A skeletally immature patient with Diamond-Blackfan anemia with Deferoxamine induced bone dysplasia: An analysis on diffusion tensor imaging.

Abstract

Deferoxamine-induced bone dysplasia is a rare but clinically significant complication of chronic iron chelation therapy, characterized by metaphyseal abnormalities and growth disturbances. While conventional imaging demonstrates abnormal endochondral ossification, the extent of physeal involvement remains poorly understood. Diffusion tensor imaging (DTI) enables microstructural evaluation of physeal architecture and may provide additional insight beyond routine MRI. We report a 9-year-old skeletally immature male with Diamond-Blackfan anemia treated with chronic deferoxamine iron chelation therapy who presented with bilateral genu valgum confirmed on alignment radiographs. MRI revealed multiple metaphyseal cartilage tongues with areas of abnormal ossification in both distal femurs. DTI of both knees was performed to assess physeal integrity prior to guided growth surgery. Tractography demonstrated preserved bilateral physeal tracts with femoral physeal volumes of 15.9 mL (left) and 13.0 mL (right), and mean tract lengths of 6.9 ± 4.0 mm and 6.4 ± 3.3 mm, respectively. Despite metaphyseal abnormalities, tract volume and fractional anisotropy values suggested ongoing physeal activity. The patient subsequently underwent bilateral hemiepiphysiodesis with early postoperative improvement in alignment. In this case of deferoxamine-associated bone dysplasia, DTI demonstrated preserved physeal microarchitecture despite marked metaphyseal abnormalities on conventional MRI. Thus, DTI tractography may serve as a useful adjunct in evaluating physeal function and surgical candidacy in pediatric patients with growth disturbances. To the best of our knowledge, this is the first reported use of DTI in this condition and suggests a potential role for assessing physeal function and surgical candidacy in pediatric growth disturbances.