Lateral Extraarticular Tenodesis in Revision Anterior Cruciate Ligament Reconstruction: An Analysis of Clinical Outcomes and Failure Rates

<b>Background/Objectives</b>: Lateral extraarticular tenodesis (LET) has been advocated in revision anterior cruciate ligament reconstruction (ACLR) to improve knee stability and furthermore, decrease failure rates. The aim of this study was to compare clinical outcomes, knee laxity, and failure rates after revision ACLR with LET (ACLR + LET) versus without LET. It was hypothesized that ACLR + LET improves clinical outcomes and reduces the failure rate. <b>Methods</b>: A retrospective analysis of prospectively collected data was conducted to examine patients who underwent revision ACLR with and without LET between 2017 and 2021 with a minimum follow-up of 24 months. Patients with coronal malalignment (>5°), posterior tibial slope >12°, and concomitant injuries to collateral ligaments were excluded. Patient reported outcome measures (PROMs) included the International Knee Documentation Committee (IKDC) subjective knee score, the Lysholm score, and the Tegner activity scale (TAS). Anterior knee laxity was measured with a Rolimeter and side-to-side difference (SSD) was determined. Revision ACLR failure was defined as ACL revision surgery and SSD > 5 mm. Group comparisons were performed using chi-square-, independent-samples students <i>t</i>-test or Mann-Whitney-U tests. <b>Results</b>: Of 56 eligible patients, 45 (80%, follow up, 23 isolated rACLR vs. 22 rACLR + LET) were included with a mean follow-up of 45.6 ± 15.8 months. Postoperative PROMs were not statistically different between rACLR and rACLR + LET groups (IKDC: 73.0 ± 18.9 vs. 68.7 ± 16.6, n.s.; Lysholm: 84.8 ± 12.3 vs. 77.7 ± 16.2, n.s.). Both groups showed similar TAS (rACLR vs. rACLR +LET (5; range 4-6 vs. 4; range 3-5; n.s.). Anterior knee laxity SSD was 2.4 ± 1.3 mm in the rACLR group and 1.8 ± 1.8 mm in the rACLR + LET group (n.s.). The failure rate was 13% in the rACLR group compared to 4.5% in the rACLR + LET group (n.s.). <b>Conclusions</b>: Isolated revision ACLR showed comparable postoperative patient-reported outcome measures and anterior knee laxity compared to ACLR + LET at mid-term follow up. The addition of a LET demonstrated a lower, though non-significant, failure rate after revision surgery. However, future studies with a prospective, randomized design and an increased number of patients are needed to clearly identify the exact indication for the use of additional LET.