Centrally sensitized patients undergoing total knee arthroplasty have higher expectations than do non-centrally sensitized patients

Purpose: The goal of this retrospective observational study is to determine whether patients with and without central sensitization (CS) undergoing total knee arthroplasty (TKA) have similar preoperative expectations. It was hypothesized that the degree of preoperative expectations is higher in patients with CS than in those without. Methods: The data of 324 patients who underwent primary unilateral TKA for knee osteoarthritis were reviewed and CS was measured using the Central Sensitization Inventory (CSI), which is a validated self-reported questionnaire consisting of a total of 25 questions. CS was defined as a CSI score of 40 or more. Patient expectations were investigated using the Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES) comprising five categories including pain relief, baseline activity, high flexion activity, social activity, and psychological well-being. The expectations of patients, the Western Ontario and McMaster Universities arthritis index (WOMAC) and American Society of Anesthesiologists (ASA) classification scores were compared between the CS and non-CS groups. Results: The top three patient expectations in both groups were pain relief, psychological well-being, and walking ability. The total score for the expectations was 55.0 ± 8.3 in the CS group and 52.3 ± 10.4 in the non-CS group, indicating that the expectations of the CS group were higher than the non-CS group before TKA (p < 0.05). When the items on the HSS-KRES scale and the five categories were compared, the CS group had significantly higher expectations for pain relief and psychological well-being than did the non-CS group (all p < 0.05). Conclusion: The expectations of patients with CS before TKA were higher than those without CS. Given the limited improvement in patient-reported outcome measures of patients with CS undergoing TKA, they should be counseled to be realistic especially with their preoperative expectations of pain relief and psychological well-being. Level of evidence: III.