Case 2: A 61 years old male (weight 75 kg, ASA status III) suffered from AS for 20 years, and was scheduled for left total hip arthroplasty (THA). He had a history of coronary heart disease and received coronary stent implantation 7 years ago. A physical examination revealed rigidity of cervical and lumbar spine, severe press pain and immobilization of left hip joints. An X-ray of the neck, chest and lower back revealed bamboo-like changes of the spine. CT of the hip joints reported necrosis of the left femoral head, and ankylosis of left hip joint. He had taken aspirin for anticoagulation therapy for a long term, and was replaced by low molecular weight heparin.
Case 4: A 65 years old male (weight 76 kg, ASA status III) was scheduled for left THA. He was diagnosed with AS for 10 years, and developed necrosis of both femoral heads, and could not walk because of pain in the left hip joint. He had a history of hypertension for 10 years, and diabetes mellitus for 7 years, and smoking history for 50 years with nearly 50 cigarettes per day. A chest X-ray revealed enhanced texture of bilateral lungs and right pleural effusion. X-ray of his pelvic revealed bilateral femoral head necrosis, narrowed joint space, osteoproliferation and bone defect under articular surface of bilateral sacra-iliac joints and hip joints, and bamboo-like changes of lower lumbar spine.