[1] Hosp Special Surg, Dept Orthopaed Surg, Weill Cornell Med Coll, Spine & Scoliosis Serv, New York, NY 10021 USA
[2] Lerdsin Gen Hosp, Minist Publ Hlth, Inst Orthopaed, Dept Med Serv, Nonthaburi, Thailand
[3] Washington Univ, Washington Univ Orthoped, Dept Orthoped Surg, St Louis, MO USA
[4] Washington Univ, Dept Neurol Surg, Washington Univ Orthoped, St Louis, MO USA
[5] Washington Univ, Dept Cerv Spine Surg, Washington Univ Orthoped, St Louis, MO USA