Outpatient continuous adductor canal block (CACB) for total knee arthroplasty: a double-blinded randomized placebo-controlled trial.

Abstract

Background: Total knee arthroplasty (TKA) is a widely performed procedure, with postoperative pain presenting as a major barrier to early mobilization and patient satisfaction. While single-injection adductor canal blocks (SACB) offer effective short-term analgesia, their limited duration often leads to rebound pain. Continuous adductor canal blocks (CACB) extend analgesic effects but are underexplored in outpatient settings. The objective of this study is to assess whether CACB improves quality of recovery and analgesia, in comparison to SACB in an outpatient or short-stay setting for TKA patients.

Methods: Double-blind randomized controlled trial comparing the Quality of Recovery-15 (QoR-15) score on postoperative day (POD) 2 (primary outcome) and opioid consumption, pain scores, hospital length-of-stay, and complications (secondary outcomes), between patients receiving CACB and SACB, when undergoing primary TKA.

Results: 60 patients were enrolled and randomized to two treatment groups: CACB (30) and SACB (30). Patients in the CACB group had significantly higher QoR-15 scores at PODs 1 (128.83±12.36 vs 109.00±15.90, p<0.001), 2 (131.27±10.23 vs 110.86±15.37, p<0.001) and 3 (131.97±13.94 vs 111.18±18.28, p<0.001). They also had lower opioid consumption and pain scores at rest and with movement during the first three PODs. No major complications or signs of local anesthetic systemic toxicity were observed.

Conclusions: In our study, CACB significantly enhanced early postoperative recovery and analgesia following TKA in an outpatient or short-stay setting, compared with SACB, and these results support its broader adoption in fast-track TKA pathways.