Atypical Presentation of Intra-Articular Osteoid Osteoma in the Proximal Femur: A Difficult Diagnosis

Osteoid osteoma is among the commonest bone tumors, primarily affecting young subjects. Often localized in the diaphysis cortex of long bones, the disease has a well-described symptomatology and imagery of choice for diagnosis. When in a different location, the diagnosis is less evident. We describe a case herein of an intra-articular osteoid osteoma of the hip misdiagnosed as a femoro-acetabular impingement and treated by means of hip arthroscopy.