[Late diagnosis of intraarticular osteoid osteoma treated as hip osteoarthritis--case report and review of the literature].

A 34-year old men with left hip pain caused by intraarticular osteoid osteoma localized in the left femoral head is described. He was treated as a hip osteoarthritis for one year before the accurate diagnosis was established. Magnetic resonance imaging showed lesion indicating osteoid osteoma. Accurate diagnosis was established based on typical appearance of the osteoid osteoma on the computed tomography (CT). Osteoid osteoma rarely occures after 30 years of age and intraarticular locallisation is uncommon. This case report pinpoints the importance of careful analysis of monoarticular pain in order to avoid the possibile misdiagnosis of osteoid osteoma especially in young adult with an isolated osteoarthritis feature on the conventional radiography and normal laboratory findings. CT is specific and sensitive imaging modality for diagnosis of osteoid osteoma.