New work performed at Mayo Clinic in Rochester, Minnesota has looked at patients who have septic arthritis of the native knee prior to total knee arthroplasty (TKA) and found that it can increase the risk of periprosthetic joint infection by 6x.
Septic Arthritis Before TKA Increases Infection Risk 6-Fold?!
2 min read Premium comments
#totalkneearthroplasty#periprostheticjointinfectionSecondary#septicarthritis
Their work, “Outcomes of Primary Total Knee Arthroplasty Following Septic Arthritis of the Native Knee,” appears in the September 15, 2021 edition of The Journal of Bone and Joint Surgery.
“I decided to do this paper because I was seeing more and more patients with prior septic arthritis wanting to undergo TKA,” explained co-author Matthew Abdel, M.D. to OTW. “While some had septic arthritis two to three decades in the past, some had it recently!”
Using a Mayo Clinic database, the researchers searched records from 1971 to 2016, finding 215 primary TKAs performed on individuals who had previously experienced septic arthritis of the native knee. They focused on survivorship that did not include infection, periprosthetic joint infection (PJI), aseptic revision, any revision, or any reoperation. These were compared to a matched cohort of patients with osteoarthritis (OA).
“There is data on this topic, but not long-term data in such a large series,” added Dr. Abdel. “Moreover, we uniquely matched these patients to routine OA patients.”
Indeed, the mean follow-up was nine years. In addition, researchers matched 1:1 on age, sex, body mass index, and surgical year to a TKA for osteoarthritis.
At 10 years, survivorships free of PJI were 90% (septic arthritis) and 99% (osteoarthritis group); survivorships free of aseptic revisions at this time point were 83% (septic arthritis) and 93% (osteoarthritis group). Survivorships free of any reoperation at 10 years were 61% (septic arthritis) and 84% (osteoarthritis group). The authors reported that when considering time from the diagnosis of native knee septic arthritis to TKA—as that increased, the relative risk of an infection decreased. The authors reported pre- and 2-year postop Knee Society scores as similar between the groups
Dr. Abdel reviewed the findings with OTW, stating, “We found that septic arthritis prior to TKA increased PJI risk by 6-fold, with a 10-year cumulative incidence of 9%. Revisions and reoperations also increased by 3-fold. We were unable to correlate the risk of PJI to timing between septic arthritis diagnosis and TKA.”
React:
Discussion
This is a fascinating development. In my practice we've seen similar outcomes with the revised protocol. The key differentiator seems to be patient selection criteria. Has anyone else noticed the correlation with BMI thresholds?
Great point. I'd push back slightly on the conclusion, the sample size in the cited study is too small to draw population-level inferences. That said, the directional signal is compelling and worth a larger RCT.
We implemented a similar approach last year. Early results are promising but we're still gathering 12-month follow-up data. Happy to share our protocol if anyone is interested.
Join the conversation
Orthopedic professionals are discussing this. Sign in and upgrade to read every comment and add your voice.