Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing

Abstract

Background and Objectives Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from pre-surgery to 3 months post-surgery and explored associations among these pre-post changes. Research Design and Methods This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N=92) using in-person performance-based tests (6-minute walk test [6MWT], stair-climb test [SCT]) prior to and 3-months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale (PCS), pre-surgery and 3- and 6-months post-surgery. Results Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-months post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3-months was associated with better WOMAC function, but not related to WOMAC pain at 6 months. Discussion and Implications Findings highlight the importance of situation-specific and in-vivo assessments of pain and catastrophizing during physical activity.

Introduction to Special Issue: Translational Research on Pain and Pain Management in Later Life

“…These retrospective appraisals raise concerns for recall bias which could lead to either the underestimation or overestimation of pain. Wilson et al (2023) focus on the role of measuring movement-evoked pain in a study of 92 middle-aged and older adults with established osteoarthritis of the knee who underwent total knee arthroplasty. Assessments were conducted prior to and 3 months after knee surgery.…”