[1] Univ Iowa Hosp & Clin, Dept Orthopaed Surg, Iowa City, IA 52242 USA
[2] Michigan State Univ, E Lansing, MI 48824 USA
[3] Univ Illinois, Urbana, IL 61801 USA
[4] Indiana Univ, Bloomington, IN USA
[5] Univ Michigan, Ann Arbor, MI 48109 USA
[6] Univ Minnesota, Minneapolis, MN 55455 USA
[7] Northwestern Univ, Evanston, IL USA
[8] Ohio State Univ, Columbus, OH 43210 USA
[9] Penn State Univ, State Coll, PA 16804 USA
[10] Purdue Univ, W Lafayette, IN 47907 USA
[11] Univ Wisconsin, Madison, WI USA