Comparison of Adductor Canal Block Before Versus After Total Knee Arthroplasty in Terms of Pain, Stress, and Functional Outcomes: A Double-Blinded Randomized Controlled Trial.
Summary
In a double-blind RCT of 100 TKA patients, preoperative adductor canal block reduced 24-hour and total morphine use, intraoperative opioid/inhalational anesthetic use, stress hormones, early pain, and 3‑month chronic pain, while improving day‑1 knee range of motion, compared with postoperative ACB. Discharge timing, ambulation distance, and complications were similar.
Key Findings
- Preoperative ACB lowered 24-hour and total morphine consumption versus postoperative ACB.
- Reduced intraoperative opioid and inhalational anesthetic use and fewer hypertensive episodes.
- Lower POD1 cortisol/ACTH, less pain within 12 hours, better day‑1 knee ROM, and reduced 3‑month chronic pain.
Clinical Implications
Prefer preoperative ACB in TKA multimodal protocols to reduce perioperative opioid exposure and stress, improve early function, and potentially lower chronic postsurgical pain at 3 months.
Why It Matters
This Level I trial provides practice-changing evidence on block timing, showing preoperative ACB offers superior analgesia and lower stress responses and chronic pain risk after TKA.
Limitations
- Single-center study with all participants of Asian (Chinese) ethnicity, limiting generalizability.
- Sample size of 100 and limited long-term follow-up beyond 3 months.
Future Directions
Multicenter trials across diverse populations with longer follow-up to confirm chronic pain reduction and evaluate functional and cost-effectiveness outcomes.
Study Information
- Study Type
- RCT
- Research Domain
- Treatment
- Evidence Level
- I - High-quality randomized controlled trial with blinding.
- Study Design
- OTHER