The anterolateral ligament complex has limited impact on anterior tibial translation or internal rotational stability in anterior cruciate ligament−deficient and anterior cruciate ligament−reconstructed knees : a systematic review of biomechanical cadaver studies

Abstract

PURPOSE : To perform an updated systematic review of the biomechanical characteristics investigating the contributions of the anterolateral ligament (ALL) complex to rotational and anterior knee stability in anterior cruciate ligament−intact (ACLI), anterior cruciate ligament−deficient (ACLD), and ACL-reconstructed knees. METHODS : Medline, Embase, Scopus, and Google Scholar were screened for studies from 2012 to 2024. Biomechanical laboratory cadaver studies were included if they described biomechanical characteristics in ACLI, ACLD, or ACL-reconstructed with (ALLR) or without ALL-reconstruction (ALLD). Studies examining other anatomical structures, such as the iliotibial band and Kaplan fibers, and alternative reconstruction techniques, such as lateral extra-articular tenodesis, were excluded. Critical Appraisal Skills Programme checklist for qualitative research and the Biomechanics Objective, Basic Science Quality Assessment Tool scale, were used for study quality assessment. Heterogeneity within and between studies was evaluated using the I 2 statistic. Publication bias was examined using funnel plots and the Egger test. RESULTS : Twenty-two studies were included in the analysis. Critical Appraisal Skills Programme assessment deemed 21 of these studies to be valuable. Biomechanics Objective, Basic Science Quality Assessment Tool evaluated, 9 studies were as moderate quality, 8 as fair quality, and 5 as poor quality. The mean load to failure varied between 49 N and 319.8 N, with a pooled mean of 171.9 N. Stiffness values ranged from 2.6 to 41.9 N/mm, yielding a pooled mean of 21.46 N/mm. Comparisons of load displacement did not reveal significant differences across the following groups for both anterior tibial translation and internal rotation for all comparisons. CONCLUSIONS : This systematic review did not find conclusive evidence that the ALL plays a significant role in limiting anterior tibial translation or internal rotation stability in either ACLI or ACLR knees at point zero during biomechanical testing of cadaver specimens. CLINICAL RELEVANCE : Biomechanical laboratory studies conducted at time zero suggest that the added benefit of combining ALLR with ACLR remains uncertain. When ACLR sufficiently restores knee stability, additional procedures may not always be necessary.