Chronic recurrent multifocal osteomyelitis: case series of four patients treated with biphosphonates

Aim: To report and describe a series of four cases of chronic recurrent multifocal osteomyelitis (CRMO) and to discuss therapeutic options, particularly bisphosphonate therapy Methods: Retrospective review of four CRMO cases in two Pediatric Units in Lisbon, between 2005 and 2010. Results: Median age of first CRMO symptoms was 11.3 years (range 9-13). The more affected sites were the metaphysis of the long bones, pelvis and coxofemoral joints. Median number of initial bony lesions for each patient was 2.3 (range 1-3) at onset and 3.8 (range 2-6) during the disease course. All patients failed to respond to NSAIDs therapy. Two patients received corticosteroids, with clinical disease remission in only one of them. All patients received bisphosphonates (alendronate in two and pamidronate in two), all with good clinical response and induction of clinical remission in two of them. After a median follow-up period of 4.3 years (range 4-5), three patients are clinically asymptomatic and one patient remains with chronic residual pain. Conclusions: The treatment of CRMO is not standardized. Bisphosphonate therapy can be of benefit to patients with relapsing symptoms. Randomized controlled multicentric trials are needed to provide better evidence for universal recommendation and definition of bisphosphonate therapy protocol.