title: [Osteoid osteoma of the base of the acetabulum presenting as coxitis in a 14-year-old girl].
abstract: It is about an unique case of an intra-articular osteoid osteoma, located in the back of the acetabulum in a 14 years old girl. Synovitis made clinical and radiological appearances very suggestive of an arthritis. Diagnosis was recalled in the view of biological negativity, the notion of nocturnal pains, reduced by aspirin, and especially radiological features with densification of the back of the acetabulum. Scintigraphy revealed hyperfixation located in the back of the acetabulum and scanner showed a picture, in the same place, buldging towards the joint, suggestive of the osteoid osteoma. The operation, made by anterior approach with anterior dislocation of the hip, allowed the "in bloc" resection of an osseus piece whose immediate radiographic examination confirmed that the whole osteoma was removed. A synovial biopsy was also performed. The pathologist confirmed the diagnosis and showed a reactional synovitis within the soft tissues. Pain disappeared as soon as the waking up. This case report is interesting because: this localization is very exceptional, the reactional synovitis was evocating of an arthritis, the iconography is absolutely complete, a review of publications is done for this subject.
mesh_terms: D000077:Acetabulum; D000293:Adolescent; D003937:Diagnosis, Differential; D005260:Female; D006621:Hip Joint; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010017:Osteoma, Osteoid / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011859:Radiography
vernacular_title: Ostéome ostéoïde du fond du cotyle chez une fille de 14 ans se présentant comme une coxite.