Complications After Revision Total Hip Arthroplasty in the Medicare Population.

BACKGROUND

The purpose of this study was to identify the incidence and types of complications after revision total hip arthroplasty (THA) within the first year, and determine the relative risk factors for these complications and of re-revision.

METHODS

The sample size of 5% Medicare claims data from 1998-2011 was studied. Primary THA patients who underwent subsequent revision were identified using ICD-9-CM codes. Outcomes and complications after revision THA were assessed. Multivariate Cox regression was used to evaluate the effect of patient demographic characteristics on the adjusted complication risk for revision THA patients.

RESULTS

Of the 64,260 primary THA patients identified between 1998 and 2011, 3555 patients (5.71%) underwent revision THA. Etiology of primary hip failure included mechanical complications such as loosening and wear (40.7%), dislocation (14.0%), and infection (11.3%). Complications after revision THA included infection and redo revision, 17.3% and 15.8% followed by venous thromboembolic disease (VTE) at 11.1%, dislocation at 5.43%, PE at 3.24%, and death at 2.11%. The rate of "new" infections after an aseptic revision was 8.13%. Patients in the 85+-year-old age group had a 100% greater adjusted risk of VTE (P < .001) and 406% higher adjusted risk of death (P < .001) than those in the 65-69 years-old age group. Patients with higher Charlson scores had higher adjusted risks of VTE (P < .001), infection (P < .001), death (P = .002), and re-revision THA (P = .011).

CONCLUSION

Advanced age is a clear risk factor for VTE and mortality, but not for dislocation, infection, or re-revision. Higher Charlson index was found to be a risk factor for every complication after revision except dislocation. Greater attention is required to address the high rate of infection and re-do revision after revision THA (17.3% and 15.8%).