Intra-articular osteoid osteoma of the hip mimicking as monoarthritis-A case report

INTRODUCTION: Osteoid osteoma is a common benign bone tumor affecting young adults with the typical clinical and radiological presentation when arising from common locations. However, when they arise from unusual locations like intra-articular regions the diagnosis may be confusing thereby leading to delay in diagnosis and appropriate management. Here we present a case with an intra-articular osteoid osteoma of the hip involving the anterolateral quadrant of the femoral head. CASE REPORT: An active 24-year-old man, with no relevant or significant medical history presented with progressive left hip pain radiating to the thigh for the past 1 year. There was no significant history of trauma. His initial symptoms were dull aching groin pain which worsened over weeks, associated with night cries, and loss of weight and appetite. CONCLUSION: The unusual site of presentation led to a diagnostic challenge and caused a delay in diagnosis. Computed tomography scan is the gold standard to detect osteoid osteoma and radiofrequency ablation can be used as a reliable and safe modality of the treatment for intra-articular lesions.