Adductor Canal Block Preserves Quadriceps Function Despite Transient Sensory Deficits Following Total Knee Arthroplasty: A Randomized Controlled Trial

Abstract

OBJECTIVE: To evaluate the effects of adductor canal block (ACB) on motor and sensory functions following total knee arthroplasty. Motor function was quantified using median frequency of surface electromyography, whereas sensory function was assessed through pain scores, cutaneous sensation, and morphine consumption in patients with and without ACB. METHODS: This randomized controlled trial enrolled 25 total knee arthroplasty patients allocated to either ACB or non-ACB groups. Measurements included median frequency of rectus femoris and vastus medialis muscles during standardized 2-minute leg extension tasks, visual analog scale pain scores, morphine consumption, and cutaneous sensory function on postoperative days 1 to 4. RESULTS: No notable differences were detected between the groups regarding median frequency of rectus femoris and vastus medialis, visual analog scale pain scores, or morphine consumption across all postoperative days. These findings suggest that ACB did not compromise postoperative quadriceps muscle strength or pain control. However, cutaneous sensory recovery occurred on postoperative day 1 for all non-ACB subjects, whereas sensory recovery was delayed in the ACB group. CONCLUSION: ACB preserves quadriceps strength while effectively managing pain after TKA, although temporary sensory deficits should be anticipated during early mobility. TRIAL REGISTRATION: Clinical Trials Registry and institutional ethical approval, March 2021.