Patellar DislocationPatellar LigamentPatellofemoral JointMedial Collateral Ligament, KneePatellaReconstructive Surgical ProceduresPatellofemoral Pain SyndromeLigamentsKnee JointLigaments, ArticularFemurPeriodontal LigamentPosterior Cruciate LigamentLongitudinal LigamentsBiomechanical PhenomenaOsteoarthritis, KneeJoint Instability