Total joint replacement is an ideal procedure to treat end stage joint disease. Good post-op pain relief could accelerate patient recovery and rehabilitation, and decrease admission days and medical cost. Local injection of LevoBupivacaine is an effective method in post-operative pain control. The effectiveness of local analgesia was noticed clinically. However, thorough studies about the pharmacokinetics of LevoBupivacaine, maintenance of effect, influence of post-operative rehabilitation are not well studied in different way of injection. The purpose of this study is to evaluate and analyze the pharmacokinetics and effect of local Levobupivacaine injection in different ways, the amount of post-operative fentanyl requirement after local injection, time to first fentanyl request, pain score, immediate post-operative function, side effect of analgesic agents, and medical cost, and to improve the quality of total joint replacement post-operative care.

Single large dose of LevoBupivacaine had been proved good analgesic effect in total joint replacement surgery. However, the safety was not well studied. For better understanding the effect and safety of local analgesic agent, we choose LevoBupivacaine with different injection way to find out. We divide patient to three groups, for comparing the effectiveness of LevoBupivacaine, and safety of LevoBupivacaine by checking intra-blood concentration. The pre-emptive analgesics and post-operative analgesics were the same as routine protocol in other total joint replacement.

Inclusion Criteria:

1. Primary total joint replacement, no previous open surgery on the same joint
2. Age 50~80 y/o, Pre-operative diagnosis: degenerative osteoarthritis
3. Pre-operative deformity: varus <15°, valgus <15°, flexion contracture <15°.
4. Patients with normal heart function
5. Willing to receive post-operative questionnaire and outpatient clinic follow-up

Exclusion Criteria:

1. Allergy to Patient-Controlled Analgesia or LevoBupivacaine
2. Mental or cognitive illness that couldn't well response to questionnaire
3. American Society Anesthesiologist more than III degree
4. Liver cirrhosis, chronic renal insufficiency, heart disease or arrhythmia, insulin-dependent diabetes mellitus, and previous narcotic abuse history.
5. Not suitable for using patient-controlled analgesia pump by evaluation of anesthesiologist

Patient blinded, observer blinded study