ACT for postsurgical pain and dysfunction in at-risk veterans: Multisite, double-blind, cluster RCT.

Persistent postsurgical pain (PPSP) and functional limitations after total knee arthroplasty (TKA) often vary in severity and duration, with higher levels seen in individuals at elevated risk. This multisite, double-blinded randomized controlled trial compared Acceptance and Commitment Therapy (ACT) to an active educational plus support attention control (AC), in Veterans "at-risk" for PPSP following TKA. Veterans indicated for unilateral TKA and at-risk for PPSP completed a 1-day (5 h) group workshop prior to surgery and at least 1 postoperative phone booster session. 336 patients who underwent TKA were randomized to ACT (N = 173) or to AC (N = 163). Of these, 95 % in the ACT group and 97 % in the AC group received at least 1 booster session. Primary outcomes included self-reported pain severity, Activities of Daily Living (ADL), and Quality of Life (QoL). The secondary outcome was time to opioid cessation. Both groups showed significant reductions in pain severity across time points: at 3 months, ACT participants had greater pain reduction (-2.78) than AC (-2.50), suggesting an earlier advantage. ADL function also improved significantly in both groups (6-month scores: ACT 31.4, AC 29.9). Median time to opioid cessation was similar overall: 2.71 weeks in both groups. Among participants without postoperative complications, ACT showed a non-significant trend toward earlier cessation (2.36 vs. 2.80 weeks). These findings suggest that brief, preoperative group-based interventions-whether ACT or educational support-can improve pain and function following TKA. ACT may offer additional early benefits in pain reduction and opioid tapering in Veterans at elevated risk for PPSP. Trial Registration:Clinicaltrials.gov under the number NCT03965897.