Legg‐Calvé‐Perthes disease (LCPD) is a juvenile form of ischemic femoral head osteonecrosis, which produces chronic hip synovitis, permanent femoral head deformity, and premature osteoarthritis. Currently, there is no medical therapy for LCPD. Interleukin‐6 (IL‐6) is significantly elevated in the synovial fluid of patients with LCPD. We hypothesize that IL‐6 elevation promotes chronic hip synovitis and impairs bone healing after ischemic osteonecrosis.