[1] Univ Virginia, Sch Med, Orthoped Res Labs, Dept Orthoped Surg, Charlottesville, VA 22908 USA
[2] North Sichuan Med Coll, Nanchong Cent Hosp, Dept Orthoped Surg, Nanchong 637000, Peoples R China
[3] North Sichuan Med Coll, Clin Inst 2, Nanchong 637000, Peoples R China
[4] Univ Virginia Hlth Syst, Dept Neurosurg, Charlottesville, VA 22908 USA