Kinesiophobia and depression affect total knee arthroplasty outcome in a multivariate analysis of psychological and physical factors on 200 patients.

PURPOSE: To evaluate the effects of kinesiophobia on the outcomes of total knee arthroplasty (TKA), and to investigate whether kinesiophobia represents an independent factor influencing the surgery success or whether the observed effects are driven by other physical or psychological aspects such as anxiety and depression.
METHODS: Two hundred patients were evaluated prospectively (mean age 65.7 ± 9.1 years, 134 women and 66 men) at 12 months after TKA. Kinesiophobia was assessed with the Tampa Scale for kinesiophobia (TSK: Activity Avoidance-TSK1 and Harm-TSK2 subscales); anxiety and depression were assessed with STAI and BDI, respectively, and preoperative pain and function, sex, age, BMI, education level, number of painful joints and years of symptoms' duration before surgery were documented as well. Results were evaluated with pain and function on 0-10 numeric rating scales, while the overall clinical outcome was documented with WOMAC and SF-12 (Physical and Mental subscales) scores.
RESULTS: TSK1 was correlated with WOMAC results at 12 months (p = 0.005, ρ = 0.197). STAI (p = 0.002, ρ = 0.222), BDI (p < 0.0005, ρ = 0.307), and sex (p = 0.004) also influenced the outcome after TKA, while other parameters, such as age, BMI, education level, and number of painful joints and years of symptoms' duration before surgery, did not correlate with the clinical outcome. The multivariate analysis confirmed the role of BDI (p = 0.006, partial η 2 = 0.038), TSK1 (p = 0.011, partial η 2 = 0.033), and sex (p = 0.048, partial η 2 = 0.020), and a synergic interaction of BDI and TSK1, which together presented an even stronger correlation (p < 0.0005, partial η 2 = 0.111) with WOMAC at 12-month follow-up.
CONCLUSIONS: Kinesiophobia is a factor influencing the outcome after TKA independently from other psychological and physical variables. This risk factor may affect TKA results, especially in women, and shows a further synergic interaction with depression in terms of lower surgical outcome. These findings are of clinical relevance because they show the impact of psychological factors such as kinesiophobia, and suggest the possibility of adopting co-interventions to overcome the fear of physical activity, and in the end improve patient recovery and final outcome after TKA. LEVEL OF EVIDENCE: IV.