Psychological Traits in Patients Waiting for Total Knee Arthroplasty. A Cross-sectional Study

To determine the prevalence of psychiatric distress in an Australian patient population waiting for total knee arthroplasty and to assess the associations between psychological distress and other baseline characteristics.

This is a cross-sectional study of prospectively collected data from patients with knee arthritis participating in the New South Wales Osteoarthritis Chronic Care Program. Participants were divided into 2 groups based on the Depression Anxiety and Stress Score. The prevalence of psychological distress was compared to reported prevalence in the Australian community. Between-group comparisons of a number of variables were made, including demographic and socioeconomic data, health and psychiatric data, patient-reported knee and quality-of-life scores, and measured function.

Data from 3103 patients were available and 2809 patients were eligible for inclusion, with 1740 (62%) females. Mean patient age was 68 years, and mean body mass index was 33.8. We found 753 (26.8%, standard deviation: 0.44) of participants reported psychological distress. Those reporting distress were more likely to be female (P = .025), younger (66.6 vs 68.8 years, P < .001), with a higher body mass index (34.5 vs 32.7, P < .001), and had more comorbidities (3.4 vs 2.8, P < .001). The distressed group had significantly worse knee pain (visual analog scale: 7.1 vs 6.2, P < .001; Knee Injury and Osteoarthritis Score pain component: 28.9 vs 41.2, P < .001), knee function, and general quality-of-health scores (P < .001).

Psychological health is an important and often overlooked predictor of severity of symptoms and dysfunction in patients with knee arthritis. As it can affect the outcome for surgery, psychological health should be better assessed and treated before surgery to help reduce preoperative dysfunction and improve postoperative outcomes of total knee arthroplasty.