A 73-year-old female (body weight 64 kg, ASA status III) who suffered from rheumatoid arthritis (RA) for 30 years was scheduled for right total knee arthroplasty (TKA). X-ray of her bilateral knee joint revealed that the joint cavity of bilateral knee joints was narrow and osteophyte formatted in the right side. The patient had hypertension for 6 years and was treated with oral nitrendipine. She also had a history of cerebral infarction 3 years ago. MRI of brain revealed multiple old softening foci in the right basal ganglia region. She had taken aspirin and ginkgo tablets for anticoagulation therapy and prevention of recurrent stroke. The preoperative visual analog scale (VAS) score of this patient was 4. The ultrasound-guided lumbar SNRB plus T12 paravertebral and sacral plexus blocks were performed with 25 mL of 0.4% ropivacaine. Pinprick test was used to confirm the success of these blocks. This technique completely met the analgesic requirement of this patient during surgery. The time of surgery was 1 hour and 12 minutes. With the PCA, the postoperative VAS scores were 0 to 1. This patient discharged on the third day after surgery. No postoperative complication was reported with her.
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.