The unhappy total knee arthroplasty (TKA) patient: higher WOMAC and lower KSS in depressed patients prior and after TKA

Patient-based and psychological factors do influence outcome in patients undergoing total knee arthroplasty (TKA). The purpose was to investigate if preoperative psychological factors influence the subjective and objective outcomes 6 weeks, 4 months and 1 year after TKA. Our hypothesis was that there is a significant influence of psychological factors on clinical outcome scores before and after TKA. A prospective, longitudinal, single-cohort study investigating the correlation of depression, control beliefs, anxiety and a variety of other psychological factors with outcomes of patients undergoing TKA was performed. A total of 104 consecutive patients were investigated preoperatively using the Beck`s depression inventory, the State-Trait Anxiety Index, the questionnaire for assessment of control beliefs and the SCL-90R inventory. The Knee Society Clinical Rating System (KSS) and the WOMAC were used. Analysis of TKA position was performed on radiographs according to Ewald et al. Correlation of psychological variables with outcomes was performed (p < .05). Self-efficacy did not influence clinical scores. More depressed patients showed higher pre- and postoperative WOMAC scores, but no difference in amelioration. KSS scores were not influenced. Patients with higher State and Trait Anxiety Indexes had higher WOMAC and lower KSS scores before and after the operation, but most significant correlations were < 0.3. Several SCL-90 dimensions had significant correlations with pre- and postoperative clinical scores, but not with their amelioration. The SCL-90 subscore for somatization and the overall SCL-90 significantly correlated with the WOMAC, KSS before and after TKA. Depression, anxiety, a tendency to somatize and psychological distress were identified as significant predictors for poorer clinical outcomes before and/or after TKA. Standardized preoperative screening and subsequent treatment should become part of the preoperative work-up in orthopaedic practice. Prognostic prospective, Level I.