IL6 and Legg-Calve-Perthes disease: In these samples, the mean concentration of IL‐6 protein (pg/mL) was significantly higher in the synovial fluid of patients with LCPD compared with that of controls (LCPD: 658.7 ± 425.3, n = 5 versus control: −3.8 ± 13.2, n = 3, p = 0.025).