Authors: Parvizi J, Azzam K, Ghanem E, Valle CD, Barrack R
Title: Periprosthetic Infection: A New Prognostic Classification
Institution: Rothman Institute, Philadelphia, PA
Purpose: The objective of this multiinstitutional study was to evaluate the outcome of surgical treatment for PJI in a series of patients and propose a prognostic classification that may aid the orthopedic surgeon in selecting the most appropriate procedure.
Methods: The medical records of 300 patients presenting with PJI to one of the four participating institutions was reviewed. The influence of numerous factors known to influence outcome of treatment were studied. Failure of treatment was defined as the need for further infectionrelated surgical intervention. Patients were then categorized into one of three groups taking into account host (comorbidity, obesity, immune status, previous infections, nutritional status, etc); organism (known versus unknown, antibiotic sensitivity, single versus multiple, etc.), and surgical factors (previous surgery, bone loss, status of soft tissues, time of presentation, twostage versus I&D, blood loss and transfusion, etc). We evaluated the outcome of I&D and twostage exchange arthroplasty separately but the outcome appeared to be generalizable to both.
Results: There was a significant difference in outcome of surgicaltreatment of PJI between the three groups. Patients in group A (healthy host, lowvirulence and sensitive organism, early presentation of infection, and good soft tissues) had between 80100% success for I&D or two-stage exchange arthroplasty. The outcome of treatment was lower in Group B patients (mild to moderate comorbidities,moderately sensitive organism, late presentation, some previous surgeries, and good soft tissue) at 50-79%. The worst outcome at below 50% success was in group C patients (severe comorbidity or resistant or unknown organism, or multiple previous surgeries, or soft tissue deficit).
Discussion and Conclusion: Although individualization of care is still needed, this prognostic classification can be used as guidelines to decide on the best treatment option for patients with PJI and allow better counseling of our patients with regard to outcome of treatment and ensuing expectations. In addition, this study highlights the importance of some reversible variables such as malnutrition, obesity, uncontrolled diabetes, and poor soft tissues that could be addressed before delivery of definitive care to these patients.