Open-wedge high tibial osteotomy and combined abrasion/microfracture in severe medial osteoarthritis and varus malalignment: 5-year results and arthroscopic findings after 2 years - Schuster, P; Schulz, M; Mayer, P; Schlumberger, M; Immendoerfer, M; Richter, J (Arthroscopy, 2015)