Multifactorial analysis of dissatisfaction after primary total knee replacement.

Background: The aims of this study were to identify the prevalence and causes of dissatisfaction in a cohort of private practice patients, and to compare the psychological characteristics of dissatisfied patients to matched, satisfied controls.

Methods: Unilateral TKR patients were evaluated to identify those dissatisfied with their TKR. Dissatisfied and satisfied patients were matched in terms of age, gender, follow-up duration and body mass index (BMI). Psychological evaluation was performed using the Pain Catastrophizing Scale (PCS), Depression, Anxiety and Stress Scale (DASS) and the Multidimensional Health Locus of Control (MHLC) scale. The preoperative grade of osteoarthritis, prevalence of comorbidities, and postoperative functional outcomes, were also compared.

Results: A cohort comprised 301 patients (response rate 71%), with 24 patients (eight percent) dissatisfied at a mean follow-up of 37months (range eight to 74months). Persistent pain was the most common reason for dissatisfaction (n=10). Dissatisfied patients reported a significantly higher mean PCS score (P=0.03), higher depression component of the DASS (P=0.02) and lower internal locus of control (P=0.02). The dissatisfied group exhibited reduced improvement (P<0.05) in the Oxford Knee Score (OKS) and range of motion (ROM), as well as a lower preoperative grade of osteoarthritis compared to satisfied patients.

Conclusions: Dissatisfied patients exhibit an altered psychological profile to matched satisfied controls. In addition, they have lesser improvements in the OKS and ROM. Thus, both physical as well as psychological factors contribute to dissatisfaction. Identification of these factors may help in planning focused interventions to address dissatisfaction.