Association of Lateral Extra-Articular Tenodesis With Improved Graft Maturity on MRI 2 Years After ACL Reconstruction With Quadriceps Tendon Autograft in Skeletally Immature Athletes.

Background: Quadriceps tendon autograft (QTA) has recently gained popularity in the treatment of anterior cruciate ligament (ACL) ruptures in pediatric patients. The addition of lateral extra-articular tenodesis (LET) to an ACL reconstruction (ACLR) has been found to reduce the risk of ACL retear in high-risk patients. Purpose: To (1) compare ACL graft maturity using signal intensity ratios (SIRs) on magnetic resonance imaging (MRI) scans in skeletally immature patients undergoing ACLR with QTA either with or without concomitant LET and (2) evaluate LET safety by calculating the physeal disturbance-related reoperation rate in the ACLR+LET group. Study Design: Cohort study; Level of evidence, 3. Methods: The records of patients aged ≤18 years who underwent ACLR between 2015 and 2021 were reviewed retrospectively. Patients undergoing ACLR with QTA who had open distal femoral and proximal tibial physes on MRI scans and a minimum 2-year follow-up data were included. SIR values were measured on sagittal MRI scans by averaging the signal at 3 regions of interest along the ACL graft and dividing by the signal of the posterior cruciate ligament at its insertion. Statistical analysis was performed to evaluate differences in SIR values at 6 months, 1 year, and 2 years postoperatively in patients who underwent ACLR alone versus ACLR+LET. Results: Overall, 29 patients were included in the study: 16 patients in the ACLR+LET group and 13 patients in the ACLR-only group. There were no significant differences in SIR values between groups at the 6-month or 1-year postoperative timepoints. At 2 years postoperatively, the median SIR of the ACLR+LET group was significantly lower than that of the ACLR-only group on both univariate (1.33 vs 1.86, respectively, Conclusion: The addition of LET to an ACLR with QTA was associated with lower average SIR values and thus improved graft maturity at 2 years postoperatively compared with ACLR alone in skeletally immature patients. The addition of LET to an ACLR was found to be safe in skeletally immature patients.