A cutting assembly for a surgical instrument. A tube assembly includes an outer tube having an outer cutting window, and an inner tube coaxially disposed within and rotatable relative to the outer tube. The inner tube includes an inner cutting window such that the inner and outer cutting windows define a cutting window of the tube assembly. A portion of the inner tube distal a proximal boundary of the cutting window may define a distal region of the inner tube. A projection is within a lumen of the inner tube with at least a portion of the projection disposed within the distal region. The projection may be an insert. The projection occupies a volume of the distal region and/or reduces a cross-sectional area of the lumen distal to the proximal boundary. The projection reduces the size of material removed through the cutting window to reduce clogging of the tube assembly.