Evaluation of Femoral Tunnel Positioning Using 3-Dimensional Computed Tomography and Radiographs after Single Bundle Anterior Cruciate Ligament Reconstruction with Modified Transtibial Technique

Abstract

BackgroundThe purpose of this study is to report a modified transtibial technique to approach the center of anatomical femoral footprint in anterior cruciate ligament (ACL) reconstruction and to investigate the accurate femoral tunnel position with 3-dimensional computed tomography (3D-CT) and radiography after reconstruction.MethodsFrom December 2010 to October 2011, we evaluated 98 patients who underwent primary ACL reconstruction using a modified transtibial technique to approach the center of anatomical femoral footprint in single bundle ACL reconstruction with hamstring autograft. Their femoral tunnel positions were investigated with 3D-CT and radiography postoperatively. Femoral tunnel angle was measured on the postoperative anteroposterior (AP) radiograph and the center of the femoral tunnel aperture on the lateral femoral condyle was assessed with 3D-CT according to the quadrant method by two orthopedic surgeons.ResultsAccording to the quadrant method with 3D-CT, the femoral tunnel was measured at a mean of 32.94% ± 5.16% from the proximal condylar surface (parallel to the Blumensaat line) and 41.89% ± 5.58% from the notch roof (perpendicular to the Blumensaat line) with good interobserver (intraclass correlation coefficients [ICC], 0.766 and 0.793, respectively) and intraobserver reliability (ICC, 0.875 and 0.893, respectively). According to the radiographic measurement on the AP view, the femoral tunnel angles averaged 50.43° ± 7.04° (ICC, 0.783 and 0.911, respectively).ConclusionsOur modified transtibial technique is anticipated to provide more anatomical placement of the femoral tunnel during ACL reconstruction than the former traditional transtibial techniques.

Comparison of Poly-L-Lactic Acid and Poly-L-Lactic Acid/Hydroxyapatite Bioabsorbable Screws for Tibial Fixation in ACL Reconstruction: Clinical and Magnetic Resonance Imaging Results

“…All reconstructions were performed with a modified transtibial technique using a quadruple hamstring tendon autograft. 12) Through the anteromedial portal, a microfracture awl was placed just behind the bifurcate ridge to make the center of the anatomical femoral tunnel. The triangular, funnel-shaped bony trough was employed to slip the eccentrically positioned guide into the anticipated anatomic center, which is part of the modified transtibial technique.…”

“…The triangular, funnel-shaped bony trough was employed to slip the eccentrically positioned guide into the anticipated anatomic center, which is part of the modified transtibial technique. 12) An ACL guide (Linvatec, Largo, FL, USA) was used to make the tibial tunnel at an angle of 47.5°, and the tunnel was positioned in the center of the remnant ACL stump. The tibial tunnel was made to have the same thickness as the graft using an expansion reamer.…”

Comparison of Femoral Tunnel Length and Obliquity Between Transtibial, Anteromedial Portal, and Outside-In Surgical Techniques in Single-Bundle Anterior Cruciate Ligament Reconstruction: A Meta-analysis

“…4-6 A more oblique graft resulting from a more horizontal femoral tunnel in the coronal plane was found to better resist rotational forces than a more vertical femoral tunnel. [7][8][9] However, increased coronal obliquity correlated with a more circular aperture of the femoral tunnel, 10 differing in shape from its normal oval anatomic footprint. The biomechanical superiority of increased coronal graft obliquity of the femoral tunnel has increased interest in independent femoral drilling techniques of ACL reconstruction, such as anteromedial (AM) portal and outside-in (OI) techniques, which are independent of tibial drilling during ACL reconstruction.…”

Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction Using the Modified Transtibial Technique

“…Unlike previous reports that state that femoral tunnels produced from traditional transtibial techniques tend to lie more proximal and anterior than the anatomic position, our modified transtibial technique can produce a femoral tunnel that is only slightly distal and posterior to the anatomic position with the funnel-shaped bone trough. 2,8,9 A recent study on 3-dimensional computed tomography evaluation after anatomic ACL reconstruction with the modified transtibial technique reported that the mean value of the femoral tunnels was between the AM and posterolateral bundle position compared with the mean 3. (A) The guide pin tends to be placed more distally and anteriorly than the anatomic center of the femoral footprint as viewed from the anterolateral portal in the left knee that is kept in flexion.…”

“…MODIFIED TRANSTIBIAL TECHNIQUE e229 value from multiple measurements of the anatomic ACL footprints in cadaveric knees from previous studies. 8 Another important factor to consider when producing an anatomic femoral tunnel during the transtibial ACL reconstruction technique is the starting point of the tibial tunnel. Recent studies have attempted to achieve anatomic femoral attachment sites by altering the starting point of the tibia bone tunnel.…”