Postoperative Pain Control After ACL Reconstruction With Semitendinosus Tendon Graft: A Randomized Controlled Trial Comparing Adductor Canal Block to Local Infiltration Analgesia.

Background: Both adductor canal block (ACB) and local infiltration (LI) are effective for postoperative pain management after arthroscopic-assisted anterior cruciate ligament (ACL) reconstruction (ACLR). While LI is a more straightforward procedure, its effectiveness remains debated.

Purpose: To evaluate morphine consumption within 48 hours after ACLR with a semitendinosus tendon graft, comparing ACB and LI; secondary objectives: to evaluate pain levels, patient satisfaction, quadriceps strength, range of knee motion, and complications.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: Patients undergoing primary ACLR with a semitendinosus tendon graft were randomized to receive either ACB (0.25% bupivacaine; 20 mL) or LI at the surgical wound, graft harvest area, and intra-articular injection. The LI group received morphine (3 mg), ketorolac (30 mg), and tranexamic acid (1 g). Morphine consumption within 48 hours was monitored using an intravenous patient-controlled analgesia device.

Results: A total of 48 patients were analyzed (n = 24 in each group); baseline characteristics were similar between groups. The LI group consumed significantly less morphine than the ACB group at 6 hours (median [interquartile range, IQR], 3 mg [0-4.8 mg] for the LI group vs 5.5 mg [2-9] for the ACB group; P = .003). However, no significant differences were observed in morphine consumption at other time points. Additionally, no significant difference was found in cumulative morphine consumption at 48 hours between the groups (median [IQR], 21.5 mg [11-34.5 mg] for the ACB group vs 16.5 mg [8.5-21.8 mg] for the LI group; P = .137). Postoperative pain scores, quadriceps strength, and patient satisfaction were similar between the 2 groups.

Conclusion: Morphine consumption at 48 hours postoperatively was comparable between the LI and ACB groups, and no significant group differences were found in postoperative pain, quadriceps strength, or patient satisfaction.

Registration: TCTR20190320003 (Thai Clinical Trial Registry).