Katakam A, Melnic CM, Bedair HS

J Arthroplasty. 2020 Dec;35(12):3710-3715.
doi: 10.1016/j.arth.2020.07.005. Epub 2020 Jul 6. PMID: 32732000.

Summary by Mohammad S. Abdelaal MD, MSc

While 2-stage revision with implantation of an antibiotic spacer is considered the gold standard treatment for chronic periprosthetic joint infection (PJI)^1,2, debridement, antibiotics, and implant retention (DAIR) procedure is an attractive alternative for acute PJI³. Although morbid obesity has been widely reported as predictive of PJI following total joint replacement (TJA), little is known regarding the efficacy of DAIR in controlling PJI in this group^4,5.

In their study, Katakam et al. retrospectively reviewed results of all DAIR procedures performed across 4 institutions. Thirty-eight patients with body mass index of at least 40 kg/m2 were matched 2:1 to a cohort of 78 patients with body mass index of <30 kg/ m2 on the basis of patient age, sex, date of surgery, and presence of staphylococcal species in culture. Date of joint aspiration for species identification was chosen as an approximation for initial presentation of symptoms and patients were stratified based on duration of symptoms less than or greater than 48 hours. Kaplan-Meier survivorship curves were constructed and multivariable Cox regression was performed for analysis. Across the entire cohort, the authors reported that 50 (43.9%) of the 114 patients suffered treatment failure following DAIR for PJI. The morbidly obese group experienced a higher treatment failure rate compared to the nonobese group (57.9% vs 36.8%; p =.035). The most common infecting microbe cultured in both groups was methicillin-sensitive Staphylococcus aureus. Following univariate Cox regression, morbid obesity and diagnosis of major depressive disorder/generalized anxiety disorder were found to be significant risk factors (p= .038 and p= .013, respectively) for treatment failure. Overall, the study revealed that, although morbidly obese patients experienced a greater reinfection rate following DAIR for PJI than nonobese patients, this risk can be nullified if morbidly obese patients receive DAIR intervention within 48 hours of symptom presentation.

Limitations of this study include the retrospective study design, small sample size, and the absence of several important potential confounding variables, including albumin levels, history of rheumatologic conditions, and history of coagulation disorders.  In addition, the Kaplan-Meier survival and regression analysis included patients with relatively short follow-up which can lead to missing potential infection recurrence in the future.

References:

1. Castelli CC, Gotti V, Ferrari R. Two-stage treatment of infected total knee arthroplasty: two to thirteen year experience using an articulating preformed spacer. Int Orthop. 2014;38(2):405-412. doi:10.1007/s00264-013-2241-6
2. Kunutsor SK, Whitehouse MR, Lenguerrand E, Blom AW, Beswick AD, INFORM Team. Re-Infection Outcomes Following One- And Two-Stage Surgical Revision of Infected Knee Prosthesis: A Systematic Review and Meta-Analysis. PLoS One. 2016;11(3):e0151537. doi:10.1371/journal.pone.0151537
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