Surgical Indications for First-Time and Recurrent Patellar Instability

Patellofemoral instability is a common problem representing 3% of all knee injuries [1–4]. The surgical indications for patients with first-time and recurrent dislocations remains unclear. One of the primary goals when managing patellofemoral instability centers on improving patient quality of life as they often have associated fear and apprehension of sustaining an additional dislocation after the sentinel event, which can occur in upwards of 90% of patients with high risk factors such as open physes and trochlear dysplasia [5]. Additionally, addressing patellofemoral instability early may help to prevent future chondral injury that may occur during subsequent recurrent dislocations [6–8]. The two primary questions that remain uncertain in the world of patellofemoral instability are: 1) Should we be indicating first time dislocators at high risk for recurrence for surgery? and 2) What is the best surgical intervention for patients with recurrent instability? The first question seeks to determine who can be treated nonoperatively after a first-time dislocation and who needs to be addressed immediately to prevent a highly likely redislocation and subsequent chondral damage. The second question seeks to understand which patient with recurrent instability will do well with an isolated medial patellofemoral ligament (MPFL) reconstruction and which patients need concomitant bony procedures. This chapter will review clinical evaluation for patients after a patellar instability event, the natural history of patellofemoral instability as well as the extensive research on surgical indications for patients with first-time and recurrent patellar dislocation and provide an overview of important factors to consider and evaluate when determining the best treatment plan for patients with patellar instability.