A comparative study between ultrasound-guided four-in-one block vs. femoral nerve block vs. adductor canal block to enhance recovery after knee replacement surgery

Background & Objective: Ultrasound-guided 4-in-1 block has been suggested as a good alternative to various other nerve blocks to control pain after total knee replacement (TKR) surgery. We compared the three regional techniques; 4-in-1 block, femoral nerve block (FNB) and adductor canal block (ACB) following TKR regarding pain scores, opioid consumption, quadriceps muscle strength and early ambulation. Methodology: We enrolled 93 patients and divided them into three equal groups of 31 each. Patients received either 4-in-1 block (Group A), FNB (Group B) or ACB (Group C) under ultrasound guidance. Outcome measures included assessment of VAS scores at 2, 4, 8, 12, 16, and 24 h). Nalbuphine consumption was calculated in the first 24 h. We also evaluated quadriceps muscle strength and early ambulation using straight leg raising (SLR) test at 12 and 24 h, and timed up-and-go (TUG) test at 24 h postoperatively. Results: Patients received 4-in-1 block showed lower pain scores and lower nalbuphine consumption compared to FNB or ACB. Also, the SLR test values at 12h were higher (p-value<0.001), and TUG test values were lower (p-value0.005) in 4-in-1 block and ACB groups compared to FNB group. Conclusion: The results of our study conclude that 4-in-1 block was found to be superior in pain control after TKR surgeries compared to FNB or ACB alone. It also facilitates early ambulation as it preserves quadriceps muscle strength.