Femoral Tunnel Length in Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction Is Correlated with Body Size and Knee Morphology

Abstract

PURPOSE: To reveal the correlation between antero-medial (AM) and postero-lateral (PL) femoral tunnel length in anatomical double-bundle anterior cruciate ligament (ACL) reconstruction and body size and knee morphology. METHODS: Thirty-four subjects undergoing anatomical double-bundle ACL reconstruction were included in this study. Pre-operative body size (height, body weight, and body mass index (BMI)) were measured. Using pre-operative MRI, quadriceps tendon (QT) thickness and the whole anterior-posterior (AP) length of the knee were measured. Using post-operative CT, axial and sagittal views of the femoral condyle were evaluated. The correlation between measured intra-operatively AM and PL femoral tunnel length, and body size, knee morphology using pre-operative MRI and post-operative CT parameters were statistically analyzed. RESULTS: Both AM and PL femoral tunnel length were significantly correlated with height, body weight, posterior condylar length, and Blumensaat’s line length. CONCLUSION: These results suggest that the femoral ACL tunnel length created using a trans-portal technique can be estimated pre-operatively by measuring the subject’s body size and/or the knee morphology using MRI or CT. For clinical relevance, surgeons should be careful to create femoral tunnel of sufficient length when using a trans-portal technique, especially subjects with smaller body size and knee morphology. Level of evidence Ⅲ.