Background Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen.This disease is characterized by easy bruising, joint hypermobility (loose joints),skin that stretches easily (skin hyperelasticity or laxity), and weakness of tissues.The patellofemoral instability developped in certain types of EDS become problematic sometimes.Because no treatment is supportive, corrective surgery may help with the joints instability.