Objective To compare and analyze the clinical application of lumbar plexus combined with sciatic nerve block and spinal anesthesia for elderly patients with knee joint surgery. Methods A total of 77 elderly patients with ASAⅠ ~ Ⅲ undergoing single knee replacement surgery were randomly divided into combined group which recieved lumbar plexus combined with sciatic nerve block and spinal anesthesia group. The baseline values,blood pressure and heart rate at multiple time points,the block area and duration,the...