An assembly including an adapter assembly and an extension assembly for connecting an end effector to an electrosurgical instrument is provided. The adapter assembly includes first and second pusher assemblies configured for converting rotational motion into linear motion and a drive member for transferring rotational motion. The extension assembly includes at least one flexible band assembly for transferring the linear motion from the adapter assembly and a trocar assembly configured for converting rotational motion into linear motion. Also provided is a connection assembly for connecting a first tubular member to a second tubular member.