that this procedure does not conform to regulations, but Centeno claims that it is exempt from FDA regulation. It has not been shown in controlled clinical trials to be effective. Prevalence and cost Total hip replacement incidence varies in developed countries between 30 (Romania) and 290 (Germany) procedures per 100,000 population per year. Approximately 0.8% of Americans have undergone the procedure. According to the International Federation of Healthcare Plans, the average cost of a total hip replacement in 2012 was $40,364 in the United States, $11,889 in the United Kingdom, $10,987 in France, $9,574 in Switzerland, and $7,731 in Spain. In the United States, the average cost of a total hip replacement varies widely by geographic region, ranging from $11,327 (Birmingham, Alabama) to $73,927 (Boston, Massachusetts). History The earliest recorded attempts at hip replacement were 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. Subsequently, he used a cement made from plaster of Paris, powdered pumice and glue. Molded-glass implants were introduced in the 1920s by Smith-Peterson in the USA. Although these showed good bio-compatibility, they were mechanically fragile so he started experiments with metallic prostheses in the 1930s. In 1938, Philip Wiles of Middlesex General Hospital, UK carried out a total hip replacement using a stainless-steel prosthesis attached by bolts. In 1940, Dr. Austin T. Moore (1899–1963) at Columbia Hospital in Columbia, South Carolina performed a hip replacement using a prototype prosthesis made of the cobalt-chrome alloy Vitallium; it was inserted into the medullary canal and "fenestrated" to promote bone regrowth. A commercial version known as the "Austin Moore Prosthesis" was introduced in 1952; it is still in use today, typically for femoral neck fractures in the elderly. Following the lead of Wiles, several UK general hospitals including Norwich, Wrightington, Stanmore, Redhill and Exeter developed metal-based prostheses during the 1950s and 1960s. Metal/Acrylic prosthesis were tried in the 1950s but were found to be susceptible to wear. In the 1960s, John Charnley at Wrightington General Hospital combined a metal prosthesis with a PTFE acetabular cup before settling on a metal/polyethylene design. Ceramic bearings were developed in the late 1970s. The means of attachment also has diversified. Early prostheses were attached by screws (e.g. Gluck, Wiles) with later developments using dental or bone cements (e.g. Charnley, Thompson) or cementless systems which