Fig. 4
From: A simple method for establishing an ostrich model of femoral head osteonecrosis and collapse
Postoperative conditions. a The normal ostrich femur head. b The ostrich femur head at postoperative week 6: the openings of the bone tunnel (yellow arrow). The focal cartilage exfoliation (black arrow). c The ostrich femur head at postoperative week 12: the changed contour of femoral head (red arrow). The covered openings of the bone tunnel (yellow arrow). Cartilage erosion (black arrow). The wrinkled cartilage at the side of trochanter (blue arrow). d The ostrich femur head at postoperative week 24: The complete collapsed femoral head (Fig. 4d, black arrow). The interrupted sclerotin of femoral neck (yellow arrow). The worn cartilage on the surface of the trochanter and the exposure of the subchondral bone (blue arrow)