Evaluation of the intercondylar roof impingement after anatomical double-bundle anterior cruciate ligament reconstruction using 3D-CT

Abstract

To reveal the relationship between anatomically placed anterior cruciate ligament (ACL) graft and the intercondylar roof using three-dimensional computed tomography (3D-CT). Twenty-four patients undergoing anatomical double-bundle ACL reconstruction were included in this study. Anatomical double-bundle ACL reconstruction was performed with two femoral tunnels (antero-medial; AM and postero-lateral; PL) and two tibial tunnels. Hamstring autograft was used in all cases. Six to eight weeks after operation and when the subjects had obtained full extension of the knee, 3D-CT was performed with full knee extension. In the 3D-CT, the ACL graft was also reconstructed and visualized three dimensionally. Tunnel placement was evaluated with 3D-CT and intra-operative radiographs. The extension angle of the knee was also evaluated with 3D-CT. No intercondylar roof impingement was observed. In 12 subjects, the ACL graft touched the roof (Touch group) but no graft deformation was observed. In 12 subjects, no roof-graft contact was observed (Non-touch group). No significant difference in femoral and tibial tunnel placement was observed between the Touch and Non-touch groups. All subjects attained full knee extension. We believe that 3D-CT is an effective means of evaluating impingement after ACL reconstruction. For the clinical relevance, when the grafts are positioned in an anatomical fashion, there is no risk of impingement, and surgeons can perform anatomical double-bundle ACL as an impingement-free reconstruction. III (Case control study).