 Methods: 55 athletes patients will be recruited from Martín Gómez Clinic from Granada Spain and Nutuality of footballers from Andalusian Spain. Patients will be randomized in two groups: quadriceps tendon versus hamstring tendon. Clinical and functional outcomes will be measured before surgery and three and six months after that. All patients will be operated on by the same senior surgeon and both group will received the same postoperative rehabilitation protocol. Prior to the surgery the participants or their legal representatives must sign the informed consent for participation in this research. 