Intraprosthetic Dislocation of Dual Mobility Total Hip Arthroplasty: A Case Report and Review of Literature.

Introduction: First introduced in Europe in the 1970s, dual mobility total hip arthroplasty (DM-THA) has gained popularity over years due to the reduced dislocation rates compared to standard THA. However, intraprosthetic dislocation (IPD), a rare complication where the femoral head separates from the polyethylene (PE) liner, remains a potential complication.

Case Report: A 67-year-old female presented with a transcervical neck of femur fracture. She was managed with a DM-THA. She dislocated her THA on post-operative day 18. Closed reduction was performed for the same under general anesthesia. However, she again dislocated her hip 2 days later. CT scan was done and an IPD was diagnosed. The PE liner was revised and the patient had a good outcome at 1 year follow-up.

Conclusion: When a DM-THA dislocates, it is important to consider the possibility of IPD which is a rare but unique complication associated with these systems. The recommended treatment for IPD is open reduction and replacement of the PE liner.