An In-Depth Analysis of Graft Rupture and Contralateral Anterior Cruciate Ligament Rupture Rates After Pediatric Anterior Cruciate Ligament Reconstruction

Abstract

Background: Reported rates of graft rupture and contralateral anterior cruciate ligament (ACL) rupture after ACL reconstruction (ACLR) are higher among pediatric patients than adults. Previous series may have underestimated postoperative event risk because of small sample sizes and high proportions of dropouts. Purpose: To calculate rates of graft rupture and contralateral ACL rupture after ACLR in a large pediatric series. Study Design: Case series; Level of evidence, 4. Methods: ACLRs performed in our tertiary care children’s hospital system over a period of >7 years were identified through billing review. Cases were sorted based on operative technique, with all-epiphyseal ACLRs considered separately. Transphyseal ACLRs were divided into 2 groups based on patient age, with a cutoff of 16 years. Clinic follow-up data as well as prospectively collected survey data were used to note graft rupture and contralateral ACL rupture events. Rates of graft rupture and contralateral ACL rupture were calculated using Kaplan-Meier survival analysis. Results: The final data set included 996 patients. A total of 161 patients underwent all-epiphyseal ACLR. Of the remaining transphyseal surgeries, 504 patients were <16 years of age at the time of surgery and 331 were ≥16 years. The 4-year cumulative rate of graft rupture via Kaplan-Meier survival analysis was 19.7% among all patients. The rate was 18.2% among all-epiphyseal ACLRs, 21.6% among transphyseal ACLRs in patients <16 years, and 16.4% among transphyseal ACLRs in patients ≥16 years (P = .855). Survival analysis estimated the 4-year cumulative rate of contralateral ACL rupture at 12.0% among all patients: 6.63% among all-epiphyseal ACLRs, 15.7% among transphyseal ACLRs in patients <16 years, and 8.05% among transphyseal ACLRs in patients ≥16 years (P = .093). Conclusion: This is the largest series of pediatric ACLRs yet reported, and it shows that the risks of another ACL injury after first-time ACLR are higher than previously reported. The risk of contralateral ACL rupture was lower than that for graft rupture. Our methods, including prospective follow-up surveys and survival analysis to generate cumulative rate estimates, provide a best-practice example for future case series calculations. Our results provide insight into the postoperative course of pediatric patients undergoing ACLR and are crucial for preoperative patient and family counseling. Understanding these risks may also influence return-to-play decisions.