Association between Neuropathic Pain and Reported Disability after Total Knee Arthroplasty

Purpose: To determine whether reporting neuropathic pain (NP) at an average of 5 years after total knee arthroplasty (TKA) was related to patient age, sex, preoperative comorbidity, arthritis self-efficacy, or disability before surgery and at 1 year after surgery. The estimate of NP prevalence and cross-sectional group differences were explored at 5 years after surgery. Methods: A subsample of participants in a formal research study was contacted via mail approximately 5 years after undergoing surgery and were sent four questionnaires: the Western Ontario and McMaster Universities Osteoarthritis Index, the Patient Health Questionnaire, the Self-Administered Leeds Assessment of Neuropathic Signs and Symptoms (S-LANSS), and a satisfaction questionnaire. NP was defined as an S-LANSS score of 12 or more. Results: Of 89 patients who met the inclusion criteria, data for 63 (71%) patients (47 women; mean age 67 [SD 8] y) were used for analysis. Of these 63, 9 (14%) were identified as having NP. None had a report of failure of prosthesis or other surgical complications according to most recent medical records. There was no relationship between preoperative patient characteristics and development of NP. However, the NP group on average had a higher report of stiffness (p = 0.020), physical dysfunction (p = 0.019), and pain (p = 0.050) at 1 year after surgery. Cross-sectional comparisons showed higher levels of pain (p = 0.001), stiffness (p = 0.008), physical dysfunction (p = 0.003), and depression (p = 0.005) and lower satisfaction (p = 0.018) at the time of the survey than the patients without NP. Conclusion: The estimated prevalence of NP was 14%. Patients with NP reported higher levels of disability as early as 1 year after surgery. They remained more disabled, with a higher level of depression and less satisfaction, at an average of 5 years after surgery.