[Problems and thoughts of preserving femoral head treatment of osteonecrosis of femoral head].

By literature review and experience summary, some problems are found in conservative treatment of osteonecrosis of femoral head(ONFH): lacking in researches of natural history of ONFH, disunion in classfication and the standard of outcome evaluation, lacking in high-level-evidence study and standard of treatment methods. It is necessary to improve the study on natural history of ONFH, unify the classfications and the standard of outcome evaluations, normalize the treatment methods, and design impeccable multi-centre study for improving the effect of conservative treatment of ONFH.