Development of non-traumatic osteonecrosis of the femoral head requires toll-like receptor 7 and 9 stimulations and is boosted by repression on nuclear factor kappa B in rats

Okazaki, Shunichiro; Nagoya, Satoshi; Matsumoto, Hiroshi; Mizuo, Keisuke; Sasaki, Mikito; Watanabe, Satoshi; Yamashita, Toshihiko; Inoue, Hiromasa

TLR stimulation induces osteonecrosis S Okazaki et al histopathological appearance of the femoral head after hematoxylin and eosin staining in the Saline þ MPSL (A), Imiquimod þ MPSL (B), and CpG-C þ MPSL (C) rats. Normal trabeculae as well as hematopoietic and fat cells were observed in the Saline þ MPSL rats (Figure 1a ). In the Imiquimod þ MPSL and CpG-C þ MPSL group, empty lacunae and pyknotic nuclei were observed within the necrotic bone trabeculae, and bone marrow cell necrosis was observed in the medullary space across most areas of the femoral head (Figure 1b and c) .