Outpatient unicompartmental knee arthroplasty: who is afraid of outpatient surgery?
BACKGROUND A subgroup of patients undergoing TKA is unhappy with the outcome of surgery and preoperative psychological factors may play a role in their dissatisfaction. QUESTIONS/PURPOSES We asked whether (1) psychological factors, as measured by preoperative self-reported questionnaires, predicted poor outcome after TKA, and (2) whether certain psychological factors examined predicted poor outcome better than others. METHODS We performed a systematic review and meta-analysis of prospective observational studies published in MEDLINE, CINAHL®, EMBASE™, and PsycINFO® databases from their date of inception to October 2013, augmented with a manual search of bibliographies. Study eligibility was performed according to an a priori protocol. Included studies were assessed for quality according to the Newcastle-Ottawa scale. Two reviewers independently performed the search, identified eligible studies, assessed their methodologic quality, and extracted data. Outcomes of interest included postoperative dissatisfaction, pain, or limited function of the patients. RESULTS A total of 19 studies (17 cohort studies and two cross-sectional surveys) containing data on 9046 TKAs performed in 8704 adult patients were included in the review. Mean patient age was 68 years and followup ranged from 6 to 60 months (mean study followup, 14 months). Clinical and methodologic heterogeneity in study design prevented the statistical pooling of data and subsequent meta-analysis. Dissatisfaction rates with TKA ranged from 7.5% to 28.3%. Psychological health was deemed a significant predictor of satisfaction, pain, or function at a minimum of 6 months after TKA in 16 studies. The remaining three studies did not find this relationship. Baseline mental health factors may affect patient satisfaction, their long-term perception of pain, and their motivation to return to the desired level of function. We were unable to determine the most relevant psychological states or the most appropriate way to assess them with our systematic review. CONCLUSIONS The preoperative psychological state of a patient may affect the outcome after a TKA. A comprehensive psychological assessment of patients is required to examine the long-term effect of such psychological factors on the eventual outcomes of TKA once the recovery phase is complete and to assess the effect that treatment for these psychological conditions may have on decreasing the dissatisfaction rate with TKA in this population.