The efficacy of bisphosphonates on pain related to benign (Langherhans cell histiocytosis, fibrous dysplasia, Paget disease) or malignant bone lesions has been widely reported. The investigators observed such efficacy in a small series of 20 patients with percutaneously hard-to-reach or recurrent OO using one to three infusions of zoledronate. The clinical efficacy assessed on pain relief was accompanied by a significantly increased mineralization of the nidus. The investigators postulated that bisphosphonates had accelerated the natural history of OO.