We present the case of a 33 year old patient who has been followed since the age of 16 for autosomal dominant spondyloepiphyseal dysplasia (SED), in an evocative familial context (his sister has the same clinical picture). The disease began in adolescence with disabling mechanical pain in the hips and knees, with a walking distance limited to 500 metres. Clinical examination showed bilateral knee flexion contracture, generalised stiffness of the hips, shoulders, elbows, wrists and fingers, girdle muscle wasting, and a BMI of 16 (47 kg for 1.67 m). The patient walks with a cane. Symptomatic treatment combining analgesics, NSAIDs and physiotherapy was initiated. The article details the diagnostic arguments, indications for bilateral hip arthroplasty, anaesthetic precautions and the role of genetic counselling. Medium term outcome was favourable, with improvement in pain and walking distance after total hip replacement.