Outcome of short versus long interval in two-stage exchange for periprosthetic joint infection: a prospective cohort study

Success Rate After 2-Stage Spacer-Free Total Hip Arthroplasty Exchange and Risk Factors for Reinfection: A Prospective Cohort Study of 187 Patients

BACKGROUND

Two-stage prosthesis exchange is the treatment of choice for chronic periprosthetic joint infection (PJI) of a total hip arthroplasty (THA), especially when the bone and surrounding soft tissues are compromised or difficult-to-treat pathogens are implicated. The aims of our study were as follows: (1) to determine the outcome of 2-stage prosthesis exchange for the treatment of PJI after THA and (2) to determine the risk factors for reinfection leading to subsequent revision surgeries after reimplantation.

METHODS

We prospectively enrolled 187 consecutive patients who underwent a 2-stage THA exchange with resection arthroplasty for PJI from 2013 to 2019. The mean (± SD) duration of follow-up was 54.2 ± 24.9 months (range, 36 to 96), and the mean interval until reimplantation was 9.8 ± 8.9 weeks (range, 2 to 38). All patients remained in a spacer-free girdlestone situation between the 2 stages of treatment. Patients who remained infection-free after their 2-stage treatment were considered to have achieved treatment success.

RESULTS

The overall success rate was 85.6%. The cumulative probability of reinfection was 11.5% after one year and 14% after 2 years after reimplantation. High virulence or difficult-to-treat pathogens were significant and independent risk factors for reinfection (HR [hazard ratio] = 3.71, 95% CI [confidence interval]: 1.47 to 9.36, P = .006 and HR = 3.85, 95% CI: 1.73 to 8.57, respectively, P = .001), as was previous 2-stage hip prosthesis exchange (HR = 3.58, 95% CI: 1.33 to 9.62, P = .01). Overall reoperation and revision rates were 26.2 and 16.6%, respectively. Re-infected patients had an 80% higher probability of reoperation than noninfected ones (P < .001, log-rank = 102.6), and they were 55% more likely to undergo revision surgery during their follow-up (P < .001, log-rank = 55.4).

CONCLUSIONS

Reinfection rates after 2-stage spacer-free THA revision for PJI still remain high but are comparable to those including cement spacers. Patients who have had prior failed 2-stage implant exchanges or are infected by high-grade or difficult-to-treat pathogens are at high risk for treatment failure.

The presence of a sinus tract is associated with reinfection after two-stage revision surgery for prosthetic hip joint infection: a case-control study

BACKGROUND

Reinfection rates after two-stage revision (TSR) for prosthetic joint infection (PJI) range from 7.9 to 14%. Many factors, including sinus tracts, are associated with reinfection after this procedure. This study aimed to delineate whether the presence of sinus tract could increase reinfection rate after TSR and to investigate other potential risk factors for reinfection after TSR.

METHODS

We conducted a case-control study by retrospectively reviewing patients who underwent TSR for prosthetic hip joint infection from 2002 to 2022. The case group included patients who developed reinfection after TSR, while the control group consisted of patients who did not experience reinfection. PJI and reinfection after TSR were defined based on Delphi-based international consensus criteria. Patient demographics, past medical history, clinical manifestations, laboratory results, interval between stages, microbiological culture results were collected. Univariate analyses were utilized to assess the effect of sinus tract on reinfection and to identify other risk factors for reinfection after TSR.

RESULTS

Six patients with reinfection after TSR were included as the case group and 32 patients without reinfection were in the control group. Significant difference was observed in percentage of patients with sinus tracts between the two groups (67% in the case group versus 19% in the control group, p = 0.031, OR = 8.7). Significant difference was also found in percentage of patients with positive cultures of synovial fluid and synovium harvested during the first-stage revision between the two groups (100% in the case group versus 50% in the control group, p = 0.030). Additionally, patients in the case group had a significantly higher C-reactive protein (CRP) level prior to the second stage revision than that of patients in the control group (8.80 mg/L versus 2.36 mg/L, p = 0.005), despite normal CRP levels in all patients.

CONCLUSIONS

Our study revealed that the presence of sinus tracts could significantly increase risk of postoperative reinfection after TSR. Positive cultures during the first stage revision and elevated CRP level prior to the second stage revision could also increase the risk of reinfection after TSR. Further studies with a larger sample size are required.

TRIAL REGISTRATION

Retrospectively registered.

High and Low Dosage of Vancomycin in Polymethylmethacrylate Cements: Efficacy and Mechanical Properties

INTRODUCTION

Prosthetic joint infections (PJIs) are difficult to treat and represent a significant burden to the healthcare system. Two-stage revision surgery with placement of an antibiotic-loaded cement spacer is currently the gold standard for treatment in the United States for late-onset infections. We evaluate the efficacy of varying doses of vancomycin added to antibiotic-containing acrylic cement spacers and discuss the biomechanical and antimicrobial properties of using high versus low doses of vancomycin in cement spacers in the hip and knee.

MATERIALS AND METHODS

Commercially available Copal cement containing either gentamicin and clindamycin (G + C) or gentamicin and vancomycin (G + V) was prepared with the manual addition of low (2 g) and high (6 g) doses of vancomycin. In vitro mechanical testing was then carried out according to ISO 5833 and DIN 53435, as well as inhibition zone assays against common PJI pathogens. Additionally, inhibition zone assays were conducted on two commercially available prefabricated spacers containing gentamicin: Copal Exchange G and Cemex Spacer-K.

RESULTS

In biomechanical testing, Copal G + V with the addition of 6 g of vancomycin failed to meet the ISO standard. Copal G + C and Copal G + V with low and high dosages of vancomycin were all effective against the tested pathogens and displayed constant efficacy for a duration of 42 days. High doses of vancomycin showed significantly lower mechanical stability. Moreover, Copal Exchange G showed significantly larger inhibition zones across 42 days.

DISCUSSION

While higher concentrations of vancomycin appear to improve the antimicrobial efficacy of cement, they also reduce its mechanical stability. Despite its smoother surface, the Copal Exchange G spacer exhibits large inhibition zones after 1 day and maintains consistently large inhibition zones over 6 weeks. Thus, it may be preferred for use in two-stage revision surgery.

CONCLUSION

Copal Exchange G is more effective than Cemex Spacer K against S. aureus and E. coli. The manual addition of vancomycin to cement containing double antibiotics is very effective. The influence on ISO compression is low, the ISO bending modulus is increased, and ISO bending, DIN bending, and DIN impact, are reduced.

Evaluation of Gentamicin Release of PMMA Cements Using Different Methods: HPLC, Elution and Inhibition Zone Testing

(1) Background: There is an ongoing discussion on the elution efficacy of antibiotic-impregnated cements. Our experiments were intended to clarify if there are differences in the antibiotic elution of HPLC compared with inhibition zone testing using eluates or PMMA discs. (2) Materials and Methods: Two cement brands with different concentrations of the active ingredient were tested in antimicrobial Kirby-Bauer (disc diffusion) assays. Cement platelets were directly applied on the agar plates and their zone of inhibition was measured. In parallel, the platelets were incubated in phosphate buffered saline (PBS) and at distinct points of time transferred into new buffer. At these time points, 50 µL of the bone cement eluates was used for zone of inhibition testing. Standard gentamicin sulfate solutions served as a control in the same test setup. To verify the microbiological investigations, the antibiotic content of the eluates was also measured via high-performance liquid chromatography (HPLC). (3) Results: The experiments with cement eluates showed better differentiable results than the direct application of the cement discs. The results were also comparable to investigations with HPLC and gentamicin sulfate standard solutions. (4) Conclusions: The results of elution rates are influenced by the test system and the period of observation chosen. The microbial test systems reflect the results of HPLC to the same degree and give evidence of the efficacy of the antibiotics. The HPLC tests on eluates were more suitable in representing differences in release characteristics.

Impact of Manual Addition of Vancomycin to Polymethylmethacrylate (PMMA) Cements

(1) Background: The addition of antibiotics to bone cements is a common practice in the treatment of periprosthetic joint infections. In revision cases, the amount and type of antibiotic is often insufficient and additional antibiotics must be added. The addition, however, changes the product itself, and the surgeon becomes the "manufacturer" of the bone cement. PMMAe wished to clarify whether the admixture of antibiotics changes the mechanical stability of the bone cements used and if the added antibiotics were still functional and released in sufficient quantities. (2) Methods: We compared two industrially manufactured vancomycin-containing PMMA cements; the low-viscous VancogenX® (TECRES, Sommacampagna, Italy) and the high-viscous Copal® G+V (Heraeus Medical GmbH, Wehrheim, Germany), with two PMMA cements loaded with aminoglycosides, to which 2.0 g of vancomycin (Hexal CT1631) were manually added-the high-viscous Smartset® GHV and the medium-viscous Antibiotic Simplex with Tobramycin (antibiotic Simplex® T). Test specimens of the bone cements were used to determine mechanical stability (bending strength and bending module), and the release of the antibiotics was determined by HLPC and modified Kirby-Bauer assays. (3) Results: All tested bone cements showed an initial high release within the first hours. Repeated testing after 24 h showed a reduced efficacy of VancogenX® and Smartset® GHV in Kirby-Bauer assays. Long-time release over days showed a release of functional antimicrobial active ingredients over this period of time in anti-microbial assays, but no activity of VancogenX® from day 21 onward. No significant differences in the ISO bending modules could be detected, but in contrast to the bending module, the ISO bending strength was substantially reduced by 10-15 mPal in comparison to both cements of the reference group. The Simplex®T met just the ISO 5833; the Smartset® GHV did not after adding vancomycin. (4) Conclusions: In conclusion, the manual addition of 2 g of vancomycin to 40 g of PMMA powder is recommended for the treatment of methicillin-resistant staphylococci. Vancomycin is released over a period of 42 days with concentrations above the MIC for typical staphylococci. The mechanical properties of the PMMA just met, or did not fulfill, ISO mechanical specification. Copal® G+V showed a better elution than VancogenX® over time.

Evaluation of time to reimplantation as a risk factor in two-stage revision with static spacers for periprosthetic knee joint infection

INTRODUCTION

We investigated the time to reimplantation (TTR) during two-stage revision using static spacers with regard to treatment success and function in patients with chronic periprosthetic joint infection (PJI) of the knee.

METHODS

163 patients (median age 72 years, 72 women) who underwent two-stage exchange for chronic knee PJI between 2012 and 2020 were retrospectively analyzed (based on the 2011 Musculoskeletal Infection Society criteria). A cutoff TTR for increased risk of reinfection was identified using the maximally selected log-rank statistic. Infection control, aseptic revisions and overall survival were analyzed using Kaplan-Meier survival estimates. Adjustment for confounding factors-the Charlson Comorbidity Index (CCI) and C-reactive protein (CRP)-was done with a Cox proportional hazards model.

RESULTS

When TTR exceeded 94 days, the adjusted hazard of reinfection was increased 2.8-fold (95% CI 1.4-5.7; p = 0.0036). The reinfection-free rate was 67% (95% CI 52-79%) after 2 years and 33% (95% CI 11-57%) after 5 years for a longer TTR compared to 89% (95% CI 81-94%) and 80% (95% CI 69-87%) at 2 and 5 years, respectively, for a shorter TTR. Adjusted overall survival and number of aseptic revisions did not differ between the longer TTR and shorter TTR groups. Maximum knee flexion was 90° (IQR 84-100) for a longer TTR and 95° (IQR 90-100) for a shorter TTR (p = 0.0431), with no difference between the groups in Oxford Knee Score. Baseline characteristics were similar (body mass index, age, previous surgeries, microorganisms) for the two groups, except that there was a higher CCI (median 4 vs. 3) and higher CRP (median 3.7 vs 2.6 mg/dl) in the longer TTR group.

CONCLUSION

A long TTR is sometimes unavoidable in clinical practice, but surgeons should be aware of a potentially higher risk of reinfection.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Optimal reimplantation timing in two-stage exchange for periprosthetic joint infection: an observative cohort study in Asian population

BACKGROUND

The optimal timing for reimplantation for periprosthetic joint infection (PJI) has not been established and varies from a few weeks to several months. The aim of this study was to assess the commendable time between implant removal and reimplantation in patients who underwent two-stage exchange arthroplasty for PJI.

METHODS

We retrospectively reviewed 361 patients who were treated with two-stage exchange arthroplasty for hip and knee chronic PJI at our institution between January 2000 and December 2018. Patient characteristics, comorbidities, surgical variables, microbiology data, and time to reimplantation were recorded. All patients were followed for a minimum of one year. Treatment failure was defined by Delphi criteria. Logistic regression analyses were used to calculate survival rates and adjusted odds ratios (ORs) of treatment failure.

RESULTS

In final analysis, 27 (7.5%) had treatment failure. Factors related to treatment failure including interim spacer exchange (OR, 3.13; confidence interval (CI), 1.04-9.09, p = 0.036), higher ESR level at reimplantation (OR, 1.85; CI, 1.05-3.57; p = 0.04), and time to reimplantation (OR, 1.00; CI, 1.003-1.005, p = 0.04). Performing revision arthroplasty surgery from 16 to 20 weeks had highest successful rate. The reimplantation over 24 weeks had a lower successful rate. However, no statistical significance in comparing each interval group.

CONCLUSION

Our study emphasized the importance of timely reimplantation in achieving successful outcomes. Factors such as ESR levels, spacer exchange, and the duration of time to reimplantation influenced the likelihood of treatment failure in two-stage exchange arthroplasty for hip and knee PJI.

[Structured approach for infected prosthesis]

BACKGROUND

Endoprosthesis infections represent a major challenge for doctors and patients. Due to the increase in endoprosthesis implantation because of the increasing life expectancy, an increase in endoprosthesis infections is to be expected. In addition to infection prophylaxis, methods of infection control become highly relevant, especially in the group of geriatric and multimorbid patients. The aim is to reduce the high 1‑year mortality from prosthesis infections through a structured algorithm.

ALGORITHM FOR PROSTHESIS INFECTIONS

Prosthesis infections can basically be divided into early and late infections. According to the criteria of the International Consensus Meeting, a late infection is defined as the occurrence more than 30 days after implantation. With respect to the planned approach, the (p)TNM classification offers an orientation. In the early postoperative interval the clinical appearance is crucial as in this phase neither laboratory parameters nor an analysis of synovial fluid show a high sensitivity. It is fundamental that, apart from patients with sepsis, environment diagnostics should be initiated. If a late infection is suspected, in addition to radiological diagnostics (X-ray, skeletal scintigraphy and if necessary, computed tomography, CT), laboratory (C-reactive protein, CRP, leukocytes, blood sedimentation, and if necessary, interleukin‑6, procalcitonin) and microbiological diagnostics (arthrocentesis with synovial analysis and microbiology) are indicated; however, in addition to the arthrocentesis result, the clinical appearance is crucial in cases where an exclusion cannot be confirmed by laboratory parameters. If an infection is confirmed, the treatment depends on the spectrum of pathogens, the soft tissue situation and the comorbidities, including a multistage procedure with temporary explantation and, if necessary, implantation of an antibiotic-containing spacer is necessary. A prosthesis preservation using the debridement, antibiotics and implant retention (DAIR) regimen is only appropriate in an acute infection situation. Basically, radical surgical debridement should be carried out to reduce the pathogen load and treatment of a possible biofilm formation for both early and late infections. The subsequent antibiotic treatment (short or long interval) should be coordinated with the infectious disease specialists.

CONCLUSION

A structured approach for prosthesis infections oriented to an evidence-based algorithm provides a sufficient possibility of healing. An interdisciplinary approach involving cooperation between orthopedic and infectious disease specialists has proven to be beneficial. Surgical treatment with the aim of reducing the bacterial load by removing the biofilm with subsequent antibiotic treatment is of intrinsic importance.

Incidence, functional outcomes and cure rate of hematogenous infection in a 2,498 Total Knee Arthroplasties cohort

PURPOSE

The primary aim of the present study is to report the late acute hematogenous (LAH) prosthetic joint infection (PJI) cure rate following Total knee arthroplasty (TKA) treated by means of debridement, antibiotics, and implant retention (DAIR) in a long-term follow-up. The secondary purpose is to report the functional outcomes at that follow-up and to compare them with a non-infected group.

MATERIAL AND METHODS

This study cohort consists of 2,498 TKA performed from September 2005 to April 2010 that had a minimum follow-up of 10 years. The diagnosis of PJI and classification into LAH was done in accordance with the Zimmerli criteria. The primary outcome was the failure rate, defined as death before the end of antibiotic treatment, a further surgical intervention for treatment of infection, life-long antibiotic suppressive treatment or chronic infection. The Knee Society Score (KSS) was used to evaluate clinical outcomes.

RESULTS

Ten patients were diagnosed with acute hematogenous PJI during the study period (0.4%). All of them were managed with DAIR, which was performed by a knee surgeon and/or PJI surgeon. The failure rate was 0% at the 8.5-year (SD, 2.4) follow-up mark. The KSS score was 82.1 vs. 84.1 (p n.s.) at final follow-up.

CONCLUSION

Although the literature suggests that TKA DAIR for LAH periprosthetic joint infection is associated with high rates of failure, the results presented here suggest a high cure rate with good functional outcomes.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Clinical Outcomes and Infection Rates Following Revision Total Knee Arthroplasty: Aseptic Failure versus Septic Failure

Background

It is controversial whether revision total knee arthroplasty (TKA) due to septic failure shows inferior clinical outcomes compared with TKA due to aseptic failure. Moreover, few studies have compared the infection rates after revision TKA between aseptic and septic failure. We aimed to compare the clinical outcomes and infection rates after aseptic and septic revision TKA.

Methods

Between April 2006 and May 2019, 68 and 26 patients underwent revision TKA due to aseptic failure (aseptic group) and septic failure (septic group), respectively. The postoperative range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis index, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and infection rates were compared between the two groups.

Results

The mean follow-up durations in the aseptic and septic groups were 44.4 and 54.8 months, respectively. The septic group showed inferior postoperative ROM (124.1° and 109.4°, p = 0.004), KSKS (88.9 and 78.8, p = 0.001), and KSFS (72.8 and 59.0, p = 0.001). Three patients of aseptic group had infection. Three patients of septic group had recurred infection (same pathogen with the first infection) and 1 patient had a new infection (different pathogen). The septic group showed slightly higher but not significantly different infection rates (4.4% and 15.4%, p = 0.089).

Conclusions

Revision TKA with septic failure showed inferior postoperative clinical outcomes compared with aseptic revision surgery. A slightly higher infection rate was observed in the septic group but it was not significantly different.

Interval between two-stage exchanges: what is optimal and how do you know?

BACKGROUND

Two-stage exchange arthroplasty remains the most popular option for the treatment of chronic periprosthetic joint infection (PJI). Determining infection eradication and optimal timing of reimplantation can be challenging. Information to allow for a truly informed evidence-based decision is scarce.

METHODS

We conducted a critical review of available evidence on the presently available tests to help determine timing of reimplantation.

RESULTS

Serology is traditionally used to follow up patients after the first stage. Despite tradition mandates waiting for normal inflammatory markers, there is actually no evidence that they correlate with persistent infection. The role of synovial fluid investigation between stages is also explored. Cultures lack sensitivity and neither differential leukocyte counts nor alternative biomarkers have proven to be accurate in identifying persistent infection with a spacer in situ. We also examined the evidence regarding the optimal time interval between resection and reimplantation and whether there is evidence to support the implementation of a two week "antibiotic holiday" prior to proceeding with reimplantation. Finally, wound healing and other important factors in this setting will be discussed.

CONCLUSION

Currently there are no accurate metrics to aid in the decision on the optimal timing for reimplantation. Decision must therefore rely on the resolution of clinical signs and down trending serological and synovial markers.

Which Patients with Chronic Periprosthetic Joint Infection Are Less Suitable to Successful Two Stage Exchange Arthroplasty Surgery? A Retrospective Clinical Trial

BACKGROUND

Two-stage exchange (TSE) arthroplasty is currently considered the gold standard for chronic periprosthetic joint infections (PJIs), despite a failure rate reported in up to 10% of patients. Little is known about the risk factors that may compromise successful TSE arthroplasty management in such patients. The main purpose of the current study was to highlight the potential risk factors of patients with chronic PJIs after THA managed by implant removal, outlining the differences between reimplanted patients and those that were never reimplanted because of a non-eradicated infection.

METHODS

We conducted a retrospective observational study of patient candidates for TSE arthroplasty surgery, managed at the authors' institution, over a four-year timeframe. The data were retrieved from the hospital's information database. The enrolled population was divided into two Groups: A, reimplanted; B, non-reimplanted because of a non-eradicated infection within one year. For each Group, demographic information, PJI-related risk factors, type of pathogen and presence of single or polymicrobial infection, were collected and analyzed.

RESULTS

In total, 21 patients were included in the study, 14 patients in Group A and 7 in Group B. Major Depression (p = 0.049) and polymicrobial infection (p = 0.04) were more commonly observed in patients that were not reimplanted in the study period. No differences between the two groups were observed when other characteristics were compared.

CONCLUSIONS

Patients with major depression, or those hosting polymicrobial periprosthetic hip infections, are more susceptible to failure of TSE arthroplasty procedures for chronic PJIs, hampering THA reimplantation. Current findings may drive further research and contribute to the understanding of the role of these risk factors in chronic PJI patients.

Is long time to reimplantation a risk factor for reinfection in two-stage revision for periprosthetic infection? A systematic review of the literature

The two-stage revision arthroplasty is a common treatment option for chronic periprosthetic infection (PJI). The time to reimplantation (TTR) reported in the literature varies substantially from a few days to several hundred days. It is hypothesized that longer TTR could be associated with worse infection control after second stage. A systematic literature search was performed according to Preferred Reporting items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in Pubmed, Cochrane Library and Web of Science Core Collection in clinical studies published until January 2023. Eleven studies investigating TTR as a potential risk factor for reinfection met the inclusion criteria (ten retrospective and one prospective study, published 2012-2022). Study design and outcome measures differed notably. The cutoff points above which TTR was regarded as "long" ranged from 4 to 18 weeks. No study observed a benefit for long TTR. In all studies, similar or even better infection control was observed for short TTR. The optimal TTR, however, is not yet defined. Larger clinical studies with homogeneous patient populations and adjustment for confounding factors are needed.

A desirability of outcome ranking (DOOR) for periprosthetic joint infection - a Delphi analysis

Background: Treatment outcomes in studies on prosthetic joint infection are generally assessed using a dichotomous outcome relating to treatment success or failure. These outcome measures neither include patient-centred outcome measures including joint function and quality of life, nor do they account for adverse effects of treatment. A desirability of outcome ranking (DOOR) measure can include these factors and has previously been proposed and validated for other serious infections. We aimed to develop a novel DOOR for prosthetic joint infections (PJIs). Methods: The Delphi method was used to develop a DOOR for PJI research. An international working group of 18 clinicians (orthopaedic surgeons and infectious disease specialists) completed the Delphi process. The final DOOR comprised the dimensions established to be most important by consensus with > 75  % of participant agreement. Results: The consensus DOOR comprised four main dimensions. The primary dimension was patient-reported joint function. The secondary dimensions were infection cure and mortality. The final dimension of quality of life was selected as a tie-breaker. Discussion: A desirability of outcome ranking for periprosthetic joint infection has been proposed. It focuses on patient-centric outcome measures of joint function, cure and quality of life. This DOOR provides a multidimensional assessment to comprehensively rank outcomes when comparing treatments for prosthetic joint infection.

Treatment of Periprosthetic Joint Infection and Fracture-Related Infection With a Temporary Arthrodesis Made by PMMA-Coated Intramedullary Nails – Evaluation of Technique and Quality of Life in Implant-Free Interval

Background

Antimicrobial coating of intramedullary nails with polymethyl methacrylate (PMMA) bone cement promises infection control and stabilization for subsequent bone healing. However, when removing the implant, bone cement can debond and remain in the medullary cavity of the long bones, representing a nidus for reinfection. This work presents a technique comprising reinforcement of PMMA-coated intramedullary nails with cerclage wire to prevent such problems in patients treated for fracture-related infection (FRI) or knee periprosthetic joint infection (PJI) with a static spacer as temporary arthrodesis allowing weight-bearing in the implant-free interval. Outcomes of this surgical treatment were evaluated in terms of (i) associated complications and (ii) patient-reported quality of life.

Methods

In this retrospective case series, 20 patients with PJI (n = 14, 70%) and FRI (n = 6, 30%) treated with PMMA-coated intramedullary nails reinforced with cerclage wire between January 2021 and July 2021 were included. Quality of life during the implant-free interval was evaluated with the EQ-5D, SF-36, and an ICD-10 based psychological symptom rating and compared with previously analyzed cohorts of successfully treated PJI and FRI patients in whom eradication of infection and stable bone consolidation was achieved.

Results

Complications during the implant-free interval comprised a broken nail in one case (5.0%) and a reinfection in one case (5.0%). Coating-specific side effects and cement debonding during removal did not occur. The mean physical health component score of SF-36 was 26.1 ± 7.6, and the mean mental health component score reached a value of 47.1 ± 18.6. The mean EQ-5D index value was 0.36 ± 0.32 and the mean EQ-5D visual analogue scale rating was 47.4 ± 19.4. The scores were significantly lower than those in the successfully treated FRI cohort but not in the PJI cohort. The mean ICD-10-based symptom rating scores revealed psychological symptom burden on the depression scale and enhanced levels of anxiety in comparison with healed FRI and PJI patients.

Conclusion

Reinforcement of PMMA bone cement-coated implants seems to be a reasonable treatment option to create a temporary arthrodesis, preventing detachment of the bone cement when the implant was removed.

Level of Evidence: IV.

Antibiotic Therapy in 2-Stage Revision for Periprosthetic Joint Infection: A Systematic Review

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) are at risk for developing periprosthetic joint infection (PJI). To treat PJI, orthopaedic surgeons can perform 1-stage or 2-stage revision arthroplasty. Although 2-stage revision yields superior long-term outcomes, the optimal antibiotic therapy duration and route of administration between stages remain uncertain. In this systematic review, we aimed to identify if variations in antibiotic therapy, duration, and administration during 2-stage hip or knee revision arthroplasty affect PJI eradication rates and surgical outcome measures.

METHODS

A literature search was performed using the PubMed and Google Scholar databases to identify all original reports from January 2000 to June 2021 involving 2-stage revision arthroplasty to treat PJI. Studies were included if they specified antibiotic duration, an intravenous (IV) route of antibiotic administration, type of antibiotic, and 2-stage revision PJI eradication rate and had a mean or median follow-up of at least 2 years after the second-stage operation. Included studies were classified into 3 groups based on the length of IV antibiotic therapy after prosthesis explantation: prolonged IV antibiotic therapy of 4 to 6 weeks, shortened IV antibiotic therapy of ≤2 weeks, and shortened course of IV antibiotic therapy followed by 6 to 12 weeks of oral antibiotics.

RESULTS

Nine studies were included. Three studies utilizing a prolonged IV antibiotic therapy had PJI eradication rates of 79% to 96%. Four studies using a shortened IV antibiotic therapy showed PJI eradication rates of 88% to 100%. Finally, 2 studies utilizing a shortened course of IV antibiotic therapy with oral antibiotics had PJI eradication rates of 95% and 97%. There was no significant difference in eradication rates across IV antibiotic duration strategies, despite a diverse array of cultured microorganisms across the studies.

CONCLUSIONS

Although the numbers are small, this systematic review suggests that prolonged IV antibiotic duration, shortened IV antibiotic duration, and shortened IV antibiotic duration supplemented with oral antibiotics confer similar PJI eradication rates after hip or knee arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

What is the appropriate extended duration of antibiotic prophylaxis after two-stage revision for chronic PJI?

Aims

To explore the effect of different durations of antibiotics after stage II reimplantation on the prognosis of two-stage revision for chronic periprosthetic joint infection (PJI).

Methods

This study involved a retrospective collection of patients who underwent two-stage revision for chronic PJI and continued to use extended antibiotic prophylaxis in two regional medical centres from January 2010 to June 2018. The patients were divided into a short (≤ one month) or a long (> one month) course of treatment based on the duration of antibiotics following stage II reimplantation. The difference in the infection control rate between the two groups was compared, and prognostic factors for recurrence were analyzed.

Results

A total of 105 patients with chronic PJI were enrolled: 64 patients in the short course group and 41 patients in the long course group. For 99 of the patients, the infection was under control during a follow-up period of at least 24 months after two-stage revision. For the short course group, the mean duration of antibiotic prophylaxis after stage II reimplantation was 20.17 days (SD 5.30) and the infection control rate was 95.3%; for the long course group these were 45.02 days (SD 15.03) and 92.7%, respectively. There was no significant difference in infection control rates between the two groups (p = 0.676). Cox regression analysis found that methicillin-resistant staphylococcus infection (p = 0.015) was an independent prognostic factor for recurrence.

Conclusion

After stage II reimplantation surgery of two-stage revision for chronic PJI, extended antibiotic prophylaxis for less than one month can achieve good infection control rate.

Cite this article: Bone Joint Res 2021;10(12):790–796.

Individual Revision Knee Arthroplasty Is a Safe Limb Salvage Procedure

Introduction: Revision total knee arthroplasty after multiple pre-surgeries is challenging. Due to severe bone defects, standard implants for metaphyseal and diaphyseal anchoring may no longer be suitable. The primary aim of this case series is to evaluate the early complication rate for individual knee implants with custom-made cones and stems after two-stage revision with severe bone defects. Methods: Ten patients who were treated with custom-made 3D-printed knee revision implants were included. Inclusion criteria were a two-stage revision due to late-onset or chronic periprosthetic joint infection as well as aseptic loosening. All severe bone defects were AORI type III. All procedure-related complications were evaluated. Postoperative range of motion after one year was measured. The time between the two surgeries was evaluated. Results: The mean follow-up was 21 months (range: 12–40). The mean time between the two-stage surgeries was 71.6 days. No fractures were observed intra- and postoperatively. Two patients were revised without changing metal components due to persistent hematoma (three weeks post-surgery) and persistent PJI (three months post-surgery). The mean passive postoperative range of motion was 92° (range: 80–110°). Conclusions: Individual custom-made implants for rTKA provide a safe procedure for patients with huge bone defects after several pre-surgeries. If standard knee systems with standard cones or sleeves are not suitable anymore, custom-made treatment offers the patient the last option for limb preservation. However, this is associated with increased costs.

Development of antibiotic resistance in periprosthetic joint infection after total knee arthroplasty

AIMS

The management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. The correct antibiotic management remains elusive due to differences in epidemiology and resistance between countries, and reports in the literature. Before the efficacy of surgical treatment is investigated, it is crucial to analyze the bacterial strains causing PJI, especially for patients in whom no organisms are grown.

METHODS

A review of all revision TKAs which were undertaken between 2006 and 2018 in a tertiary referral centre was performed, including all those meeting the consensus criteria for PJI, in which organisms were identified. Using a cluster analysis, three chronological time periods were created. We then evaluated the antibiotic resistance of the identified bacteria between these three clusters and the effectiveness of our antibiotic regime.

RESULTS

We identified 129 PJIs with 161 culture identified bacteria in 97 patients. Coagulase-negative staphylococci (CNS) were identified in 46.6% cultures, followed by Staphylococcus aureus in 19.8%. The overall resistance to antibiotics did not increase significantly during the study period (p = 0.454). However, CNS resistance to teicoplanin (p < 0.001), fosfomycin (p = 0.016), and tetracycline (p = 0.014) increased significantly. Vancomycin had an 84.4% overall sensitivity and 100% CNS sensitivity and was the most effective agent.

CONCLUSION

Although we were unable to show an overall increase in antibiotic resistance in organisms that cause PJI after TKA during the study period, this was not true for CNS. It is concerning that resistance of CNS to new antibiotics, but not vancomycin, has increased in a little more than a decade. Our findings suggest that referral centres should continuously monitor their bacteriological analyses, as these have significant implications for prophylactic treatment in both primary arthroplasty and revision arthroplasty for PJI. Cite this article: Bone Joint J 2021;103-B(6 Supple A):171-176.

Comparison of elution characteristics and mechanical properties of acrylic bone cements with and without superficial vancomycin coating (SVC) in the late phase of polymerization

INTRODUCTION

Antibiotic-loaded bone cements (ALBCs) are used as spacers in two-stage revision arthroplasty for periprosthetic joint infection. We previously described a new technique applying vancomycin powder coating to custom-made cements. To our best knowledge, this method of superficial vancomycin coating (SVC) has not been assessed before. We therefore performed an in-vitro study to determine: (1) whether manually applied SVC strengthened the cements' antibiotic effect; and (2) whether the mechanical requirements for the cements were fulfilled.

HYPOTHESIS

SVC increases the antibiotic effect of cement within the first 24hours.

METHODS

Cuboid blocks were produced from two commercially available acrylic ALBCs (Palacos R+G and Copal G+V) with and without SVC. Each block was eluted in phosphate-buffered saline at 37°C. Eluates obtained at 1, 2, 3, 4, 5, 10, 15, 30 and 60minutes and 3, 6 and 24hours were evaluated against Staphylococcus aureus (Palacos, Copal) and methicillin-resistant Staphylococcus aureus (MRSA) (Copal) using zone of inhibition tests. Mechanical test results (bending modulus, bending strength) were compared to ISO requirements (≥1800MPa, ≥50MPa).

RESULTS

Palacos with SVC produced significantly greater zones of inhibition against Staphylococcus aureus than Palacos without SVC (p=0.002). Copal with SVC showed greater zones of inhibition against both Staphylococcus aureus and MRSA (p=0.002). The antibiotic effect was enhanced by SVC in both cements at every time point within 24hours. The bending modulus and bending strength of Palacos with SVC (2089±166MPa, 60.8±2.6 MPA) and Copal with SVC (2283±195MPa, 56.9±2.4MPa) were significantly above ISO requirements.

CONCLUSION

SVC boosts the antibiotic effect of ALBCs in the first 24hours, while maintaining sufficient stability. These findings endorse SVC as a promising additive in septic revision surgery.

LEVEL OF EVIDENCE

III; case control study.

Analysis of Culture Positive First and Second Stage Procedures in Periprosthetic Knee and Hip Joint Infections

BACKGROUND

A positive microbiological result at reimplantation may lead to a failed 2-stage revision arthroplasty in the treatment of periprosthetic joint infections. Little is known about changes in microbiological spectrum and resistance pattern between culture positive first and second stage procedures in revision knee and hip arthroplasty.

METHODS

Between January 2011 and December 2019, we performed 327 two-stage revision arthroplasties on 312 patients. There were 37 of 312 (11.9%) patients (20 hips/17 knees) who had a positive microbiological culture during the first and second stage procedure. We analyzed the microbiological spectrum, antimicrobial resistance pattern, and clinical outcome of culture positive first and second stage procedures as well as subsequent re-revisions.

RESULTS

Re-revision was necessary in 40.5% (15/37) of patients with culture positive first and second stage procedure at a median follow-up of 3.5 years. We found microbiological changes in 83.8% (31/37) of patients between the first and second stage and in 88.9% (8/9) between the second stage and subsequent culture positive re-revision. Polymicrobial infections were found in 21.6% (8/37) of first and in 16.2% (6/37) of second stage procedures. In 27% (10/37) of patients, microorganisms persisted between the first and second stage procedure. The antimicrobial resistance pattern changed in 60% of persistent microorganisms between the first and second stage procedure.

CONCLUSION

Changes in microbiological spectrum and resistance pattern are common between culture positive first and second stage procedures as well as subsequent re-revisions. This has to be considered in the antimicrobial treatment of periprosthetic joint infections.

[Prosthetic infections and the increasing importance of psychological comorbidities : An epidemiological analysis for Germany from 2009 through 2019]

Hintergrund

Die periprothetische Gelenkinfektion (PJI) ist eine gefürchtete Komplikation in der Orthopädie und Unfallchirurgie. Ein potenzieller Anstieg an PJI-Diagnosen, insbesondere in Verbindung mit psychologischen Komorbiditäten, kann zu einer besonderen Herausforderung für Akteure im Gesundheitswesen werden. Bisher ist die Prävalenz für Deutschland unbekannt. Dies erschwert es, den zukünftigen Behandlungsbedarf abzuschätzen und Entwicklungen vorherzusehen, die durch eine Anpassung von Präventions- und Therapiemaßnahmen beeinflusst werden können.

Ziel der Arbeit

Die vorliegende Arbeit gibt eine detaillierte Übersicht über die Epidemiologie periprothetischer Gelenkinfektionen und psychologischer Komorbiditäten.

Material und Methoden

Ein Datensatz vom Statistischen Bundesamt (Destatis) aus jährlichen, deutschlandweiten ICD-10-Diagnosekodes von 2009 bis 2019 wurde analysiert. Prävalenzraten des Kodes „T84.5 – Infektion und entzündliche Reaktion durch eine Gelenkendoprothese“ wurden nach Altersgruppe, Geschlecht und in Verbindung mit einer Nebendiagnose des Kapitels F quantifiziert und aufgeschlüsselt.

Ergebnisse

Seit 2009 steigen die PJI-Diagnosen kontinuierlich an, die Häufigkeit war im Jahr 2018 rückläufig. Im Jahr 2019 wurden 16.174 Fälle entsprechend einer Prävalenz von 23,8/100.000 Einwohner verzeichnet. Eine Entwicklung hinsichtlich mehr Diagnosen bei älteren Patienten wurde evident. Ein Viertel aller Patienten wiesen eine Nebendiagnosen im Bereich psychischer Störungen und Verhaltensstörungen auf, wobei sich die Anzahl an Patienten mit psychologischen Komorbiditäten im letzten Jahrzehnt verdoppelte.

Schlussfolgerung

Richtlinien zu Präventionsstrategien und psychologische Unterstützungsangebote sollten in der Unfallchirurgie implementiert werden.

Long-Term Patient-Related Quality of Life after Knee Periprosthetic Joint Infection

BACKGROUND

We aimed to evaluate the impact of knee periprosthetic joint infection (PJI) by assessing the patients' long-term quality of life and explicitly their psychological wellbeing after successful treatment.

METHODS

Thirty-six patients with achieved eradication of infection after knee PJI were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.

RESULTS

At a follow-up of 4.9 ± 3.5 years the mean SF-36 score was 24.82 ± 10.0 regarding the physical health component and 46.16 ± 13.3 regarding the mental health component compared to German normative values of 48.36 ± 9.4 (p < 0.001) and 50.87 ± 8.8 (p = 0.003). The mean EQ-5D index reached 0.55 ± 0.33 with an EQ-5D VAS rating of 52.14 ± 19.9 compared to reference scores of 0.891 (p < 0.001) and 68.6 ± 1.1 (p < 0.001). Mean scores of the ISR revealed the psychological symptom burden on the depression scale.

CONCLUSION

PJI patients still suffer from significantly lower quality of life compared to normative data, even years after surgically successful treatment. Future clinical studies should focus on patient-related outcome measures. Newly emerging treatment strategies, prevention methods, and interdisciplinary approaches should be implemented to improve the quality of life of PJI patients.

Fluorescent tetracycline bone labeling as an intraoperative tool to debride necrotic bone during septic hip revision: a preliminary case series

A plausible cause of persistent infection after septic hip revision may be the presence of nonviable osteomyelitic bone. Since surgical excision of these necrotic fragments is often challenging, the use of fluorescent tetracycline bone labeling (FTBL) as an intraoperative tool may pose an additional assessment aid to provide a visual index of surgical debridement. Methods: We present a single-center study performed in a university hospital from January 2018 to June 2020, in which all consecutive cases of chronic hip periprosthetic joint infection (PJI) undergoing revision using FTBL were retrospectively reviewed. In all cases, the patient was under treatment with tetracyclines at the moment of the revision surgery. During the surgery, all bone failing to fluoresce was considered nonviable and thus removed and sent for both culture and histology. Results: We include three cases in which the FTBL technique was used. In all cases, the histopathological examinations of the nonfluorescent removed bone were consistent with chronic osteomyelitis. Conclusion: The intraoperative use of FTBL successfully aided the surgeon to detect the presence of nonviable bone in all the presented cases of chronic prosthetic hip infection.

Explantation, Followed by Serial Debridement Without Antibiotic Spacers and Subsequent Revision With Cementless Components, Is Associated With High Remission Rates and Low Mortality in Periprosthetic Hip Joint Infections

BACKGROUND

In difficult-to-treat cases, it is necessary to add debridement steps in prosthesis-free interval of 2-stage exchange. We aimed to analyze the functional and clinical outcome of patients treated with a multistage exchange of total hip arthroplasty without the use of spacers, rather only cementless implants.

METHODS

Between 2009 and 2018, 84 patients (mean age: 67.3 [39-90] years) suffering chronic late-onset periprosthetic joint infection (PJI) were treated using a multistage prosthesis exchange without spacers. The mean follow-up was 70 ± 45.3 [14-210] months. The treatment included prosthesis exchange and at least 1 additional revision step before a reimplantation, owing to ongoing acute infection in the prosthesis-free interval. High-efficiency antimicrobial therapy was administered in between, which was discontinued after cementless revision implantation.

RESULTS

The mean number of revisions between explantation and implantation was 2.6 (1-9). The most common microorganism was Staphylococcus epidermidis (53.6%) followed by Staphylococcus aureus (16.7%) and Cutibacterium acnes (11.9%). The bacterial load was more than one bacterium per patient in 38% of cases. All patients could be treated using a cementless implant. PJI remission was achieved in 92% of cases. Overall, 9 prostheses (11%) were replaced because of an ongoing PJI or fracture. The mean modified Harrison Hip Score was 63.4 (22-88) points. No patient died.

CONCLUSION

Multistage total hip arthroplasty exchange showed high remission rates and low mortality in difficult-to-treat cases. Spacer-free and multistage treatment had no negative effect on the success rate or functional outcome, consistent with the results of published 2-stage exchange studies. Implantation of an uncemented press-fit prosthesis was possible in all patients with no elevated periprosthetic fracture rate.

Clinical use of linezolid in periprosthetic joint infections - a systematic review

Introduction: The most common causative organism in periprosthetic joint infections (PJIs) is Gram-positive bacteria that are increasingly drug resistant. In these cases the use of linezolid may be warranted. However, there are conflicting reports regarding its role in antibiotic treatment of PJIs. The aim of this review is to gather and analyze clinical results and treatment details on linezolid in patients with PJIs. Methods: In August 2019, a comprehensive literature search using MEDLINE (Pubmed and Ovid) and Cochrane Library was performed. A total of 504 records were screened, and a total of 16 studies including 372 patients treated with linezolid for a PJI were included in this review based on the PRISMA criteria and after quality analysis using the MINOR score and Newcastle–Ottawa scale, as well as assessing level of evidence. Pooling analysis as well as descriptive analysis was performed. Results: Based on the results from the studies included, infection control was achieved in 80 % (range 30 %–100 %) of patients after a mean follow-up period of 25 (range 2–66) months. The mean duration of treatment was 58 d intravenous and orally at a median dose of 600 mg bis in die (b.i.d.) (range 400–900 b.i.d.). A combination therapy with rifampicin was used in 53 % of patients. MRSA (methicillin-resistant Staphylococcus aureus) infections were present in 29 % and resistant CoNS (coagulase-negative Staphylococcus) in 46 %. Adverse effects occurred in 33 % of cases, mostly anemia, thrombocytopenia and gastrointestinal complaints leading to treatment discontinuation in 9 %. However, great heterogeneity was found with respect to surgical treatment, diagnosis of infection and indication for linezolid. Discussion: Linezolid is an appropriate option for treatment of resistant Gram-positive organisms in PJIs. Most commonly 600 mg b.i.d. is used, and a combination with rifampicin appears feasible although one must consider individual increases in doses in these cases. However, adverse effects are common and there are limited data for long-term use and optimal antibiotic combinations or individual doses.

How to manage treatment failure in prosthetic joint infection

BACKGROUND

Management for prosthetic joint infections remains a challenging area for both infectious diseases and orthopaedic surgery, particularly in the setting of treatment failure. This is compounded by a lack of level 1 evidence to guide approaches. The optimal management of prosthetic joint infections requires a multi-disciplinary approach combined with shared decision making with the patient.

AIMS

This article describes the approach to prosthetic joint infections in the setting of treatment failure.

SOURCES

Narrative review based on literature review from PubMed. There was no time limit on the studies included. In addition, the reference list for included studies were reviewed for literature saturation with manual searching of clinical guidelines. Management approaches described incorporate evidence- and eminence-based recommendations from expert guidelines and clinical studies, where applicable.

CONTENT

The surgical and antimicrobial approaches for prosthetic joint infections are described for first-line treatment of prosthetic joint infections and approaches in the event of treatment failure. Management approaches are based on an understanding of the role the biofilm plays in the pathogenesis of prosthetic joint infections. The management of these infections aims to fulfil two key goals: to eradicate the biofilm-associated microorganisms and, to maintain a functional joint and quality of life. In treatment failure, these goals are not always feasible, and the role of the multi-disciplinary team and shared-decision making are prominent.

IMPLICATIONS

Prosthetic joint surgery is a high-volume surgery, and the demand for this surgery is continually increasing. With this, the number of infections requiring expert care will also increase. Eminence-based management approaches have been established to guide treatment failure until knowledge gaps in optimal management are addressed by well-designed, clinical trials.

Clinical Characteristics, Etiology, and Initial Management Strategy of Newly Diagnosed Periprosthetic Joint Infection: A Multicenter, Prospective Observational Cohort Study of 783 Patients

Background

Periprosthetic joint infection (PJI) is a devastating complication of joint replacement surgery. Most observational studies of PJI are retrospective or single-center, and reported management approaches and outcomes vary widely. We hypothesized that there would be substantial heterogeneity in PJI management and that most PJIs would present as late acute infections occurring as a consequence of bloodstream infections.

Methods

The Prosthetic joint Infection in Australia and New Zealand, Observational (PIANO) study is a prospective study at 27 hospitals. From July 2014 through December 2017, we enrolled all adults with a newly diagnosed PJI of a large joint. We collected data on demographics, microbiology, and surgical and antibiotic management over the first 3 months postpresentation.

Results

We enrolled 783 patients (427 knee, 323 hip, 25 shoulder, 6 elbow, and 2 ankle). The mode of presentation was late acute (>30 days postimplantation and <7 days of symptoms; 351, 45%), followed by early (≤30 days postimplantation; 196, 25%) and chronic (>30 days postimplantation with ≥30 days of symptoms; 148, 19%). Debridement, antibiotics, irrigation, and implant retention constituted the commonest initial management approach (565, 72%), but debridement was moderate or less in 142 (25%) and the polyethylene liner was not exchanged in 104 (23%).

Conclusions

In contrast to most studies, late acute infection was the most common mode of presentation, likely reflecting hematogenous seeding. Management was heterogeneous, reflecting the poor evidence base and the need for randomized controlled trials.

Functional recovery after two-stage short-interval revision of chronic periprosthetic knee joint infection

PURPOSE

The objective of this study was the functional recovery analysis of patients treated in two-staged short-interval procedure due to knee periprosthetic joint infection (PJI).

MATERIALS AND METHODS

In the period from January 2015 to December 2018, a two-stage short-interval revision TKA was performed in 35 patients with PJI. Synovial fluid analysis, tissue samples and sonication method were used to diagnose PJI. Active range of motion (AROM) and Hospital for Special Surgery (HSS) score were analysed.

RESULTS

Functional recovery analysis demonstrated higher AROM and HSS score after the revision TKA. Median pre-operative active flexion motion was 80° with full active extension, and median post-operative active flexion was 105° with full active extension. Median HSS score pre-operatively was 22 and post-operatively was 48. Isolated bacteria in both tissue and sonication fluid were S. epidermidis (27%) and other coagulase-negative staphylococci (25%), followed by S. aureus (10%).

CONCLUSION

Two-stage short-interval procedure of chronic knee PJI significantly improved functional status of patients in a short period of time. Thirty three out of 35 patients returned to their everyday activities. Adequate surgical technique and implant selection can lead to satisfactory functional outcome.

Enterococcal periprosthetic joint infection: clinical and microbiological findings from an 8-year retrospective cohort study

Background

Treatment of enterococcal periprosthetic joint infections (PJI) is challenging due to non-standardized management strategies and lack of biofilm-active antibiotics. The optimal surgical and antimicrobial therapy are unknown. Therefore, we evaluated characteristics and outcome of enterococcal PJI.

Methods

Consecutive patients with enterococcal PJI from two specialized orthopedic institutions were retrospectively analyzed. Both institutions are following the same diagnostic and treatment concepts. The probability of relapse-free survival was estimated using Kaplan-Meier survival curves and compared by log-rank test. Treatment success was defined by absence of relapse or persistence of PJI due to enterococci or death related to enterococcal PJI. Clinical success was defined by the infection-free status, no subsequent surgical intervention for persistent or perioperative infection after re-implantation and no PJI-related death within 3 months.

Results

Included were 75 enterococcal PJI episodes, involving 41 hip, 30 knee, 2 elbow and 2 shoulder prostheses. PJI occurred postoperatively in 61 episodes (81%), hematogenously in 13 (17%) and by contiguous spread in one. E. faecalis grew in 64 episodes, E. faecium in 10 and E. casseliflavus in one episode(s). Additional microorganism(s) were isolated in 38 patients (51%). Enterococci were susceptible to vancomycin in 73 of 75 isolates (97%), to daptomycin in all 75 isolates, and to fosfomycin in 21 of 22 isolates (96%). The outcome data was available for 66 patients (88%). The treatment success after 3 years was 83.7% (95% confidence interval [CI]; 76.1–96.7%) and the clinical success was 67.5% (95% CI; 57.3–80.8%). In 11 patients (17%), a new PJI episode caused by a different pathogen occurred. All failures occurred within 3 years after surgery.

Conclusion

About half of enterococcal PJI were polymicrobial infections. The treatment success was high (84%). All treatment failures occurred within the first 3 years after revision surgery. Interestingly, 17% of patients experienced a new PJI caused by another pathogen at a later stage.

Trial registration

The study was retrospectively registered with the public clinical trial identification NCT0253022 at https://www.clinicaltrials.gov on 15 July 2015.

Complications of Resection Arthroplasty in Two-Stage Revision for the Treatment of Periprosthetic Hip Joint Infection

Little data is available regarding complications associated with resection arthroplasty in the treatment of hip periprosthetic joint infection (PJI). We assessed complications during and after two-stage revision using resection arthroplasty. In this retrospective study, 93 patients undergoing resection arthroplasty for hip PJI were included. Patients were assigned to a prosthesis-free interval of ≤10 weeks (group 1; 49 patients) or >10 weeks (group 2; 44 patients). The complication rates between groups were compared using the chi-squared test. The revision-free and infection-free survival was estimated using a Kaplan-Meier survival analysis. Seventy-one patients (76%) experienced at least one local complication (overall 146 complications). Common complications were blood loss during reimplantation (n = 25) or during explantation (n = 23), persistent infection (n = 16), leg length discrepancy (n = 13) and reinfection (n = 9). Patients in group 1 experienced less complications after reimplantation (p = 0.012). With increasing severity of acetabular bone defects, higher incidence of complications (p = 0.008), periprosthetic bone fractures (p = 0.05) and blood loss (p = 0.039) was observed. The infection-free survival rate at 24 months was 93.9% in group 1 and 85.9% in group 2. The indication for resection arthroplasty needs to be evaluated carefully, considering the high rate of complications and reduced mobility, particularly if longer prosthesis-free intervals are used.

Twenty common errors in the diagnosis and treatment of periprosthetic joint infection

Background

Misconceptions and errors in the management of periprosthetic joint infection (PJI) can compromise the treatment success. The goal of this paper is to systematically describe twenty common mistakes in the diagnosis and management of PJI, to help surgeons avoid these pitfalls.

Materials and methods

Common diagnostic and treatment errors are described, analyzed and interpreted.

Results

Diagnostic errors include the use of serum inflammatory biomarkers (such as C-reactive protein) to rule out PJI, incomplete evaluation of joint aspirate, and suboptimal microbiological procedures (such as using swabs or collection of insufficient number of periprosthetic samples). Further errors are missing possible sources of distant infection in hematogenous PJI or overreliance on suboptimal diagnostic criteria which can hinder or delay the diagnosis of PJI or mislabel infections as aseptic failure. Insufficient surgical treatment or inadequate antibiotic treatment are further reasons for treatment failure and emergence of antimicrobial resistance. Finally, wrong surgical indication, both underdebridement and overdebridement or failure to individualize treatment can jeopardize surgical results.

Conclusion

Multidisciplinary teamwork with infectious disease specialists and microbiologists in collaboration with orthopedic surgeons have a synergistic effect on the management of PJI. An awareness of the possible pitfalls can improve diagnosis and treatment results.