Recurrent patellofemoral instability: diagnosis and treatment algorithm

The aetiology of recurrent patellofemoral instability (PFI) is multifactorial. These factors include both demographic and anatomic risk factors. Demographic risk factors for recurrent instability include young age, female sex, family history and most importantly, a history of previous ipsilateral or contralateral patellar dislocations. Anatomic factors include generalized ligamentous laxity, neuromuscular imbalance, coronal or axial malalignment, trochlear dysplasia, patella alta and an elevated tibial tuberosity to trochlea groove (TT-TG) distance. Understanding and recognizing these different risk factors for each individual patient who presents with recurrent PFI is fundamental to achieving good outcomes when treating this often-complex patient group.

The main focus of this review is to explore the clinical assessment, radiological investigations and different surgical treatment options available for patients who present with recurrent PFI.