Sofia Zoo marmoset, and macaques. The predator sector houses big cats, bears and small predators, including lions, tigers, leopards, pumas and brown bears. In January 2011 the zoo received eight Humboldt penguins on loan from Germany. The penguins are on loan for about 18 months, after which they will be returned, with any offspring to stay at the zoo. The zoo has some 1,400 individual birds representing 192 species. Waterbirds are housed in a lake, and Imperial eagles, Griffon vultures, Egyptian vultures and buzzards in a large walk-through aviary. Other species of birds at the zoo include ostriches, Silver pheasants, peacocks, flamingos,
Hip replacement carried out in Germany in 1891 by Themistocles Gluck (1853–1942), who used ivory to replace the femoral head (the ball on the femur), attaching it with nickel-plated screws, Plaster of Paris, and glue. On September 28, 1940 at Columbia Hospital in Columbia, South Carolina, American surgeon Dr. Austin T. Moore (1899–1963) performed the first metallic hip replacement surgery. The original prosthesis he designed was a proximal femoral replacement, with a large fixed head made of the cobalt-chrome alloy Vitallium. It was about a foot in length and bolted to the resected end of the femoral shaft (hemiarthroplasty). A later version,