Professor Kenji Takagi in Tokyo has traditionally been credited with performing the first arthroscopic examination of a knee joint, in 1919. He used a 7.3 mm cystoscope for his first arthroscopies. Recently it has been discovered that the Danish physician Severin Nordentoft reported on arthroscopies of the knee joint in 1912 at the Proceedings of the 41st Congress of the German Society of Surgeons at Berlin. He called the procedure (in Latin) "arthroscopia genu", and used sterile saline or boric acid solution as his optic media, and entering the joint by a portal on the outer border of the patella. It is not clear if these examinations were of deceased or of living patients.