Successful treatment of avascular bone necrosis of the knee with neridronate: a case report

Abstract

Sir, Osteonecrosis (ON) is characterized by the necrosis of all components of bone tissue and represents the Wnal result of diVerent pathological conditions that lead to reduced vascularization of trabecular bone. The potential risk factors of ON include traumatic events, hemoglobinopathies, endocrine disorders, environmental factors, drugs and vascular diseases. Magnetic resonance imaging (MRI) is the most accurate tool for detecting early alterations in ON, with a sensitivity and a speciWcity level of almost 100%. Medical treatment of ON, which is reasonable only in the early stages of the disease before serious bone deformity has appeared, is based on the elimination of causative factors, on the use of drugs able to improve vascularization, such as vasodilators and anti-platelet drugs and on the reduction of joint load-bearing. However, in 85% of patients with ON, the progression to the end stages of the disease occurs over a period of 2 years [1]. We report a case of ON of the femoral condyle successfully treated with the bisphosphonate neridronate.