The efficacy and safety of local infiltration analgesia vs femoral nerve block after anterior cruciate ligament reconstruction: A retrospective trial protocol

Abstract

Background: Several previous trials have attempted to compare the efficacy of femoral nerve block (FNB) and local infiltrative analgesia (LIA) for patients received anterior cruciate ligament (ACL) reconstruction, but reached inconsistent conclusions. The primary purpose of this present research was to compare the FNB and LIA in the reconstruction of ACL.

Methods: This investigation was conducted and then reported on the basis of Strengthening the Reporting of Observational studies in the Epidemiology checklist. From our registry database, we retrospectively determined 688 patients who received the primary reconstruction of ACL from 2016 to 2019 at our academic institutions. This current retrospective cohort study was approved through the institutional review committee at our hospital. Inclusion criteria contained the primary or autograft bone-patellar tendine-bone reconstruction of ACL in the patients over 16 years of age. Patients in the LIA group underwent intraoperative infiltration at the harvested site after tendon harvest, with use of 2 mg/mL of ropivacaine 20 mL and 5 mg/mL of epinephrine, respectively. After the reconstruction of ACL, 5 Lg/mL of epinephrine, and 20 mL of ropivacaine (2 mg/mL) were injected at the site of surgical trauma. The patient in FNB group was given 40 mL of ropivacaine (2 mg/mL), and the ropivacaine was injected into femoral nerve sheath at femoral triangle level. The primary outcome was the consumption of morphine 24 h after the operation. And the secondary results involved the complications, functional results, and the scores of pain.

Results: It is assumed that the efficacy of LIA in the early postoperative pain is no less than that of FNB. For our study, the major limitation is the lack of randomization. Nevertheless, these data were prospectively harvested, with high response rate of patient.

Trial registration: This study protocol was registered in Research Registry (researchregistry6277).