RetroBRACE: clinical, socioeconomic and functional-biomechanical outcomes 2 years after ACL repair and InternalBrace augmentation in comparison to ACL reconstruction and healthy controls-experimental protocol of a non-randomised single-centre comparative study - Müller, S; Bühl, L; Nüesch, C; Pagenstert, G; Mündermann, A; Egloff, C (BMJ Open, 2022)