Psychological factors associated with pain after total knee arthroplasty: a prospective monocentric study

Persistent pain after total knee arthroplasty (TKA) remains a major cause of patient dissatisfaction despite satisfactory surgical results. The primary objective was to identify psychological predictors of persistent pain. Several studies have investigated psychological predictors of postoperative pain, but few prospective studies have simultaneously evaluated psychological factors alongside clinical, radiological, and surgical parameters. Therefore we performed a prospective investigation aiming: (1) to identify psychological predictors of persistent pain, (2) to evaluate the relationship between psychological factors, postoperative pain, patient satisfaction, and functional outcomes at one year.

We hypothesized that preoperative psychological factors would be independently associated with pain one year after primary TKA.

This prospective monocentric study included 111 consecutive patients undergoing primary TKA for knee osteoarthritis between February 2022 and May 2024. Preoperative evaluation included demographic and clinical data, psychological assessment using the Hospital Anxiety and Depression Scale (HADS), Pain Catastrophizing Scale (PCS), and Amsterdam Preoperative Anxiety and Information Scale (APAIS), as well as neuropathic pain screening. Radiological parameters and perioperative surgical variables were collected. Persistent pain was defined as a numeric rating scale (NRS) score ≥4 at one year, corresponding to at least moderate pain intensity. Functional outcomes and patient satisfaction were recorded at one year. Variables with p < 0.20 in univariate analysis were entered into multivariate logistic regression models.

A total of 111 patients were analyzed, of whom 28 (25.2%) reported persistent pain at one year. In multivariate analysis, a higher number of medical comorbidities (OR 1.74, 95% CI: 1.10-2.77 (p = 0.019)) and preoperative pain catastrophizing (PCS > 30) (OR 4.94, 95% CI: 1.60-15.25 (p = 0.005)) were independently associated with persistent pain. Radiological alignment and surgical variables were not associated with residual pain.

Preoperative psychological factors, particularly pain catastrophizing, are independently associated with persistent pain after TKA and with poorer clinical outcomes. Integrating psychological evaluation into preoperative assessment may improve patient selection and perioperative management.

III; prospective observational cohort study.