Authors: Parvizi J, Suh D, Mehdi SM, Mullan A, Rothman Institute, Philidelphia PA
Title: Aseptic Loosening of Total Hip Arthroplasty:Are They All Truly Aseptic?
Purpose: The aim of our study was to determine if patients with failure for aseptic loosening are properly evaluated for infection prior to revision surgery. Patients developing infection following revision for an aseptic failure were evaluated in detail to a
Methods: Between 2000 and 2007, 923 revision THAs for aseptic loosening were performed at out institution. We reviewed the medical records of all of these patients to extract information pertinent to PJI workup including ESR, CRP, joint aspiration, and also pathology report and culture results of the specimens taken intraoperatively. We compared this cohort to a matched control group of revision cases who did not develop infection after revision.
Results: Postoperatively 37 of 891 patients (4.1%) developed infection including 21 females and 16 males. Their average age was 63 years (range, 38 to 79). Average time to failure due to infection was 11.5 months (range, 2 weeks to 51 months). Evaluations revealed that 8 patients from the cohort (21.6%) were in fact mislabeled as aseptic and fulfilled all criteria for infection prior to revision arthroplasty.
Discuassion and Conclusion: It seems that aseptic loosening, as defined by the failure to observe clinical signs of infection and/or isolate bacteria via ordinary microbiologic techniques, is a mislabel in almost one-fifth of patients who in fact have infection. Better methods for diagnosis of PJI are desperately needed.