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Paper of the week: Risk Factors for Failure After 1-Stage Exchange Total Knee Arthroplasty in the Management of Periprosthetic Joint Infection.

Paper of the week: Risk Factors for Failure After 1-Stage Exchange Total Knee Arthroplasty in the Management of Periprosthetic Joint Infection. Citak M, Friedenstab J, Abdelaziz H, Suero EM, Zahar A, Salber J, Gehrke T. J Bone Joint Surg Am. 2019 Jun 19;101(12):1061-1069. doi: 10.2106/JBJS.18.00947.

Summary by Dr Sreeram Penna

In this case control study researchers analyzed the causes of and risk factors for failure following 1-stage exchange total knee arthroplasty. In this study cases consist of total knee joints treated for periprosthetic joint infection with 1 stage exchange arthroplasty that subsequently had revision procedures. These were matched with controls who had 1 stage exchange arthroplasty that did not require further revision. Cases included 91 patients, of these patients reason for failure was infection (n = 42), aseptic loosening (n = 37), patellar problems (n=3), periprosthetic fracture (n=3) and knee dislocation (n=1). Risk factors associated with reoperation in 1 stage procedure included weight more than 100, history of DVT, more than 4 prior procedures, history of poly microbial infection, prior one stage exchange, prior two stage exchange, extensive osseous defects requiring tantalum cones, surgical time more than 4 hours, persistent wound drainage, and isolation of enterococcus. Further bivariate analysis of infection subgroup showed all above risk factors except extensive osseous defect. It also identified two additional risk factors including isolation of streptococcus and wound revision due to healing disorders. Please see table below for odds ratios (OR).

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Paper of the week: Continuous Antibiotic Therapy Can Reduce Recurrence of Prosthetic Joint Infection in Patients Undergoing 2-Stage Exchange.

Paper of the week: Continuous Antibiotic Therapy Can Reduce Recurrence of Prosthetic Joint Infection in Patients Undergoing 2-Stage Exchange. Ascione T, Balato G, Mariconda M, Rotondo R, Baldini A, Pagliano P. J Arthroplasty. 2018 Dec 20. pii: S0883-5403(18)31218-X. doi: 10.1016/j.arth.2018.12.017

Summary and editorial by Sreeram Penna

The main aim of this observational cohort study is to compare infection recurrence in patients who had continuous antibiotic therapy versus antibiotic holiday period prior to reimplantation following two-stage revision for periprosthetic joint infection (PJI). Researchers also analyzed factors associated with poor outcome in patients undergoing two-stage revision procedure who had normalization of serum markers and improvement of symptoms prior to reimplantation. All patients in the study had two weeks of intravenous antibiotics followed by six weeks targeted oral antibiotics.

A total of 196 patients were included in the study. 110 patients had continuous antibiotic therapy prior to reimplantation, and 82 patients had an antibiotic holiday. Overall 169 (86%) patients had a favorable outcome, and 14% had PJI recurrence. In the group that had continuous antibiotics, the cure rate was 91% (104/110) versus 79% (65/82) in patients who had antibiotic holiday prior to reimplantation, and this result was statistically significant (p=0.029). Further analysis revealed that the cure rate was significantly (p=0.02) better in immunocompromised patients receiving continuous antibiotics (41/46, 89%) versus patients who had an antibiotic holiday (20/31, 65%). Immunocompromised patients included those with diabetes, liver cirrhosis, autoimmune disease, and those who were on immunosuppressive medication.

The study also found that serum markers, body mass index, and positive microbiology at reimplantation did not affect the overall outcome. Immunocompromised patients and culture-negative cases were associated with poor outcome following a two-stage procedure. Of the culture positive cases, patients with Gram-positive cultures had a better outcome compared to Gram-negative cases. In another study done by Herman et al., researchers found that CRP and other classic markers like synovial white cell count and PMN % performed poorly in identifying residual infection prior to reimplantation.[1] In addition as researchers noted in this study that antibiotic holiday was shown to have poor outcomes especially in immunocompromised patients, as conditions for bacterial regrowth are still present. This paper puts forth an important argument to continue antibiotic treatment until reimplantation. However further research is needed to identify the optimal time and predictive factors to calculate the success of reimplantation.

References

[1] Herman A, Albers A, Garbuz DS, Duncan CP, Masri BA. Classic Markers for Infection Perform Poorly in Predicting Residual Infection Prior to Reimplantation. Orthopedics 2019;42:34–40. doi:10.3928/01477447-20190103-03.

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Paper of the week: Mortality During Total Hip Periprosthetic Joint Infection.

Paper of the week. Mortality During Total Hip Periprosthetic Joint Infection. Natsuhara KM, Shelton TJ, Meehan JP, Lum ZC. J Arthroplasty. 2018 Dec 24. pii: S0883-5403(18)31225-7. doi: 10.1016/j.arth.2018.12.024.

Summary and Editorial by Sreeram Penna

This publication is a systemic review of the literature and its main aim is to identify the mortality rate following two-stage procedure for total hip periprosthetic joint infection (PJI). The review included 23 studies on 19169 patients. Average weighted age of the patients was 65 years and average follow up was 3.7 years. Researchers showed that average overall mortality after total hip PJI was 5.4% and mortality per year increased 4.22% year after year following total hip PJI. This data translates to around 21.12% five-year mortality for total hip PJI. This pooled data result is similar to big studies included in this review. [1,2] Among the issues highlighted by researchers include underreported mortality and inadequate follow up in the studies included in the systemic review. Researchers also noticed no change in trends of mortality rate over time. Although some studies show that a substantial decline in PJI mortality rate without changes in PJI risk over time.[3] Overall this research highlights fact that PJI has considerable mortality and morbidity and considerable research needed to be done in this respect.

References

[1] Zmistowski B, Karam JA, Durinka JB, Casper DS, Parvizi J. Periprosthetic Joint Infection Increases the Risk of One-Year Mortality. The Journal of Bone and Joint Surgery-American Volume 2013;95:2177–2184. doi:10.2106/JBJS.L.00789.

[2] Cancienne JM, Werner BC, Bolarinwa SA, Browne JA. Removal of an Infected Total Hip Arthroplasty: Risk Factors for Repeat Debridement, Long-term Spacer Retention, and Mortality. J Arthroplasty 2017;32:2519–22. doi:10.1016/j.arth.2017.03.018.

[3] Kurtz SM, Lau EC, Son M-S, Chang ET, Zimmerli W, Parvizi J. Are We Winning or Losing the Battle With Periprosthetic Joint Infection: Trends in Periprosthetic Joint Infection and Mortality Risk for the Medicare Population. J Arthroplasty 2018;33:3238–45. doi:10.1016/j.arth.2018.05.042.