RT Journal Article SR Electronic T1 Acute onset of knee pain JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 744 OP 746 VO 68 IS 9 A2 Marc Williams A1 Jean Schils A1 Mitchell Kline YR 2001 UL http://www.ccjm.org/content/68/9/744.abstract AB