.

4 . The high-speed surgical bur assembly of claim 1 , wherein the projection of the proximal portion of the nose tube includes a flat surface that is parallel to the axis of the proximal portion of the nose tube, the flat surface configured to abut a surface of the surgical handpiece assembly to prevent relative rotation between the nose tube and the surgical handpiece assembly.

5 . The high-speed surgical bur assembly of claim 1 , wherein the alignment portion has an outer surface tapering toward the axis as the alignment portion extends from the drive portion to a proximal end of the driveshaft, the alignment portion configured to engage the rotatable drive chuck of the surgical handpiece assembly to align the drive portion to a driving orientation for the drive portion of the driveshaft to engage the rotatable drive chuck.

6 . The high-speed surgical bur assembly of claim 1 , wherein the alignment portion comprises a proximal edge for engaging the rotatable drive chuck of the surgical handpiece assembly to align the drive portion to a driving orientation for the drive portion of the driveshaft to engage the rotatable drive chuck.

7 . The high-speed surgical bur assembly of claim 6 , wherein the alignment portion comprises a proximal surface disposed proximally of the proximal edge to prevent the proximal edge from further engagement with the rotatable drive chuck of the surgical handpiece assembly after the drive portion is aligned in the driving orientation.

8 . The high-speed surgical bur assembly of claim 7 , wherein the proximal surface comprises a planar surface perpendicular to the axis.

9 . The high-speed surgical bur assembly of claim 1 , wherein the outer surface of the proximal portion of the nose tube has a proximal shoulder that defines a proximal end of the recess, and wherein the proximal shoulder is tapered, and wherein the proximal shoulder is configured to engage the biasing member of the surgical handpiece assembly to force the nose tube into the surgical handpiece assembly.

10 . The high-speed surgical bur assembly of claim 1 , wherein the proximal region of the driveshaft comprises the retention portion, and wherein the retention portion is disposed outside of the lumen of the nose tube.

11 . The high-speed surgical bur assembly of claim 1 , further comprising a middle bushing disposed within the lumen of the nose tube between the proximal and distal bushings, the middle bushing preventing contact between the driveshaft and the nose tube within the lumen of the nose tube.

12 . The high-speed surgical bur assembly of claim 11 , wherein the middle bushing is fixed to the nose tube.

13 . The high-speed surgical bur assembly of claim 11 , wherein the proximal and distal bushings retain the middle bushing within the lumen of the nose tube.

14 . The high-speed surgical bur assembly of claim 11 , wherein the middle bushing is retained in the lumen of the nose tube by a bend in the nose tube and a corresponding bend of the middle bushing.