The effects of NF-I on the hip have been underreported in literature. The bony changes in the hip can be mild to severe and are often present, but not diagnosed. Dislocation of the hip has been described but protrusio acetabulum is underdiagnosed and has only been reported from one institute. This is the first case where an open biopsy has been taken from the hip joint by surgical dislocation with preservation of the blood supply to the femoral head. Gross and microscopic pathology in the neurofibromatosis of the hip has been described for the first time in our report.

A 16-year-old girl presented with history of pain, limp and stiffness in the right hip for several years. Radiographs, CT scan showed severe protrusio acetabulum. Histological analysis from the tissue taken from the hip was a neurofibroma. There was very minimal hyaline cartilage in the acetabulum at operation. Therefore the floor of the acetabulum was grafted with the autologous cancellous bone chips obtained from her greater trochanter. The aim of this was to lateralize the hip center to a normal position. At six months follow up she was doing well. Her range of movements had increased by 20%.