Review Question - QID 3638

ACL reconstruction with 12 o'clock femoral fixation would lead to a vertically placed graft and result in continued instability with cutting activities, and a positive pivot shift exam due to failure to reconstruct the posterolateral bundle of the ACL. Current standards for anatomic ACL reconstruction stress the importance of more horizontal graft placement (10:30 in a right knee vs 1:30 in the left knee), to try and reconstruct both the anteromedial bundle which provides anterior-posterior stability, and the posterolateral bundle which provides the rotational stability. Improper femoral graft placement is one of the most common reasons for ACL revision surgery.

Denti et al studied results of patients undergoing ACL revision surgery and had moderate follow-up. Their results shows that patients undergoing revision ACL surgery can still have good results similar to those found in patient with primary ACL reconstruction with utilization of similar techniques in motivated patients.

Noyes et al also looked at patients undergoing revision ACL surgery with the use of patellar BTB autograft. In contrast, although functional limitations decreased and patient satisfaction improved, their results were not as good as the rate of graft failure was three times higher than their reported failure rate after primary ACL reconstructions. Additionally, they advocated correction of knee varus malalignment with high tibial osteotomy along with addressing any associated posterolateral ligament deficiencies prior to ACL surgery.

Illustration A shows appropriate ACL tunnel placement in the coronal and sagittal planes. Illustration B demonstrates a "clock face" for orientation of the femoral tunnel placement.