Periarticular Injection Versus Femoral Nerve Block for Pain Relief After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial.

PURPOSE: To compare the effectiveness and safety of periarticular injection (PI) with those of femoral nerve block (FNB) after anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 129 patients scheduled for ACL reconstruction were randomly assigned to receive PI or FNB. Other perioperative interventions were identical for all patients. The primary outcome was the postoperative pain score 24 hours after surgery, which was measured using a 100-mm visual analog scale (VAS). The pain scores were also assessed to determine whether the VAS score would reach the threshold values reported for the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS).

RESULTS

The PI group had significantly lower VAS scores 24 hours after ACL reconstruction than the FNB group (21 mm vs 39 mm; P < .0001). Consequently, the primary outcome reached the level of clinical significance as indicated by the threshold values of an MCID of 9.9 and a PASS of 33. The PI group also had a significantly lower VAS score at rest at 4 hours, 8 hours, and 2 days after surgery (30 mm vs 39 mm [P = .025], 25 mm vs 33 mm [P = .022], and 22 mm vs 32 mm [P = .0022], respectively). The opioid consumption during the initial 24 hours was significantly lower in the PI group (354 μg vs 503 μg; P = .0003). The complication rate, including opioid-related complications, was not significantly different between groups.

CONCLUSION

The patients treated with PI had significantly better pain scores and lower opioid consumption than those treated with FNB without elevating the complication rate.

LEVEL OF EVIDENCE: Level I, randomized controlled trial.