Update: Unexplained deaths following knee surgery--Minnesota, 2001.

Since November 13, 2001, the Minnesota Department of Health (MDH), in collaboration with CDC, has been conducting an investigation of three patients who died unexpectedly within 1 week following knee surgery. Patient 1 had received a knee osteochondral allograft, and patients 2 and 3 had undergone total knee replacement surgery. Epidemiologic and microbiologic investigations have not linked the deaths of the three patients.