Risk Factors and Time to Recurrent Ipsilateral and Contralateral Patellar Dislocations

Background:Previous studies have reported variable rates of recurrent lateral patellar instability mainly because of limited cohort sizes. In addition, there is currently a lack of information on contralateral patellar instability.Purpose:To evaluate the rate of recurrent ipsilateral patellar dislocations and contralateral patellar dislocations after a first-time lateral patellar dislocation. Additionally, risk factors associated with recurrent dislocations (ipsilateral or contralateral) and time to recurrence were investigated.Study Design:Cohort study; Level of evidence, 3.Methods:This population-based study included 584 patients with a first-time lateral patellar dislocation occurring between 1990 and 2010. A retrospective review was conducted to gather information about the injury, subsequent dislocations (ipsilateral or contralateral), and structural characteristics including trochlear dysplasia, patella alta, and tibial tubercle to trochlear groove (TT-TG) distance. Risk factors were assessed to del...