A surgical cutting instrument for cutting tissue includes an outer cannula witha cutting opening and a cutting member within the cannula. The cutting memberis connected to a source of reciprocation, and as the cutting member reciprocatesthe cutting member head is guided by a sloped member within the cannula to essentiallya zero clearance position relative to a cutting edge of the cutting opening ofthe cannula. The instrument cleanly severs tissue extending through the cuttingopening into the outer cannula.