# Investigating the dynamic relationship between joint function outcomes and kinesiophobia following total knee arthroplasty

## TL;DR

This study examines how joint function and fear of movement change together after knee replacement surgery, finding that their influence shifts over time.

## Contribution

The novel finding is the bidirectional and time-dependent relationship between joint function and kinesiophobia after TKA.

## Key findings

- Joint function improved over time while kinesiophobia decreased significantly post-TKA.
- Kinesiophobia was a stronger early predictor of joint function, while joint function later predicted kinesiophobia.
- A bidirectional relationship was confirmed, suggesting the need for phased rehabilitation strategies.

## Abstract

To investigate the temporal trends and bidirectional predictive relationships between joint function outcomes and kinesiophobia in patients following total knee arthroplasty (TKA).

Using a convenience sampling method, 242 patients who underwent TKA in the orthopedics departments of two Grade A Tertiary hospitals in Panzhihua City between October 2024 and March 2025 were selected as study participants. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Tampa Scale for Kinesiophobia-11 (TSK-11) were used to assess joint function and kinesiophobia at 1 month (T1), 3 months (T2), and 6 months (T3) postoperatively. A cross-lagged analysis was employed to analyze the causal relationships between the variables.

Joint function in TKA patients improved significantly over time, while kinesiophobia levels gradually decreased, with statistically significant differences in scores across all time points (P < 0.05). By 6 months post-surgery, the excellent and good outcome rate reached 72.31%, indicating that joint function still retained potential for further improvement. Cross-lagged analysis revealed a bidirectional causal relationship between joint function and kinesiophobia. In the early rehabilitation phase (T1–T2), kinesiophobia was a stronger predictor of joint function (β = 0.368, P < 0.001). Conversely, in the middle to late rehabilitation phase (T2–T3), joint function became a more prominent predictor of kinesiophobia (β = 0.218, P < 0.001).

We found a bidirectional relationship between joint function and kinesiophobia during TKA recovery, with the dominant influence shifting from kinesiophobia early on to joint function later. This suggests that rehabilitation strategies should be phased, initially addressing fear and later focusing on functional training to optimize outcomes.