Large ceramic femoral heads offer several advantages
that are potentially advantageous to patients undergoing both primary
and revision total hip replacement. Many high-quality studies have
demonstrated the benefit of large femoral heads in reducing post-operative instability.
Ceramic femoral heads may also offer an advantage in reducing polyethylene wear
that has been reported Cite this article: Bone Joint J 2013;95-B, Supple A:63–6.
Large femoral heads have been used with increasing
frequency over the last decade. The prime reason is likely the effect
of large heads on stability. The larger head neck ratio, combined
with the increased jump distance of larger heads result in a greater
arc of impingement free motion, and greater resistance to dislocation
in a provocative position. Multiple studies have demonstrated clear
clinical efficacy in diminishing dislocation rates with the use
of large femoral heads. With crosslinked polyethylene, wear has
been shown to be equivalent between larger and smaller heads. However,
the stability advantages of increasing diameter beyond 38 mm have
not been clearly demonstrated. More importantly, recent data implicates
large heads in the increasing prevalence of groin pain and psoas impingement.
There are clear benefits with larger femoral head diameters, but
the advantages of diameters beyond 38 mm have not yet been demonstrated
clinically.