[Hip subluxation and coxa valga secondary to an osteoïd osteoma].

We report on the case of a 2-year-old child with extra-articular osteoïd osteoma of the proximal femur leading to subluxation and coxa valga deformity of the hip joint at 10 year follow-up. The osteoïd osteoma reccured twice after surgical excision and percutaneous drilling. Patient's clinical history also reported a prolonged use of medications as treatment for these two recurrences. Second recurrence was combined with migration of the femoral head and retraction of the adductors: surgical treatment consisted in varus osteotomy to facilitate excision of the lesion, combined with a tenotomy of the hip adductors. Functional outcomes were satisfactory after 4-year follow-up. Reviews of the literature report two cases of hip subluxation secondary to intra-articular osteoïd osteoma. From our experience, it seems that hip subluxation in the present case could have been avoided with early surgical management.