Patterns of bone diseases in transfusion-dependent homozygous thalassaemia major: predominance of osteoporosis and desferrioxamine-induced bone dysplasia

Abstract

Objective: To study the radiographic skeletal changes in transfusion-dependent homozygous β-thalassaemia. Materials and methods: This was a retrospective review of radiographs of 41 homozygous β-thalassaemic patients over 3 years. These included 55 left hand radiographs for bone age, 37 chest radiographs, 7 scanograms of lower limbs, 8 knee radiographs and 3 skull radiographs. The radiographs were evaluated for the skeletal changes owing to medullary expansion, as well as for the skeletal dysplasia related to desferrioxamine therapy. The combined cortical width of the mid shaft of the second metacarpal was measured on left hand radiographs to assess osteoporosis. Results: Sixteen patients had radiographic evidence of desferrioxamine-induced bone dysplasia. These included metaphyseal sclerosis in long bone (n=16), irregular sclerosis at the costochondral junction (n=3) and platyspondyly (n= 1). Two patients had radiographic evidence of medullary expansion with widening of medulla and marked thinning of cortex in the tubular bones. Osteoporosis, as indicated by thinning of metacarpal cortex, was noted in 17 patients (8 with and 9 without desferrioxamine-induced bone dysplasia). Conclusions: With provision of the modern regime of regular transfusion and desferrioxamine chelation, desferrioxamine-induced bone dysplasia was a much more frequently detected radiographic abnormality in β-thalassaemia major than radiographic features owing to medullary expansion. Osteoporosis, as indicated by thinned metacarpal cortices, remained a frequent feature irrespective of the status of the skeletal dysplasia.