Postoperative wound complications such as wound dehiscence, skin necrosis, persistent wound drainage, delayed healing, and superficial skin infection could have devastating consequences, leading to arthroplasty failure and patient morbidity requiring additional operations and prolonging hospitalization with substantial burden in cost of care. Recently, interest and research on central sensitization (CS) have been increasing. CS is closely correlated with excessive pain. It has two main characteristics: allodynia and hyperalgesia. CS is an abnormal and intense enhancement of pain mechanism by the central nervous system. One of the mechanisms by which this excessive pain occurs in CS is reduced activation of descending inhibitory pathway associated with deficiency in pathways primarily in response to serotonin and norepinephrine. Serotonin plays an important role in normal wound healing by affecting the formation of neovascularization, inflammatory reactions, fibroblasts and tissue proliferation essential for wound healing. Norepinephrine is also closely related to wound healing by controlling chemotaxis of macrophage essential for normal wound healing. CS is a risk factor for the development of postoperative wound complication after primary Total Knee Arthroplasty (TKA). Preclinical models of central sensitization suggest that duloxetine is effective in the treatment. Investigators will compare the wound complication following TKA of central sensitization patients in duloxetine group (n=40) with those in non-duloxetine group (n=40). Investigators will classify the central sensitization patients by central sensitization inventory and divide the central sensitization patients in to 2 groups (duloxetine and non-duloxetine group) randomly. Investigators checks the wound complication after primary TKA and visual assessment scale at preoperative, postoperative 2 days and 1, 2,6,12 weeks. All participants will receive postoperative pain control after TKA using the same pain control regimen and wound dressing regimen except duloxetine.

Inclusion Criteria:

• Patients for total knee arthroplasty
• having medicare insurance
• Central sensitization inventory (CSI)> 40 (Central sensitization patient )

Exclusion Criteria:

• Rheumatoid arthritis
• Other inflammatory arthritis
• Neuropsychiatric patients
• Allergy or intolerance to study medications
• Patients with an American society of anesthesiologist (ASA) classification of IV (angina, congestive heart failure, dementia, cerebrovascular accident)
• Chronic gabapentin or pregabalin use (regular use for longer than 3 months)
• Chronic opioid use (taking opioids for longer than 3 months)
• Alcohol, drug abuser
• Narcotics addiction