Atypical findings of the combined scintigraphy of bone marrow and labeled leukocytes in osteonecrosis of the hip secondary to infection

Avascular osteonecrosis can be associated with septic arthritis and osteomyelitis. Combined labeled leukocyte-marrow imaging scintigraphy has demonstrated excellent accuracy for the detection of infection since both tracers accumulate in the bone marrow and only leukocytes accumulate in infection. We report an unusual total absence of 99mTc HMPAO leukocytes/9mTc-sulfur colloid tracer accumulation, not only in the femoral head but also in the acetabulum and hip in hip osteonecrosis secondary to septic arthritis and osteomyelitis.