A cutting assembly for a surgical instrument having a drive assembly is described. The cutting assembly comprises a tube assembly comprising a cutting window near a distal end and adapted to be applied to a surgical site of a patient, an outer tube, an inner tube coaxially disposed within and rotatable relative to the outer tube with the drive assembly with the inner tube comprising a lumen. The cutting assembly further comprising a drive hub coupled to the inner tube with the drive hub defining an aperture adapted to slidably receive a proximal end of the inner tube, and defining a reduced aperture in communication with the aperture. A diameter of the reduced aperture is less than a diameter of the aperture and a diameter of the lumen of the inner tube is less than the diameter of the reduced aperture when the proximal end of the inner tube is slidably received within the aperture to reduce clogging of the surgical instrument as removed material moves from the lumen to the reduced aperture of the drive hub.
