Double-bundle anterior cruciate ligament reconstruction: a cadaveric study on the posterolateral tunnel position and safety of the lateral structures.

PURPOSE

The aim of this study was to identify the anatomic relation between the posterolateral drill hole and the lateral structures of the knee. The length of the posterolateral tunnel and the feasibility of the EndoButton CL (Smith & Nephew, Andover, MA) as posterolateral graft fixation device was also evaluated.

METHODS

An anatomic descriptive study was performed on 24 cadaveric knees. The double-bundle anterior cruciate ligament (ACL) was reconstructed using standard arthroscopic techniques and the EndoButton CL fixation system. The study protocol was as follows: first, an arthroscopy with posterolateral pin placement and drilling of the posterolateral tunnel was performed. Subsequently, the lateral structures were dissected and the distance between the pin and the different anatomic structures was measured. From outside in, the length of the posterolateral tunnel was also measured.

RESULTS

This study shows that there is no increased risk of injuring the lateral collateral ligament during posterolateral tunnel placement in double-bundle ACL reconstruction, when performed through a low anteromedial portal in high flexion. Furthermore, a safe margin was noted between the posterolateral tunnel and the adjacent lateral gastrocnemius and popliteus tendons. The length of the posterolateral tunnel was between 32 and 44 mm (mean, 36.92 mm).

CONCLUSIONS

We conclude that the posterolateral tunnel can be created safely in double-bundle ACL reconstruction without additional risk to the surrounding structures. A 15-mm EndoButton CL fixation device is routinely advised as posterolateral graft fixation in order to avoid the risk of over-advancing the device or overdrilling.

CLINICAL RELEVANCE

This study has shown that there is no risk of iatrogenic lesion to the lateral collateral ligament, lateral gastrocnemius tendon, or popliteus tendon with a posterolateral tunnel drilled through a low anteromedial portal in high flexion.