An adapter assembly for selectively interconnecting a surgical end effector that is configured to perform a function and a surgical device that is configured to actuate the end effector, the end effector including at least one axially translatable drive member, and the surgical device including at least one rotatable drive shaft (118, 120, 122), the adapter assembly comprising: an adapter knob housing configured and adapted for connection with the surgical device and to be in operative communication with each of the at least one rotatable drive shaft of the surgical device, the adapter knob housing defining a lumen extending longitudinally therethrough; an outer tube having a proximal end supported by the adapter knob housing and a distal end configured and adapted for connection with the end effector, wherein the distal end of the outer tube is in operative communication with each of the at least one axially translatable drive member of the end effector; a drive transmitting assembly including: a proximal rotatable drive shaft rotatably supported in the adapter knob housing and having a spur gear supported on a distal end thereof and a proximal end connectable to a rotatable drive shaft of the surgical device; and a ring gear formed in an inner surface of the lumen of the adapter knob housing, the ring gear defining an internal array of gear teeth which are engaged with the spur gear of the proximal rotatable drive shaft; wherein rotation of the rotatable drive shaft of the surgical device results in rotation of the proximal drive shaft, and wherein rotation of the proximal drive shaft results in rotation of adapter knob housing via the ring gear, and rotation of the distal coupling assembly to rotate the end effector. an adapter knob housing configured and adapted for connection with the surgical device and to be in operative communication with each of the at least one rotatable drive shaft of the surgical device, the adapter knob housing defining a lumen extending longitudinally therethrough; an outer tube having a proximal end supported by the adapter knob housing and a distal end configured and adapted for connection with the end effector, wherein the distal end of the outer tube is in operative communication with each of the at least one axially translatable drive member of the end effector; a drive transmitting assembly including: a proximal rotatable drive shaft rotatably supported in the adapter knob housing and having a spur gear supported on a distal end thereof and a proximal end connectable to a rotatable drive shaft of the surgical device; and a ring gear formed in an inner surface of the lumen of the adapter knob housing, the ring gear defining an internal array of gear teeth which are engaged with the spur gear of the proximal rotatable drive shaft; wherein rotation of the rotatable drive shaft of the surgical device results in rotation of the proximal drive shaft, and wherein rotation of the proximal drive shaft results in rotation of adapter knob housing via the ring gear, and rotation of the distal coupling assembly to rotate the end effector. a proximal rotatable drive shaft rotatably supported in the adapter knob housing and having a spur gear supported on a distal end thereof and a proximal end connectable to a rotatable drive shaft of the surgical device; and a ring gear formed in an inner surface of the lumen of the adapter knob housing, the ring gear defining an internal array of gear teeth which are engaged with the spur gear of the proximal rotatable drive shaft; wherein rotation of the rotatable drive shaft of the surgical device results in rotation of the proximal drive shaft, and wherein rotation of the proximal drive shaft results in rotation of adapter knob housing via the ring gear, and rotation of the distal coupling assembly to rotate the end effector.