Predicting Risk of Recurrent Patellar Dislocation

Lateral patellar dislocation (LPD) is one of the most common injuries of the knee, especially in a young patient. It is multifactorial with several underlying risk factors. The purpose of this review is to present the most recent data concerning risk factors and their predictive value to estimate recurrent LPD risk.

Several demographic risk factors (age, skeletal immaturity, sex, bilaterality), mechanism of injury, and anatomic risk factors (trochlear dysplasia, patella alta, excessive tibial tubercle lateralization, increased patellar tilt) have been recognized. The combination of different risk factors, their relative contribution to instability, weightage of each factor, and multivariate analysis have led to the development of a prediction model and instability scoring system. If recurrent instability and poor outcomes could be predicted based on these prediction tools, then alternative treatment or early surgical intervention after first-time LPD could be considered. This information can also be used to predict contralateral LPD and failure of surgical treatment. Current prediction tools are mainly based on retrospective studies. In the future, prospective validation of these prognostic factors would be beneficial.