A new generation of hip replacement gives a more natural result and reduces the risk of dislocation.
The Rubin Institute for Advanced Orthopedics at the Sinai Hospital, Baltimore, is offering new all-metal hip replacements which have a larger than usual hipball design. The human hipball, at the head of the femur, has a diameter of 36 to 55 millimeters, but the hipball of a standard hip replacement is usually only about 26 to 28 millimeters in diameter.

This means that someone with a standard hip replacement can never regain the natural feel and walking style of a human hip. With the new design, the natural walking style is retained, with a fuller range of motion, which may allow people to live a fuller and more active life. This will become increasingly important as the number of hip replacements done increases, especially if these are in the younger age group.

The larger hipball is less invasive to insert and allows more bone preservation. The new design is also all metal, whereas a standard hip replacement is metal and plastic. It's known that the plastic component does wear down over time and may even lead to joint infection. An all metal design minimises the risk of such complications.