Pelvic Type of chronic recurrent multifocal osteomyelitis (CRMO) in children and adolescents: clinical aspects, radiological and pathological findings in 11 cases

We report about the juvenile and adolescent pelvic type of CRMO in 7 girls and 4 boys. The results show from solitary up to 7 pelvic lesions (average 3 lesions) predominantly in the acetabular and paraacetabular region (somet imes with hipjoint effusion as a sign for concomitant coxitis). Tc99m-bone-scan is helpful to evaluate exactly the pattern of bone affectio n. We find 3 stages of an primarily chronic, nonpurulent osteomyelitis goin g along with a "plasma-cell-sclerotic process", leading to a Garre-type scl erosing end-stage, which probably heals after some years spontaneously, pro jecting on clinical symptoms and radiological appearance. The concomitant c oxitis ("sympathetic coxitis") is clinically often in the foreground, but r eversible. Pain in case of CRMO responds surprisingly well on medication wi th acithromycine. Knowing about CRMO in its different clinical appearances - especially conce rning what we call "sympathetic coxitis" - can be a useful for pediatric rh eumatologists and orthopedic surgeons, as well as MRI-focused radiologists and pathologists. Therapy might find a useful drug in acithromycine. In conclusion we d like to point out, that CRMO is one entity under the "ro of" of the so called SAPHO-syndrome, which again shows us, that SAPHO-syndr ome ist not a diagnosis itself but more a sign-post on the way to a correct diagnosis.