Paper of the Week: Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision. Srivastava K, Bozic KJ, Silverton C, Nelson AJ, Makhni EC, Davis JJ.J Bone Joint Surg Am. 2019 Jan 2;101(1):14-24. doi: 10.2106/JBJS.17.00874.
Summary and Editorial by Sreeram Penna
In this study, researchers used decision analysis to determine the optimal decision for the management of chronic periprosthetic infection (PJI) following total knee arthroplasty (TKA). Researchers constructed an expected-value decision tree to estimate the quality-adjusted-life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created one was for all pathogens, a second decision tree was constructed for difficult to treat organisms including methicillin-resistant. A Markov model was used to calculate the QALYs over a 15-year period. The model input was based on values such as mortality rates and reinfection rates published in original studies since 2000. Cost data were obtained from Medicare data.
Results showed that 1-stage revision was the optimal decision in producing greater health utility in both decision trees in the analysis. Some of the issues with research are that there is limited data on infection eradication 1-stage revisions for PJI. Seven studies included in the above simulation for 1-stage revision showed reinfection rates of 7% compared to 15% for 2-stage revision. Researchers contend that even if we assume reinfection rate for 2-stage revision to be around 10% infection rates of 1-stage be more than 30% to be considered non-optimal strategy compared to 2-stage revision as decision model captures significant morbidity and mortality associated with a 2-stage procedure. The simulation also captures cost savings of around $19,000 to $27,000 per infection (depending on pathogen) for 1-stage revision.
Normally in PJI treatment 2 stage revision procedure is considered the gold standard for infection eradication. However, it is known that such strategy place significant morbidity on the patient. In addition, a significant number of patients does not complete the reimplantation procedure in 2-stage operation. This study gives an opportunity for orthopaedic community to rethink options in managing patients with PJI and further research is required.
 Gomez MM, Tan TL, Manrique J, Deirmengian GK, Parvizi J. The Fate of Spacers in the Treatment of Periprosthetic Joint Infection. J Bone Joint Surg Am 2015;97:1495–502. doi:10.2106/JBJS.N.00958.