Factors affecting outcome in the treatment of streptococcal periprosthetic joint infections: results from a single-centre retrospective cohort study

Periprosthetic shoulder infection management: one-stage should be the way: a systematic review and meta-analysis

BACKGROUND

There is still no consensus among surgeons on whether to perform a 1- or 2-stage surgical revision in infected shoulder arthroplasties. The aim of this systematic review and meta-analysis is to rigorously synthesize published studies evaluating the clinical outcomes, recurrence of infection, and other clinical complications in order to discuss which is the best strategy for treating periprosthetic joint infection after shoulder arthroplasty.

METHODS

Upon research using the PubMed, Scopus, and Web of Science databases, in November 2022, studies that presented 1- or 2-stage surgical revision as a treatment for periprosthetic joint infection after shoulder arthroplasty and assessed the reinfection rate on these patients, as well as other clinical outcomes, with a minimum follow-up of 12 months, were included. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) score. Reinfection and complication rates were extracted, and pooled estimates were calculated using the random-effect model.

RESULTS

After careful screening, 44 studies were included, 5 reporting on 1-stage and 30 on 2-stage revisions and 9 assessing both strategies. A total of 185 shoulders were reported in 1-stage revision studies, whereas 526 shoulders were reported in 2-stage revision studies. The overall pooled random-effects reinfection rate was 6.68% (95% confidence interval [CI]: 3.76-10.13), with low heterogeneity (I2 = 28%, P = .03). One-stage revision showed a reinfection rate of 1.14% (95% CI: 0.00-4.88), whereas 2-stage revision analysis revealed a reinfection rate of 8.81% (95% CI: 4.96-13.33). There were significant statistical differences between 1- and 2-stage reinfection rates (P = .04). The overall pooled rate for other clinical complications was 16.76% (95% CI: 9.49-25.15), with high heterogeneity (I2 = 70%, P < .01). One-stage revision had a complication rate of 6.11% (95% CI: 1.58-12.39), whereas the 2-stage revision complication rate was 21.26% (95% CI: 11.51-32.54). This difference was statistically significant (P = .03).

CONCLUSIONS

This is the first systematic review and meta-analysis showing significant statistical differences between 1- and 2-stage surgical revision in infected shoulder arthroplasties. Provided the right conditions exist, 1-stage revision shows better results in infection control, with lower clinical complications and possible better clinical outcomes.

Periprosthetic Joint Infection Diagnosis: A Narrative Review

Replacement of native joints aims to restore patients' quality of life by relieving pain and improving joint function. While periprosthetic joint infection (PJI) affects a small percentage of patients, with an estimated incidence of 1-9% following primary total joint replacement, this postoperative complication necessitates a lengthy hospitalisation, extended antibiotic treatment and further surgery. It is highlighted that establishing the correct diagnosis of periprosthetic infections is critical in order for clinicians to avoid unnecessary treatments in patients with aseptic failure. Of note, the PJI diagnosis could not purely rely upon clinical manifestations given the fact that heterogeneity in host factors (e.g., age and comorbidities), variability in infection period, difference in anatomical location of the involved joint and discrepancies in pathogenicity/virulence of the causative organisms may confound the clinical picture. Furthermore, intra-operative contamination is considered to be the main culprit that can result in early or delayed infection, with the hematogenous spread being the most prevalent mode. To elaborate, early and hematogenous infections often start suddenly, whereas chronic late infections are induced by less virulent bacteria and tend to manifest in a more quiescent manner. Last but not least, viruses and fungal microorganisms exert a role in PJI pathogenesis.

Genomic characterization of beta-haemolytic streptococci isolated from prosthetic joint infections

Prosthetic joint infection (PJI) is an increasing concern for the medical profession, as higher numbers of arthroplasty surgeries lead to rising PJI-related costs. Streptococcal PJIs constitute approximately 10% of PJIs, but their genetic features and characteristics remain largely unexplored. Little is known about antimicrobial resistance (AMR) rates, whether some sequence types (ST) dominate, and whether certain virulence-associated genes are overrepresented. We used whole-genome sequencing of Streptococcus dysgalactiae (n = 22), Streptococcus agalactiae (n = 10) and S. pyogenes (n = 1) to elicit genomic data on 33 beta-haemolytic streptococci isolated from PJIs in Region Örebro county, Sweden. Relatedness was inferred based on single nucleotide polymorphisms in S. dysgalactiae and S. agalactiae. The genomic data were screened for virulence-associated genes available in the Virulence Factor Database. All isolates were screened for both phenotypic and genotypic resistance. The S. dysgalactiae and S. agalactiae isolates were genetically diverse, although 32% of S. dysgalactiae isolates (n = 7) were ST20. The speS and PI-2A genes were less represented in these isolates among virulence-associated genes, and AMR was more frequently observed in S. agalactiae. We conclude that PJIs caused by beta-haemolytic streptococci are not dominated by genetically similar beta-haemolytic streptococci. There were distinct inter-species differences in AMR between S. agalactiae and S. dysgalactiae.

The Use of Rifampin in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis of Comparative Studies

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication of total joint arthroplasty (TJA). Rifampin is an antibiotic with the ability to penetrate bacterial biofilms, and thus has been considered as a potentially important adjunct in the prevention and treatment of PJI. The aim of this systematic review is to evaluate and summarize the use of rifampin in TJA, particularly in the context of PJI.

METHODS

A literature search of all relevant electronic databases was performed. All comparative studies assessing the use of rifampin in the context of TJA were included. Descriptive data are reported, and a meta-analysis was performed using all studies which compared the addition of rifampin to standard care in treating PJI.

RESULTS

A total of 33 studies met inclusion criteria. A meta-analysis of 22 studies comparing the addition of rifampin to standard care for treating PJI found a significant reduction in failure rates (26.0% vs 35.9%; odds ratio 0.61, 95% confidence interval 0.43-0.86). The protective effect of rifampin was maintained in studies which included exchange arthroplasty as a treatment strategy, but not in studies only using an implant retention strategy. Among studies reporting adverse events of rifampin, there was a 20.5% adverse event rate.

CONCLUSION

Overall, rifampin appears to confer a protective effect against treatment failure following PJI. This treatment effect is particularly pronounced in the context of exchange arthroplasty. Further high-level evidence is needed to clarify the exact indications and doses of rifampin which can most effectively act as an adjunct in the treatment of PJI.

LEVEL OF EVIDENCE

Level III, Systematic Review and Meta-Analysis of Level I-III Studies.

In Vitro Activity of Rifampin, Rifabutin, and Rifapentine against Enterococci and Streptococci from Periprosthetic Joint Infection

After staphylococci, streptococci and enterococci are the most frequent causes of periprosthetic joint infection (PJI). MICs and minimum biofilm bactericidal concentrations of rifampin, rifabutin, and rifapentine were determined for 67 enterococcal and 59 streptococcal PJI isolates. Eighty-eight isolates had rifampin MICs of ≤1 μg/ml, among which rifabutin and rifapentine MICs were ≤ 8 and ≤4 μg/ml, respectively. There was low rifamycin in vitro antibiofilm activity except for a subset of Streptococcus mitis group isolates.

IMPORTANCE Rifampin is an antibiotic with antistaphylococcal biofilm activity used in the management of staphylococcal periprosthetic joint infection with irrigation and debridement with component retention; some patients are unable to receive rifampin due to drug interactions or intolerance. We recently showed rifabutin and rifapentine to have in vitro activity against planktonic and biofilm states of rifampin-susceptible periprosthetic joint infection-associated staphylococci. After staphylococci, streptococci and enterococci combined are the most common causes of periprosthetic joint infection. Here, we investigated the in vitro antibiofilm activity of rifampin, rifabutin, and rifapentine against 126 Streptococcus and Enterococcus periprosthetic joint infection isolates. In contrast to our prior findings with staphylococcal biofilms, there was low antibiofilm activity of rifampin, rifabutin, and rifapentine against PJI-associated streptococci and enterococci, apart from some Streptococcus mitis group isolates.