A CUTTING ASSEMBLY AND A DRIVE ASSEMBLY FOR A SURGICAL INSTRUMENT

A cutting assembly (12) for a surgical instrument including a drive assembly (14) having a handpiece (40) defining a handpiece irrigation path (42) comprises an outer hub (34), an outer tube (16) extending from the outer hub (34) and defining a distal tube opening (186), a seal (30) coupled to the outer hub (34), a cutting implement (18) comprising a cutting shaft (22) coaxially disposed within the outer tube (16), and a bur (82). The cutting assembly (12) further comprises a drive hub (24) coupled to a proximal end of the cutting shaft (22) and configured to be removably coupled with the drive assembly (14) for rotating the cutting shaft (22) within the outer tube (16), wherein the cutting shaft (22) and the drive hub (24) are axially movable relative to the outer hub (34). An irrigation spacer (170) is coupled to the outer hub (34) and positioned distal to the drive hub (24), the irrigation spacer (170) defining a bore (174) through which the cutting shaft (22) is rotatably disposed, and further defining irrigation passageways (178) configured to be arranged in fluid communication with the handpiece irrigation path (42) of the handpiece (40). The irrigation spacer (170) is configured to provide a stop of distal axial movement of the cutting shaft (22) and the drive hub (24) for permitting fluid to flow through the irrigation passageways (178).