Use of autologous bone marrow stem cells can be successfully treated cases of fracture not healing, the bone loss and regenerate bone tissue necrosis in humans. Objectives: To assess the effectiveness of the collection process, volume extraction of stem cells from bone marrow by gradient centrifugation method according to the proportion of cells. Subjects and methods: 126 patients with nonunion of long bone, short stature and in limb length discrepancy that were lengthened by Lizarov's principle, aseptic osteonecrosis of the femoral head stage I, II (ARCO), Each patient was withdrawn 250 militer of bone marrow from the pelvis. Mononuclear cells component was separated by the gradient density centrifugation method using Ficoll solution 1.077. Results: The volume of block bone marrow stem cells to 32.19 + or - 5.62 militer, the number of cells of 49.08 + or - 30.79 G/L, mononuclear cells the majority (57.38 + or - 13.86 percent )
number of CD 34+ cells 16.98 + or - 9.89 G/L
Keep mononuclear cells ratio 34.89 + or - 12.05 percent
hold rate of CD 34+ cells 55.96 + or - 30.46 percent
CD 34+ cells in 1 militer of 5.67 + or - 3.15 times
RBC removal rate 99.60 + or - 0.48 percent, the rate of removing hemoglobin 99.32 + or - 0.41 percent. Conclusion: The process of collecting, extracting stem cells from bone marrow fluid mass by gradient centrifugation method according to the proportion of cells for high performance.