Total Hip Replacement: Psychometric Validation of the Italian Version of Forgotten Joint Score (FJS-12)

Background: One million Total Hip Replacements (THA) are thought to be performed annually. To measure prosthesis awareness throughout daily activities, the FJS-12 patient-reported outcome scale was developed. This article’s goal is to undertake a psychometric validation of the Italian FJS-12 among a sample of related THA patients. Methods: Between January and July 2019, data from 44 patients were retrieved. The participants were required to complete the Italian version of FJS-12 and of the WOMAC at preoperative follow-up, after two weeks, 1, 3, and 6 months postoperatively. Results: The Pearson correlation coefficient between the FJS-12 and WOMAC was 0.287 (p = 0.002) at preoperative follow-up, r = 0.702 (p < 0.001) at 1 month, r = 0.516 (p < 0.001) at 3 months and r = 0.585 (p < 0.001) at 6 months. The ceiling effect surpassed the acceptable range (15%) for FJS-12 in 1 month (25.5%) and WOMAC in 6 months follow-up (27.3%). Conclusions: The psychometric validation of the Italian version of this score for THA was executed with acceptable results. FJS-12 and WOMAC reported no ceiling and floor effects. Therefore, to distinguish between patients who had good or exceptional results following UKA, the FJS-12 could be a reliable score. Under the first four months, FJS-12 had a smaller ceiling effect than WOMAC. It is recommended to use this score in clinical research concerning the outcomes of THA.