Femoral Block Provides Superior AnalgesiaCompared With Intra-Articular Ropivacaine AfterAnterior Cruciate Ligament Reconstruction
Henri Iskandar, M.D, Antoine Benard, M.D, Joelle Ruel-Raymond, M.D,Gyslaine Cochard, M.D, and Bertrand Manaud, M.D.
Background and Objectives: Arthroscopic anterior cruciate ligament (ACL) reconstruction of the knee is apainful procedure requiring intensive postoperative pain management. This prospective study investigatesanalgesic quality after a femoral block as compared with intra-articular injection of local anesthetic.
Methods: Eighty patients scheduled for elective ACL repair under general anesthesia were included in ourstudy. Upon completion of surgery, the patients were randomly assigned into 1 of 2 groups: femoral group (n 40) received a femoral block with 20 mL 1% ropivacaine; intra-articular group (n 40) received 20 mL 1%ropivacaine injected intra-articularly. During the rst 24 hours after surgery, all patients received 2 g propac-etamol and 100 mg ketoprofen, intravenously. Additional postoperative analgesia was available with parenteralmorphine if required. Analgesic duration was dened as the time from end of surgery to the rst requirementfor a supplemental analgesic. Data collection included patient demographics, visual analog scale (VAS) scores,analgesic duration, and morphine use. Analysis of variance (ANOVA) test was used to compare the 2 groups
Results: VAS score in the recovery room and during rehabilitation was higher in the intra-articular groupthan in the femoral group (P .001). Morphine use was lower in the femoral group than in the intra-articulargroup (P .001). Similarly, analgesic duration was longer in the femoral group than the intra-articular group(P .0001).
Conclusions: Compared with intra-articular injection of local anesthetic, femoral nerve block (FNB) providesbetter analgesia and allows a signicant morphine-sparing effect after ACL repair.Reg Anesth Pain Med 2003;28:29-32.
Key Words: Regional anesthesia, ACL repair, Analgesia, Femoral block, intra-articular ropivacaine.
Arthroscopic anterior cruciate ligament (ACL)reconstruction is associated with signicantpostoperative pain, with 50% of patients requiringopioid analgesia in the absence of other therapy.1 Itis recognized that adequate postoperative analgesiagreatly facilitates early rehabilitation.2 Effectivepostoperative analgesia has been achieved by usingepidural analgesia and patient-controlled analgesiawith opioids.3 These techniques require expensiveequipment and monitoring and are associated with
side effects, which limit their use. A femoral nerveblock (FNB) after ACL surgery also provides im-proved patient comfort and reduces parenteral nar-cotic administration.4 Postoperative intra-articularanesthetics have been shown to be effective foranalgesia of the knee for knee arthroscopic sur-gery.5 Many investigators suggest that the instilla-tion of local anesthetics into the knee joint at theend of arthroscopic surgery under general anesthe-sia reduces postoperative pain.6,7 Therefore, we de-signed a randomized blinded clinical trial to com-pare pain and opioid consumption after ACLsurgery in patients who received either a FNB or anintra-articular injection of local anesthetic immedi-ately after completion of the surgical procedure.
Materials and Methods
After informed consent and institutional ap-proval, 80 American Society of Anesthesiologists(ASA) physical status I patients scheduled to un-dergo elective ACL reconstruction were prospec-
From the Clinique chirurgicale Bordeaux-Merignac (H.I., J.R-R., G.C., B.M.), Merignac, France; and ISPED, Universite Bor-deaux 2 (A.B.), Bordeaux, France.Accepted for publication October 25, 2002.Presented in part at the French Society of Anesthesiology
Annual Meeting, Paris, France, 1999.Reprint requests: Henri Iskandar, M.D., Clinique chirurgicale
Bordeaux-Merignac, 9 rue Jean-Moulin, 33700 Merignac,France. E-mail: email@example.com
2003 by the American Society of Regional Anesthesia andPain Medicine.1098-7339/03/2801-0006$35.00/0doi:10.1053/rapm.2003.50019
Regional Anesthesia and Pain Medicine, Vol 28, No 1 (JanuaryFebruary), 2003: pp 2932 29
tively enrolled in this study. Patients with a historyof allergic reaction to any of the study drugs, prioropioid use, and peripheral neuropathies were ex-cluded.A standardized anesthetic technique was used for
all patients. Premedication consisted of 5 mg oralmidazolam 1 hour before surgery. General anesthe-sia was induced with propofol 3 mg/kg and sufen-tanyl 0.35 g/kg, and maintained with isouraneand 50% N2O with O2 via a laryngeal mask airway.All patients subsequently underwent ACL repairusing hamstring tendon (semitendinosus and gra-cilis tendons) autograft through anatomical tibialand femoral tunnels. Surgical technique was iden-tical for all patients. A tourniquet was used in allcases. Upon completion of surgery, patients wererandomized by a computer-generated list into 1 of 2groups: femoral group (n 40) received a FNBwith 20 mL 1% ropivacaine; intra-articular group(n 40) received 20 mL 1% ropivacaine injectedintra-articularly.The FNB was performed at the end of surgery
using Winnies landmarks with a 24-gauge, 25-mmneedle (Stimuplex D, Braun, Germany) connectedto a nerve stimulator (Stimuplex, Braun) by a ster-ile cable. The femoral nerve was localized by amotor response (movement of the patella) obtainedat 0.5 mA. The effectiveness of FNB was con-rmed by the criterion of decreased anterior thighsensation. The intra-articular instillation was per-formed by the surgeon at the end of surgery, 10minutes before tourniquet release.Nurses and physical therapists, who were un-
aware of study group and assignments, used thevisual analog scale (VAS) to rate postoperative painat rest and during passive mobilization (0 no painand 100 the worst imaginable pain). Assessmentswere performed in the postanesthesia care unit(PACU) and at 4, 8, 12, and 24 hours after surgery,at rest, and during early mobilization (initiated 6hours after surgery).The postoperative analgesia protocol was initi-
ated in the PACU and continued on the surgicalward. Analgesia in the PACU was provided by mor-phine titration in increments of 2 mg every 5 min-utes until VAS scores 30 mm were obtained. Apatient-controlled analgesia (PCA) pump (Alaris,Bordeaux, France) was then connected, deliveringa bolus of 1 mg of morphine, with 5-minute lockoutperiod, and no limit or background infusion.Side effects attributed to morphine included re-
spiratory depression (rate 10 breaths/minute),sedation (awakening or not awakening, in responseto painful stimulation), or nausea or vomiting re-quiring treatment.During the 24 hours after surgery, all patients
received 2 g propacetamol and 100 mg ketoprofen,
infused intravenously at 8-hour intervals. Analgesicduration was dened as the time from end of sur-gery to rst requirement of morphine.Data collection included patient demographics,
VAS scores, analgesic duration, and morphine use.Data analysis was performed using STATA version7.0 (STATA, College Station, TX) and SAS Software,version 6.12 (Allison, 1995). We dened VAS scoreat t0, morphine intake and analgesic duration asprincipal outcomes. All variables had a normal dis-tribution except postoperative analgesia duration;Kaplan-Meier estimate was used to present thisdata. ANOVA test was used to compare the 2 groupsaccording to the VAS scores at t4, t12, and t24. Wefound unequal variance between the 2 groups forVAS scores at t0, t8, and for morphine use. Thus,we used ANOVA test modied for heteroskedastic-ity (Welchs ANOVA) to compare the 2 groups ac-cording to these variables.8 For these tests, a Pvalue .05 was considered to be statistically signif-icant. For the comparison of VAS score at t0 andmorphine intake between groups, we used t testmodied for heteroskedasticity. For these tests, us-ing Bonferroni correction, a P value .017 wasconsidered to be statistically signicant. Two-sidedsignicance tests were used throughout.
There were no signicant differences between thetreatment groups with respect to age, sex, weight, orduration of surgery (P .05, Table 1). No patient wasexcluded from the study. By the criterion of decreasedanterior thigh sensation, nerve block was successfullyachieved in all patients in the femoral group. Therewere no adverse effects linked to the FNB or intra-articular injection of ropivacaine.
The VAS pain scores were signicantly lower inthe femoral group than in the intra-articular groupduring PACU stay (P .001) and during rehabili-
Table 1. Patient Demographics and Surgical Data
Age (yr) mean SD 26.8 8.4 28.3 7.8Weight (kg) mean SD
70.0 12.4 71.6 11.6
Sufenta (g) mean SD
25.0 1.6 24.5 3.0
Surgery Duration (min)mean SD
48.4 3.8 46.2 2.2
Male, n (%) 28 (70) 31 (77.5)NOTE. No statistically signicant differences were observed
between the groups.
30 Regional Anesthesia and Pain Medicine Vol. 28 No. 1 JanuaryFebruary 2003
tation (P .001). No signicant difference wasobserved among the groups for VAS scores (Table2).
The total morphine use over the entire postoper-ative period was signicantly higher in the intra-articular group than in the femoral group (Table 2).
Analgesic duration was signicantly longer infemoral group than in intra-articular group (Fig 1).
The incidence of nausea and sedation was higherin the intra-articular group (Table 3).
Surgical treatment of the ACL-decient knee hasevolved from open and extra-articular proceduresto endoscopic rec