An adapter assembly for selectively interconnecting a surgical end effector and a handle assembly having a rotatable drive shaft, the adapter assembly comprising: a knob housing configured to couple to the handle assembly, the knob housing including a drive coupling housing; and a drive converter assembly configured to mechanically interconnect the rotatable drive shaft and a portion of a surgical end effector, wherein the drive converter assembly is configured to convert rotation of the rotatable drive shaft into rotation of the surgical end effector, wherein the drive converter assembly includes a first drive converter assembly including: a drive element rotatably supported in the knob housing; a first gear disposed in mechanical cooperation with a distal portion of the drive element; a second gear disposed in mechanical cooperation with the first gear; a gear ring disposed in mechanical cooperation with the second gear and disposed in mechanical cooperation with an end effector-engaging portion of the adapter assembly, the gear ring being fixed from rotation with respect to the knob housing; wherein rotation of the drive element causes rotation of the first gear, rotation of the first gear causes rotation of the second gear, rotation of the second gear causes rotation of the gear ring, and rotation of the gear ring causes rotation of the end effector-engaging portion of the adapter assembly, characterized in that the first drive converter assembly includes: a rotation bearing, wherein the drive coupling housing is rotationally fixed to the rotation bearing, and wherein the knob housing is rotatable with respect to the rotation bearing; wherein the proximal portion of the knob housing is positioned around the rotation bearing, and wherein said rotation bearing is both rotatable and longitudinally translatable with respect to the knob housing, wherein said rotation bearing allows for free, unimpeded rotational movement of the surgical end effector. a knob housing configured to couple to the handle assembly, the knob housing including a drive coupling housing; and a drive converter assembly configured to mechanically interconnect the rotatable drive shaft and a portion of a surgical end effector, wherein the drive converter assembly is configured to convert rotation of the rotatable drive shaft into rotation of the surgical end effector, wherein the drive converter assembly includes a first drive converter assembly including: a drive element rotatably supported in the knob housing; a first gear disposed in mechanical cooperation with a distal portion of the drive element; a second gear disposed in mechanical cooperation with the first gear; a gear ring disposed in mechanical cooperation with the second gear and disposed in mechanical cooperation with an end effector-engaging portion of the adapter assembly, the gear ring being fixed from rotation with respect to the knob housing; wherein rotation of the drive element causes rotation of the first gear, rotation of the first gear causes rotation of the second gear, rotation of the second gear causes rotation of the gear ring, and rotation of the gear ring causes rotation of the end effector-engaging portion of the adapter assembly, characterized in that the first drive converter assembly includes: a rotation bearing, wherein the drive coupling housing is rotationally fixed to the rotation bearing, and wherein the knob housing is rotatable with respect to the rotation bearing; wherein the proximal portion of the knob housing is positioned around the rotation bearing, and wherein said rotation bearing is both rotatable and longitudinally translatable with respect to the knob housing, wherein said rotation bearing allows for free, unimpeded rotational movement of the surgical end effector. a drive element rotatably supported in the knob housing; a first gear disposed in mechanical cooperation with a distal portion of the drive element; a second gear disposed in mechanical cooperation with the first gear; a gear ring disposed in mechanical cooperation with the second gear and disposed in mechanical cooperation with an end effector-engaging portion of the adapter assembly, the gear ring being fixed from rotation with respect to the knob housing; wherein rotation of the drive element causes rotation of the first gear, rotation of the first gear causes rotation of the second gear, rotation of the second gear causes rotation of the gear ring, and rotation of the gear ring causes rotation of the end effector-engaging portion of the adapter assembly, characterized in that the first drive converter assembly includes: a rotation bearing, wherein the drive coupling housing is rotationally fixed to the rotation bearing, and wherein the knob housing is rotatable with respect to the rotation bearing; wherein the proximal portion of the knob housing is positioned around the rotation bearing, and wherein said rotation bearing is both rotatable and longitudinally translatable with respect to the knob housing, wherein said rotation bearing allows for free, unimpeded rotational movement of the surgical end effector. a rotation bearing, wherein the drive coupling housing is rotationally fixed to the rotation bearing, and wherein the knob housing is rotatable with respect to the rotation bearing; wherein the proximal portion of the knob housing is positioned around the rotation bearing, and wherein said rotation bearing is both rotatable and longitudinally translatable with respect to the knob housing, wherein said rotation bearing allows for free, unimpeded rotational movement of the surgical end effector.