Background: The treatment of dislocation following primary total hip arthroplasty usually requires the use of expensive hospital resources and sometimes requires revision surgery. The hospital costs associated with treating this complication have not been previously analyzed, to our knowledge. The purpose of this study was to assess the financial impact of treating dislocations at our institution.

Methods: Between 1997 and 2001, 3671 patients underwent a total of 4054 consecutive primary total hip arthroplasties at our institution. The patients were prospectively followed at regular intervals, and their follow-up data were recorded in an institutional total joint registry. Ninety-nine hips (2.4%) in ninety-nine patients dislocated. The costs to our institution to treat these dislocations were evaluated by determining the cost of each treatment episode required to reestablish hip stability and were expressed as the percent increase in cost compared with that of an uncomplicated primary total hip replacement.

Results: Of the ninety-nine hips that dislocated, sixty-two (63%) remained stable after one or more closed reductions and thirty-seven (37%) ultimately required revision surgery. The hospital cost of each closed reduction episode represented 19% of the hospital cost of an uncomplicated total hip replacement. When revision surgery was eventually needed, the average hospital costs of one or more closed reductions and the subsequent revisions represented 148% of the hospital cost of an uncomplicated primary total hip replacement.

Conclusions: Dislocation after primary hip replacement continues to be a prevalent and costly complication that diminishes the cost-effectiveness of an otherwise very successful surgical procedure.