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Paper of the week: The 2018 new definition of periprosthetic joint infection improves the diagnostic efficiency in the Chinese population.

Paper of the week:  The 2018 new definition of periprosthetic joint infection improves the diagnostic efficiency in the Chinese population. Haitao Guan, Jun Fu, Xiang Li, Wei Chai, Libo Hao, Rui Li, Jing Zhao, and Jiying Chen. J Orthop Surg Res. 2019; 14: 151. Published online 2019 May 24. doi: 10.1186/s13018-019-1185-y

Summary by Dr Sreeram Penna

The purpose of this retrospective study was to validate the 2018 ICM criteria on Chinese patients that underwent revision for total hip arthroplasty (THA) and total knee arthroplasty (TKA) for the periprosthetic joint infection (PJI) or aseptic loosening. This study excluded patients with antibiotic-loaded cement spacer in their joint at admission, patients who had a long antibiotic history prior to surgery, and those who had multiple prior surgical procedures. Patients were classified in PJI or not using major criteria in MSIS, 2013 ICM, and 2018 ICM criteria. Researchers then compared minor criteria between the 2018 ICM definition and the 2013 ICM and IDSA criteria.

The study cohort included 98 PJI cases and 168 aseptic revision patients. Statistical analysis showed that overall sensitivity, specificity, positive predictive value, and negative predictive value of 2018 ICM criteria was 94.9%, 95.2%, 92.1%, and 96.1% respectively. For 2013 ICM criteria the results were 53.1%, 98.4%, 96.3%, and 78.8% respectively. For IDSA criteria results were 72.4%, 86.7%, 76.3% and 84.1% respectively.

Overall researchers conclude that 2018 ICM criteria are applicable in the Chinese population. Also, the 2018 ICM criteria was shown to have higher sensitivity compared to the 2013 ICM criteria and IDSA criteria for the diagnosis of PJI.

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ICM Document Update: Chinese Translation Available Online

ICM Chinese translation is available online at the following link

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Paper of the week: Reevaluating Current Cutoffs for Acute Periprosthetic Joint Infection: Current Thresholds are Insensitive

Reevaluating Current Cutoffs for Acute Periprosthetic Joint Infection: Current Thresholds are Insensitive. Chi Xu, Timothy L. Tan, Feng-Chih Kuo, Karan Goswami, Qiaojie Wang, Javad Parvizi. J Arthroplasty 2019, doi: 10.1016/j.arth.2019.06.048.

Summary and editorial by Dr. Marjan Wouthuyzen-Bakker

In this paper of the week, Xu et al. evaluated the sensitivity of serum CRP (> 100 mg/L), synovial leucocyte count (> 10,000 cells/μL) and its percentage of PMN (>90%) in the diagnosis of an acute PJI. Intraoperative cultures were used as a gold standard. 218 patients were evaluated. The reported sensitivity was 55%, 60% and 51%, respectively. Combining all 3 tests resulted in a sensitivity of 84%. Sensitivity greatly depended on the microorganism causing the infection, with the lowest sensitivity observed in infections caused by Coagulase Negative Staphylococci.

Sensitive markers to diagnose an acute PJI are needed in our field in order to decide whether a DAIR procedure should be performed or if a conservative, “wait and see” approach is an acceptable option. The study performed by Xu et al. clearly demonstrates that serum CRP and synovial leucocyte counts are insufficient and should not be used in this decision making process. Techniques with a higher diagnostic accuracy to detect a bacterial infection are needed, especially with a high negative predictive value. Until then, a DAIR should be performed as soon as a clinical suspicion of an infection arises, and should not be postponed [1].

Although the specificity of the studied biomarkers were not evaluated in the study of Xu et al., it is important to realize that according to the current diagnostic criteria, a proportion of the acute PJIs will probably be misqualified as “culture negative PJIs” based on serological testing [3-4]. As a result, these patients will be subjected to unnecessary long-term antibiotic treatment. In contrast to chronic infections, planktonic, free-floating bacteria are abundantly present in acute infections, and these types of bacteria are easy to culture. Thus, a PJI can be ruled out in patients with negative cultures, provided that a sufficient number of cultures were obtained and the patient was not on antibiotic treatment. To conclude about the specificity of the current markers, a control arm of patients with a clinical suspicion of an acute PJI, but with negative cultures during DAIR should be performed.

References

  1. Triantafyllopoulos GK, Poultsides LA, Sakellariou VI et al. Irrigation and debridement for periprosthetic infections of the hip and factors determining outcome. Int Orthop. 2015; 39(6):1203-9.
  2. Triantafyllopoulos GK, Poultsides LA, Zhang W et al. Periprosthetic knee infections treated with irrigation and debridement: outcomes and preoperative predictive factors. J Arthroplasty. 2015; 30(4):649-57.
  3. Bedair H, Ting N, Jacovides C et al. The Mark Coventry Award: diagnosis of early post-operative TKA infection using synovial fluid analysis. Clin Orthop Relat Res 2011; 469: 34-4-.
  4. Kim SG, Kim JG, Jang KM et al. Diagnostic value of synovial white blood cell count and serum C-reactive protein for acute periprosthetic joint infection after knee arthroplasty. J Arthoplasty 2017; 32: 3724-8.
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Paper of the week: General anesthesia might be associated with early periprosthetic joint infection: an observational study of 3,909 arthroplasties.

Paper of the week: General anesthesia might be associated with early periprosthetic joint infection: an observational study of 3,909 arthroplasties. Scholten R, Leijtens B, Hannink G, Kamphuis ET, Somford MP, van Susante JLC. Acta Orthop. 2019 Jul 24:1-9. doi: 10.1080/17453674.2019.1644069.

Summary by Dr Sreeram Penna

This single institution retrospective observational study aims to identify if an association exists with choice of anesthesia and 3-month periprosthetic joint infection risk in total joint arthroplasty patients. Final cohort of 3909 patients were included in the study. It consists of 2,111 (54%) hips and 1798 (46%) Knees. Of 3909 patients 1630 (42%) received general anesthesia and 2,279 (58%) received spinal anesthesia. Researchers utilized propensity score-matched univariable logistic regression analysis to control for allocation bias. 47 early PJI discovered utilizing MSIS criteria in total cohort. Of these 28 (1.7%) occurred in general anesthesia group and 19 (0.8%) occurred in spinal anesthesia group. Statistical analysis using multivariable logistic regression model demonstrated an odds ratio for PJI of 2.0 (95% CI 1.0 – 3.7) after general anesthesia relative to the propensity score-matched patients who received spinal anesthesia.

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ICM update: Search feature and links to individual questions available in document

Dear Delegates

We hope you are all well. We wanted to share with you the following:

1) The App and the website now house the document that has been broken down to each question. So you can click on the desired question and it will take you to the relevant document

2) We have also implemented a search function that will allow you to search your desired question and get to the document faster

3) The document has been translated to Spanish, Russian, Chinese, Ukrainian, Persian, and Japanese. The translations will be or already housed on the App and the website. More translations are on the way.

4) The App usage is approaching 10,000 users. Please speared the word and have people download the App.

5) please feel free to tell us how to improve the App and/or website. Please also feel free to propose a paper of the week whenever you wish