Abstract
Aim: To determine the ultra-structural morphology of bone in CLLLD.
Materials and Methods: Bone biopsies were taken from 8 patients with CLLLD undergoing surgery for limb reconstruction procedures. Specimens were fixed and processed for Electron microscopy using standard processing protocol. Ultra-thin araldite sections were stained with uranyl acetate and lead citrate and viewed in Philips CM12 electron microscope. Muscle biopsies were also undertaken.
Results: There were 5 boys and 3 girls of a mean age of 8.8 years (range 3 to 14 years). 6 had predominantly femoral deficiencies and 2 had combined femoral and fibular deficiencies. All specimens showed abnormal collagen fibril morphology. They showed variable diameter with irregular outlines in transversely section bundles and appeared unravelled in longitudinally sectioned bundles. The osteoid was disorganised in 4 of the 8 specimens and osteoblasts showed necrotic changes in 5 out of 8 specimens. Patchy mineralisation and increased proteoglycan distribution was observed in 3 out of 8 specimens.
Conclusion: Bone in CLLLD shows ultra-structural changes in collagen and osteoblasts that may account for the retarded bone growth and poor regenerate formation that occurs during limb lengthening in these patients.
The abstracts were prepared by the Editorial Secretary Robin W Paton. Correspondence should be addressed to him c/o BOA, 35–43 Lincoln’s Inn Field, London WC2A 3PN.
