Purpose: The methods for pain control after total knee arthroplasty (TKA) vary and have been extensively studied in recent years. Femoral nerve block (FNB) is used as the standard method due to its effective pain control following TKA, but it may weaken the quadriceps strength. Adductor canal block (ACB) is a newly developing analgesic protocol with fast functional recovery and good pain control after TKA. A meta-analysis was conducted to try to find out if ACB is better than FNB in pain treatment and joint functional recovery after TKA.
Methods: The databases PubMed, Web of Science, Embase, and Cochrane Library were systematically searched. Of 66 records identified, eight randomised controlled trials (RCT) involving 434 patients (504 knees) were eligible for data extraction and meta-analysis according to criteria included.
Results: Meta-analysis showed that ACB can significantly decrease visual analogue scale (VAS) score at rest within eight hours (p < 0.001) and at 24 hours (p < 0.001) after operation compared to FNB after TKA, and improve quadriceps strength (p < 0.001) and mobilization ability (p < 0.001). However, the differences in VAS score at rest at 48 hours, VAS score with activity within two days after operation, opioid consumption, hip adductor strength, patient satisfaction, and tourniquet times were not significant between the two groups.
Conclusion: ACB provide better ambulation ability, faster functional recovery and better pain control at rest after TKA compared to FNB. The use of ACB post TKA is worthy of being recommended to replace FNB as a standard analgesic protocol for pain treatment after TKA.
Keywords: Adductor canal block; Femoral nerve block; Meta-analysis; Total knee arthroplasty.