Medial Retinacular Plication Versus Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability

Inclusion Criteria: * Recurrent lateral patellar instability has been described by the patient Imaging criteria include: * TT-TG distance (on CT or MRI) is between 10-20 mm * Insall-Salvati Index is between 0.9 - 1.2 * Trochlea angle is lower than 145 degrees Exclusion Criteria: * Only a single event of lateral patellar instability occured Imaging criteria include: * TT-TG distance (on CT or MRI) is below 10 mm or above 20 mm * Insall-Salvati Index is below 0.9 or above 1.2 * Trochlea angle is above 145 degrees * Other concomitant intra-articular patholgies, injuries, and surgeries, besides the patella instability, with were recorded at the lower limbs and did not uneventfuly healed, and as a result cause dysfunction of the lower limbs * Significant ligamentous injuries of the knees, including cruciate and collateral injuries, as well as meniscal injuries that interfere with function