Abstract
Over the past ten years we have seen a move to less invasive surgical approaches and simplification of OR procedures; hence, there has been a renewed interest in the use of rectangular wedge-taper design hip stems. I present a personal series of over five hundred Accolade (Stryker) stems with a high (6%) early failure rate.
Cases are drawn from a personal database. These patients presented with either pain or difficulty with stair-climbing. Several remain asymptomatic, but radiographs are early identical in all cases. Impressive radio-lucent and sclerotic lines are seen on the lateral radiograph in Gruen zones VIII and XIV at between three and six months, and later appear in Gruen I. Most occurred in type A or AA bone. These failures are interesting as they are due to rotational loosening, not axial subsidence. To date, 6 of 12 have been revised, all showing complete lack of ingrowth to proximal porous coating.
Rectangular wedge-taper design stems have enjoyed high success rates in several published series. However, the author believes that the use of this stem in Type A or AA bone leads to preferential distal (diaphyseal) taper engagement, which negates proximal (meta-diaphyseal) taper engagement, and predisposes the stem to rotational micromotion, failure of ingrowth, and subsequent loosening.
To our knowledge, this is the first paper to recognise this mode of failure. The authors strongly believe stems of this type should be used with caution in males with type A or AA bone.
