Tibial tuberosity avulsion is a rare fracture in adolescence.Due to the shear forces on the immature epiphysis. Thirteenyears old girl was admitted to the emergency departmentwith knee pain and tenderness in both knees afterjumping from a height of about one meter. İn examinationshe had tenderness and swelling over both tibial tuberosities.The patient could not do active knee extension. TypeIIA fracture on the left and type IIIA fracture on the rightknee were detected. For the patient’s fractures, closedreduction and fixation with 3 smooth Kirschner wires wasperformed. After immobilization in long-leg brace for threeweeks the brace was removed and she include in therehabilitation program. In this report, we discuss similarcases in the literature and the results of the treatment appliedto our patient.Key words: Tuberositas tibia, avulsion fracture, percutaneouspinnin