The role of trochleoplasty in patellofemoral instability.

The management of recurrent patellofemoral instability is challenging. The etiology of the instability is multifactorial, requiring the examination of lower limb alignment, relationship of the patella to the trochlear groove and tibial tubercle, and the soft-tissue restraints. As initial surgical efforts were aimed at isolated soft-tissue repair or reconstruction, patients often had continued instability. Thus, a heightened interest in trochleoplasty has occurred as trochlear dysplasia has been found in 85% of patients with recurrent instability. Different types of trochleoplasties have been developed depending on the type of dysplasia including the trochlear lengthening osteotomy, the proximal open trochleoplasty, the deepening trochleoplasty, and the arthroscopic deepening trochleoplasty. The techniques, benefits, and results of these trochleoplasties will be presented in this review.