Relationships among pain intensity, pain-related distress, and psychological distress in pre-surgical total knee arthroplasty patients: a secondary analysis.

The current study aimed to examine the relationships between movement and resting pain intensity, pain-related distress, and psychological distress in participants scheduled for total knee arthroplasty (TKA). This study examined the impact of anxiety, depression, and pain catastrophizing on the relationship between pain intensity and pain-related distress. Data analyzed for the current study (N = 346) were collected at baseline as part of a larger Randomized Controlled Trial investigating the efficacy of TENS for TKA (TANK Study). Participants provided demographic information, pain intensity and pain-related distress, and completed validated measures of depression, anxiety, and pain catastrophizing. Only 58% of the sample reported resting pain >0 while 92% of the sample reported movement pain >0. Both movement and resting pain intensity correlated significantly with distress (r = .86, p < .01 and .79, p < .01, respectively). About three quarters to two thirds of the sample (78% for resting pain and 65% for movement pain) reported different pain intensity and pain-related distress. Both pain intensity and pain-related distress demonstrated significant relationships with anxiety, depression, and catastrophizing. Of participants reporting pain, those reporting higher anxiety reported higher levels of distress compared to pain intensity. These findings suggest that anxious patients may be particularly distressed by movement pain preceding TKA. Future research is needed to investigate the utility of brief psychological interventions for pre-surgical TKA patients.