Anterior cruciate ligament (ACL) tears are the most common ligament injury in young population who want to participate in sports activities, such as basketball, soccer and skiing. The current standard treatment for this ligament injury is mimicking the native ACL by fixation of an autograft or allograft in the drilled bone tunnels. Orthopedic surgeons hope the reconstructed ACL can restore joint stability and diminish subsequent meniscal and articular cartilage injuries. Although many decades have passed since ACL reconstruction was developed, there still have been numerous changes in surgical methods.
For a long time before the mid-2000s, isometricity of the ACL through knee motion was the main objective of ACL reconstruction to prevent a retear. Isometric ACL reconstruction using the transtibial (TT) technique was considered as the standard surgical method. How about now? Science is evolving and the then overwhelming technique yielding good clinical outcomes is now considered as an old-fashioned one that cannot restore rotational stability after ACL tears1). The current primary concern of many researchers has shifted to how to accurately restore the native anatomic attachment of the ligament. In response, numerous laboratory studies have been conducted to investigate the detailed anatomy of ACL, revealing previously unknown facts such as direct/indirect insertion and ribbon-like structure of the ACL2,3). Unfortunately, it has not yet been perfectly reproduced even with the anteromedial (AM) portal or outside-in (OI) technique.
Will these methodological developments improve the clinical outcomes of ACL reconstruction and prevent later arthritic changes? We cannot be sure yet4). Recently, a Danish Knee Ligament Reconstruction Registry study reported a rather increased risk of revision ACL surgery when using the AM technique for femoral drill hole placement, compared with the TT technique5). Therefore, long-term evaluation of high level studies is necessary to convince us the superiority of the latest technique pursuing anatomic ACL reconstruction and if results are not satisfactory, it will be replaced by another technique in later decades. However, the recent newly introduced surgical methods are considered as innovative efforts of clinicians who wish to overcome the limitations of the pre-existing techniques.
Femoral tunnel placement is known to be more crucial to restore biomechanical properties of the native ACL6,7). Although controversy still exists regarding the best method for approaching the anatomical femoral footprint, independent femoral drilling using the AM portal or OI technique are documented to have advantages of unconstrained anatomic placement compared to the TT technique8).
The current issue of