Main Article Content
Background: Chronic Recurrent Multifocal Osteomyelitis (CRMO) is a rare aseptic autoinflammatory disease with a wide and vague clinical presentation that often mimics infection, malignancy, or benign conditions, leading to a delayed diagnosis.
Methods: Children diagnosed with CRMO at a single tertiary pediatric hospital in the United States between 2012 and 2022 who were evaluated by a pediatric orthopaedic surgeon were retrospectively reviewed for clinical data. The differential diagnoses from the surgeons were recorded from their initial presentation. The Jansson criteria and Bristol Criteria were retrospectively applied to evaluate patients who could have been spared a biopsy.
Results: 80 children (65% female) with CRMO were identified. The mean age at diagnosis was 10.28 + 3.52, follow up of 37.13 + 27.67 months and delay in diagnosis of 6.21 + 9.75 months. Common presenting symptoms were antalgic gait (45%), local inflammation (30%), and fever/fatigue (26.25%). 58% presented clinically unifocal, but 81% had multifocal disease on imaging. Radiographs were unremarkable in 35%, had periosteal reaction/sclerosis (23%), or a lytic lesion (22%). On MRI, 72% of patients had marrow edema, periosteal reaction (23%), and/or osteitis (19%). 69% of patients received a whole-body MRI, and 78% received a bone biopsy. The femur, tibia, pelvis, and spine were involved in >30%. The most common differential diagnoses given were related to infection (34%) and neoplasm (21%). The Jansson Criteria was found to be more sensitive than the Bristol criteria for diagnosing CRMO (OR 3.94, P <0.001) and identified 80% could have been spared biopsy.
Conclusions: This cohort of 80 patients with CRMO in the US displayed an ambiguous presentation. A combination of whole-body MRI, prompt referral to rheumatology, clinical scoring tools, and bone biopsy when necessary, should be used to appropriately evaluate patients with suspicion for CRMO.