In-Hospital Pain Reporting Among Total Knee Arthroplasty Patients with Anxiety Diagnoses.

Purpose: To determine the association between anxiety disorder diagnoses and in-patient opioid usage, pain perception, and discharge disposition post-total knee arthroplasty (TKA).

Design: Retrospective review of elective primary TKA.

Methods: Patients diagnosed with anxiety were assigned to the anxiety group, and those without a mental health diagnosis were assigned to the control group. Variables of interest included self-reported pain scores (at rest and with activity) collected immediately after surgery and at discharge, inpatient opioid usage, and discharge disposition.

Results: A total of 4,404 patients (492 in the anxiety group) were included in the analysis. There were differences between groups in median pain scores reported immediately postoperatively at rest (anxiety group: 2, interquartile range [IQR] 0-6, control group: 0, IQR 0-5, p = .003) and with activity (anxiety group: 4, IQR 0-6, control group: 3, IQR 0-60, p = .011), at discharge at rest (anxiety group: 3, IQR 2-5, control group: 3, IQR 1-4, p < .001), and with activity (anxiety group: 5, IQR 3-6, control group: 4, IQR 2-6, p < .001). In the anxiety group, 60% of patients had opioid usage greater than the median of 61 morphine milligram equivalents while in-patient compared with 48% of patients in the control group (p < .001).

Conclusions: This study provides evidence of the complex relationships between anxiety and in-hospital outcomes in patients undergoing primary TKA.