Introduction: The anterior cruciate ligament rupture is common and produces great knee instability; reconstruction is the ideal treatment. Objective: To determine the functional evolution of patients undergoing anterior cruciate ligament reconstruction with external anchoring and internal expansion systems. Design: Analytical, observational, longitudinal and ambispective study. Location: Orthopedics and Traumatology Department, Hospital Nacional de Policía “Luis Nicasio Saenz”, Lima, Peru. Participants: All patients who met the inclusion and exclusion criteria from January to December 2014. Interventions: Data collection was based on medical history, physical examination and application of the Lysholm and Tegner Knee Scoring Scales at baseline and after 6 and 12 months follow-up. Results were analyzed with descriptive and inferential statistics with the Shapiro-Wilk and Mann-Whitney...