Abstract:

Objective： To compare the pain control efficiency of continuous adductor canal block (ACB) and femoral nerve block (FNB) in total knee arthroplasty. Methods: From April to September 2016, patients with severe knee osteoarthritis undergoing primary unilateral total knee arthroplasty (TKA) were prospectively observed, and all the patients were randomized received ultrasound-guided continuous ACB or FNB after surgery. Numeric pain rating scales（NPRS）pain scores in rest and activity 2, 6, 12, 24 and 48 h after surgery were collected, and the preoperative and postoperative quadriceps strength at 24 and 48 h were analyzed. Opioids consumption and anesthesia related adverse effects were also recorded. Results: In the study, 40 patients were enrolled, with 20 patients in each group, male ∶female=7 ∶33, the age: (63.8±10.1) years , and the body mass index (BMI): (28.5±3.5) kg/m2.The general conditions were comparable between the two groups. Though the rest pain 2 h after surgery ［ACB=0.0(0,6), FNB=3.0(0,5), P=0.004］ and activity pain 12 h post operation ［ACB=3.0(3,0), FNB=5.5(0,10), P=0.004］ were lower in ACB group compared with FNB group, there was no statistical difference in the other pain checking points between the two groups. The quadriceps strength 24 h and 48 h after surgery were(85.3±27.6) N and (80.0±30.1) N in ACB group, (69.0±29.4) N and (64.4±32.0) N in FNB group, both of them were declined by time. The exact data were higher in ACB group, however, there was no statistical difference between the two group by repeated measurements variance analysis（F=2.703, P=0.108）.Four patients in ACB group and five in FNB acquired additional use of dolantin once (100 mg/per time) within 24 h. And among them, three patients acquired once dolantin in ACB, two in FNB, from 24 to 48 h postoperation. There were five patients who suffered nausea postoperation in ACB group, and one who reported xerostomia. Four patients in FNB had nausea with vomiting, and three experienced xerostomia. Deep vein thrombosis appeared in 2 patients in FNB group, but no one in ACB group. Conclusion: Continuous ACB is not superior in pain control after TKA compared with FNB, and the quadriceps strength could be reserved more by this method, which performed early benefits in fast rehabilitation.

Key words: Adductor canal block, Total knee arthroplasty, Treatment outcome, Analgesia, Quadriceps strength