168 – THE IMPACT OF BASELINE MENTAL HEALTH STATUS ON OUTCOMES FOR PRIMARY KNEE REPLACEMENT PATIENTS

Abstract

Purpose: The purpose of this study was to examine the effects of baseline mental health on functional outcomes after primary knee arthroplasty by reviewing the data collected in a multi-center prospective observational cohort study. We hypothesized that those patients with lower baseline mental health status would demonstrate significantly worse outcomes vs. their counterparts with higher mental status following primary total knee arthroplasty.

Method: Data from a multi-center prospective cohort study of PS (posterior stabilizing implant) and CR (cruciate retaining implant) primary knee arthroplasty were compared to determine the relationship between baseline mental health status and functional outcomes post-surgery. Subjects were followed from the time of the index surgery to monitor outcomes and complications. Validated quality of life instruments, including SF-36, WOMAC, Knee Society Score, and an activity scale were used. The rates of improvement from 0 to 12 months were analyzed for this study.

Results: Baseline data was available for 436 subjects in the primary PS study and 493 subjects in the primary CR study. Patients improved significantly on all SF-36 and WOMAC components between baseline and 12 months post-surgery. Correlation and regression analysis between WOMAC and SF-36 showed that Global Health (GH), Mental Health (MH), and Mental Component Score (MCS) subscales on the SF-36 were significantly associated with positive post-operative changes in WOMAC scores.

Conclusion: This study examined the effects of baseline mental health on functional outcomes after primary knee arthroplasty and found that baseline mental health was a significant predictor of functional outcomes twelve months after surgery. This relationship between mental health and outcomes needs to be examined carefully to help surgeons better prepare their patients for surgery.