Assessment of Surgical Correction of Patello-femoral Instability by EOS 3D Kinematics

Inclusion Criteria: * Age above 15 years and 3 months (minimal age to be allowed for adult orthopedic surgery in the hospital) * Patients with patello-femoral instability (at least one patella dislocation) * Patients with corrective surgery planned * Patients must be covered by public health insurance * Signed informed consent form by the patient or by the parents or legal guardian of the patient (if patient is under 18) Exclusion Criteria: * Previous existing surgery for patella instability on the same knee * Previous existing surgery on the extensor apparatus of the knee * Female patients with pregnancy * Patients deprived of liberty by administrative or court order