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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: Irrigation and debridement with chronic antibiotic suppression for the management of infected total knee arthroplasty

Irrigation and debridement with chronic antibiotic suppression for the management of infected total knee arthroplastyWeston JT, Watts CD, Mabry TM, Hanssen AD, Berry DJ, Abdel MP. Bone Joint J. 2018 Nov;100-B(11):1471-1476.
doi: 10.1302/0301-620X.100B11.BJJ-2018-0515.R1.

Summary and editorial by Sreeram Penna

Above study is a single center retrospective review of 134 infected total knee arthroplasty cases ( acute post-operative infection in 23 and acute hematogenous infection in 111). All patients had Irrigation debridement using normal saline and retention of components except modular poly-ethylene components which were replaced. All patients had organism-specific antibiotic followed by long-term antibiotic suppression.

The study found the infection-free survival of 72% at two years and 66% at five years. The study also showed that age less than 60 and infection with staphylococcal species was associated with increased risk of subsequent infection. Culture-negative infection cases have a lower risk of recurrence or subsequent infections. Musculoskeletal Infection Society host type, body mass index (BMI), the duration of symptoms, gender, and the presence of a monoblock tibial component did not have any influence on the outcome.

In another study Siqueira et al., has shown similar infection-free prosthetic implant survival (68.5% at five years) following irrigation and debridement, polyethylene exchange and chronic antibiotic suppression. [1] However in that study cases with staphylococcal infection fared better following chronic antibiotic suppression compared to those who did not receive suppressive antibiotics following irrigation and debridement. Similarly Rao et al., showed favorable results in 86% of patients at 5 years were able to maintain functioning prosthesis.[2] In another study on patients with osteomyelitis Nowak et al showed successful suppression of the disease. [3] In this study diabetes was associated with a high failure rate and also there was a high incidence (25%) of adverse reactions associated with suppressive antibiotics.

References

[1] Siqueira MBP, Saleh A, Klika AK, O’Rourke C, Schmitt S, Higuera CA, et al. Chronic Suppression of Periprosthetic Joint Infections with Oral Antibiotics Increases Infection-Free Survivorship. J Bone Joint Surg Am 2015;97:1220–32. doi:10.2106/JBJS.N.00999.

[2] Rao N, Crossett LS, Sinha RK, Le Frock JL. Long-term suppression of infection in total joint arthroplasty. Clin Orthop Relat Res 2003:55–60. doi:10.1097/01.blo.0000087321.60612.cf.

[3] Nowak MA, Winner JS, Beilke MA. Prolonged oral antibiotic suppression in osteomyelitis and associated outcomes in a Veterans population. Am J Health Syst Pharm 2015;72:S150-155. doi:10.2146/sp150022.