A surgical instrument, comprising: (a) a shaft (128, 228) configured to articulate from a first configuration toward a second configuration, including: (i) a distal shaft end, (ii) a proximal shaft end, (iii) a shaft sidewall extending from the distal shaft end to the proximal shaft end and configured to move the distal shaft end relative to the proximal shaft end, and (iv) a shaft window opening extending through the shaft sidewall; (b) a cutting member (130, 230) disposed within the shaft and configured to cyclically move relative to the shaft, wherein the cutting member is further configured to articulate within the shaft from the first configuration toward the second configuration, including: (i) a distal member end, (ii) a proximal member end, (iii) a member sidewall extending from the distal member end to the proximal member end and configured to move the distal member end relative to the proximal member end, (iv) a cutting window opening extending through the member sidewall and configured to align with the shaft window during cyclical movement relative thereto and receive a tissue for cutting, and characterised in that the instrument further comprises: (c) an axial adjustment coupling longitudinally securing the shaft relative to the cutting member and configured to longitudinally move the proximal member end relative to the proximal shaft end while articulating the shaft and the cutting member from the first configuration toward the second configuration to inhibit movement of the distal member end relative to the distal shaft end for maintaining alignment between the shaft window opening and the cutting window opening. (a) a shaft (128, 228) configured to articulate from a first configuration toward a second configuration, including: (i) a distal shaft end, (ii) a proximal shaft end, (iii) a shaft sidewall extending from the distal shaft end to the proximal shaft end and configured to move the distal shaft end relative to the proximal shaft end, and (iv) a shaft window opening extending through the shaft sidewall; (i) a distal shaft end, (ii) a proximal shaft end, (iii) a shaft sidewall extending from the distal shaft end to the proximal shaft end and configured to move the distal shaft end relative to the proximal shaft end, and (iv) a shaft window opening extending through the shaft sidewall; (b) a cutting member (130, 230) disposed within the shaft and configured to cyclically move relative to the shaft, wherein the cutting member is further configured to articulate within the shaft from the first configuration toward the second configuration, including: (i) a distal member end, (ii) a proximal member end, (iii) a member sidewall extending from the distal member end to the proximal member end and configured to move the distal member end relative to the proximal member end, (iv) a cutting window opening extending through the member sidewall and configured to align with the shaft window during cyclical movement relative thereto and receive a tissue for cutting, and characterised in that the instrument further comprises: (i) a distal member end, (ii) a proximal member end, (iii) a member sidewall extending from the distal member end to the proximal member end and configured to move the distal member end relative to the proximal member end, (iv) a cutting window opening extending through the member sidewall and configured to align with the shaft window during cyclical movement relative thereto and receive a tissue for cutting, and characterised in that the instrument further comprises: (c) an axial adjustment coupling longitudinally securing the shaft relative to the cutting member and configured to longitudinally move the proximal member end relative to the proximal shaft end while articulating the shaft and the cutting member from the first configuration toward the second configuration to inhibit movement of the distal member end relative to the distal shaft end for maintaining alignment between the shaft window opening and the cutting window opening.