18 patients (28 hips) with early-stage osteonecrosis of the femoral head (ONFH) were randomly assigned to receive core decompression with or without an autologous bone marrow stem cell injection. The purpose of this study was to investigate the clinical effects of concentrated bone marrow injection when used in combination with core decompression, and observe its effects on disease progression. The combined treatment resulted in a significantly greater improvement in both VAS pain and WOMAC scores when compared to core decompression alone. The use of bone marrow injection also demonstrated greater benefit in slowing or reversing disease progression (as assessed by MRI) compared to core decompression surgery alone.