Adductor canal block versus continuous femoral nerve block in primary total knee arthroplasty: A meta-analysis.

OBJECTIVE: Continuous femoral nerve block (CFNB) is considered the preferred analgesia after TKA. However, it may weaken quadriceps muscle strength, subsequently increasing the risk of falling. Adductor canal block (ACB) is a new sensory block technique that effectively relieves postoperative pain while preserving quadriceps strength. Thias meta-analysis was conducted to determine whether ACB of CFNB provides better pain relief and functional recovery after TKA.

METHOD: The PubMed, Embase, Web of Science and Cochrane Library databases were comprehensively searched. Seven studies comparing ACB with CFNB in patients with TKA were enrolled in our meta-analysis. Review Manager 5.3 for Windows was used to analyse the extracted data.

RESULTS: Compared with the CFNB group, the ACB exhibited a significant decrease in visual analogue scale (VAS) score at rest within 24 h (p < 0.00001), as well as significant decreases in the length of hospital stay (P < 0.0001) and post-operative nausea (P = 0.03). ACB patients also exhibited greater improvements in ambulation ability (P = 0.01) and ambulation distance (P < 0.00001). There were no significant differences in the VAS score at rest 8 and 48 h following surgery, nor in the ambulation VAS score and opioid consumption two days following surgery.

CONCLUSIONS: Compared with CFNB, ACB provides equally effective analgesia after TKA. ACB results in fast pain relief and early ambulation while decreasing post-operative nausea. ACB thus has the potential to replace CFNB as the gold standard for pain management in TKA patients.