[1] Johns Hopkins Sch Med, Dept Phys Med & Rehabil, Baltimore, MD USA
[2] Univ Maryland, Sch Med, Dept Orthopaed, R Adams Cowley Shock Trauma Ctr, Baltimore, MD 21201 USA
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Hlth Policy & Management, Baltimore, MD USA
[4] Inova Fairfax Med Campus, Dept Orthopaed Surg, Orthopaed Trauma, In ova Fairfax Med Campus, Fairfax, VA USA
[5] Vanderbilt Univ, Med Ctr, Dept Orthopaed Surg, Nashville, TN USA
[6] Vanderbilt Univ, Med Ctr, Dept Phys Med & Rehabil, Nashville, TN USA
[7] Univ Arizona, CORE Inst, Coll Med, Banner Univ,Med Ctr, Phoenix, AZ USA
[8] Carolinas Med Ctr, Dept Orthopaed Surg, Charlotte, NC 28203 USA
[9] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Biostat, Baltimore, MD USA