Arthroscopic excision of osteoid osteomas of the hip in children.

The atypical presentation of intra-articular osteoid osteoma in the hip joint frequently results in delayed diagnosis compared with the diagnosis of extra-articular osteoid osteoma. We present 2 cases of hip joint osteoid osteoma in children treated by hip arthroscopy. Intra-articular osteoid osteoma was suspected when computed tomography (CT) findings were reviewed. Of the various surgical options including wide-open or CT-guided minimally invasive techniques, arthroscopic excision was selected for our patients to avoid damage to the adjacent growth plate (the triradiate cartilage) and to treat concomitant synovitis. Under arthroscopic visualization, biopsy specimens were obtained first, and the lesions were excised. In both cases, postoperative CT showed complete excision and histologic examination confirmed the diagnosis. Both patients enjoyed excellent clinical outcomes. We conclude that the arthroscopic excision of the hip joint osteoid osteoma in children is effective because it causes minimal damage to normal bone or the adjacent growth plate, and because synovectomy for concomitant synovitis may be performed. Hip arthroscopy also yields a biopsy specimen adequate for pathologic examination.