Sclerotic metaphyseal lines in children and adolescents treated with alendronate.

INTRODUCTION Bisphosphonates inhibit bone resorption by interfering with the action of osteoclasts. Among the adverse effects, sclerotic lines observed in the metaphysis of long bones have been described as the main imaging finding in pediatric patients. OBJECTIVE To evaluate the frequency of radiographic changes caused by alendronate in children and adolescents with low bone density or calcinosis. PATIENTS AND METHODS We conducted a cross-sectional study with 21 patients who were treated with once-weekly alendronate for at least 10 months. Patients underwent x-rays of long bones before the start of alendronate and approximately one year after its use. RESULTS Eleven patients (52.3%) had sclerotic lines in the metaphysis of long bones. The most frequent site was the tibia (8/11 patients), followed by the femur (7/11), humerus (6/11), radius (4/11), ulna (3/11), and fibula (2/11). Regression of radiographic changes during the study period (up to 1.1 years after discontinuation of alendronate) was not observed. CONCLUSION If used carefully, alendronate is safe and radiographic changes have not been shown to be clinically relevant.