[Patellar hypertrophy: rare abnormality associated with a multiple epiphyseal dysplasia].

Multiple epiphyseal dysplasia is a genotypic chondrodystrophy characterized by an abnormal shape of numerous epiphyses. Diagnosis is usually made during childhood on an abnormal gait and a reduction of joint mobility associated with radiological changes of the ossification centres. This observation reports on a woman who only consulted at adulthood. Diagnosis was based on a short stature, slight shortening of the extremities and precocious osteoarthritis on the radiographs. Lateral x-rays of the knees revealed a globular hypertrophy of both patellae. This association has rarely been mentioned. A late fusion of an antero-posterior duplication of the ossification centre of the patella seems to be the most plausible physiopathologic hypothesis. Persistence of both ossification centres could result in a coronal double-layered patella, which is also occasionally observed in patients with multiple epiphyseal dysplasia.