Tibial Tubercle Osteotomy: Anterior, Medial and Distal Corrections

Tibial tubercle osteotomies (TTOs) are a versatile procedure that can be used to treat several conditions due to its ability to manipulate both extensor mechanism tracking and patellofemoral joint contact forces. This permits a wide array cut geometries that can be titrated to the individualized needs of each patient. Most common is the anteromedializing (AMZ) TTO, which has been a workhorse procedure for realigning extensor mechanism tracking. The patella can also be distalized, which becomes indicated when pathological patella alta is present. When treating patellar instability, a successful outcome depends on the clinician's understanding of the destabilizing factors. These risk factors are often additive, and if significant enough they can collectively breach a given stability threshold. Threedimensional models provide a useful perspective of the joint morphology, curvature, and congruency which can be particularly helpful for developing an optimal plan for restoring balanced tracking. To decide when to perform a TTO, the decision centers on how well a TTO provides a solution to a tracking or articular loading problem, compared with the added morbidity that accompanies an osteotomy. Details regarding tubercle anteriorization, medialization and distalization are discussed, along with technical considerations and surgical technique.