It has been well known that central sensitization (CS) is a risk factor for inferior outcomes following total knee arthroplasty (TKA). However, there are still insufficient studies on the relationship between CS and neuropathic pain (NP), and the effects of CS and NP on the patient-reported outcome measures (PROMs) of patients who underwent TKA. The purpose of this study was to investigate the relationship between CS and NP and whether CS and NP were associated with PROM in patients undergoing TKA.

A total of 312 patients who underwent primary TKA for end stage knee OA were enrolled. CS was defined as a patient with a score of 40 or higher using central sensitization inventory (CSI). NP was defined as a patient with a score of 12 or more using pain detect questionnaire (PDQ). PROMs were also evaluated based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score preoperatively and at postoperative 1 year. The patients were divided into 4 groups, group 1 with CS and NP positive, group 2 with only CS positive, group 3 with only NP positive, and group 4 with CS and NP negative, and PROM was compared between the groups.

Inclusion Criteria:

• Primary knee degenerative osteoarthritis
• Patients for total knee arthroplasty over the age of 60
• Patients with 2 year postoperative medical records

Exclusion Criteria:

• Rheumatoid arthritis
• Other inflammatory arthritis
• Neuropsychiatric patients
• Hepatic insufficiency
• Renal insufficiency
• Allergy or intolerance to study medications
• Patients with an acetylsalicylic acid of IV (angina, congestive heart failure, dementia, cerebrovascular accident)
• Chronic opioid use (taking opioids for longer than 3 months)
• Alcohol, drug abuser
• Narcotics addiction

This study was approved by the Institutional Review Board of our hospital. Between May 2019 and February 2020, a total of 332 primary TKAs were performed at our institution by a single surgeon. Only patients with a follow-up period of more than two years were included in the study. The remaining 316 patients with primary TKAs were enrolled in this study.