Evaluation of Intra-Aarticular Graft Length using Sagittal Radiograph in Anatomic Single Bundle Anterior Cruciate Ligament Reconstruction

Objective:

Preoperative estimation of graft length may help surgeons in planning anterior cruciate reconstruction (ACL) surgery. Concomitant intra-operative direct and radiographic measurements of the distance between ACL insertion sites were not published so far. The aim of this study was to evaluate this distance during anatomic single bundle ACL reconstruction and determine a potential radiographic measurement for preoperative planning.

Methods:

The study included fifty two patients who underwent anatomic single bundle ACL reconstruction surgery of the knee. Femoral and tibial bone tunnels were drilled through the ACL footprint insertions sites. The intra-articular distance between bone tunnels was measured with the knee in 90º of flexion position using an arthroscopic ruler and verified by fluoroscopy.

Results:

The mean intra-articular distance between the femoral and tibial bone tunnels was 22±2 mm (range, 18-26 mm). In a true sagittal fluoroscopic view of the knee this distance was observed repetitively between two points in the distal femur. The first point was the intersection of the posterior femoral cortex and the Blumensaat`s lines. The second point was created by a line that angled from the Blumensaat`s line (the angle was similar to the tibial drilling angle where its apex was the first point) at the intersection on the distal femoral articular surface.

Conclusions:

The intra-articular distance between femoral and tibial graft tunnels in anatomic single bundle anterior cruciate ligament reconstruction varies within a narrow range and can be measured by using a true sagittal radiographic view of the knee. This measurement is useful for preoperative assessment of the required graft length.