Lake Placid (pps) Having just recovered from a second back injury, the comeback of U.S. luger Christian Niccum has been derailed. After 10 days of on-ice training in Park City, Utah, with his doubles partner Jayson Terdiman, the 34-year old tore his Achilles tendon while playing basketball back home in Woodinville (U.S. state of Washington). According to USA Luge Niccum, who earned a sixth-place finish at the 2009 World Championships in Lake Placid, has already undergone surgery. The earliest possible return date to luge racing for Niccum is the Viessmann Luge World Cup final on the future 2014 Olympic track in Sochi, Russia, at the end of February. Originally, the doubles team was scheduled to compete in the World Cup event in Winterberg (January 19-20, 2013). Niccum and Terdiman have been the top U.S. doubles in the previous two years; at the 2012 World Championships in Altenberg (Germany) they claimed an 11th place-finish.