Comparative Magnetic Resonance Imaging Study of Cross-Sectional Area of Anatomic Double Bundle Anterior Cruciate Ligament Reconstruction Grafts and the Contralateral Uninjured Knee

Purpose To evaluate the differences between cross-sectional area of the reconstructed graft by 2 anatomic double-bundle anterior cruciate ligament (ACL) reconstruction techniques, transportal and outside-in and contralateral uninjured knee. Methods In prospective, randomized controlled trials, magnetic resonance imaging of both the reconstructed anatomic double-bundle ACL graft side and the contralateral uninjured knee of 92 patients (mean age, 34.7 ± 10.7 years) between November 2010 and January 2013 were compared. The 3-dimensional curved multiplanar reconstruction function of OsiriX v5.6 was used. Cross-sectional area was measured from the femoral insertion site to the tibial insertion site at 5 different locations, including the midsubstance. Results A significant difference was observed between areas of the uninjured side and reconstructed side at the 5 locations. The area of the reconstructed graft at the femoral insertion site (64 ± 13 mm²) and midsubstance (62 ± 11 mm²) was larger that of the normal ACL (femoral insertion site; 60 ± 13 mm², P =.005 and midsubstance; 47 ± 13 mm², P =.0001), whereas at the tibial insertion site (71 ± 13 mm²) it was smaller than normal ACL (97 ± 22 mm², P =.0001). The measured area between the reconstructed graft and normal uninjured side at the femoral insertion site was relatively closer than that at midsubstance and the tibial insertion-site area. Conclusions A double-bundle anterior cruciate ligament reconstruction graft relatively closely restored the cross-sectional area of the femoral footprint area but was smaller than that of the tibial footprint area; however, the cross-sectional area of graft was much larger than that of the midsubstance. Level of evidence Level II, prospective comparative study.