BONE-MARROW IN PATIENTS PRESENTING NON UN ION

Purpose of the study The recent observations that osteoblasts develop from a stem cell found in the medullary stroma suggest that, as alread y suspected in classical histological studies, many consolidation mech anisms are based on bone marrow. Since cells characteristics can now b e studied in tissue culture, it has become possible to investigate the activity of the bone marrow in non union. The working hypothesis for this study was if the bone marrow plays a part in bony callus formatio n, bone marrow from non union site should manisfest anomalous activity whatever the origin of the focus sampled. Therefore, the aim of this study was to seek in vitro, using cell cloning techniques, anomalies o f bone marrow from non union site. Materials This study characterizes the bone marrow from 35 non union sites, not only with respect to the medullary stroma but also the hematopoietic compartment. in this study , we look for systemic anomalies which could explain susceptibility to non union, we also compare in vitro activity of bone marrow taken fro m non union with others samples taken from the iliac crest of the same patient. Methods The cell density in the bone marrow in these sites w as studied in vitro with material taken from the non union site. Sampl es were taken by aspiration with a trocar located by image intensifica tion. Assays of CFU-GM were chosen to quantify the hematopoietic activ ity of the marrow, and of CFU-F to quantify stroma cells activity. Cel l densities in the non union site were compared to those in patients o wn iliac crests, and also to iliac crests densities of a control popul ation of bone marrow donors. Results The bone marrow of non union site contained low levels of progenitor cells. Especially surprising was t hat progenitors were also sparse in the bone marrow of the iliac crest of patients with non union, compared with control bone marrow donors. In several cases, certain general factors are probably responsible fo r the abnormally low levels of progenitor cells, not only in the non u nion site, but also in the iliac crest.