Technique
ICON Hip Resurfacing Prostheses are manufactured from a cobalt-chromium-molybdenum cast alloy with a high carbon content in acc. with DIN ISO 5832-4.
ICON implants are not tempered, thereby retaining a high proportion of surface-covering block carbides, which in turn guarantee maximum surface hardness and resistance to wear.
The material is exactly the same as that of the ring prosthesis (metal on metal bearing) and has been documented with the greatest success as since the 60s.
To exclude the possibility of grinding of third bodies into the metal bearings, the ICON Hip Resurfacing comprise one casting.
Detachment of sintered surface enlargements, titanium plasma or other structures applied by heat treatment is thus excluded. Apart from this, the extremely hard block carbides dissolve under heat treatment and crystallise upon cooling into a small and finely distributed form, the carbide content in the alloy, however, decreasing as a result.
This figure shows the cross-section of the outer surface of the ICON cup. The ball structure of the outer surface offers optimum biological prosthesis anchorage, as this is enclosed by the bone. The dendritic block carbides and the particle border-free single-casting ball structure are clearly identifiable.
Four small antirotation wings enhance the primary stability of the implant in the acetabulum.
In addition, the ICON cup is coated with 65 µm hydroxylapatite (HAP), which has been demonstrated to promote ossal integration and hence secondary stability (HAP is considerably softer than CoCr and soluble in the long-term, no third body effect occurs, and application does not alter the structure of the carbides).
Our metal bearings are ground to a roundness and high-quality surface with the greatest precision.
The radial mismatch is optimised in such a way, on the one hand, to enable penetration of the synovial fluid and a hydrostatic lubricating effect and, on the other hand, to avoid equatorial press-fit. At the same time, adhesion and surface friction are reduced to achieve maximum lifetime.
