Abstract
In this study, we report a case of avascular necrosis of the femoral head (ANFH) caused by the bilateral intravenous injection of heroin into the femoral vein. The patient had not used steroids, did not smoke and did not drink excessively. The patient did not present with any systemic diseases that may cause ANFH. ANFH often causes changes to the bone mass of the femoral head, particularly, the weight-bearing bone region. Imaging examination revealed that in addition to the bilateral hip joints, widespread changes to the bone mass existed in the peripheral area, where phlebitis and disseminated thrombosis had been caused by the injection of heroin. These results suggest that this ANFH case was related to the injection of heroin. This case is different from other cases of ANFH which have been caused by steroids and other factors, including smoking, alcohol intake and cytotoxic agents.