Noise after total knee arthroplasty has limited effect on joint awareness and patient-reported clinical outcomes: retrospective study

Some patients complain of noise after total knee arthroplasty (TKA). Controversy still exists on how the noise affects the clinical outcomes, including joint awareness, after TKA. The Forgotten Joint Score-12 (FJS-12) measures the clinical outcomes focusing on joint awareness after surgery. The Knee Society Scoring System-2011 (KSS-2011) includes questionnaires for satisfaction, expectation, and functional activities. The aim of this study is to clarify the relationship among FJS-12, KSS-2011, and the noise. Furthermore, the relationship between FJS-12 and KSS-2011 was validated. Using FJS-12 and KSS-2011, 295 knees from 225 patients who underwent TKA were retrospectively evaluated. Noise perception was evaluated by a questionnaire with five grades, a method that follows the questionnaire form of FJS-12 ("Are you aware of the noise of your artificial joint?"; never, almost never, seldom, sometimes, mostly). Correlations among FJS-12, KSS-2011, and noise were analyzed. The patients were divided into four groups based on the mechanism of their implant [cruciate retaining, posterior stabilized, cruciate sacrificed, and bicruciate stabilized (BCS)]. FJS-12, KSS-2011, and noise were compared among the groups. A strong correlation was found between FJS-12 and total score of KSS-2011 (0.70; P