[1] Univ Calif Davis, Dept Orthopaed Surg, Sacramento, CA 95817 USA
[2] Stanford Univ, Sch Med, Dept Pathol, Stanford, CA 94305 USA
[3] Weill Cornell Med Coll, Dept Pathol & Lab Med, New York, NY 10065 USA
[4] Hosp Special Surg, Res Div, New York, NY 10021 USA