gms | German Medical Science

Objectives: It is known that personality traits, such as dispositional optimism and pessimism, have impact on a variety of health related problems. Influence on post-operative outcome in Total Knee Arthroplasty (TKA) could only be shown for another personality trait concept, the explanatory style, but not for dispositional optimism/pessimism. We aimed to examine the association of dispositional optimism/pessimism with pre-operative joint function and post-operative outcome in TKA.

Methods: Data were acquired in a multicentre, cross-sectoral, prospective study design (the PROMISE Trial). Patients were followed for 12 months post-operatively. Dispositional optimism/pessimism was measured pre-operatively via the revised Life Orientation Test (LOT-R), pre- and post-operative function was measured via the 12 Item Knee- osteoarthritis outcome Scores (KOOS-12). Log-linear regression models considering known confounders and t-test were carried out to show the association of LOT-R scores with pre- and post-operative KOOS-12 scores.

Results: 740 patients were analysed. Optimistic LOT-R was significantly positively associated to the mean scores of KOOS-12 pre- and post-operative, while pessimistic LOT-R was significantly associated negatively (pre-operative: optimistic p=.001, pessimistic p=.001; post-operative optimistic: 3M p= .001, 6M p= .001, 12M p= .001; post-operative pessimistic: 3M p=0.01, 6M p= .004, 12M p= .001).

Conclusion: Optimism was positively associated with pre-operative joint function and, more importantly, post-operative functional outcome in TKA, while pessimism was associated with the opposite. Assessing patients’ general personality traits prior to surgery to identify pessimistic patients, hence being at risk for poor outcome in TKA, should be considered to react to the patients’ special needs and possible pessimistic expectations, i.e. through a cognitive-behavioral intervention, to potentially increase optimism and hereby post-operative outcome in TKA.