Bone mineral density and bone scintigraphy in children and adolescents with osteomalacia

In order to demonstrate the role of bone mineral density (BMD) measurement and bone scans in the management of patients with osteomalacia, radioisotope bone scintigraphy using technetium-99m methylene diphosphonate (MDP) and BMD measurements of the lumbar spine and femur by means of dual X-ray absorptiometry (DXA) were performed at the time of diagnosis and 6 months after therapy in 26 Saudi patients (17 females and nine males). Their mean age was 13.5 years (range, 5-16). BMD measurements were compared with those of normal Saudi subjects matched for age and sex. Bone scan showed an increase in tracer uptake throughout the skeleton ("superscan") in all children and demonstrated multiple stress fractures in eight. The mean BMD for the lumbar spine was 0.53 g/cm2 (Z-score, -3.1) and for the femoral neck 0.55 g/cm2 (Z-score, -2.8). Repeated bone scan and BMD after 6 months of therapy with oral vitamin D, calcium and proper sun exposure demonstrated a significant increase (P<0.001) in BMD and healing of pseudofractures. In conclusion, as a non-invasive method with minimal radiation exposure, measurements of BMD in children with osteomalacia are to be recommended in the initial assessment of the severity of osteopenia and in the follow-up to monitor the response to therapy. Bone scintigraphy is valuable in demonstrating the site and severity of stress fractures.