IMPORTANCE: Despite growing evidence supporting lateral extra-articular procedures (LEAP) in anterior cruciate ligament reconstruction (ACLR), clear guidelines on their indication in patients younger than 21 years are lacking, complicating clinical decision-making in this high-risk population. OBJECTIVE: To evaluate whether concomitant LEAP provides clinical benefits compared with isolated ACLR in patients aged ≤ 21 years, while also exploring potential differences between LEAP techniques. EVIDENCE REVIEW: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was preregistered on the International Prospective Register of Systematic Reviews (PROSPERO) (>). Studies which investigated patients younger than 21 years undergoing primary ACLR combined with a LEAP were included. The primary outcome measure was anterior cruciate ligament (ACL) graft failure. Secondary outcomes comprised patient-reported outcome measures (PROMs), clinical findings, return-to-sport parameters, postoperative complications, reoperation rates, and time to ACL graft failure. A comprehensive literature search was performed in Embase, MEDLINE, PubMed, and Scopus without date restrictions and limited to studies published in English or German. Level I-IV clinical studies with a minimum follow-up of 12 months were included. Study selection and data extraction were conducted independently by two reviewers, and methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Due to anticipated heterogeneity, narrative synthesis without meta-analysis was performed. FINDINGS: Overall, the evidence was derived from nine studies including a total of 598 patients with a mean age across studies ranged from 13.0 to 17.0 years. Included studies had a mean follow-up period ranging from 2.0 to 4.3 years. Primary outcomes showed ACL graft failure ranging from 0 to 5.3% following ACLR with LEAP. In comparative studies, graft failure occurred less frequently in ACLR with LEAP (0-6%) than in isolated ACLR (5-12%). Secondary outcomes demonstrated high postoperative functional scores, with Lysholm scores ranging from 92 to 95 and International Knee Documentation Committee (IKDC) scores from 82 to 93, and Tegner activity scores indicating return to moderate-to-high activity levels (7-9). Objective knee stability outcomes showed low rates of grade III pivot shift and limited anterior-posterior laxity. Return-to-sport rates ranged from 88% to 100%, with 61-76% of patients returning to their pre-injury level and mean time to return to sport of approximately 9-11 months. The included studies demonstrated considerable heterogeneity in study design, patient characteristics, and reported outcomes, limiting comparability of the results. CONCLUSION AND RELEVANCE: In individuals ≤21 years, the addition of a LEAP to primary ACLR may be associated with lower ACL graft failure, improved functional outcomes and rotatory knee stability in comparison to isolated ACLR. However, these findings should be interpreted with caution given the limited and heterogeneous evidence. LEVEL OF EVIDENCE: Level IV. PROSPERO REGISTRATION NUMBER: CRD420251083532.
Kienberger et al. (Fri,) studied this question.