[Clinical application of nerve block in early analgesia after anterior cruciate ligament reconstruction].

Abstract

Objective: To explore clinical effective and safety of subarachnoid block (SA), adductor canal block (ACB), and femoral nerve block (FNB) for early analgesia in anterior cruciate ligament (ACL) reconstruction.

Methods: From September 2022 to October 2023, 90 patients with ACL rupture who received unilateral knee arthroscopic ACL reconstruction were selected and divided into ACB group, FNB group and SA group according to different anesthesia methods, with 30 patients in each group. There were 12 males and 18 females in ACB group, aged from 18 to 60 years old with an average of (33.3±13.8) years old;14 patients with gradeⅠand 16 patients with gradeⅡaccording to American Society of Aneshesiologists (ASA);13 patients on the left side and 17 patients on the right side. There were 15 males and 15 females in FNB group, aged from 18 to 60 years old with an average of (33.5±12.9) years old;15 patients with gradeⅠand 15 patients with gradeⅡ;16 patients on the left side and 14 patients on the right side. There were 16 males and 14 females in SA group, aged from 18 to 60 years old with an average of (31.0±12.6) years old;18 patients with grade I and 12 patients with gradeⅡ;17 patients on the left side and 13 patients on the right side. In ACB and FNB groups, the nerve block of ACB and FNB were performed under ultrasound guidance before SA anesthesia with 15 ml of 0.3% ropivacaine. Visual analogue scale (VAS) and quadriceps muscle strength at rest and passive movement were recorded and compared among 3 groups at 4, 8, 12, 16, 24 and 48 h after operation, as well as the dosage of tramadol injection analgesics, incidence of nausea and vomiting, nerve block time and other complications within 48 h after operation were compared.

Results: All patients were followed up for 11 to 20 (15.8±2.4) months. VAS at 4, 8, 12, 16, 24 and 48 h after operation of SA group was significantly higher than that of ACB and FNB groups, with statistical significance (P<0.05). There were no significant difference in VAS of rest and passive movement at 4, 8, 12, 16, 24 and 48 h after operation between ACB group and FNB group(P>0.05). At 4, 8, 12 and 16 h after operation, the quadriceps muscle strength in SA and ACB groups was higher than that in FNB group, with statistical significance (P<0.05);but there was no statistical significance in quadriceps muscle strength among three groups at 24 and 48 h after operation(P>0.05). One patient occurred nausea and vomiting in ACB group, 2 patients in FNB group and 5 patients in SA group, and no significant difference among three groups (χ²=0.352, P=0.171). The dosage of tramadol in SA group was (300.00±136.50) mg, which was higher than that in FNB group (168.33±73.70) mg and ACB(163.33±70.70) mg, and the difference was statistically significant (P<0.05). There was no significant difference in nerve block time between ACB group and FNB group (t=1.964, P=0.054). There was no puncture site bleeding, local anesthesia drug poisoning and hematoma formation among three groups.

Conclusion: Both FNB and ACB could provide good early analgesia after ACL reconstruction, but ACB group has little effect on quadriceps muscle strength. Patients could have early postoperative functional training without pain, which is more beneficial to the recovery of knee joint function, and could reduce the use of analgesic drugs, without serious complications, which is safe and reliable method.