KIRA is a non-invasive outpatient device that allows the assessment of dynamic laxity during the pivot shift phenomenon. The device enables precise quantification of the extent of laxity. The unit of measurement is millimeters per second squared (mm/s²).

This test allows evaluation of the anterior translation of the tibia relative to the femur with the knee flexed at 90 degrees. An increased translation suggests an anterior cruciate ligament (ACL) injury. It is graded on a scale from 0 to 3.

Using targeted questionnaires previously applied in the same clinical unit, the type, level, and frequency of sports activity before injury and at follow-up will be investigated. Validated scores such as the Sports Score and IMPACT activity level score will be used. The SPORTS (Subjective Patient Outcome for Return To Sports) Score is a subjective questionnaire that assesses the level of return to sports compared to pre-injury condition on a numeric scale (0, 3, 6, 9, 10) alongside a verbal rating from "disabled" (0) to "good" (10). The IMPACT activity level score objectively evaluates knee impact based on the type of sport, classifying activities into "Low," "Intermediate," and "High" impact. This allows comparison of the sport impact level before and after surgery.

The VAS is a unidimensional 10-point numeric scale used to quantify pain, represented by a 10 cm horizontal line without visible numbers, with endpoints marked as "no pain" (0) and "worst possible pain" (10). The patient marks a point on the line representing their current pain intensity, and the clinician measures the distance from zero to quantify the pain. This scale will be used to assess pain before and after surgery in the lateral compartment of the knee. Pain at the site of metal plate placement for lateral tenodesis fixation scoring above 2 on the VAS will be considered significant lateral compartment pain; scores of 2 or less will be considered as absence of pain in this area.

The Tegner Score estimates a person's level of physical activity on a scale from 0 to 10, where 0 represents 'disability' and 10 represents 'participation in competitive sports,' such as national or international level soccer. This score is the most commonly used to define the activity level of patients with knee disorders. In the study, the Tegner Score will be completed by the investigator through an interview with the patient.

The IKDC questionnaire is a subjective knee evaluation tool that assesses limitations in daily and sports activities, as well as the presence or absence of symptoms. It focuses on three main domains: symptoms (pain, stiffness, swelling, locking), sports and daily activities, and current versus pre-injury knee function. The questionnaire includes 10 questions: seven about symptoms, one about sports participation, one about difficulties in daily activities, and one about current knee function. Scores range from 0 to 100, where 100 indicates no symptoms or limitations (excellent result). Scores are classified as excellent (80-100), good (60-80), fair (30-60), and poor (0-30).

Any complications and subsequent interventions will be documented and recorded in the Case Report Form (CRF). The staff responsible for distributing and collecting the questionnaires will place an identification code on the front page of each questionnaire to ensure the privacy of the study participants.

Clinical and imaging materials available from the patient will be collected. Additionally, as part of standard clinical practice, anteroposterior (AP) radiographs of the lower limb will be performed, along with a second AP radiograph under valgus stress to assess the degree of medial compartment opening when the knee is stressed in valgus. This approach avoids the usual lateral radiograph typically performed during a standard two-view knee X-ray.