Abstract
Background:
There is limited literature examining the effect on postoperative pain of peripheral nerve blocks in adolescent ACL reconstruction (ACLR) patients (1). Previous studies in adults show ultrasound-guided geniculate nerve blocks may decrease knee pain after total knee arthroplasty (2) and surgeon-administered geniculate nerve blocks may decrease pain after ACL reconstruction (3).
Objectives:
Postoperative pain scores and total narcotics administered in the post anesthesia care unit (PACU) following pediatric ACLR are not equal between patients receiving adductor alone versus adductor plus geniculate peripheral nerve blocks before surgery.
Methods:
We performed a retrospective chart review of 173 consecutive adolescent patients (age <19 years) undergoing primary ACLR with quadriceps tendon bone (QTB) autograft by a single surgeon from 2021 to 2024. Pediatric anesthesiologists performed ultrasound-guided single-shot peripheral nerve blocks before all surgeries. Nerve blocks included adductor canal alone (“Ad”, n=72) or adductor canal plus geniculate (“AdG”, n=101). Patients received intraoperative and postoperative narcotic medication per standard anesthesiologist / nursing protocol and local anesthetic infiltration by the surgeon at procedure end. Standard PACU Visual Analog Scale (VAS) scores at 15-minute intervals were recorded until PACU discharge. Additional independent variables collected were gender, tourniquet time, lateral extra-articular tenodesis (LET), normalized intraoperative narcotic dose, concomitant meniscal surgery.
Results:
Average patient age was 16.66 years (13.4 – 18.9). There were 87 males, 106 LET, and 123 concomitant meniscal surgeries. Average BMI was 26.1 (17.4-41.7). 107 patients did not receive any narcotic medication in the PACU before discharge. Patients receiving narcotic medication in the PACU received an average of .102 morphine equivalents per kg body weight. Logistic regression analysis demonstrated female gender (OR 3.14) and LET (OR 2.80) significantly increased the odds of receiving any narcotic medication in the PACU, while AdG significantly decreased the odds (OR 0.43). The Ad group had a 2.48 times higher initial VAS score compared to the AdG group (p < .001). A proportional odds model analysis demonstrated male gender (p=0.011) and AdG (p=0.043) were associated with lower initial PACU VAS pain scores.
Conclusion:
Adolescent ACLR patients who received geniculate plus adductor canal nerve blocks had significantly better first postoperative pain scores and significantly lower odds of receiving narcotics in PACU. Geniculate plus adductor canal nerve blocks are an effective technique in reducing short-term post-operative pain after adolescent ACLR. Future planned studies should describe nerve block complications, quantify narcotic consumption after PACU discharge, and assess patient satisfaction with pain control in both groups.