[Pseudarthrosis treated by percutaneous autologous bone marrow graft].

PURPOSE

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 looked for systemic anomalies which could explain susceptibility to non union. We also compare the in vitro activity of bone marrow taken from non union sites with that of samples taken from the iliac crest, of the same patient.

MATERIAL AND METHODS

We included 6 groups: 26 cases of post-traumatic non union. 2 cases of non union following arthrodesis of the knee for infected prosthesis, 1 case of a non union of a tibiotarsal arthrodesis. 4 cases of regenerated illizarov extensions, which showed no evidence of ossification three months after operation, 2 cases of patients suffering from congenital abnormalities. Samples were taken from a population of 30 "bone marrow donors", to act as controls for the iliac crest samples.

RESULTS

Cell density in the iliac crest bone marrow of non union patients is significantly lower than that of controls (p < 0.01). In the hematopoietic compartment of the bone marrow, the number of progenitors (GM-CFU) obtained after culture of iliac crest bone marrow is consistently lower for patients presenting a non union than for controls (p < 0.01). Only infection of non union site (4 cases) seems to be associated with an increase in GM-CFU in the iliac crest. The difference in the average number of F-CFU obtained after culture of bone marrow from non union patients and from controls is lower but is nevertheless significant. 14 of the non union patients have less than half the F-CFU observed as normal in controls and 10 of them yielded less than one quarter. Out of these ten patients, in whom non union was associated with a marked abnormality in the number of F-CFU in the iliac crest (less than one quarter of the total obtained from controls), in 8 cases were other factor or disease which could account for the abnormality such as age (2 cases), clear alcoholic intoxication (1 case), heavy smoking (2 cases), history of chemotherapy (2 cases), and Lobstein's disease (1 case). The values found in non union sites and extension regenerated fibrous tissue suggest that there are relatively few F-CFU to differentiate into fibroblasts. In 12 out of 35 patients studied, the bone marrow generated no F-CFU. Same patients have abnormal low levels of F-CFU obtainable from their iliac crest bone marrow. The number of GM-CFU in fracture site is also extremely low. No local increases in GM-CFU levels are seen in septic focuses. The population of F-CFU and GM-CFU vary with time, in the same patient, at the same site of aspiration. Higher levels of osteogenic activity are seen at the beginning of extension.

CONCLUSION

This study suggests that problems related to consolidation may be linked with an overall reduction of bone marrow progenitor cells, as a result of some general physiological problem (chemotherapy, smoking, alcoholic poisoning).