A surgical cutting instrument comprising: a cannula having a proximal end and a distal end defining a length dimension of said cannula and a central bore along the length of said cannula, said cannula further defining a cutting opening having a first cutting edge adjacent said distal end; a handpiece for supporting said cannula at said proximal end; a cutting member slidably disposed within said central bore of said cannula, said cutting member having a tubular cutting head portion sized to prevent said tubular cutting head from fully exiting said central bore through said cutting opening, said cutting head portion having a proximal and distal end, said distal end of said cutting head portion defining a second cutting edge, said cutting member also having a body portion between said proximal end of said cutting head portion and said proximal end of said cannula; a connecting member within said handpiece for connecting said body portion of said cutting member to a source of reciprocating motion to reciprocate said cutting member along the length dimension within said cannula so that said second cutting edge traverses said first cutting edge a sloped member being configured and positioned relative to said cutting opening to guide said cutting head portion upwardly toward said cutting opening as said cutting head portion advances toward said distal end of said cannula, thereby forming an essentially zero clearance between said first and second cutting edges, characterized by said sloped member formed in an inner surface of said cannula in the form of an indentation protruding into said central bore of said cannula so as to be oppositely located from said cutting opening and extending toward said cutting opening a cannula having a proximal end and a distal end defining a length dimension of said cannula and a central bore along the length of said cannula, said cannula further defining a cutting opening having a first cutting edge adjacent said distal end; a handpiece for supporting said cannula at said proximal end; a cutting member slidably disposed within said central bore of said cannula, said cutting member having a tubular cutting head portion sized to prevent said tubular cutting head from fully exiting said central bore through said cutting opening, said cutting head portion having a proximal and distal end, said distal end of said cutting head portion defining a second cutting edge, said cutting member also having a body portion between said proximal end of said cutting head portion and said proximal end of said cannula; a connecting member within said handpiece for connecting said body portion of said cutting member to a source of reciprocating motion to reciprocate said cutting member along the length dimension within said cannula so that said second cutting edge traverses said first cutting edge a sloped member being configured and positioned relative to said cutting opening to guide said cutting head portion upwardly toward said cutting opening as said cutting head portion advances toward said distal end of said cannula, thereby forming an essentially zero clearance between said first and second cutting edges, characterized by said sloped member formed in an inner surface of said cannula in the form of an indentation protruding into said central bore of said cannula so as to be oppositely located from said cutting opening and extending toward said cutting opening