Knochendefektheilung mit mesenchymalen Vorläuferzellen — hat die osteogene Differenzierung der Zellen einen Einfluss auf die Heilung?

Abstract

The healing of bone defects with Tissue engineering methods like mesenchymal precursor cells in a physiological matrix becomes increasing importance in orthopedic and trauma surgery. The effect of the osteogenic differentiation of bone marrow cells in vitro on the healing of the defect in vivo is still unclear.Autologous mesenchymal precursor cells were isolated from tibial bone chips from 15 adult Chinchilla Bastard rabbits. The cells were seaded in a concentration of 5 Mio/ml in fibrin glue (Beriplast®;, Aventis, Germany), diluted 1:7 with 0.9% NaCl. The autologous mesenchymal precursor cells were used unstimulated or stimulated for 1 week with dexamethasone or vitamin D3. The fibrin-cell-beads were implanted in cylindrical bone defects of the lateral distal femur (diameter 8.25×6 mm). Untreated defects, defects treated with fibrin glue alone or with autologous bone chips served as controls. The animals were sacrificed after 6 weeks. The healing of the defects was evaluated by fluorochrome labeling and micro-x-rays. After 6 weeks an average of 66.38% of the volume of the untreated defects were filled with bone tissue. Fibrin glue alone had no influence on the healing of the defect (67.01%). With fibrin glue and unstimulated cells an averidge defect healing of 73.37% was achived (p > 0.05). The stimulation of the transplanted cells with dexamethasone (61.16%) or vitamin D3 (57.47%) had no significant effect. Only the treatment with autologous spongiosa chips had a significant influence on the healing of the defects (96.98%).No positive effect of the osteogenic differentiation of autologous mesenchymal precursor cells was detectable in the healing of bone defects in the demonstrated rabbit model. The treatment of bone defects with autologous spongiosa chips is still the treatment of choice in orthopedic and trauma surgery.