Arthroscopy was performed in the past. Arthroscopic knee surgery is one of the most common orthopaedic procedures, performed approximately 2 million times worldwide each year. The procedures are more commonly performed to treat meniscus injury and to perform anterior cruciate ligament reconstruction. While knee arthroscopy is commonly used for partial meniscectomy (trimming a torn meniscus) on middle aged to older adults with knee pain, the claimed positive results seem to lack scientific evidence. During an average knee arthroscopy, a small fiberoptic camera (the arthroscope) is inserted into the joint through a small incision, about 4 mm (1/8 inch) long. More incisions
Effect of spaceflight on the human body Effect of spaceflight on the human body Venturing into the environment of space can have negative effects on the human body. Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton (spaceflight osteopenia). Other significant effects include a slowing of cardiovascular system functions, decreased production of red blood cells, balance disorders, eyesight disorders and a weakening of the immune system. Additional symptoms include fluid redistribution (causing the "moon-face" appearance typical in pictures of astronauts experiencing weightlessness), loss of body mass, nasal congestion, sleep disturbance, and excess flatulence. The engineering problems associated with leaving Earth and developing