A shaft assembly for interconnecting at least a first and a second rotatable drive shaft (118, 120) of a hand-held electromechanical surgical device, and an end effector actuatable by an axial drive force, the shaft assembly comprising: a shaft coupling assembly configured and adapted for selective connection to a connecting portion of the surgical device and to be in operative communication with each of the first and second rotatable drive shaft of the surgical device; an outer tube having a proximal end supported by the shaft coupling assembly, the outer tube defining a central longitudinal axis; a proximal neck housing supported at a distal end of the outer tube; a distal neck housing pivotally connected to the proximal neck housing, wherein a distal end of the distal neck housing is configured and adapted for operative connection with the end effector; a flexible drive cable rotatably supported in the outer tube, the flexible drive cable having a proximal end that is supported in the proximal neck housing and a distal end that is supported in the distal neck housing; an articulation rod at least partially slidably supported in the proximal neck housing; and an articulation link having a proximal end pivotally connected to the distal end of the articulation rod, and a distal end pivotally connected to the distal neck housing; wherein actuation of the first rotatable drive shaft of the hand-held surgical device when connected to the articulation rod causes the articulation rod to axially translate; and wherein axial translation of the articulation rod causes the distal neck housing to pivot off axis relative to the proximal neck housing; the proximal end (242a, 242b) of the flexible drive cable being configured to be operatively connected to the second rotatable drive shaft of the hand-held surgical device, wherein, in a linear, non-articulated condition the flexible drive cable defines a longitudinal axis B off-set a radial distance from the longitudinal axis X of the outer tube, the shaft assembly further comprising a rotation nut, wherein the rotation nut is connected to a distal end of the flexible drive cable wherein rotation of the flexible drive cable results in a corresponding rotation of the rotation nut and wherein the rotation nut is configured to selectively connect with a rotatable drive axle of the end effector, characterized in that the shaft assembly further comprises: a rotation hub rotatably supported at a distal end of the distal neck housing such that the hub defines an axis of rotation that is co-axial with the longitudinal axis X, wherein the rotation nut is rotatably supported in the hub, and whereby the distal end of the flexible drive cable is free to rotate about the longitudinal axis X as the rotation hub is rotated about the longitudinal axis X. a shaft coupling assembly configured and adapted for selective connection to a connecting portion of the surgical device and to be in operative communication with each of the first and second rotatable drive shaft of the surgical device; an outer tube having a proximal end supported by the shaft coupling assembly, the outer tube defining a central longitudinal axis; a proximal neck housing supported at a distal end of the outer tube; a distal neck housing pivotally connected to the proximal neck housing, wherein a distal end of the distal neck housing is configured and adapted for operative connection with the end effector; a flexible drive cable rotatably supported in the outer tube, the flexible drive cable having a proximal end that is supported in the proximal neck housing and a distal end that is supported in the distal neck housing; an articulation rod at least partially slidably supported in the proximal neck housing; and an articulation link having a proximal end pivotally connected to the distal end of the articulation rod, and a distal end pivotally connected to the distal neck housing; wherein actuation of the first rotatable drive shaft of the hand-held surgical device when connected to the articulation rod causes the articulation rod to axially translate; and wherein axial translation of the articulation rod causes the distal neck housing to pivot off axis relative to the proximal neck housing; the proximal end (242a, 242b) of the flexible drive cable being configured to be operatively connected to the second rotatable drive shaft of the hand-held surgical device, wherein, in a linear, non-articulated condition the flexible drive cable defines a longitudinal axis B off-set a radial distance from the longitudinal axis X of the outer tube, the shaft assembly further comprising a rotation nut, wherein the rotation nut is connected to a distal end of the flexible drive cable wherein rotation of the flexible drive cable results in a corresponding rotation of the rotation nut and wherein the rotation nut is configured to selectively connect with a rotatable drive axle of the end effector, characterized in that the shaft assembly further comprises: a rotation hub rotatably supported at a distal end of the distal neck housing such that the hub defines an axis of rotation that is co-axial with the longitudinal axis X, wherein the rotation nut is rotatably supported in the hub, and whereby the distal end of the flexible drive cable is free to rotate about the longitudinal axis X as the rotation hub is rotated about the longitudinal axis X.