Fig. 2

Case presentation of bilateral cementless bilateral total hip arthroplasty for three different degrees of hips involvement with ankylosing spondylitis. a The radiograph showed bilateral hips involved preoperatively and physical examination showed no total loss of range of motion. b The radiograph showed bilateral hips involved and no trabecula bridged the hip joint plane preoperatively and physical examination showed total loss of range of motion. c The radiograph showed bilateral hips involved and trabecula bridged the hip joint plane preoperatively and physical examination showed total loss of range of motion. d The pelvis radiograph at the latest follow-up (78 months for both hips) for Fig. 1a showed excellent prosthesis position, no loosening and migration of the component. e The pelvis radiograph at the latest follow-up (82 months for right hip and 81 months for left hip) for Fig. 1b showed excellent prosthesis position, no loosening and migration of the component. f The pelvis radiograph at the latest follow-up (80 months for both hips) for Fig. 1c showed excellent prosthesis position, no loosening and migration of the component