A 46-year-old male (body weight 69 kg, ASA status II) was scheduled for right total hip arthroplasty (THA). He suffered from ankylosing spondylitis for 20 years. Physical examination indicated that the cervical and lumbar spine was rigid and the right hip joint was immobilized. The bamboo-like changes of spine were found in the spinal anterioposterior and lateral radiographs (Fig. ). X-ray and CT examination indicated degenerative osteoarthrosis of bilateral hip joints and sacroiliitis on the right side. The patient appeared potentially difficult to be intubated as the examination of airway revealed that the interincisor distance was 2 cm and a Mallampati class III. The preoperative visual analog scale (VAS) score of this patient was 4. This patient received ultrasound-guided lumbar SNRB plus T12 paravertebral and sacral plexus blocks, and 25 mL of 0.4% ropivacaine was used. Pinprick test was used to confirm the success of these blocks. The time of surgery was 1 hour and 26 minutes. He also did not complain any painful during surgery and in PACU. With the PCA, the postoperative VAS scores were 0 to 1. This patient discharged on the second day after surgery. No postoperative complication was reported with him.
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.