Abstract: Objective To investigate the morbidity and characteristics of adult osteonecrosis of the femoral head (ONFH) in Chengdu, and to further explore its related risk factors.Methods Self-designed questionnaires were used to collect data by the way of household or field survey. From January,2016 to February, 2018, a total of 544 cases (797 hips) diagnosed as ONFH were included in the study. The medical data including general condition, risk factors, diagnosis, disease stages and treatment were collected. Based on the data, the risk factors were analyzed statistically.Results The average age of 544 patients (392 males and 152 females) was 55 years old (range: 19 to 90 years); the bilateral incidence was 46.51% (253 cases). The proportion of Association Research Circulation Osseous stages was accounted respectively 3.64% for stage I, 6.15% for stage II, 8.41% for stage III and 81.81% for stage IV when confirmed ONFH initially. In all the reasons of ONFH, 52.39% were alcohol-associated osteonecrosis, 16.18% for steroid-induced osteonecrosis, 11.58% for traumatic osteonecrosis, 5.88% for dysplastic osteonecrosis, and 13.97% for other reasons.Conclusion The incidence of ONFH was higher in men than in women. Stages III-IV accounted for the highest proportion. The high intake of alcohol or overuse of steroid was the leading causes of adult ONFH, among which alcohol-associated osteonecrosis was the main for the males and steroid-induced osteonecrosis for the females.

Key words: femoral head, osteonecrosis, adult, epidemiology, risk factors