Dislocated Dual-Mobility Hip Implants Are Unlikely to Be Successfully Closed Reduced and Are More Likely to Require Revision Than Standard Articulation Implants

Background

The natural history of dislocated dual-mobility (DM) total hip arthroplasties remains unclear, particularly regarding closed reduction success and revision rates compared to standard articulations (SAs). This study compared closed reduction success and subsequent reoperation rates between dislocated DM and SA hips.

Methods

A retrospective review was conducted across a large health system, identifying patients with dislocated total hip arthroplasties using International Classification of Disease, Tenth Revision codes. Inclusion required an attempted closed reduction. Patients were stratified by implant type (DM vs SA). Data collected included demographics, prior surgeries, reduction attempts, intraprosthetic dissociation (IPD), subsequent instability, and revision surgery. Outcomes were compared between groups.

Results

Seventy-four patients met the inclusion criteria (26 DM, 48 SA). Successful closed reduction was significantly lower in the DM vs SA group (34.6% vs 90%; P < .001). Among the 26 dislocated DM hips, 15 experienced IPD, including five initially missed. Revision surgery was more frequent in the DM group compared to SA (79.2% vs 53.4%; P < .004). Among those with initially successful closed reductions, rates of recurrent instability requiring revision surgery did not differ significantly (DM 44.4% vs SA 41.9%; P = .84).

Conclusions

Dislocated DM implants are significantly less likely to be successfully closed reduced and more likely to require revision surgery than SA implants, largely due to the high rate of IPD. Missed IPD contributes substantially to the increased reoperation risk and highlights the importance of accurate diagnosis following dislocation.