RESEARCH ARTICLE

nd Background intraosseous hypertension, intravascular fat embolism, and Zhang et al. BMC Musculoskeletal Disorders (2015) 16:132 DOI 10.1186/s12891-015-0606-2while apoptosis was absent or rare in specimens fromProvince 710004, P. R. China Full list of author information is available at the end of the articleMany studies have shown that glucocorticoid (GC) ther-apy is the most common non-traumatic cause of osteo-necrosis of the femoral head, termed steroid-induced avascular necrosis of the femoral head (SANFH). The underlying mechanisms of SANFH are still unclear. Several mechanisms have been postulated, including coagulation, compression of vessels by progressive accumulation of marrow fat stores. Studies have demonstrated the strong association of osteoblast and osteocyte apoptosis with SANFH [1–4]. Weinstein and his colleagues have studied osteocyte apoptosis in femoral head specimens of 14 patients with necrosis of the femoral head using TUNEL staining assay [5], showing the appearance of marked osteocyte apoptosis in specimens from patients with SANFH