The dynamic impact of Joint Awareness on Quality of Life after Total Knee Arthroplasty: a longitudinal study

BACKGROUND: Joint Awareness is thought to be closely linked to Quality of Life (QoL) for patients undergoing Total Knee Arthroplasty (TKA), yet to date there have been no longitudinal studies to explore how Joint Awareness actually affects QoL. The purpose of this study was therefore to examine the development of Joint Awareness and QoL after TKA as well as the dynamic impact of Joint Awareness on QoL. METHODS: A total of 342 patients were followed up at 3 months (T1), 6 months (T2), and 12 months (T3) after TKA. Joint Awareness was evaluated using the Forgotten Joint Score-12 (FJS-12), and QoL was measured by SF-36. We used repeated measures analysis of variance to estimate the development of Joint Awareness and QoL and employed a cross-lagged model to examine the dynamic relationship between Joint Awareness and QoL. RESULTS: Both Joint Awareness and QoL improved with postoperative time (p < 0.001). Importantly, T1 Joint Awareness positively predicted T2 physical QoL (p < 0.001), and T2 Joint Awareness positively predicted T3 physical QoL (p < 0.001). Nevertheless, Joint Awareness had no predictive effect on mental QoL (p = 0.082–0.931). CONCLUSIONS: In different periods after TKA, Joint Awareness and QoL both increased monotonically, and Joint Awareness positively predicted physical QoL. These findings indicate that focusing on Joint Awareness may be a priority when trying to improve the postoperative life of patients.