Role of Routine Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention for Acute Periprosthetic Joint Infections.

Background: The first-line management strategy for acute periprosthetic joint infections (PJIs) is debridement, antibiotics, and implant retention (DAIR). Suppressive antibiotic therapy (SAT) after DAIR is proposed to improve outcomes, yet its efficacy remains under scrutiny. Methods: We conducted a multicenter retrospective study in patients with acute PJI of the hip or knee who were treated with DAIR in centers from Europe and the United States. We analyzed the effect of SAT using a Cox model landmarked at 12 weeks. The primary covariate of interest was SAT, which was analyzed as a time-varying covariate. Patients who experienced treatment failure or were lost to follow-up within 12 weeks were excluded from the analysis. Results: The study included 510 patients with 66 treatment failures with a median follow-up of 801 days. We did not find a statistically significant association between SAT and treatment failure (hazard ratio, 1.37; 95% CI, .79-2.39; P = .27). Subgroup analyses for joint, country cohort, and type of infection (early or late acute) did not show benefit for SAT. Secondary analysis of country cohorts showed a trend toward benefit for the US cohort (hazard ratio, 0.36; 95% CI, .11-1.15; P = .09), which also had the highest risk of treatment failure. Conclusions: The utility of routine SAT as a strategy for enhancing DAIR's success in acute PJI remains uncertain. Our results suggest that SAT's benefits might be restricted to specific groups of patients, underscoring the need for randomized controlled trials. Identifying patients most likely to benefit from SAT should be a priority in future studies.

Characteristics and management of periprosthetic joint infections caused by rapidly growing mycobacteria: a retrospective study and a review of the literature.

Background: Periprosthetic joint infection (PJI) following total joint arthroplasty is a serious complication associated with significant morbidity. While Gram-positive cocci are the predominant causative organisms, PJIs caused by rapidly growing mycobacteria (RGM) have been reported, albeit at a lower frequency. This study aimed to investigate the characteristics and management of PJI caused by RGM. Methods: A retrospective review was conducted using an institutional PJI database to identify patients diagnosed with PJI due to RGM from January 2010 to December 2021. Clinical data, including demographics, symptoms, comorbidity information, laboratory parameters, surgical procedures, medical treatment and outcomes, were collected and analyzed. Results: A total of eight patients were identified with PJI caused by RGM during the study period. The median age was 66 years old, and most cases occurred in patients with total knee arthroplasty (n=6). The isolated RGM species included Mycobacterium abscessus (three cases), M. fortuitum (three cases), and one case each of M. immunogenum and M. mageritense. Surgical debridement was performed in all cases, with six patients undergoing two-stage revision and two patients requiring amputation. Combination antimicrobial therapy was administered based on antimicrobial susceptibility testing, and the median duration of treatment was 7.5 months. Adverse events related to therapy occurred in 75 % of cases. No relapses were observed during the median follow-up period of 39.6 months. Conclusions: PJI caused by RGM is a rare complication of total joint arthroplasty. Surgical debridement and combination antimicrobial therapy are the mainstays of treatment. Although clinical cure rates are high, amputation may be required in severe cases.

Defeating the Hidden Foe: Antibiotic Therapy and Clinical Outcomes of Cutibacterium acnes Spinal Implant Infections.

Background: Cutibacterium acnes can cause spinal implant infections. However, little is known about the optimal medical management and outcomes of C. acnes spinal implant infections (CSII). Our study aims to describe the management of patients with CSII and evaluate the clinical outcomes. Methods: We performed a retrospective cohort study of patients aged 18 years or older who underwent spinal fusion surgery with instrumentation between January 1, 2011, and December 31, 2020, and whose intraoperative cultures were positive for C. acnes. The primary outcome was treatment failure based on subsequent recurrence, infection with another organism, or unplanned surgery secondary to infection. Results: There were 55 patients with a median follow-up (interquartile range) of 2 (1.2-2.0) years. Overall, there were 6 treatment failures over 85.8 total person-years, for an annual rate of 7.0% (95% CI, 2.6%-15.2%). Systemic antibiotic treatment was given to 74.5% (n = 41) of patients for a median duration of 352 days. In the subgroup treated with systemic antibiotics, there were 4 treatment failures (annual rate, 6.3%; 95% CI, 1.7%-16.2%), all of which occurred while on antibiotic therapy. Two failures occurred in the subgroup without antibiotic treatment (annual rate, 8.8%; 95% CI, 1.1%-31.8%). Conclusions: Our study found that the estimated annual treatment failure rate was slightly higher among patients who did not receive antibiotics. Of the 6 failures observed, 4 had recurrence of C. acnes either on initial or subsequent treatment failures. More studies are warranted to determine the optimal duration of therapy for CSII.

Taking the route less traveled: on the way to COpAT.

Antimicrobial therapy is an essential practice within medicine. Over the last 4 years, complex outpatient antimicrobial therapy (COpAT) with oral antimicrobials has become a rapidly developing area of practice and is non-inferior to outpatient parenteral antimicrobial therapy (OPAT) in certain infectious syndromes. Currently, the available literature does not describe the implementation of oral antimicrobials within the current outpatient antimicrobial therapy process. Throughout this article, the authors present a review of current literature, a proposed definition of COpAT and offer methods readers can utilize to implement an integrated COpAT/OPAT program with oral antimicrobial-specific monitoring within their current practice.

Sex-specific analysis of clinical features and outcomes in staphylococcal periprosthetic joint infections managed with two-stage exchange arthroplasty.

Background: Differences in susceptibility and response to infection between males and females are well established. Despite this, sex-specific analyses are under-reported in the medical literature, and there is a paucity of literature looking at differences between male and female patients with periprosthetic joint infection (PJI). Whether there are sex-specific differences in presentation, treatment tolerability, and outcomes in PJI has not been widely evaluated. Methods: We undertook a retrospective case-matched analysis of patients with staphylococcal PJI managed with two-stage exchange arthroplasty. To control for differences other than sex which may influence outcome or presentation, males and females were matched for age group, causative organism category (coagulase-negative staphylococci vs. Staphylococcus aureus), and joint involved (hip vs. knee). Results: We identified 156 patients in 78 pairs of males and females who were successfully matched. There were no significant baseline differences by sex, except for greater use of chronic immunosuppression among females (16.4 % vs. 4.1 %; p = 0.012 ). We did not detect any statistically significant differences in outcomes between the two groups. Among the 156 matched patients, 16 recurrent infections occurred during a median follow-up time of 2.9 (IQR 1.5-5.3) years. The 3-year cumulative incidence of relapse was 16.1 % for females, compared with 8.8 % for males ( p = 0.434 ). Conclusions: Success rates for PJI treated with two-stage exchange arthroplasty are high, consistent with previously reported literature. This retrospective case-matched study did not detect a significant difference in outcome between males and females with staphylococcal PJI who underwent two-stage exchange arthroplasty.

Chronic Q fever presenting as bilateral extensor tenosynovitis: a case report and review of the literature.

Musculoskeletal manifestations of Coxiella burnetii are rare. We describe an elderly, immunosuppressed male with bilateral Coxiella burnetii extensor tenosynovitis treated with incision and debridement and chronic doxycycline and hydroxychloroquine. Additionally, disease etiology, risk factors, pertinent features of the history, testing modalities, and treatment strategies of musculoskeletal Q fever are reviewed.

Deep Brain Stimulator Device Infection: The Mayo Clinic Rochester Experience.

Background: Deep brain stimulator (DBS)-related infection is a recognized complication that may significantly alter the course of DBS therapy. We describe the Mayo Clinic Rochester experience with DBS-related infections. Methods: This was a retrospective study of all adults (≥18 years old) who underwent DBS-related procedures between 2000 and 2020 at the Mayo Clinic Rochester. Results: There were 1087 patients who underwent 1896 procedures. Infection occurred in 57/1112 (5%) primary DBS implantations and 16/784 (2%) revision surgeries. The median time to infection (interquartile range) was 2.1 (0.9-6.9) months. The odds of infection were higher with longer operative length (P = .002), higher body mass index (BMI; P = .006), male sex (P = .041), and diabetes mellitus (P = .002). The association between infection and higher BMI (P = .002), male sex (P = .016), and diabetes mellitus (P = .003) remained significant in a subgroup analysis of primary implantations but not revision surgeries. Infection was superficial in 17 (23%) and deep in 56 (77%) cases. Commonly identified pathogens were Staphylococcus aureus (65%), coagulase-negative staphylococci (43%), and Cutibacterium acnes (45%). Three device management approaches were identified: 39 (53%) had complete device explantation, 20 (27%) had surgical intervention with device retention, and 14 (19%) had medical management alone. Treatment failure occurred in 16 (23%) patients. Time-to-event analysis showed fewer treatment failures with complete device explantation (P = .015). Only 1 individual had complications with brain abscess at failure. Conclusions: Primary DBS implantations had higher rates of infection compared with revision surgeries. Complete device explantation was favored for deep infections. However, device salvage was commonly attempted and is a reasonable approach in select cases given the low rate of complications.

Outcomes and risk factors for failure after débridement, antibiotics, and implant retention for elbow periprosthetic joint infection.

BACKGROUND: Evidence for the management of periprosthetic joint infection (PJI) after total elbow arthroplasty is sparse, particularly in regard to débridement, antibiotics, and implant retention (DAIR). This study explored the outcomes of DAIR and analyzed risk factors for failure. METHODS: A retrospective cohort study of patients 18 years or older diagnosed with elbow PJI and managed with DAIR between January 1, 2003, and December 31, 2018, at a single institution was performed. Twenty-six elbows met the inclusion criteria during the study period. All DAIR procedures included in this study represented an attempt to manage an acute PJI with surgical irrigation and débridement without removal of the elbow arthroplasty components, followed by long-term systemic antimicrobial therapy. DAIR failure was defined as recurrence of PJI, unplanned re-operation for infection, or death secondary to infection. A Cox proportional hazards model was used to identify possible risk factors for failure. RESULTS: DAIR failed in 17 cases of elbow PJI with a failure rate of 65% at 2 years (95% confidence interval: 41.3%-79.6%). The median time to failure from DAIR was 43 days (interquartile range: 27-114). We found that DAIR failed in all cases with sinus tracts or negative cultures. The group with favorable outcomes had a shorter median duration of symptoms (5 vs. 18 days, P = .65) and a higher proportion of monomicrobial infections (58.8% vs. 88.9%, P = .19) compared to those with unfavorable outcomes. However, with the numbers available, none of the possible risk factors analyzed for association with failure reached statistical significance. CONCLUSION: DAIR for elbow PJI was associated with high rates of failure. Possible risk factors for failure may include the presence of sinus tract, longer duration of symptoms, and culture-negative infection. Although the relatively low morbidity of DAIR compared with total elbow arthroplasty implant resection for a one-stage or two-stage reimplantation is attractive, patients considered for DAIR must know that the chance of success is limited to approximately 35%.

Factors Impacting the Yield of Image-Guided Biopsy in Native Vertebral Osteomyelitis: A 10-Year Retrospective Study.

Background: Image-guided biopsies in patients with suspected native vertebral osteomyelitis (NVO) are recommended to establish the microbiological diagnosis and guide antibiotic therapy. Despite recent advances, the microbiological yield of this procedure remains between 48% and 52%. A better understanding of factors associated with this low yield may lead to improved microbiological diagnosis. Methods: We retrospectively identified patients with suspected NVO undergoing image-guided biopsies from January 2011 to June 2021 at our institution. Two hundred nine patients undergoing 248 percutaneous biopsies were included. Demographic data, biopsy and microbiologic techniques, clinical characteristics, and antibiotic use were collected. Multivariable logistic regression analysis was conducted to determine factors associated with microbiological yield. Results: A total of 110 of 209 (52.6%) initial image-guided biopsies revealed positive microbiological results. This number increased to 121 of 209 (57.9%) when repeat image-guided biopsies were included. In multivariable analysis, aspiration of fluid was associated with a 3-fold increased odds of yielding a positive result (odds ratio [OR], 3.13; 95% confidence interval [CI], 1.39-7.04; P = .006), whereas prior antibiotic use was associated with a 3-fold decreased yield (OR, 0.32; 95% CI, .16-.65; P = .002). A univariate subgroup analysis revealed a significant association between the length of the antibiotic-free period and microbiological yield, with the lowest rates of pathogen detection at 0-3 days and higher rates as duration increased (P = .017). Conclusions: Prior antibiotic use in patients with suspected NVO was associated with a decrease in the microbiological yield of image-guided biopsies. An antibiotic-free period of at least 4 days is suggested to maximize yield. Successful fluid aspiration during the procedure also increases microbiological yield.

Truth in DAIR: Duration of Therapy and the Use of Quinolone/Rifampin-Based Regimens After Debridement and Implant Retention for Periprosthetic Joint Infections.

Background: The optimal duration of antibiotic therapy after debridement and implant retention (DAIR) for periprosthetic joint infections (PJIs) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR. Methods: We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008 and 31 December 31, 2018 at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed. Results: We examined 247 cases of PJI with a median follow-up of 4.4 years (interquartile range [IQR], 2.3-7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days; IQR, 38-42) and treatment failure (P = .119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (P = .005; eg, 90-day vs 1-year duration; hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.48-8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both P = .025). There was no significant association between fluoroquinolone (FQ) use and failure (HR, 0.62; 95% CI, .31-1.24; P = .172). Conclusions: The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.

Clinical Profile of Monomicrobial Corynebacterium Hip and Knee Periprosthetic Joint Infections.

Background: Corynebacterium periprosthetic joint infection (PJI) is a poorly described infectious syndrome. Prior studies included cases of polymicrobial infections. This series describes the clinical characteristics, management, and outcomes of monomicrobial Corynebacterium PJI. Methods: We queried the Mayo Clinic Total Joint Registry for cases of monomicrobial Corynebacterium knee and hip PJI in adults (age ≥18 years) between 2010 and 2019. Results: A total of 20 (1%) out of 2067 PJI cases met our inclusion criteria. Most were males (55%), and the median age was 64 years. Seventy percent had chronic symptoms (>4 weeks). PJI was delayed to late (>3 months postimplantation) in 90%. Three species were identified: C. striatum (70%), C. jeikeium (20%), and C. amycolatum (10%). All tested isolates were susceptible to vancomycin (100%) and linezolid (100%), and most had a minimum inhibitory concentration ≤0.06 mcg/mL to daptomycin (75%). Other agents were less reliable, with high resistance to oral agents commonly used for suppression. Nineteen patients were treated: 37% debridement and implant retention (DAIR), 47% 2-stage exchange, and 16% resection without reimplantation. Of these, failure occurred in 29%, 11%, and 0%, respectively. Conclusions: Corynebacterium PJIs pose a therapeutic challenge due to limited antimicrobial armamentarium and undefined optimal surgical intervention. Vancomycin and linezolid remain the most reliable agents for treatment. DAIR may be attempted for acute PJI, but verification of durable chronic suppression options will be critical for this approach.

Diagnosis of vertebral osteomyelitis.

Native vertebral osteomyelitis (NVO) is a potentially fatal infection which has seen a gradual increase in its incidence over the past decades. The infection is insidious, presenting with symptoms of back pain. Fever is present in about 60 % of patients. Prompt diagnosis of NVO is important to prevent the development of complications. Numerous laboratory and imaging tools can be deployed to accurately establish the diagnosis. Imaging techniques such as magnetic resonance, nuclear imaging, and computed tomography are essential in diagnosing NVO but can also be useful in image-guided biopsies. Laboratory tools include routine blood tests, inflammatory markers, and routine culture techniques of aspirated specimens. Recent advances in molecular techniques can assist in identifying offending pathogen(s). In this review, we detail the arsenal of techniques that can be utilized to reach a diagnosis of NVO.

Disproportionate Impact of COVID-19 on Racial and Ethnic Minority Groups in the United States: a 2021 Update.

The COVID-19 pandemic's disproportionate impact on people from some racial and ethnic groups in the U.S. persisted throughout 2021. Black, Latinx, and American Indian persons have been hospitalized and died at a higher rate than White persons consistently from the start of the pandemic. Early data show that hospitalization and mortality rates for Black, Latinx, and American Indian children are higher than White children in a worrying trend. The pandemic has likely worsened the gaps in wealth, employment, housing, and access to health care: the social determinants of health that caused the disparities in the first place. School closures will have a long-lasting impact on the widening achievement gaps between Black and Latinx students and White students. In the earlier vaccination phase, Black and Latinx persons were being vaccinated at a lower rate than their proportion of cases due to vaccine hesitancy, misinformation, and barriers to access. Vaccine hesitancy rates among these groups have since decreased and are now comparable to White persons. Aggregated data make it challenging to paint a picture of the actual impact of COVID-19 on Asian Americans as they are a diverse group with significant disparities. All of this highlights that we have much work to do in dismantling systemic racism, engaging communities we serve, and advancing health equity to prepare us for future pandemics and a more just healthcare system.

Microbiology of hip and knee periprosthetic joint infections: a database study.

OBJECTIVES: Knowledge of the microbiological aetiology of periprosthetic joint infection (PJI) is essential to its management. Contemporary literature from the United States on this topic is lacking. This study aimed to identify the most common microorganisms associated with types of arthroplasty, the timing of infection, and clues to polymicrobial infection. METHODS: We performed an analytical cross-sectional study of patients 18 years of age or older with hip or knee PJI diagnosed at our institution between 2010 and 2019. PJI was defined using the criteria adapted from those of the Musculoskeletal Infection Society. Cases included PJI associated with primary or revision arthroplasty and arthroplasty performed at our institution or elsewhere. RESULTS: A total of 2067 episodes of PJI in 1651 patients were included. Monomicrobial infections represented 70% of episodes (n = 1448), with 25% being polymicrobial (n = 508) and the rest (5%, n = 111) culture-negative. The most common group causing PJI was coagulase-negative Staphylococcus species (other than S. ludgunensis) (37%, n = 761). The distribution of most common organisms was similar regardless of arthroplasty type. The S. aureus complex, Gram-negative bacteria, and anaerobic bacteria (other than Cutibacterium species) were more likely to be isolated than other organisms in the first year following index arthroplasty (OR 1.7, 95%CI 1.4-2.2; OR 1.5, 95%CI 1.1-2.0; and OR 1.5, 95%CI 1.0-2.2, respectively). The proportion of culture-negative PJIs was higher in primary than revision arthroplasty (6.5% versus 3%, p 0.0005). The presence of a sinus tract increased the probability of the isolation of more than one microorganism by almost three-fold (OR 2.6, 95%CI 2.0-3.3). CONCLUSIONS: Joint age, presence of a sinus tract, and revision arthroplasties influenced PJI microbiology.

Fungal and mycobacterial cultures should not be routinely obtained for diagnostic work-up of patients with suspected periprosthetic joint infections.

AIMS: Fungal and mycobacterial periprosthetic joint infections (PJI) are rare events. Clinicians are wary of missing these diagnoses, often leading to the routine ordering of fungal and mycobacterial cultures on periprosthetic specimens. Our goal was to examine the utility of these cultures and explore a modern bacterial culture technique using bacterial blood culture bottles (BCBs) as an alternative. METHODS: We performed a retrospective review of patients diagnosed with hip or knee PJI between 1 January 2010 and 31 December 2019, at the Mayo Clinic in Rochester, Minnesota, USA. We included patients aged 18 years or older who had fungal, mycobacterial, or both cultures performed together with bacterial cultures. Cases with positive fungal or mycobacterial cultures were reviewed using the electronic medical record to classify the microbiological findings as representing true infection or not. RESULTS: There were 2,067 episodes of PJI diagnosed within the study period. A total of 3,629 fungal cultures and 2,923 mycobacterial cultures were performed, with at least one of these performed in 56% of episodes (n = 1,157). Test positivity rates of fungal and mycobacterial cultures were 5% (n = 179) and 1.2% (n = 34), respectively. After a comprehensive review, there were 40 true fungal and eight true mycobacterial PJIs. BCB were 90% sensitive in diagnosing true fungal PJI and 100% sensitive in detecting rapidly growing mycobacteria (RGM). Fungal stains were performed in 27 true fungal PJI but were only positive in four episodes (14.8% sensitivity). None of the mycobacterial stains was positive. CONCLUSION: Routine fungal and mycobacterial stains and cultures should not be performed as they have little clinical utility in the diagnosis of PJI and are associated with significant costs. Candida species and RGM are readily recovered using BCB. More research is needed to predict rare non-Candida fungal and slowly growing mycobacterial PJI that warrant specialized cultures. Cite this article: Bone Joint J 2022;104-B(1):53-58.

The Characteristics of Capnocytophaga Infection: 10 Years of Experience.

BACKGROUND: Capnocytopha ga is a gram-negative, facultative anaerobe. Human infection is rare but can lead to devastating outcomes. Capnocytophaga canimorsus can cause sepsis following an animal bite, whereas human-oral-associated Capnocytophaga infections were reported in immunocompromised patients. Current data on these infections are not robust. Our goal is to provide a contemporary description of a unique characteristic of Capnocytophaga infections. METHODS: We performed a retrospective review of all patients with Capnocytophaga infection from January 2010 to August 2020 at 3 main hospitals of Mayo Clinic in Rochester, Minnesota; Scottsdale, Arizona; and Jacksonville, Florida. We collected baseline demographic data, clinical characteristics, microbiological data, and outcomes of C. canimorsus and human-oral-associated Capnocytophaga infection. RESULTS: Among 82 patients with Capnocytophaga infection, 46 patients (56.0%) had bacteremia. The most common species identified in this group was C. sputigena (57.9%), followed by C. canimorsus (34.8%). Patients with human-oral-associated Capnocytophaga bacteremia were often immunocompromised, presented with neutropenic fever, and had worse 6-month all-cause mortality compared to C. canimorsus bacteremia (36.4% vs 6.2%, P = .03). They also had a higher ß-lactamase production rate (36.4% vs 0.0%, P = .02). Among patients without bacteremia, the main clinical syndrome was polymicrobial head and neck infections (47.2%). CONCLUSIONS: Human-oral-associated Capnocytophaga bacteremia occurs primarily in immunocompromised patients, particularly those with hematologic malignancy. In contrast, C. canimorsus bacteremia is more likely to present with community-onset infection related to zoonotic exposure. Human-oral-associated Capnocytophaga infection without bacteremia is frequently isolated in polymicrobial infection; this phenomenon's significance is yet to be fully understood.

Safety and tolerability of liquid amikacin in antibiotic-loaded bone cement - a case series.

High-dose liquid antibiotics are uncommon in bone cement. We present a case series of patients in which up to 16 mL of liquid amikacin (250 mg mL - 1 ) was successfully incorporated into bone cement to treat periprosthetic joint infections. We did not observe adverse drug reactions definitively attributed to its use.