Arthroscopy 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. Pioneering work began as early as the 1920s with the work of Eugen Bircher. He published several papers in the 1920s about his use of arthroscopy of the knee for diagnostic purposes. After diagnosing torn tissue, he used open surgery to remove or repair the damaged tissue. Initially, he used an electric Jacobaeus thoracolaparoscope for his diagnostic procedures, which produced a dim view of the joint. Later, he developed a double-contrast approach to improve visibility.
Composition of the human body mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life. All of the mass of the trace elements put together (less than 10 grams for a human body) do not add up to the body mass of magnesium, the least common of the 11 non-trace elements.