Anterolateral Complex (ALC) and Lateral Extra Articular Procedure (LEAP)

The exact composition of the antero-lateral complex (ALC) is still a matter of scientific debate. However, the concept of anterolateral supporting structures can be found in several early anatomic descriptions. In his desmographic work from 1752, anatomist and founder of syndesmology Josias Weitbrecht described a series of fibres that reinforce the anterolateral joint capsule of the knee, firmly attached to the back of the “sickle-shaped cartilage”. In 1879, gynaecologist Paul Segond described the eponymous anterolateral tibial avulsion fracture as the result of forced internal tibial rotation and excessive tension of a “pearly, resistant and fibrous band”. Modern ACL reconstruction techniques fail to restore native rotational knee kinematics. Even though a central rotatory axis is re-established through ACL reconstruction, residual dynamic rotatory laxity, clinically manifested by a positive pivot-shift test, is increasingly recognised as a common finding following ACL reconstruction. As a result, lateral extra articular procedures (LEAP) are currently re-introduced. The benefit and indications of LEAP are still a matter of scientific debate.