Total Knee Replacement (TKR) performed under general anesthesia is a common successful orthopedic procedure. Nonetheless, in elder patients with diabetes mellitus (DM) this procedure can present unique challenges to orthopedic surgeon and anesthesiologist alike. Many diabetic patients have clinical or subclinical neuropathy. Although there is no evidence that the neuropathy is exacerbated by neural blockade, recent studies have suggested that the peripheral nerves in diabetic patients may be more susceptible to trauma and local anaesthetic toxicity. Therefore, The investigators observe peripheral nerve blocks with ropivacaine on diabetic patients or non-diabetic patients undergoing TKR by assessing the management of intraoperation and the Postoperative Recovery and complications.