Department of Orthopedics, Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China;
Department of Orthopedics, Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China;
Department of Orthopedics, Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China;
Department of Orthopedics, Second Hospital, Xi'an Jiaotong University, Xi'an 710004, China;
femoral head necrosis; pathology; nitric oxide; hemorheology; early diagnosis index;