An epidemiological study of etiology and clinical characteristics in patients with nontraumatic osteonecrosis of the femoral head

Background: Osteonecrosis of the femoral head (ONFH) is a common disease with high disability rate. However, a few studies investigate the etiology and clinical characteristics of nontraumatic ONFH patients in China. Therefore, we conducted this cross‑sectional study. Materials and Methods: Totally, information of 7268 nontraumatic ONFH patients treated between August 2005 and August 2015 was extracted from the medical records. The extracted information included the age, gender, diagnostic criteria, cause of nontraumatic ONFH, types of steroid use, and types of alcohol. Results: Among these included patients, there were 5126 (70.5%) male patients with average age of 44.5 years and 2142 (29.5%) female patients with average age of 47.6 years (P = 0.54). The number of steroid‑, alcohol‑, steroid/alcohol‑, and idiopathic‑induced nontraumatic ONFH men patients was 1684, 2310, 364, and 768, respectively, and nontraumatic ONFH women patients was 1058, 482, 140, and 462, respectively. Meanwhile, we found that both the levels of triglycerides (P = 0.03) and low‑density lipoprotein (P = 0.02) were significantly changed in the idiopathic‑induced nontraumatic ONFH patients. Conclusion: These results indicated the earlier onset of nontraumatic ONFH in male patients than in female patients, different main etiology for male (alcohol consumption) and female (steroid use) patients, and close relationship between the lipid metabolism and idiopathic‑induced nontraumatic ONFH. Our findings could be helpful for researchers to investigate the pathogenesis of ONFH and aid the clinicians in the early prevention and diagnosis of nontraumatic ONFH.