Total knee replacement may be done on people, usually over 55, whose knees have been damaged by arthritis, trauma, or other destructive diseases of the joint resulting in severe limiting knee pain and significant stiffness, instability (constant giving way) and deformity (lock-knees or bowlegs) of the knee.
The Mexican government has a Federal District, which houses the federal government. The Federal District is a physical place and a territory, bordering Mexico City, which is the country's capital city. This is not counted as one of the states, and is much like the United States' District of Columbia.
President of Mexico. The President of the United Mexican States (Spanish: Presidente de los Estados Unidos Mexicanos) is the head of state and government of Mexico. Under the Constitution, the president is also the Supreme Commander of the Mexican armed forces. The current President is Enrique PeÃ±a Nieto, who took office on December 1, 2012.