Hematogenous infections may appear at any time after joint replacement operations. As distinguished from delayed infections where general symptoms of infection are absent, hematogenous infections cause malaise, chills and fever, usually of the septic type. Roentgenograms of the joint at an early stage of hematogenous infection do not show any sign of infection as these take time to develop. Nor is the scintigram positive at an early stage. The diagnosis is beyond doubt only when the same strain of bacteria is cultured from the joint, a primary focus and blood.