Fig. 2

Presentation of osteonecrosis of the femoral head in severely affected MPS III patients. a An 8-year-old male MPS IIIA patient with severe dysplasia of both hips and osteonecrosis of both femoral heads. b An 8-year-old female MPS IIIA patient with physiological acetabular coverage, but osteonecrosis of the femoral head on both sides. c A 12-year-old male MPS IIIA patient with coxa vara and severely dysplastic acetabular coverage. d A 10-year-old male MPS IIIA patient with osteonecrosis of both femoral heads and dislocation of the right hip joint