Abstract ID: A31

Abstract Title: Comparison of levobupivacaine in intra-articular vs. femoral nerve block as postoperative analgesia treatment in arthroscopy reconstruction of anterior cruciate ligament of the knee

Poster Type: Poster


ABSTRACT BODY

Introduction: Arthroscopy reconstruction of anterior cruciate ligament (ACL) of the knee with bone-to-bone (BTB) autologus patellar tendon graft technique is a frequent procedure. The aim of this study was to compare the postoperative analgesic effect of intra-articular local anesthetic infiltration versus femoral nerve block.
Material and methods: After approval of the ethical committee and informed consent the study was done in 50 soccer player patients, physical status ASA I-II that were scheduled for ALC BTB arthroscopy reconstruction. The same surgical team with the same technique operated them on. They were submitted to spinal lumbar anesthesia (L2/3 or L3/4) in the lateral position with 10-12 mg of 0.5% hyperbaric bupivacaine with out epinephrine by means of a 27 G Withacre pencil point needle. Surgery was carried out with the help of a thigh tourniquet (400 mm/Hg). At the end of surgery the patients were randomly assigned to two randomized groups. Group A had 100 mg of levobupivacaine in a 40 ml volume divided in 30 ml as intra-articular injection and 10 ml as infiltrate in tendon donor zone. Group B had 100 mg of levobupivacaine in a 40 ml volume as femoral nerve block (nerve stimulation at 0.4-0.5 mA with quadricep femoralis muscle twitch response). Post-operative scheduled analgesic treatment consisted of diclofenac 50 mg TID + acetaminophen/codeine 325/15 mg QID, rescue analgesia consisted of tramadol 100 mg IV if VAS>3. The variables controlled were duration time of spinal block (minutes), onset pain time (minutes), pain at rest and in movement (assessed with the visual analog scale 0-10 VAS), rescue analgesic if needed (number of doses), and intra and postoperative side effects or complications. Statistical analysis was performed with Student’s t-test (statistical significance p<0.05); mean values and standard deviations are presented.
Results: There were no statistical significant differences between groups neither in demography nor in duration of surgical procedure (90-120 minutes) or in tourniquet duration time (50-80 minutes). The results are shown in the table below. There was neither pain nor complications during the surgical period. Patients in the femoral nerve block group had statistically significant longer postoperative analgesia than patients in the intra-articular group (840 minutes vs. 462 minutes). VAS scores did not differ significantly although they tended to be lower in the femoral nerve block group. The side effect observed consisted in temporal ( 12 h duration time) paresthesias in the anterior thigh in 14 patients on the femoral nerve block group that subsided completely afterwards with no sequelae.
See table of results in additional files
Discussion: Femoral nerve block (levobupivacaine) provides a longer analgesia duration time but it is associated to short time lived postoperative thigh paresthesias as a complication that gave no sequelae. On the other hand, intra-articular local anesthetic injection (levobupivacaine) also provides adequate postoperative analgesia with no secondary effects. It is concluded that both are effective postoperative analgesic options but the later is safer.
References: - Mehdi SA, Dalton DJN, Sivarajan V, Leach WJ. BTB ACL reconstruction: femoral nerve block has no advantage over intra-articular local anaesthetic infiltration. S.A. Knee Surg. Sports Traumatol Arthrosc 2004; 12: 180-183
- Espinosa W; Salazar CH; Rovira M. Analgesia intra-articular en cirugía de rodilla. Rev Esp Anestesiol Reanim 2001; 48(S): 87

ATTACHED FILES

A31_Table of results.doc





Reg Anesth Pain Med 2004; 29(2):A31