The Influence of Primary Femoral Bone Tunnel Position on Postoperative Outcomes and Femoral Bone Tunnel Creation in Revision ACL Reconstruction.

Abstract

Purpose: The impact of primary femoral tunnel position on rerupture rates following revision anterior cruciate ligament reconstruction (ACLR) remains unclear. This study aimed to explore whether the anatomical placement of the primary femoral tunnel affects rerupture risk, tunnel positioning at revision surgery, and postoperative clinical outcomes.

Methods: Among 165 patients who underwent revision ACLR at our institution between 2018 and 2022, 78 cases with a minimum of two years of follow-up were included. The primary femoral tunnel position was evaluated using Bernard and Hertel's quadrant method on 3D CT scans. Patients were categorized into Group A (anatomical position) and Group N (non-anatomical position). Rerupture rate, tunnel position at revision ACLR, and clinical outcomes were compared between the groups. Subgroup analyses were conducted based on primary surgical technique (single-bundle vs. double-bundle). Additionally, multivariate logistic regression analysis was performed to identify independent predictors of rerupture.

Results: Rerupture occurred in 3 of 39 cases (7.7%) in Group A and 6 of 39 cases (15.4%) in Group N (p = 0.48). There were no significant differences in age, sex, height, weight, sports type, or posterior tibial slope. Anatomical tunnel placement at revision was achieved in 94.9% of Group A and 79.5% of Group N (p = 0.087). No significant differences in Knee Injury and Osteoarthritis Outcome Score or Anterior Cruciate Ligament-Return to Sport after Injury scale were observed at two years postoperatively. Subgroup analysis based on primary surgical technique (single-bundle vs. double-bundle) revealed no significant differences in rerupture rates or femoral tunnel positioning at revision. Multivariate logistic regression identified anatomical tunnel placement during the revision surgery as the only independent protective factor against rerupture (odds ratio, 0.145; 95% CI, 0.022-0.951; p = 0.044).

Conclusion: Anatomical tunnel placement during primary ACLR appears to be a key factor associated with a reduced risk of rerupture following revision ACLR. These exploratory findings underscore the importance of accurate tunnel positioning and should be interpreted cautiously due to limited sample size.