Summary
Loosening of the acetabular cup is one of the most common complications following
total hip replacement and has an incidence rate of 1.8% to 36.8%. The objective of
this study was to describe the surgical technique for the application of a cementless
acetabular component specifically designed for treatment of cup loosening and preliminary
clinical experience. The Kyon revision cup is composed of two components; the first
is a perforated titanium outer shell with holes for 2.4 mm titanium screws, which
is impacted into the acetabulum after removal of the loose cup and reaming of the
acetabulum. It is secured with a variable number of screws. The second component is
an inner plain titanium cup with an ultra-high-molecular-weight polyethylene insert,
which is impacted into the outer shell to obtain press-fit stability. This revision
cup was used in 31 dogs with cup loosening and a minimum follow-up period of six months.
There were four intra-operative complications and two postoperative complications.
The main intra-operative complication was difficulty inserting the inner cup into
the outer shell. Postoperative complications included craniodorsal hip luxation in
one dog, which was successfully managed, and cup loosening in another dog, which required
explantation of the prosthesis. The main advantage of the revision cup appears to
be increased implant stability afforded by screw fixation. Our initial clinical results
in 31 dogs were promising; all but one dog had a successful clinical outcome.
Keywords
Total hip replacement - cementless - revision - acetabular - cup loosening