Revision of a Dislocated Articulating Antibiotic Hip Spacer as an Alternative to Girdlestone Arthroplasty: A Case Report.

Introduction: Dislocation of an articulating antibiotic spacer is a rare but significant complication following the first stage of revision hip arthroplasty for infection. This report describes a case of posterior dislocation of a right hip articulating antibiotic spacer, its management, and subsequent total hip arthroplasty (THA). Case Report: A 67-year-old man presented with chronic right hip pain and limited mobility. Radiographs and laboratory work confirmed septic arthritis of the native hip, with aspiration cultures positive for methicillin-sensitive Staphylococcus aureus. He initially underwent right hip resection arthroplasty with articulating antibiotic spacer placement, which dislocated shortly thereafter. Closed reduction was unsuccessful. He subsequently underwent revision of the dislocated spacer with a new articulating spacer. Intraoperative cultures were positive for Bacillus species, and intravenous antibiotics were administered. Definitive THA was later performed as a second-stage procedure. At the latest follow-up, he was ambulating independently with minimal pain and no recurrent infection. Conclusion: Spacer dislocation is a rare yet serious complication that can compromise infection control and mechanical stability. Adequate techniques should be employed to ensure this does not happen, and if it does, a surgeon should consider a revision antibiotic spacer instead of Girdlestone arthroplasty.