Abstract
Dislocation is among the most commonly reported complications following revision total
hip arthroplasty. Dual-mobility bearings may lower the risk of dislocation. The authors
report the results of a multicenter study evaluating the use of a dual-mobility acetabular
cup design that was cemented into a metal shell as part of complex acetabular reconstructions
or in cases where the risk of dislocation was felt to be high, such as isolated bearing
exchanges. Eighteen patients were identified for being at high risk of dislocation
who underwent cementation of a dual-mobility shell that is specifically made for cementation,
into a fully porous metal revision acetabular cup (10 patients) or into a well-fixed
cup at the time of revision without removal of the existing acetabular component (eight
patients). Patients were assessed clinically and radiographically at a minimum of
2 years for the evidence of dislocation, revision surgery, and implant loosening.
At a mean of 36 months (range, 25–56 months), one patient died and one was lost to
follow-up. There were no known cases of hip dislocation. There was one repeat revision,
for a deep infection treated with irrigation and debridement. The mean preoperative
Harris Hip Score of 46 (range, 40–79) improved to a mean of 65 points (range, 41–97)
at the most recent evaluation. Acetabular components were retained in 8 out of 18
cases and the dual-mobility shell was cemented into it. Cementation of a dual-mobility
cup into a shell at the time of a revision surgery is a safe and reliable construct
at minimum of 2 years for patients at high risk of dislocation. There were no complications
related to the cementation of the cup into the metal shell. Longer follow-up is required
to further assess the durability of this construct.
Keywords
dual-mobility cup - revision total hip arthroplasty - dislocation - cement
