Analysis of the current status and factors influencing post-traumatic stress disorder in elderly patients with knee osteoarthritis: a cross-sectional study

Existing studies have focused on post-traumatic stress disorder (PTSD) after surgery in patients with knee osteoarthritis (KOA), whereas PTSD in non-operated elderly KOA patients has not been adequately studied. The aim was to assess the current status of PTSD and its influencing factors among non-surgical elderly KOA patients. From October to November 2021, a cross-sectional study was conducted among 320 consecutive patients aged ≥ 65 years with radiologically confirmed KOA and no history of knee surgery or psychiatric disorders, recruited from three community hospitals in Changsha, Hunan Province. A total of 314 participants completed validated assessments for PTSD (PTSD Checklist-Civilian Version), pain (Numerical Rating Scale), anxiety (Generalized Anxiety Disorder Scale), depression (Patient Health Questionnaire-9), and social support (Social Support Rating Scale). Data were analyzed using non-parametric tests and Spearman correlation. Structural equation modeling (SEM) was performed with Amos 24.0, employing maximum likelihood estimation and 1000 bootstrap samples to test mediation effects. Among 314 analyzed participants (mean age 72.91 ± 6.384 years; 60.80% female and 39.20% males), PTSD prevalence was 18.20%. Significantly higher PTSD risk was associated with low education levels (Z=-2.398, P = 0.016), low salaries (H = -2.398, P = 0.005), unemployed patients (H = 10.030, P = 0.007), no exercise (H = 9.328, P = 0.025), smoking (Z = -2.504, P = 0.012) and no leisure activities (Z=-2.074, P = 0.038). Structural equation modeling revealed a direct effect of depression on PTSD with the path coefficient of 0.701 (95% CI 0.518-0.879, P = 0.001) and an indirect effect of pain on PTSD through social support with the path coefficient of -0.014 (95% CI -0.049 to -0.001, P = 0.035 < 0.05). Non-surgical elderly patients with knee osteoarthritis exhibit clinically significant post-traumatic stress disorder rates (18.20%), primarily driven by depression and mediated through pain-social support pathways. These findings underscore the need for integrated biopsychosocial interventions targeting pain management, mental health screening, and social support enhancement in this population.