Biomechanical stability of single-bundle PCL reconstruction with and without suture tape augmentation: a cadaveric study

Abstract

Background: Residual laxity after single-bundle posterior cruciate ligament (PCL) reconstruction remains a clinical concern that may compromise functional outcomes. Suture tape augmentation has been introduced as an internal bracing technique to enhance graft protection and reduce early postoperative laxity. This study aimed to determine whether suture tape augmentation reduces posterior tibial translation (PTT) and graft elongation under cyclic loading in single-bundle PCL reconstruction. Methods: Eight fresh-frozen human cadavers (16 knees) underwent bilateral single-bundle PCL reconstruction. One knee in each pair received suture tape augmentation, while the contralateral knee served as control. Posterior tibial translation was measured at 90° of flexion under four conditions: intact, after partial PCL transection, after reconstruction, and after 1000 loading cycles at 1 Hz. Graft elongation, diameter, and tibial tunnel size were recorded. Paired t-tests compared groups. Results: No significant differences in PTT were found between groups in the intact, cut, or reconstructed states. After cyclic loading, the suture tape group showed lower PTT than controls (4.60 ± 2.24 mm vs 5.49 ± 1.52 mm, p = 0.06). The increase in PTT from reconstruction to post-cyclic loading was smaller with suture tape (1.09 ± 0.65 mm vs 1.57 ± 0.65 mm, p < 0.05). Graft elongation was similar, while graft diameter and tibial tunnel size were slightly larger with suture tape (p < 0.05). Conclusion: Suture tape augmentation limited the increase in posterior tibial translation under cyclic loading, indicating improved dynamic stability and potential graft protection in single-bundle PCL reconstruction. Level of evidence: Basic Science, Laboratory Study (Biomechanical).