After the completion of the local area flight, the pilot maneuvered the airplane for the approach to the runway. The airplane was not oriented with the runway during approach, so the pilot applied full engine power to perform a go-around. During the go-around, the tailwheel impacted a taxiway sign, and the tailwheel sustained damage. The pilot completed the go-around and landed on the runway. During the landing, there was no tailwheel control due to the previous impact damage from the taxiway sign, and the airplane departed the runway to the right. The airplane came to rest upright on a grass field near the runway. The pilot was able to egress from the airplane without further incident. The airplane sustained substantial damage to the rudder and the underside of the empennage. The pilot reported there were no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation.