title: [Study on relationship between osteoporosis and mRNA expressions of vascular endothelial growth factor and bone morphogenetic protein 2 in nontraumatic avascular necrosis of femoral head].
authors.affiliation: Department of Orthopaedics, No.7 People's Hospital of Zibo, Zibo Shandong, 255040, PR China. wwjwjx118@sina.com
authors.forename: Weijun
authors.initials: W
authors.lastname: Wang
authors.forename: Sisheng
authors.initials: S
authors.lastname: Li
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Niu