Controlled, randomized multicenter study to compare compatibility and safety of ChondroFiller liquid (cell free 2-component collagen gel) with microfracturing of patients with focal cartilage defects of the knee joint

Aim: Verification of the functionality of a newly acellular liquid collagen type-I gel (ChondroFiller liquid) to treat defined small and medium sized cartilage defects of the knee joint. Methods: In this prospective randomized study are overall