Microstructural analysis of severe bone lesions in seven thalassemic patients treated with deferoxamine.

Osteochondrodystrophic lesions, mainly affecting long bone metaphyses, can be radiologically evident in homozygotic thalassemic patients treated with deferoxamine, and their incidence rate varies among authors. The clinical and radiological appearance of these lesions is described in the literature, but microstructural data are still lacking. The aim of our research was to evaluate the microstructure of five tibial biopsy specimens from thalassemic patients with bone lesions (5 cases out of 180 patients followed for the last 10 years, i.e., 2.8%) and two bone biopsy specimens from thalassemic patients with no radiological alteration of the long bones. As control, bone tissue taken from autoptic tibiae of two subjects with no skeletal pathology was used. Using microradiography and X-ray diffraction (XRD), we found a reduced and irregular mineralization of the bone (compared with controls) in thalassemic subjects. Bone tissue microhardness was also significantly reduced. Nevertheless, bone apatite lattice was unaltered and no 'foreign' crystallographic phase was recorded by XRD. In conclusion, all the patients shared a similar picture of abnormal bone, even with no radiological evidence of lesion.