Purpose: Placement of the femoral tunnel is critical to graft function after posterior cruciate ligament (PCL) reconstruction. To date, however, the location of the femoral tunnel aperture has not been compared by in vivo 3-dimensional computed tomography (3D-CT) during PCL reconstruction with the outside-in (OI) and inside-out (IO) techniques. This study used 3D-CT analysis to compare the location of the femoral tunnel aperture in patients who underwent PCL reconstruction with the OI and IO techniques.
Methods: A total of 77 patients underwent single-bundle PCL reconstruction using the OI (n = 46) or IO (n = 31) technique. The location of the femoral tunnel aperture was assessed by 3D-CT and measured by the anatomic coordinate axis method to construct 3D surface models.
Results: The mean location of the femoral tunnel aperture in the low-to-high direction did not differ significantly in the OI and IO groups (75.0 vs. 75.2%, P = 0.869). However, in the deep-to-shallow direction, the femoral tunnel aperture was positioned more shallowly in the IO than in the OI group (75.7 vs. 81.1%, P < 0.001).
Conclusion: The IO technique of single-bundle PCL reconstruction yielded a shallower femoral tunnel in the deep-to-shallow direction than did the OI technique. However, femoral tunnel location in the low-to-high direction was similar using the two techniques.
Keywords: 3D-CT; Femoral tunnel; Inside-out; Outside-in; PCL reconstruction.