Optimal flexion angle for graft fixation in lateral extra-articular tenodesis combined with anterior cruciate ligament reconstruction: A systematic review

Purpose: This systematic review aims to investigate the knee flexion angles used for graft fixation in lateral extra-articular tenodesis (LET) during anterior cruciate ligament reconstruction (ACLR) and their impact on clinical outcomes. Methods: Following PRISMA guidelines, MEDLINE/PubMed and EMBASE were searched up to February 2024. The inclusion criteria were original clinical studies (levels I–IV evidence) with at least 12 months of follow-up, reporting knee flexion angles during LET graft fixation in ACLR. Exclusion criteria included non-English articles, reviews, biomechanical studies, and case reports. Data on study design, patient numbers, fixation angles, and clinical outcomes were extracted, and study quality was assessed using the RoB 2 tool. Results: Out of 1134 studies identified, 21 met the inclusion criteria. The reported flexion angles for LET graft fixation ranged from full extension to 90°. Ten studies fixed the graft at 30°, consistently showing improved knee stability, reduced pivot-shift rates, and better functional outcomes, especially in high-risk patients. Three studies focused on graft fixation at 45° of flexion. Another four studies investigated fixation at 60° of knee flexion. Lastly, two studies assessed outcomes with fixation at 90°. Conclusion: LET combined with ACLR effectively restores knee stability across various flexion angles. While fixation at 30° is most commonly associated with positive outcomes, the lack of consensus on an optimal angle reflects differences in surgical techniques and patient-specific factors. Further prospective research with long-term follow-up is needed to validate these findings and guide clinical practice toward optimal knee flexion angles for graft fixation in LET procedures. Level of Evidence: Level III.