Comparison of the Effect of Continuous Femoral Nerve Block and Adductor Canal Block after Primary Total Knee Arthroplasty

Abstract

BackgroundThis study aimed to compare the effects of femoral nerve block and adductor canal block on postoperative pain, quadriceps strength, and walking ability after primary total knee arthroplasty.MethodsBetween November 2014 and February 2015, 60 patients underwent primary total knee arthroplasty. Thirty patients received femoral nerve block and the other 30 received adductor canal block for postoperative pain control. Before spinal anesthesia, the patients received nerve block via a catheter (20 mL 0.75% ropivacaine was administered initially, followed by intermittent bolus injection of 10 mL 0.2% ropivacaine every 6 hours for 3 days). The catheters were maintained in the exact location of nerve block in 24 patients in the femoral nerve block group and in 19 patients in the adductor canal block group. Data collection was carried out from these 43 patients. To evaluate postoperative pain control, the numerical rating scale scores at rest and 45° flexion of the knee were recorded. To evaluate quadriceps strength, manual muscle testing was performed. Walking ability was assessed using the Timed Up and Go test. We also evaluated analgesic consumption and complications of peripheral nerve block.ResultsNo significant intergroup difference was observed in the numerical rating scale scores at rest and 45° flexion of the knee on postoperative days 1, 2, 3, and 7. The adductor canal block group had significantly greater quadriceps strength than did the femoral nerve block group, as assessed by manual muscle testing on postoperative days 1, 2, and 3. The 2 groups showed no difference in walking ability on postoperative day 1, but on postoperative days 2, 3, walking ability was significantly better in the adductor canal block group than in the femoral nerve block group. No significant intergroup difference was observed in analgesic consumption.ConclusionsThe groups showed no difference in postoperative pain control. Adductor canal block was superior to femoral nerve block in preserving quadriceps strength and walking ability. However, adductor canal block was inferior to femoral nerve block in maintaining the exact location of the catheter.

Postoperative Pain Management in Total Knee Arthroplasty

“…The adductor canal is located in the middle one‐third of the thigh and runs from the apex of the femoral triangle proximally to the adductor hiatus distally. ACB could block the saphenous nerve, which is the largest sensory branch of the femoral nerve to the knee, while spare the major motor branches of the femoral nerve.…”

“…ACB could block the saphenous nerve, which is the largest sensory branch of the femoral nerve to the knee, while spare the major motor branches of the femoral nerve. Therefore, ACB could provide postoperative pain relief as effectively as FNB without impairment of quadriceps muscle strength, and it is becoming increasingly popular. Except for better quadriceps muscle power, patients with ACB have better early rehabilitation, longer ambulation distance, and shorter length of hospital stay compared with FNB.…”

“…However, TKA is followed by moderate to severe postoperative pain. In patients received TKA, 60% experience severe postoperative knee pain and 30% experience moderate pain. Some patients even put off this operation because of the fear of this acute postoperative pain.…”

Comparison of Adductor Canal Block and Femoral Nerve Block for Early Ambulation After Primary Total Knee Arthroplasty: A Randomized Controlled Trial

“…The effect of block technique on postoperative strength of the quadriceps muscle has also been previously assessed, and the efficacy of the AC block for preservation of quadriceps strength is well documented in the literature. Seo et al utilized manual muscle testing (MMT) to directly evaluate quadriceps strength, and results demonstrated significantly greater strength among patients receiving AC block compared to patients receiving FN block [12]. Kim et al demonstrated similar findings, and also directly assessed quadriceps strength using a dynamometer [4].…”

“…Prospective randomized controlled trials by Shah et al and Kim et al demonstrated no statistically significant difference in reported postoperative pain scores between the two groups [4,11]. Similarly, a retrospective study by Seo et al compared numeric rating scale (NRS) pain scores between groups postoperatively and found that overall, no significant difference existed between the two analgesic techniques for pain relief in TKA [12]. Of note, transient occurrences of significantly greater pain scores among the FN group compared to the AC group were found at rest on PODs 1, 2, and 3, and with the knee at 45 degrees of flexion on days 1 and 2, which were inconsistent with our findings.…”