Single-Shot Versus Continuous Nerve Blocks for Pediatric Anterior Cruciate Ligament Reconstruction: Analgesic Efficacy and Postoperative Outcomes

Background: Postoperative pain management is critical after anterior cruciate ligament (ACL) reconstruction, especially in the pediatric population. Regional anesthesia is often used to minimize postoperative pain, enable early mobilization, and improve patient/family satisfaction. Little is known about the effects of nerve blocks on functional and patient-reported outcomes in pediatric ACL reconstruction. Our objective is to compare analgesic efficacy, postoperative strength, and patient-reported outcomes between pediatric patients undergoing single-shot femoral nerve block (SSNB) and femoral nerve catheter (FNC). Methods: Children and adolescent patients (≤18 years old) who underwent primary ACL reconstruction at a tertiary children’s hospital between January 2018 and August 2019 were included. Patients were grouped based on their anesthesia technique (SSNB or FNC) and compared to identify differences in occurrence of uncontrolled postoperative pain and opioid refill needs. Patient-Reported Outcomes Measurement Information System (PROMIS) scores, active range of motion (AROM), and isokinetic strength testing at multiple postoperative timepoints were also collected. Linear regression multiple imputation analysis was performed to account for variable outcome measure availability. Results: 78 patients were included (SSNB: 42, FNC: 36). There were no differences in demographics or injury patterns between groups. The groups had similar pain medication needs and pain scores at 1 week. The FNC group had significantly longer in-room to incision times (P<0.001), were less likely to return to school by 1-week after surgery (P=0.03), and had lower PROMIS physical function – mobility scores at the 1-week postoperative visit. Patients in the SSNB group had significantly weaker quadriceps at 3 months (P=0.02), although this difference resolved by the 6-month visit. No cases of infection or neuropathy were identified. Conclusion: Our findings indicate that both FNC and SSNB are safe options with similar efficacy for postoperative pain management in pediatric ACL reconstruction. Although FNC was associated with lower PROMIS physical function – mobility scores at 1-week, delayed return to school, and 30 minutes of additional operating room time, there were no significant differences in function or PROMIS scores by 6-months post-surgery.