| abstract |
Joint device comprising a concave sphere portion (14) of a first inner radius, a convex sphere portion (16) of a second outer radius, a plurality of balls (18) disposed in the space formed between both sphere portions (14 and 16), their diameter being equal to the difference between the first and second radius, and a rigid element (20) integral with the convex sphere portion (16) capable of performing angular movements by using the convex sphere portion (16) as a first ball joint. The balls (18) are captive in the space between both sphere portions (14 and 16) in a circular groove (30) in which they are no longer subjected to friction and can therefore be easily recycled. The unit is contained in a spherical cupule (12) in which the concave sphere portion (14) can move in firm frictional engagement, thereby functioning as a second ball joint. Such a dual ball joint device can be used as an articular prosthesis. |