摘要 |
A prosthetic hip cup is provided which is generally similar to the usual basically hemispherical form except that: the inner and outer surfaces have their spherical centres displaced, rather than coincident, to provide a greater wall thickness at the bottom of the cup compared to the side; and the axes of symmetry of the inner and outer surfaces are mutually angled to off-set the thickest part of the cup relative to the axis of the outer surface. This overall eccentricity provides greatest thickness in the main load bearing region of the cup, without introducing any significant disadvantage. An associated femoral device is also provided which is again generally similar to the usual ball headed tapered stem form except that: the ball is connected to the stem through a necked part without introducing a flange; and the stem is tapered in at least two different transverse directions. The absence of a flange simplifies the associated sectioning requirements for the femur, and the multiple tapering of the stem promotes better extrusion of gap-filling cement.
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