Dislocation of the hip after reimplantation for infection: an analysis of risk factors.

Dislocation is a well documented complication after a two-stage revision arthroplasty for a deep periprosthetic hip infection. We are aware of no reports specifically evaluating the risk factors for dislocation after reimplantation for infection. We hypothesized greater age, increase in the number of operations on the hip, increase in the length of time from resection to reimplantation, greater limb length discrepancy, smaller femoral offset, and using smaller femoral heads would increase the risk of dislocation. We retrospectively reviewed 34 patients who had a two-stage hip revision for periprosthetic infection with a minimum followup of 2 years. Risk factors for dislocation were evaluated. We compared the rate of dislocation in this group to those patients having revision for aseptic failure. Sixteen dislocations occurred in five (14.7%) of 34 patients. Dislocation occurred in three (1.7%) of 171 patients having revision for aseptic failure. In this small series, age at reimplantation, number of previous operations on the hip, length of time from resection to reimplantation, limb length discrepancy, femoral offset, and femoral head size did not seem to be risk factors for dislocation.