Objective: Precise anatomical placement of the femoral tunnel is critical for successful outcomes in anterior cruciate ligament (ACL) reconstruction. Intraoperative fluoroscopic guidance is widely employed to improve tunnel accuracy, particularly using the Bernard–Hertel quadrant method on true lateral views. However, the influence of trochlear dysplasia, commonly seen in patients with patellofemoral instability, on the radiographic identification of the ACL femoral footprint remains unclear. Using the quadrant method, this study evaluated whether trochlear dysplasia affects fluoroscopic localization of the ACL femoral footprint.
Materials and Methods: 43 3D-printed femoral models were created from CT scans of patients with (n = 21) and without (n = 22) trochlear dysplasia. A consensus panel identified the anatomical ACL femoral footprint and marked it with a radiopaque thumbtack. True lateral fluoroscopic images were obtained under standardized conditions. Two independent observers performed radiographic measurements of the ACL footprint location using the ACL-X mobile application, applying the quadrant method. Intra- and inter-observer reliability was assessed using intraclass correlation coefficients (ICC). Group comparisons were made for the depth and height coordinates of the footprint.
Results: Radiographic measurements demonstrated excellent intra-observer reliability (ICC range: 0.854–0.912) and inter-observer (ICC range: 0.817–0.913). There was no significant difference in ACL footprint location between groups. The mean depth was 22.6 ± 4.1% in the dysplasia group and 21.4 ± 3.8% in the control group (p = 0.807). Similarly, the mean height was 37.8 ± 6.3% in the dysplasia group and 39.3 ± 5.4% in controls (p = 0.617). These findings indicate that trochlear dysplasia does not significantly affect radiographic footprint localization.
Conclusion: Trochlear dysplasia does not compromise the accuracy of fluoroscopic identification of the ACL femoral footprint using the quadrant method. Intraoperative fluoroscopic guidance remains reliable for anatomical femoral tunnel placement in ACL reconstruction, regardless of underlying trochlear morphology.