The influence of tibial slope on anterior cruciate ligament graft failure risk is dependent on graft positioning

Abstract

Background: Increased lateral tibial posterior slope (LTPS) is associated with higher anterior cruciate ligament (ACL) reconstruction (ACLR) failure rate. Transportal central femoral footprint ACLR is associated with higher failure rate compared to transtibial high anteromedial footprint ACLR due to graft anisometry. The purpose of this study was to investigate whether the influence of tibial slope on ACL graft failure risk is dependent on graft positioning. Material: Of the 1480 consecutive hamstring ACLRs, 30 transportal (central femoral tunnel placement) and 30 transtibial (high anteromedial tunnel placement) ACLR failures were evaluated and matched one-to-one with non-failure control participants by age, sex, graft and surgical technique. Lateral tibial slope was assessed on MRI. Results: The risk of graft failure in the transportal group increased by 40.5% per degree of increasing LTPS (odds ratio 1.4; 95% confidence interval 1.05–1.87; p = 0.02). The transportal failure group showed a significantly higher mean tibial slope of 8.6° compared to both the transportal control group with 7.1° (p = 0.03) and the transtibial failure group with 7.2° (p = 0.04). Increased tibial slope was associated with shorter time to reconstruction failure (p = 0.002). The difference between slopes in the transtibial failure group (7.2°) compared to the transtibial control group (7.1°) was not significant (p = 0.56). Conclusion: Increased LTPS is associated with significantly increased risk of graft failure only in transportal ACLR, not in transtibial ACLR. Slope-related graft strain may be potentiated by anisometric ACL graft placement.

Posterior Tibial Slope in Patients With Torn ACL Reconstruction Grafts Compared With Primary Tear or Native ACL: A Systematic Review and Meta-analysis

“…Previous studies reached similar conclusions with respect to intact ACLs compared with torn ACLs. 14 , 39 , 80 , 81 Additional studies have also reported increased PTS with 1 or more patients undergoing revision ACLR compared with those undergoing primary ACLR. 20 , 31 , 72 A previous meta-analysis that included 14 studies reported greater lateral PTS in individuals with ACL injury than in those with intact ACLs.…”

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction: Letter to the Editor

“…In the majority of the patients, the transtibial ACLR technique was used. In our own previously published study on this topic, 2 we found that an increased tibial slope had a solely significant impact on the failure risk after transportal ACLR, not after transtibial ACLR. Given the admirable number of patients in the present report, an isolated evaluation of the effect of an increased tibial slope on the revision risk after transportal ACLR would be of great interest.…”

Increased Posterior Tibial Slope Is Associated With Greater Risk of Graft Roof Impingement After Anatomic Anterior Cruciate Ligament Reconstruction

“…In this study, the abnormal value of PTS was considered ≥12° based on the results of previous literature. 7,25,28,30,38…”

“…In this study, the abnormal value of PTS was considered 12°based on the results of previous literature. 7,25,28,30,38 MRI Evaluations. MRI was performed using a 1.5-T superconducting magnet (Signa; GE Medical Systems) using a standardized institutional protocol.…”