Recurrent Legg-Calvé-Perthes disease revisited: fake or reality?

The objective of this study was to assess the course, the epidemiologic features and the prognosis of recurrent Legg-Calvé-Perthes disease. We reviewed seven reported cases and one personal case of recurrent Perthes' disease. In all cases, complete recovery from the previous episode was documented, and a thorough diagnostic work-up to rule out other diseases was undertaken. There were five boys. Age at onset ranged from 2 to 6 years. Five patients had bilateral involvement. Recurrence took place 1-5 years after complete healing of the initial one. Clinical and radiological pictures were similar to those found in primary Perthes' disease of the adolescent and consisted in a greater epiphyseal involvement. Recurrent Perthes' disease is very rare. We did not identify any risk factors for recurrence. A worse outcome is more closely related to an older age of the patient at recurrence than to recurrence itself.