Regional anesthesia and functional outcomes after anterior cruciate ligament reconstruction surgery in adolescent patients: Society of Pediatric Anesthesia Improvement Network (SPAIN)

Background Regional anesthesia is commonly used for adolescent anterior cruciate ligament reconstruction, but its effect on functional recovery is uncertain. We examined whether the use or type of nerve block influenced recovery. Methods 15 institutions contributed to a prospective observational registry of patients aged 12-17 years undergoing anterior cruciate ligament reconstruction. Functional recovery was assessed using the Lysholm Knee Score (range 0-100; higher scores indicate better function) at postoperative day 1, day 3, week 6 and month 6, and the Limb Symmetry Index (percentage of operative to non-operative limb performance; values ≥90% indicate readiness to return to sport) at 6-9 months. Results A total of 519 patients were enrolled. Lysholm Scores improved over time in all groups. At week 6, patients who received both anterior and posterior blocks had a median Lysholm Score of 83 (good function) compared with 78 for those with no block or anterior block alone (p=0.041). By month 6, scores were similar across groups, with most patients reaching the good to excellent range. Younger patients (12-15 years) reported higher scores than older adolescents (median 89 vs 86, p<0.05), while females reported lower scores than males at several time points. High early postoperative pain (numerical rating scale ≥7) predicted lower function through week 6. Positive temperament and lower preoperative anxiety/depression scores predicted better outcomes. At 6-9 months, 67% achieved a Limb Symmetry Index ≥90%. Younger age increased the odds of a suboptimal Limb Symmetry Index (<90%) (OR 2.54, p=0.03). Nerve block type was not associated with Limb Symmetry Index. Conclusions Regional anesthesia did not impair functional outcomes after adolescent anterior cruciate ligament reconstruction. Most patients regained good knee function by 6 months, and two-thirds achieved readiness for return to sport by 9 months. Recovery was more strongly influenced by age, sex, and psychological profile than by nerve block use.