Aida® short stem

The Aida® short stem is designed to provide metaphyseal-only cementless anchorage within the spongiosa of the proximal femur. It is proximally supported at the calcar as well as laterally via the distal tip. Axial and rotational stability also arise from the tapered and trapezoidal cross-sectional geometries. The prosthesis has a circumferential proximal microporous coating, consisting of commercially pure titanium (cpTi) and hydroxyapatite (HA), proximally for secondary osseointegration. The Aida® short stem is highly polished distally, hence load transmission can only occur in the proximal area as no fixation can occur distally.

Studies on the primary stability of the Aida® hip stem (size 1 standard and size 1 lateralised) demonstrated that the majority of micro-movement was, according to the literature, within the acceptable limits for secondary fixation / bone ingrowth to occur. In those areas where the most micro-motion was observed, problems of ingrowth rarely occur in practice. The distribution of load in both the standard and lateralised version of the stem does not give cause for concern with regards to local failure of the supporting bone.

Additional finite element analysis (FEA) confirmed the Aida® system's excellent fixation properties - which fully meet the requirements of a modern short stem system.