The study is intended to include all patients who will undergo surgical reconstruction of the anterior cruciate ligament (ACL). The patients will be monitored and evaluated preoperatively and also at 6 months and 1, 2 and 5 years after the intervention through a clinical visit or telephone interview. Such assessments will include the administration of questionnaires to determine the patient's functional symptoms and the objective examination of the knee during a medical examination to quantify its stability.

The literature presents a number of studies on the reconstruction of the anterior cruciate ligament, as well as numerous registers, but the identification of factors and parameters determining the clinical outcomes remains largely debated. The study aims to offer new elements to analyze this treatment and potentially identify the factors responsible for the outcomes and the factors useful to optimize the clinical outcome in the future. In fact, in addition to collect patient data in terms of features and clinical-functional status, objective data will be documented and correlated. In particular the quantification of knee laxity will be performed using an innovative device based on the use of inertial sensors (a methodology recently developed and already validated at the Istituto Ortopedico Rizzoli). The study is intended to include all patients who will undergo surgical reconstruction of the anterior cruciate ligament (ACL). These patients will be followed and evaluated preoperatively, at 6 months and at 1, 2 and 5 years after surgery during a clinical visit or a telephone interview. Such evaluations will include the submission of questionnaires to determine the patient's functional symptoms and also knee joint assessment during a medical examination to quantify the knee joint stability.

Moreover, the following clinical scores will be adopted: IKDC-subjective, IKDC-objective, SF12, Marxs, Koos, Tegner, VAS for pain assessment, EQ-VAS for overall health status assessment. Also it will be recorded the lapse of time for returning to work and sports, the degree of patient satisfaction,the adverse events, the failures and any new treatments on the same site.

Inclusion Criteria:

1. Patients who have provided informed written written consent;
2. Patients aged between 18 and 60;
3. Patients undergoing reconstructive surgical treatment of the anterior cruciate ligament (ACL)

Exclusion Criteria:

1. Patients unable to understand and to want;
2. Patients who have not signed informed consent;

Patients with ACL lesions and undergoing to surgical ACL reconstruction