Jp. Cassella et al., A MORPHOLOGICAL AND ULTRASTRUCTURAL-STUDY OF BONE IN OSTEOGENESIS IMPERFECTA, Calcified tissue international, 58(3), 1996, pp. 155-165
A morphological and electron microscopic study of bone from patients w
ith osteogenesis imperfecta (OI) has been performed. Bone from OI pati
ents from various anatomical sites has been compared with that from no
rmal, age-, site-, and sex-matched controls. The morphology of OI bone
appeared variable among patients and sites of bone examined. Immature
woven bone and a poor lamellar pattern were the significant morpholog
ical features and demonstrated that OI could not be characterized on t
he basis of a single histological pattern. At the ultrastructural leve
l, a number of previously unreported features were evident. Abnormal c
ollagen fibers and an altered mineral composition were found in many O
I patients, however, the panoramic heterogeneity between clinical type
s and indeed within a single clinical type made it difficult to classi
fy OI in this manner. The presence of intermitochondrial inclusions co
ntaining calcium and phosphorus and the presence of a stromal calcific
ation in the bone in some OI patients suggested an abnormal mineral fo
rmation. Qualitatively, no obvious difference in the number of osteobl
asts or osteoclasts was observed. The morphology and ultrastructure of
OI bone were good indicators of the disease and serve a role in asses
sing the progress of a patient through diagnosis and treatment. This r
eport presents new ultrastructural findings in collagen and in mineral
formation in OI compared with normal human bone.