To the best of our knowledge, there have been no controlled clinical trials examining BMP, osteocalcin, osteoprotegerin or, in particular, Runx2 messenger RNA (mRNA) expression in femoral head tissue of patients with ONFH at Ficat Stage III-IV and osteoarthritis. In this non-randomized, parallel-controlled trial, we will use real-time PCR (RT-PCR) to detect Runx2, BMP-2, BMP-7 and osteoprotegerin mRNA expression in femoral head tissue from patients with ONFH at Ficat Stage III-IV. Simultaneously, we will detect osteocalcin immunoreactivity using an immunohistochemical staining method, and compare with osteoarthritis patients for the purpose of clarifying mechanisms of these factors in bone reconstruction post-ONFH.