Patellofemoral instability part 2 (Bony procedure for patellar surgical stabilization): State of the art.

Surgery for patellofemoral instability is usually considered in patients with recurrent patellar dislocation and after a first-time patellar dislocation in the presence of either an associated osteochondral fracture or high risk of recurrence due to the presence of several risk factors. Risk factors include demographics such as age, contralateral dislocation, as well as anatomic risk factors (ARF) such as abnormal coronal and rotational alignment, trochlear dysplasia, lateral quadriceps vector, and patella alta. Surgery with soft tissue procedures includes restoring the medial patellar restraints and balancing the lateral side of the joint, which can be successful in most patients. However, patients that have excessive and/or several ARFs have a high risk of failure with isolated soft tissue stabilization procedures; associated surgical correction of select ARFs is recommended. This article will discuss an approach to evaluate the risk-benefit of adding bony procedures which may decrease the chances of recurrence of patellar instability but can increase surgery-related complications. Approaching patellofemoral instability in a patient-specific approach and combining corrective osteotomies and trochleoplasties with a shared decision with the patient/family, guides surgeons to deliver optimal care for the patellar instability patient.