Anteromedial tibial tubercle transfer

Abstract

Anteromedial tibial tubercle transfer (also called anteriorization of the tibial tubercle or AMZ) is most useful for unloading symptomatic patellofemoral articular lesions on the lateral and distal aspect of the patella while centering patella tracking [1]. The classic patient who benefits from anteromedial tibial tubercle transfer has Ficat's excessive lateral pressure syndrome (ELPS) [2]. A patient who has had long-standing lateral tracking of the patella with overload of the lateral facet generally breaks down the articular cartilage of the lateral patella and trochlear facets (Fig. 20.1), sometimes resulting in chronic pain. The typical pattern also breaks down distal patella articular damage as the patella courses from an abnormally lateral position in extension across the proximal lateral trochlea in early flexion, breaking down distal as well as lateral articular cartilage. Fortunately, the vast majority of patients with this aberration also are left with intact medial patella articular cartilage, particularly on the more proximal aspect of the medial patella.