RT Journal Article SR Electronic T1 Spontaneous osteonecrosis of the knee. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1416 OP 1416 VO 33 IS 7 A1 John Y Kim A1 David R Finger YR 2006 UL http://www.jrheum.org/content/33/7/1416.abstract AB