Comparison of Opioid and Duloxetine for Postoperative Pain Control After Total Knee Arthroplasty: Randomized Controlled Trial

For patients undergoing TKA for osteoarthritis of the knee joint, pain control will be performed using the same pain control technique (pain control using NSAID) until discharge (1 week after surgery) after surgery. By evaluating the Visual Analogue Scale (VAS), which is known as the patient's pain criterion, the study will be conducted only on patients whose score is more severe than 4 points. Among these subjects, only patients who agreed to the study will be assigned to the group taking duloxetine and the group taking opioids with the same probability according to the randomization table for one week after surgery, that is, upon discharge. In our hospital, almost all patients with total knee arthroplasty are discharged one week after surgery, except for special cases such as morbidity of systemic diseases such as cardiopulmonary dysfunction or acute infection after surgery.

Among the co-researchers, one researcher who is in charge of only patient assignment is selected, and the person in charge creates a randomization table through computer generated randomization. During the assignment process, the assignee will not know in advance the next assignment group, and the randomization table is kept in secret. The assignee does not intervene in any other process of this study, and participates only in the task of selecting the assigned group using random checks. The evaluation is evaluated by an evaluator who is not aware of the patient allocation according to the randomization table among researchers participating in the clinical study. Such a study plan will be fully explained to the patient in the process of seeking consent for the study before discharge, as it is recorded in detail in the subject description, and only patients who have obtained this consent will be the subject of the study.

This criterion is established because both duloxetine and opioid are not used for all patients after surgery, but for additional pain control after surgery. Prior to discharge, the drug is prescribed for a total of 6 weeks by dividing the duloxetine-administered group and the opioid-administering group, respectively. In general, if duloxetine is not taken for more than 10 weeks, the frequency of discontinuation syndrome that can occur after discontinuation is remarkably low, so the administration period of 6 weeks was set as the administration period. The follow-up periods for out-patient clinic are 2 weeks, 6 weeks, 3 months, 6 months, and 1 year after the TKA surgery. During the follow-up period, NSAIDs will be prescribed the same in both groups.

As an additional rescue medication, 650 mg of acetaminophen will be allowed to use up to 2g per day.

Before surgery, 1 week after surgery, 2 weeks, 6 weeks, 3 months, 6 months, 1 year The degree of pain will be measured using the VAS pain scale, WOMAC pain scale, Brief pain inventory (BPI), Intermittent and Constant Osteoarthritis The pain (ICOAP) score is used to measure additional pain scales in various ways. In addition, SF-36 will be measured before surgery, at 6 weeks, 3 months, 6 months, and 1 year after surgery.