Williams BA et al.

◊ BACKGROUND:
We previously reported that continuous perineural femoral analgesia reduces pain with movement during the first 2 days after anterior cruciate ligament reconstruction (ACLR, n = 270), when compared with multimodal analgesia and placebo perineural femoral infusion. We now report the prospectively collected general health and knee function outcomes in the 7 days to 12 wk after surgery in these same patients.

◊ METHODS:
At three points during 12 wk after ACLR surgery, patients completed the SF-36 General Health Survey, and the Knee Outcome Survey (KOS). Generalized Estimating Equations were implemented to evaluate the association between patient-reported survey outcomes and (1) preoperative baseline survey scores, (2) time after surgery, and (3) three nerve block treatment groups.

◊ RESULTS:
Two hundred seventeen patients' data were complete for analysis. In univariate and multiple regression Generalized Estimating Equations models, nerve block treatment group was not associated with SF-36 and KOS scores after surgery (all with P > or = 0.05). The models showed that the physical component summary of the SF-36 (P < 0.0001) and the KOS total score (P < 0.0001) increased (improved) over time after surgery and were also influenced by baseline scores.

◊ CONCLUSION:
After spinal anesthesia and multimodal analgesia for ACLR, the nerve block treatment group did not predict SF-36 or knee function outcomes from 7 days to 12 wk after surgery. Further research is needed to determine whether these conclusions also apply to a nonstandardized anesthetic, or one that includes general anesthesia and/or high-dose opioid analgesia.

◊ Reviewed by Stephan A Schug,
Pharmacology and Anaesthesiology Unit,
Chair of Anaesthesiology,
Royal Perth Hospital,
Perth

This study describes the long-term follow-up of a trial in anterior cruciate ligament (ACL) reconstruction, which has been reported by the same authors previously [1]. In this preceding publication the authors described significantly better analgesia on movement for the first 4 postoperative days with a femoral nerve block followed by continuous infusion compared to systemic multimodal analgesia. The authors concluded that a perineural femoral catheter should be routinely used in these patients.

As such an approach was shown to have beneficial effects for up to 6 weeks after total knee joint replacement [2, 3], the authors aimed at a long-term follow-up to confirm these benefits after ACL repair. Neither a general health assessment tool (SF-36) nor a knee specific survey (KOOS) demonstrated statistically significant differences at any point in time between 1 and 12 weeks post-surgery although, as expected, all improved over time.

Authors interprete these results correctly in stating that ACL repair is by far less invasive than total knee joint replacement and accordingly the long-term benefit from perineural infusion in ACL repair is less as well. However, these results do not negate the improved analgesia in the early postoperative period, which makes the regional technique a worthwhile endeavour.

◊ References:

1. Williams BA, Kentor ML, Vogt MT et al.
Reduction of verbal pain scores after anterior cruciate ligament reconstruction with 2-day continuous femoral nerve block: a randomized clinical trial. Anesthesiology.  2006; 104(2):315-327.

2. Singelyn FJ, Deyaert M, Joris D et al.
Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty. Anesthesia & Analgesia.  1998; 87(1):88-92.