Double-bundle ACL reconstruction: how big is the learning curve?

The study aim was to determine whether an experienced ACL surgeon could convert from a single-bundle to a double-bundle technique with relative accuracy. We also wanted to determine whether there was a significant learning curve. Ten double-bundle ACL reconstruction procedures were carried out on suitable individuals. Following the procedure, all patients underwent a CT scan of the relevant knee. Femoral and tibial tunnel locations were then measured and compared to reference anatomical locations previously described in the literature. The results were not known to the surgeon until all 10 cases were completed. The total percentage difference between the sum of all four study tunnel locations from their reference anatomical positions was calculated for each patient to assess overall accuracy in tunnel placement. Surgical time and all complications were recorded. There were no complications. The surgical time for patient 1 was 125 min and 65 min for patient 10. There was a tendency to place the anteromedial tunnel on the femur more distal than its anatomical location. The femoral posterolateral tunnel position was placed distal to its anatomical location in all cases. As a consequence, it was also slightly anterior compared to its anatomical location. Accurate tibial tunnel placement was achieved for both the AM and the PL tunnels. An improvement in tunnel placement was observed over the 10 cases. This present study shows that it is possible for an experienced ACL surgeon to convert from a transtibial single-bundle technique to a medial portal double-bundle reconstruction with relative accuracy.