Changing trends in acute osteomyelitis in children: impact of methicillin-resistant Staphylococcus aureus infections

C-reactive protein can be used to guide the empiric antimicrobial therapy of acute osteomyelitis in children

This study was to identify some indicators that could be used to distinguish methicillin-resistant Staphylococcus aureus (MRSA) from methicillin-sensitive Staphylococcus aureus (MSSA) to more accurately guide empirical antibiotics. Data of 91 cases of acute osteomyelitis in children with Staphylococcus aureus infection (including 29 cases of MRSA and 62 cases of MSSA) from July 2017 to March 2024 were retrospectively analyzed. Age, sex, duration of onset, maximum body temperature at onset, and inflammatory indicators detected after admission were compared between the MRSA group and the MSSA group. According to the receiver operating characteristic (ROC) curve, the diagnostic efficiency of MRSA infection was evaluated. Logistic regression analysis was used to determine independent risk factors for MRSA infection. There were no significant differences in age, sex, duration of onset, maximum body temperature, white blood cell count, neutrophil count, and erythrocyte sedimentation rate between the MRSA group and the MSSA group (P > 0.05). The median C-reactive protein in the MRSA group and the MSSA group was 97.93 and 58.10 mg/L, respectively, with statistical significance (P < 0.05). The sensitivity, specificity, and area under the curve of C-reactive protein for detecting MRSA infection were 41.4, 90.3, and 0.646%, respectively. Logistic regression analysis showed that C-reactive protein greater than 116.46 mg/L (odds ratio = 6.588, 95% confidence interval: 2.149-20.197) was an independent risk factor for predicting MRSA infection (P < 0.05). C-reactive protein greater than 116.46 mg/L can independently predict the likelihood of MRSA infection, and it is recommended to empirically select anti-MRSA treatment for such children.

Updates in non-neoplastic orthopaedic pathology: what you don't know can hurt you!

Even though the average surgical pathologist reviews far more non-neoplastic orthopaedic pathology on a daily basis, most current research focuses on rare tumours and their even less frequent molecular events. Our experiences among consults and focused conferences strongly suggest that there remains a practice gap regarding knowledge and diagnosing specific non-neoplastic orthopaedic conditions. One of the most frequent intraoperative consultations performed in the USA, among both academic and private institutions, relates to revision arthroplasty and the determination of infection in periprosthetic joints. Pathologists play a critical role in this algorithm, helping determine intraoperatively whether patients require antibiotic spacers prior to reimplantation. Many pathology departments have abandoned the examination of arthroplasty specimens because they (and their surgeons) mistakenly believe there is little clinically relevant information to be gained by thorough pathological examination. However, recent literature has challenged this concept, emphasising the importance of distinguishing avascular necrosis (from osteoarthritis/degenerative joint disease with secondary osteonecrosis), subchondral insufficiency fracture, septic arthritis (from so-called 'sterile' osteomyelitis/pseudoabscesses), underlying crystalline diseases and incidental/occult neoplasia. Histological evaluation of historically insignificant orthopaedic specimens, such as tenosynovium from carpal tunnel syndrome/trigger finger, is now seen as valuable in early diagnosis of cardiac amyloidosis. Not infrequently, orthopaedic conditions like haemosiderotic synovitis, osteocartilaginous loose bodies or rheumatoid nodules, may histologically mimic bona fide neoplasms, notably diffuse tenosynovial giant cell tumour, synovial chondromatosis and epithelioid sarcoma, respectively. Here is a review of the more common non-neoplastic orthopaedic conditions, those likely to be examined by the practising surgical pathologist, with updates and guidelines for establishing clinically relevant diagnoses.

Navigating the Enigma of Pediatric Musculoskeletal Infections: A Race Against Time

Musculoskeletal infection (MSKI) in children is a critical condition in pediatric orthopedics due to the potential for serious adverse outcomes, including multiorgan dysfunction syndrome, which can lead to death. The diagnosis and treatment of MSKI continue to evolve with advancements in infectious organisms, diagnostic technologies, and pharmacologic treatments. It is imperative for pediatric orthopedic surgeons and medical teams to remain up to date with the latest MSKI practices.

Plasma Microbial Cell-Free DNA Sequencing for Pathogen Detection and Quantification in Children With Musculoskeletal Infections

BACKGROUND

Nearly half of all pediatric musculoskeletal infections (MSKIs) are culture negative. Plasma microbial cell-free DNA (mcfDNA) sequencing is noninvasive and not prone to the barriers of culture. We evaluated the performance of plasma mcfDNA sequencing in identifying a pathogen, and examined the duration of pathogen detection in children with MSKIs.

METHODS

We conducted a prospective study of children, aged 6 months to 18 years, hospitalized from July 2019 to May 2022 with MSKIs, in whom we obtained serial plasma mcfDNA sequencing samples and compared the results with cultures.

RESULTS

A pathogen was recovered by culture in 23 of 34 (68%) participants, and by initial mcfDNA sequencing in 25 of 31 (81%) participants. Multiple pathogens were detected in the majority (56%) of positive initial samples. Complete concordance with culture (all organisms accounted for by both methods) was 32%, partial concordance (at least one of the same organism(s) identified by both methods) was 36%, and discordance was 32%. mcfDNA sequencing was more likely to show concordance (complete or partial) if obtained prior to a surgical procedure (82%), compared with after (20%), (RR 4.12 [95% CI 1.25, 22.93], p = .02). There was no difference in concordance based on timing of antibiotics (presample antibiotics 60% vs no antibiotics 75%, RR 0.8 [95% CI 0.40, 1.46], p = .65]). mcfDNA sequencing was positive in 67% of culture-negative infections and detected a pathogen for a longer interval than blood culture (median 2 days [IQR 1, 6 days] vs 1 day [1, 1 day], p < .01).

CONCLUSIONS

Plasma mcfDNA sequencing may be useful in culture-negative pediatric MSKIs if the sample is obtained prior to surgery. However, results must be interpreted in the appropriate clinical context as multiple pathogens are frequently detected supporting the need for diagnostic stewardship.

A Novel Risk Score to Guide the Evaluation of Acute Hematogenous Osteomyelitis in Children

OBJECTIVES

To identify independent predictors of and derive a risk score for acute hematogenous osteomyelitis (AHO) in children.

METHODS

We conducted a retrospective matched case-control study of children >90 days to <18 years of age undergoing evaluation for a suspected musculoskeletal (MSK) infection from 2017 to 2019 at 23 pediatric emergency departments (EDs) affiliated with the Pediatric Emergency Medicine Collaborative Research Committee. Cases were identified by diagnosis codes and confirmed by chart review to meet accepted diagnostic criteria for AHO. Controls included patients who underwent laboratory and imaging tests to evaluate for a suspected MSK infection and received an alternate final diagnosis.

RESULTS

We identified 1135 cases of AHO matched to 2270 controls. Multivariable logistic regression identified 10 clinical and laboratory factors independently associated with AHO. We derived a 4-point risk score for AHO using (1) duration of illness >3 days, (2) history of fever or highest ED temperature ≥38°C, (3) C-reactive protein >2.0 mg/dL, and (4) erythrocyte sedimentation rate >25 mm per hour (area under the curve: 0.892, 95% confidence interval [CI]: 0.881 to 0.901). Choosing to pursue definitive diagnostics for AHO when 3 or more factors are present maximizes diagnostic accuracy at 84% (95% CI: 82% to 85%), whereas children with 0 factors present are highly unlikely to have AHO (sensitivity: 0.99, 95% CI: 0.98 to 1.00).

CONCLUSIONS

We identified 10 predictors for AHO in children undergoing evaluation for a suspected MSK infection in the pediatric ED and derived a novel 4-point risk score to guide clinical decision-making.

Mapping disease regulatory circuits at cell-type resolution from single-cell multiomics data

Resolving chromatin-remodeling-linked gene expression changes at cell-type resolution is important for understanding disease states. Here we describe MAGICAL (Multiome Accessibility Gene Integration Calling and Looping), a hierarchical Bayesian approach that leverages paired single-cell RNA sequencing and single-cell transposase-accessible chromatin sequencing from different conditions to map disease-associated transcription factors, chromatin sites, and genes as regulatory circuits. By simultaneously modeling signal variation across cells and conditions in both omics data types, MAGICAL achieved high accuracy on circuit inference. We applied MAGICAL to study Staphylococcus aureus sepsis from peripheral blood mononuclear single-cell data that we generated from subjects with bloodstream infection and uninfected controls. MAGICAL identified sepsis-associated regulatory circuits predominantly in CD14 monocytes, known to be activated by bacterial sepsis. We addressed the challenging problem of distinguishing host regulatory circuit responses to methicillin-resistant and methicillin-susceptible S. aureus infections. Although differential expression analysis failed to show predictive value, MAGICAL identified epigenetic circuit biomarkers that distinguished methicillin-resistant from methicillin-susceptible S. aureus infections.

Early Transition to Oral Antimicrobial Therapy Among Children With Staphylococcus aureus Bacteremia and Acute Hematogenous Osteomyelitis

BACKGROUND

Staphylococcus aureus bacteremia (SAB) is a frequent complication of acute hematogenous osteomyelitis (AHO) in children, but data on the optimal duration of parenteral antibiotics prior to transition to oral antibiotics remains sparse. We examined clinical outcomes associated with early transition to oral antimicrobial therapy among children admitted to our institution with AHO and SAB, and evaluated the utility of a severity of illness score (SIS) to guide treatment decisions in this setting.

METHODS

Children with AHO and SAB admitted to our institution between January 1, 2009, and December 31, 2018, were retrospectively reviewed and stratified according to a previously validated SIS into mild (0-3), moderate (4-7) and severe (8-10) cohorts. Groups were assessed for differences in treatment (eg, parenteral and oral antibiotic durations, surgeries) and clinical response (eg, bacteremia duration, acute kidney injury, length of stay and treatment failure).

RESULTS

Among 246 children identified with AHO and SAB, median parenteral antibiotic duration differed significantly between mild (n = 80), moderate (n = 98) and severe (n = 68) cohorts (3.6 vs. 6.5 vs. 14.3 days; P ≤ 0.001). SIS cohorts also differed with regard to number of surgeries (0.4 vs. 1.0 vs. 2.1; P ≤ 0.001), duration of bacteremia (1.0 vs. 2.0 vs. 4.0 days; P ≤ 0.001), acute kidney injury (0.0% vs. 3.0% vs. 20.5%; P ≤ 0.001), hospital length of stay (4.8 vs. 7.4 vs. 16.4 days; P ≤ 0.001) and total duration of antibiotics (34.5 vs. 44.7 vs. 60.7 days; P ≤ 0.001). Early transition to oral antimicrobial therapy among mild or moderate SIS cohorts was not associated with treatment failure despite SAB.

CONCLUSIONS

SAB is associated with a wide range of illness among children with AHO, and classification of severity may be useful for guiding treatment decisions. Early transition to oral antimicrobial therapy appears safe in children with mild or moderate AHO despite the presence of SAB.

Osteomyelitis, Oxidative Stress and Related Biomarkers

Bone is a very dynamic tissue, subject to continuous renewal to maintain homeostasis through bone remodeling, a process promoted by two cell types: osteoblasts, of mesenchymal derivation, are responsible for the deposition of new material, and osteoclasts, which are hematopoietic cells, responsible for bone resorption. Osteomyelitis (OM) is an invasive infectious process, with several etiological agents, the most common being Staphylococcus aureus, affecting bone or bone marrow, and severely impairing bone homeostasis, resulting in osteolysis. One of the characteristic features of OM is a strong state of oxidative stress (OS) with severe consequences on the delicate balance between osteoblastogenesis and osteoclastogenesis. Here we describe this, analyzing the effects of OS in bone remodeling and discussing the need for new, easy-to-measure and widely available OS biomarkers that will provide valid support in the management of the disease.

The Use of Biomarkers in the Early Diagnosis of Septic Arthritis and Osteomyelitis-A Pilot Study

BACKGROUND

The diagnosis of septic arthritis (SA) and osteomyelitis (OM) has remained challenging in the pediatric population, often accompanied by delays and requiring invasive interventions. The purpose of this pilot study is to identify a novel panel of biomarkers and cytokines that can accurately differentiate SA and OM at initial presentation using serum alone.

METHODS

Twenty patients below 18 years old whose working diagnosis included SA (n=10) and OM (n=10) were identified. Serum was collected at initial evaluation. Each sample underwent seven ELISA [C1-C2, COMP, CS-846, hyaluronan, procalcitonin, PIIANP, C-terminal telopeptide of type II collagen (CTX-II)] and 65-plex cytokine panels. Principal component and Lasso regression analysis were performed to identify a limited set of predictive biomarkers.

RESULTS

Mean age was 4.7 and 9.5 years in SA and OM patients, respectively (P=0.029). 50% of SA patients presented within 24 hours of symptom onset, compared with 0% of OM patients (P=0.033). 30% of SA patients were discharged home with an incorrect diagnosis and re-presented to the emergency department days later. At time of presentation: temperature ≥38.5°C was present in 10% of SA and 40% of OM patients (P=0.12), mean erythrocyte sedimentation rate (mm/h) was 51.6 in SA and 44.9 in OM patients (P=0.63), mean C-reactive protein (mg/dL) was 55.8 in SA and 71.8 in OM patients (P=0.53), and mean white blood cells (K/mm3) was 12.5 in SA and 10.4 in OM patients (P=0.34). 90% of SA patients presented with ≤2 of the Kocher criteria. 100% of SA and 40% of OM patients underwent surgery. 70% of SA cultures were culture negative, 10% MSSA, 10% Kingella, and 10% Strep pyogenes. 40% of OM cultures were culture negative, 50% MSSA, and 10% MRSA. Four biomarkers [CTx-II, transforming growth factor alpha (TGF-α), monocyte chemoattractant protein 1 (MCP-1), B cell-attracting chemokine 1] were identified that were able to classify and differentiate 18 of the 20 SA and OM cases correctly, with 90% sensitivity and 80% specificity.

CONCLUSIONS

This pilot study identifies a panel of biomarkers that can differentiate between SA and OM at initial presentation using serum alone.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Predictive Algorithms in the Diagnosis and Management of Pediatric Hip and Periarticular Infection

➤ Although the criteria of Kocher et al. were an important advancement in our ability to diagnose septic arthritis of the hip early, the changing microbial landscape and availability of advanced imaging have rendered it insufficient for contemporary clinical use.➤ Routine use of magnetic resonance imaging and recognition of disseminated disease have prompted the development of algorithms to predict concurrent osteoarticular infection in cases of septic arthritis and osteomyelitis that were previously assumed to be "isolated."➤ Recent research has attempted to stratify childhood bone and joint infection (BJI) by severity to guide treatment planning. This is valuable, as patients with multifocal disease, more virulent pathogens, and immunocompromise can have longer hospital stays and require multiple surgeries.➤ The increasing prevalence of clinical prediction algorithms in childhood BJI is not completely matched by quality in methodology. Clinicians need to be wary of adopting predictive algorithms prior to robust external validation.

Osteoarticular infections in infants under 3 months of age

BACKGROUND

Acute osteoarticular infections (OAI) in infants under 3 months of age (≤3M) are rare and remain a diagnostic challenge. Orthopedic complications and functional sequelae have been less well described in this age group. Our aims were to evaluate trends in aetiology, management, and outcomes of OAI ≤ 3M, and to compare these younger children who have OAI with older children.

METHODS

A longitudinal observational study was conducted of OAI cases admitted to tertiary care pediatric hospital from 2008 to 2018. OAI ≤ 3M was compared with children above 3 months. Clinical, microbiological, imaging, and outcome data were analyzed.

RESULTS

We identified 24 (9.1%) of the 263 OAI in children under 3 months. Analyzing OAI ≤ 3M there was a twofold increase since 2014; 54% were males with a median age of 28 days (IQR: 13.5-60.0), 10 (41.7%) were premature and nine (37.5%) had healthcare-associated infections. Microbiological causes were identified in 87.5%, mostly Staphylococcus aureus (57.1%) and Group B Streptococcus (23.8%), and 25% were multidrug-resistant (5 methicillin-resistant S. aureus and 1 Enterobacter cloacae). Bacteremia (100% vs 36.8%, P = 0.037), multidrug resistant bacteria (75% vs 16, P = 0.04), and healthcare-associated infections (100% vs 26.3%, P = 0.014) were associated with sequelae. Comparing OAI ≤ 3M with older children, OAI ≤ 3M were treated with longer antibiotic courses, had more complications and sequelae (17.4% vs 3.2%, P = 0.002).

CONCLUSIONS

S. aureus is still the most common cause of OAI ≤ 3M, and 25% of causative bacteria were multidrug-resistant bacteria. Complications and sequelae were more frequent in OAI ≤ 3M when compared with older children.

Clinical Presentation of Acute Osteomyelitis in the Pediatric Emergency Department

OBJECTIVES

Acute osteomyelitis is a challenging diagnosis to make in the pediatric emergency department (ED), in part because of variability in its presentation. There are limited data detailing the presenting features of pediatric osteomyelitis, factors that are essential to understand to inform diagnostic decision making. We sought to describe relevant clinical data that contributed to the diagnosis of acute osteomyelitis in children presenting to a pediatric ED.

METHODS

This was a 10-year retrospective cohort study of patients 18 years or younger diagnosed with acute osteomyelitis in the ED of a large tertiary care children's hospital. Collected data included demographics, clinical history, patient-reported symptoms, vital signs, physical examination findings, and results of basic laboratory, microbiologic, and imaging studies. Descriptive statistics were used to summarize key findings.

RESULTS

Two hundred eleven cases of acute osteomyelitis were identified during the study period. The median age was 8.4 years, with 61.1% male. One hundred twenty-seven patients (60.2%) presented to care more than once before being diagnosed. Common symptoms included pain (94.3%), functional limitation (83.9%), and fever (76.3%). Common examination findings included functional limitation (78.2%), focal tenderness (73.5%), and swelling (52.1%). One hundred seventeen patients (55.5%) were febrile during their ED evaluation. Elevated C-reactive protein (>0.8 mg/dL, 92.9%) and erythrocyte sedimentation rate (>10 mm/h, 94.3%) were the most sensitive laboratory markers.

CONCLUSIONS

Fever may be absent in up to a quarter of pediatric patients with acute osteomyelitis. Although highly sensitive, inflammatory marker elevations were more modest than those reported previously in cases of pediatric septic arthritis.

Pediatric osteoarticular infection: trend in surgically treated patients and association of methicillin-resistant Staphylococcus aureus with requirement of secondary procedures

Acute pediatric osteoarticular infection demonstrates variability in both presentation and response to treatment. Many respond to antibiotics ± single operation, while some require multiple surgeries. Currently, it is difficult to predict who may require additional procedures. Infections due to methicillin-resistant Staphylococcus aureus (MRSA) have been associated with more complications. The purpose of this study is to determine MRSA trends and degree of association with the occurrence of multiple procedures. We performed a retrospective analysis of surgically treated pediatric (1 month-18 years) patients for acute osteomyelitis and septic arthritis at a tertiary children's hospital from 2003-2017. The cohort was divided into single-procedure and multiple-procedure groups. A total of 753 patients were studied with a mean age of 7.05 years (2.4 months-17.9 years). We identified 645/753 (85.6%) patients who were treated with a single-procedure and 108/753 (14.4%) patients who required multiple- procedures. The lower extremity (hip, knee, tibia, and femur) was most commonly involved. The epidemiologic trend runs almost parallel between two groups with a peak in 2009. The odds ratio for multiple-procedures was 2.0 [95% confidence interval (CI), 1.2-3.1; P = 0.002] with dual infection (osteomyelitis + septic arthritis), 2.6 (95% CI, 1.6-4.4; P = 0.001) with high-risk conditions and 4.6 (95% CI, 3.0-7.1; P < 0.001) if MRSA was present. MRSA significantly predicts the requirement of additional operative procedures for the treatment of osteoarticular infections in children. Besides clinical deterioration and other markers, the presence of MRSA can be a considerable indicator for a planned secondary-procedure. Level III retrospective cohort study.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 Guideline on Diagnosis and Management of Acute Hematogenous Osteomyelitis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute hematogenous osteomyelitis (AHO) in children was developed by a multidisciplinary panel representing Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with AHO, including specialists in pediatric infectious diseases, orthopedics, emergency care physicians, hospitalists, and any clinicians and healthcare providers caring for these patients. The panel's recommendations for the diagnosis and treatment of AHO are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of AHO in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

[Acute haematogenous osteomyelitis in Lisbon: An unexpectedly high association with myositis and arthritis]

INTRODUCTION

Despite the current trend towards less aggressive therapeutic approaches, acute haematogenous osteomyelitis (AHO) continues to be a challenge and is associated with significant morbidity worldwide. Our aim was to determine if 80% compliance with current protocol was achieved, identify complications and associated risk factors and analyse trends in aetiology and management of AHO in children.

METHODS

We conducted a longitudinal, observational, single-centre study in patients with AHO aged less than 18 years admitted to a paediatric hospital, between 2008 and 2018, divided into 2 cohorts (before and after 2014). Demographic, clinical data and disease progression were analysed.

RESULTS

The study included 71 children with AHO, 56% male, with a median age of 3 years (interquartile range, 1-11). We found a 1.8-fold increase of cases in the last 5 years. The causative agent was identified in 37% of cases: MSSA (54%), MRSA (4%), Streptococcus pyogenes (19%), Kingella kingae (12%), Streptococcus pneumoniae (8%), and Neisseria meningitidis (4%). Complications were identified in 45% of patients and sequelae in 3.6%. In recent years, there was an increase in myositis (30% vs. 7%; p=0.02), septic arthritis (68% vs. 37.2%; p=0.012) and in the proportion of patients treated for less than 4 weeks (37% vs. 3.5%; p=0.012), with a similar sequelae rates. The risk factors for complications were age 3 or more years, CRP levels of 20mg/l or higher, time elapsed between onset and admission of 5 or more days and positive culture, although on multivariate analysis only positive culture was significant. The presence of complications was a risk factor for sequelae at 6 months.

CONCLUSIONS

Our study confirms that AHO can be aggressive. The identification of risk factors for complications may be fundamental for management.

Unremitting Pain and Fever in a 15-Year-Old Boy With Osteomyelitis

A previously healthy 15-year-old boy from a rural county in the southeastern United States was evaluated in the emergency department with fever and worsening toe pain in the absence of trauma. He initially presented to his primary care physician 4 weeks before with upper respiratory symptoms and was treated with corticosteroids for presumed reactive airway disease. His respiratory symptoms resolved. One week after this presentation, he developed fever and right great toe pain and presented to an outside hospital. Inflammatory markers were elevated. MRI confirmed a diagnosis of osteomyelitis with associated periosteal abscess. He was treated with intravenous antibiotics and drainage of the abscess. Ten days after his discharge from the outside hospital, he developed fever and had increasing drainage of the toe and pain refractory to oral pain medications. He presented to our facility for further evaluation. Repeat MRI and inflammatory markers corroborated his worsening disease, and he was admitted to the hospital for intravenous antibiotics and underwent serial surgical debridement. He developed painful subcutaneous nodules on his lower extremities and was found to have lung abnormalities on chest radiograph. A multispecialty team collaborated in the management of this patient and unveiled a surprising diagnosis.

Improving Care and Outcomes for Pediatric Musculoskeletal Infections

BACKGROUND

Pediatric musculoskeletal infection (MSKI) is a common cause of hospitalization with associated morbidity. To improve the care of pediatric MSKI, our objectives were to achieve 3 specific aims within 24 months of our quality improvement (QI) interventions: (1) 50% reduction in peripherally inserted central catheter (PICC) use, (2) 25% reduction in sedations per patient, and (3) 50% reduction in empirical vancomycin administration.

METHODS

We implemented 4 prospective QI interventions at our tertiary children's hospital: (1) provider education, (2) centralization of admission location, (3) coordination of radiology-orthopedic communication, and (4) implementation of an MSKI infection algorithm and order set. We included patients 6 months to 18 years of age with acute osteomyelitis, septic arthritis, or pyomyositis and excluded patients with complex chronic conditions or ICU admission. We used statistical process control charts to analyze outcomes over 2 general periods: baseline (January 2015-October 17, 2016) and implementation (October 18, 2016-April 2019).

RESULTS

In total, 224 patients were included. The mean age was 6.1 years, and there were no substantive demographic or clinical differences between baseline and implementation groups. There was an 81% relative reduction in PICC use (centerline shift 54%-11%; 95% confidence interval 70-92) and 33% relative reduction in sedations per patient (centerline shift 1.8-1.2; 95% confidence interval 21-46). Empirical vancomycin use did not change (centerline 20%).

CONCLUSIONS

Our multidisciplinary MSKI QI interventions were associated with a significant decrease in the use of PICCs and sedations per patient but not empirical vancomycin administration.

A 10-year retrospective survey of acute childhood osteomyelitis in Stockholm, Sweden

AIM

Children with osteomyelitis present with a range of signs and symptoms and with varying degree of severity. The purpose of this study was to provide data on a population-based 10-year material of children with acute osteomyelitis.

METHODS

All children, 0-14 years in Stockholm Region with acute osteomyelitis hospitalised in July 2005-June 2015, were retrospectively studied. Time to hospital presentation, disease localization, inflammation markers, imaging procedures, microbiology, severity classified by the presence of complications, surgical procedures, hospital length of stay and seasonal variation were recorded.

RESULTS

There were 430 children with acute osteomyelitis; 61% were boys. The incidence per 100 000 person-years was 11.6; 9.3 in girls and 13.1 in boys. Median age at admission was 2.9 years with no peak later in childhood. Median time from first symptom to diagnosis was 4 days (range 1-21) and 48% of the cases were localised to femur or tibia. Mean C-reactive protein was 59 mg/L (range 1-376). Blood (n = 82) or tissue cultures (n = 54) were positive in 118 (28%) children. The most common pathogen was Staphylococcus aureus (n = 88) followed by Streptococcus pyogenes (n = 12). Surgery was performed in 71 children (17%). There was no mortality. Severe complications were seen in 14 (3.3%) children, five of whom were admitted to intensive care. Median hospital length of stay was 4 days (range 1-60).

CONCLUSIONS

Osteomyelitis in children is a diagnostic challenge with a low yield of positive bacterial cultures. Few children with uncomplicated disease need surgery, but the risk of severe complications is not negligible.

Existing and emerging methods of diagnosis and monitoring of pediatric musculoskeletal infection

Methods of diagnosing and monitoring pediatric musculoskeletal infections are rapidly evolving. Key serologic tests are typically used in screening patients with suspected infections, and remain an integral part of the initial work-up. Synovial studies from arthrocentesis in possible septic arthritis, and source-specific cultures have been the foundation of our treatment algorithm. Given the prevalence of soft tissue abscesses and osteoarticular infections, advanced imaging is an advantageous tool. More affordable use and expanded access to MRI has made it a valuable adjunct to clinical picture and existing tests in order to comprehensively visualize the extent of musculoskeletal infections in children. Ongoing validation for criteria to help determine the patients that stand to benefit the most from MRI, even when surgical intervention may be delayed, remains of significant clinical interest. Given the rates of culture-negative infections, and the need for timely diagnosis, new diagnostic techniques are always being considered. The search for more accurate biomarkers, and technology such as Whole genome sequencing (WGS) and next-generation sequencing (NGS) that can rapidly identify pathogens of all types of phyla based on a small sample of DNA, has promising clinical implications. While once novel and prohibitively expensive, these tests are now being applied in university and tertiary care centers in certain scenarios. Applying these techniques to pediatric musculoskeletal will require a large change in lab workflow and training. However, the benefits of acquiring diagnostic information along with will make them a superior tool in our arsenal of diagnostic tests.

Acute infectious osteomyelitis in children: new treatment strategies for an old enemy

BACKGROUND

Acute osteomyelitis still represents a significant clinical challenge, with an increasing incidence in paediatric population. A careful assessment and a rapid diagnosis with proper timing and choice of empirical antimicrobial therapy are necessary to avoid sequelae. The initial treatment should consist of empirical antibiotic therapy, to cover the major responsible pathogens in each age group.

DATA SOURCES

We made a literature search with PubMed and Cochrane database from 2000 to 2019 in English, French, and Spanish languages using the key words "osteomyelitis, children, clinical, diagnosis, and treatment".

RESULTS

The child's clinical features, age, and the microbiological profile of the geographic area should be evaluated for diagnosis and in the choice of antibiotic treatment. Latest data suggest the administration of intravenous antibiotics for a short period, with subsequent oral therapy, according to the improvement of clinical status and inflammatory markers. For children older than 3 months, the shift to oral medications is already possible after a short course of intravenous therapy, until recovery. The timing for the shift from cefazolin to cephalexin or cefuroxime, intravenous clindamycin to oral clindamycin, and intravenous ceftriaxone + oxacillin to oral equivalents will be decided according to the improvement of clinical status and inflammatory markers. We also present the approach to osteomyelitis due to difficult pathogens, such as Methicillin-resistant Staphylococcus aureus (MRSA) and Panton-Valentine leukocidin (PVL)-positive S. aureus infections.

CONCLUSION

In this review, we present the current approach to the clinical diagnosis and management of osteomyelitis in childhood, with an update on recent recommendations, as a useful instrument to understand the rationale of antibiotic therapy.

Alantolactone Enhances the Phagocytic Properties of Human Macrophages and Modulates Their Proinflammatory Functions

Aim of the Study

Phagocytosis is a crucial element of innate immune defense involved in bacterial killing. The aim of our study was to evaluate the influence of alantolactone on phagocytosis and cytokines release by THP1-derived macrophages. We assessed whether antimicrobial compound alantolactone (a sesquiterpene lactone present in Inula helenium L.) is able to stimulate immune functions of macrophages by increase of S. aureus uptake, phagosome acidification and further stimulation of phago-lysosomes formation. Simultaneously, we tested influence of alantolactone on cytokines/chemokines production and p65 NF-κB concentration. The activity of alantolactone was compared with clarithromycin at concentration 20 µM.

Methods

The cytotoxicity of alantolactone as well as S. aureus uptake, pH of phagosomes and phago-lysosomes fusion were analysed with flow cytometry. Reactive oxygen species and superoxide production were evaluated spectrophotometrically. The efficiency of phagocytosis was evaluated via quantifying viable bacteria (CFU). The effect on p65 protein concentration and cytokine production by macrophages were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Alantolactone enhanced phagocytosis via increase of S. aureus uptake, acidification of phagosomes, and later stimulation of phago-lysosomes fusion. Alantolactone treatment resulted in ROS and superoxide production decrease. Furthermore, alantolactone inhibited production of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8 as well as decreased p65 concentration, the subunit responsible for NF-κB activation and cytokine production and simultaneously stimulated release of anti-inflammatory mediators (IL-10 and TGF-β).

Conclusion

Results of our study indicate that alantolactone enhances clearance of S. aureus, and simultaneously modulates immune response, preventing collateral damage of the surrounding tissues. Considering the importance of phagocytosis in the pathogen killing, alantolactone may have a great potential as the supportive treatment of S. aureus infections. Further in vivo studies are warranted to confirm this hypothesis.

Clinical characteristics and outcomes of culture-negative versus culture-positive osteomyelitis in children treated at a tertiary hospital in central Taiwan

BACKGROUND

The causative pathogen of pediatric osteomyelitis is often unidentified despite culturing attempts. This study evaluated and compared the clinical characteristics, therapeutic approach, and outcomes of osteomyelitis caused by unknown pathogens and identified microorganisms.

METHOD

This 17-year retrospective study was conducted at a tertiary hospital in central Taiwan. Medical records of children aged less than 18 years with a diagnosis of osteomyelitis between 2003 and 2019 were reviewed.

RESULT

In total, 70 patients (median age = 6.4 years; male = 65.7%) fulfilled the inclusion criteria, of whom 33 (47.1%) were culture negative. Staphylococcus aureus was the main pathogen (67.6% of identified bacteria). The proportion of methicillin-resistant S. aureus (MRSA) was 44% and 54.5% of the MRSA isolates exhibited clindamycin resistance. Compared to children with culture-positive osteomyelitis, those with culture-negative osteomyelitis had a lower rate of concomitant septic arthritis (40.5% vs. 15.2%, p = 0.019) and leukocytosis on presentation (45.9% vs. 21.2%, p = 0.030); they also required fewer surgical interventions (56.8% vs. 24.2%, p = 0.006) and received a shorter course of total antibiotic therapy (49.0 vs. 43.0 days, p = 0.045). In the culture-negative group, the MRSA coverage rate was 18.8% during initial empirical therapy and increased to 59.4% during further adjusted therapy. The overall complication rate was 18.6% and was lower in the culture-negative group (32.4% vs. 3.0%, p = 0.002).

CONCLUSION

In areas where community-associated MRSA and clindamycin resistance strains are a concern, empirical glycopeptide-based therapy is suggested in pediatric osteomyelitis, particularly in those with culture-negative infections.

Update on Acute Bone and Joint Infections in Paediatrics: A Narrative Review on the Most Recent Evidence-Based Recommendations and Appropriate Antinfective Therapy

Acute bone and joint infections (BJIs) in children may clinically occur as osteomyelitis (OM) or septic arthritis (SA). In clinical practice, one-third of cases present a combination of both conditions. BJIs are usually caused by the haematogenous dissemination of septic emboli carried to the terminal blood vessels of bone and joints from distant infectious processes during transient bacteraemia. Early diagnosis is the cornerstone for the successful management of BJI, but it is still a challenge for paediatricians, particularly due to its nonspecific clinical presentation and to the poor specificity of the laboratory and imaging first-line tests that are available in emergency departments. Moreover, microbiological diagnosis is often difficult to achieve with common blood cultures, and further investigations require invasive procedures. The aim of this narrative review is to provide the most recent evidence-based recommendations on appropriate antinfective therapy in BJI in children. We conducted a review of recent literature by examining the MEDLINE (Medical Literature Analysis and Retrieval System Online) database using the search engines PubMed and Google Scholar. The keywords used were “osteomyelitis”, OR “bone infection”, OR “septic arthritis”, AND “p(a)ediatric” OR “children”. When BJI diagnosis is clinically suspected or radiologically confirmed, empiric antibiotic therapy should be started as soon as possible. The choice of empiric antimicrobial therapy is based on the most likely causative pathogens according to patient age, immunisation status, underlying disease, and other clinical and epidemiological considerations, including the local prevalence of virulent pathogens, antibiotic bioavailability and bone penetration. Empiric antibiotic treatment consists of a short intravenous cycle based on anti-staphylococcal penicillin or a cephalosporin in children aged over 3 months with the addition of gentamicin in infants aged under 3 months. An oral regimen may be an option depending on the bioavailability of antibiotic chosen and clinical and laboratory data. Strict clinical and laboratory follow-up should be scheduled for the following 3–5 weeks. Further studies on the optimal therapeutic approach are needed in order to understand the best first-line regimen, the utility of biomarkers for the definition of therapy duration and treatment of complications.

New Insights into Adult and Paediatric Chronic Non-bacterial Osteomyelitis CNO

Purpose of Review

To describe in detail the clinical synopsis and pathophysiology of chronic non-bacterial osteomyelitis and SAPHO syndrome.

Recent Findings

Chronic non-bacterial osteomyelitis (CNO) has been identified as a disease entity for almost 50 years. This inflammatory bone disorder is characterized by osteolytic as well as hyperostotic/osteosclerotic lesions. It is chronic in nature, but it can present with episodic flairs and phases of remission, which have led to the denomination “chronic recurrent osteomyelitis”, with its severe multifocal form “chronic recurrent multifocal osteomyelitis” (CRMO). For almost three decades, an infectious aetiology had been considered, since especially Propionibacterium acnes had been isolated from bone lesions of individual patients. However, this concept has been challenged since long-term antibiotic therapy did not alter the course of disease and modern microbiological techniques (including PCR) failed to confirm bone infection as an underlying cause. Over recent years, a profound dysregulation of cytokine expression profiles has been demonstrated in innate immune cells of CNO patients. A hallmark of monocytes from CNO patients is the failure to produce immune regulatory cytokines interleukin-10 (IL-10) and IL-19, which have been linked with genetic and epigenetic alterations. Subsequently, a significant upregulation of pro-inflammatory, NLRP3 inflammasome-dependent cytokines (IL-1β and TNF-α), has been demonstrated.

Summary

The current knowledge on CNO, the underlying molecular pathophysiology, and modern imaging strategies are summarized; differential diagnoses, treatment options, outcome measures, as well as quality of life studies are discussed.

Characteristics of Pyogenic Musculoskeletal Infections in Older Children and Adolescents

The characteristics and clinical consequences of pyogenic bone and joint infections in older children and adolescents have received little attention. This study evaluated the presentation and complications of musculoskeletal infections involving the pelvis and extremities in children older than 10 years. Thirty patients 10 to 17 years old (mean, 12.7 years old) were treated for musculoskeletal infections. Mean time to diagnosis was 9.2 days. Prior to correct diagnosis, 83% were assessed by at least 1 outpatient provider. At the time of admission, 55% were weight bearing and 93% were afebrile. Twenty-eight percent had a multifocal infection. More than one-third had serious medical complications or orthopedic sequelae; compared with patients without complications, this group had a significantly higher admission C-reactive protein and longer hospital stay. Symptoms of musculoskeletal infection common among young children may be absent in adolescents. Axial imaging is recommended to identify adjacent or multifocal disease. The Kocher criteria are less sensitive for septic hip arthritis in the adolescent population. Prompt recognition and treatment are critical to avoid medical and musculoskeletal complications. [Orthopedics. 2020;43(4):e291-e298.].

Defining the volume of consultations for musculoskeletal infection encountered by pediatric orthopaedic services in the United States

Objective

Adequate resources are required to rapidly diagnose and treat pediatric musculoskeletal infection (MSKI). The workload MSKI consults contribute to pediatric orthopaedic services is unknown as prior epidemiologic studies are variable and negative work-ups are not included in national discharge databases. The hypothesis was tested that MSKI consults constitute a substantial volume of total consultations for pediatric orthopaedic services across the United States.

Study design

Eighteen institutions from the Children’s ORthopaedic Trauma and Infection Consortium for Evidence-based Study (CORTICES) group retrospectively reviewed a minimum of 1 year of hospital data, reporting the total number of surgeons, total consultations, and MSKI-related consultations. Consultations were classified by the location of consultation (emergency department or inpatient). Culture positivity rate and pathogens were also reported.

Results

87,449 total orthopaedic consultations and 7,814 MSKI-related consultations performed by 229 pediatric orthopaedic surgeons were reviewed. There was an average of 13 orthopaedic surgeons per site each performing an average of 154 consultations per year. On average, 9% of consultations were MSKI related and 37% of these consults yielded positive cultures. Finally, a weak inverse monotonic relationship was noted between percent culture positivity and percent of total orthopedic consults for MSKI.

Conclusion

At large, academic pediatric tertiary care centers, pediatric orthopaedic services consult on an average of ~3,000 ‘rule-out’ MSKI cases annually. These patients account for nearly 1 in 10 orthopaedic consultations, of which 1 in 3 are culture positive. Considering that 2 in 3 consultations were culture negative, estimating resources required for pediatric orthopaedic consult services to work up and treat children based on culture positive administrative discharge data underestimates clinical need. Finally, ascertainment bias must be considered when comparing differences in culture rates from different institution’s pediatric orthopaedics services, given the variability in when orthopaedic physicians become involved in a MSKI workup.

Pediatric Community-Acquired Bone and Joint Staphylococcus Aureus Infections In Europe: Severe Infections are Associated to Panton-Valentine Leucocidin Presence

To analyze host and pathogen factors related to disease severity of community-acquired bone and joint infections in children, a cohort of pediatric patients was prospectively recruited from 13 centers in 7 European countries. A total of 85 children were included, 11 (13%) had a severe infection. Panton-Valentine leukocidin-positive isolates were 17%, and 6% of the isolates were methicillin-resistant Staphylococcus aureus. Multivariate analysis identified Panton-Valentine leukocidin presence (adjusted odds ratio, 12.6; P = 0.01) as the only factor independently associated with severe outcome, regardless of methicillin resistance.

Oral Antibiotics Are Effective for the Treatment of Hand Osteomyelitis in Children

Background: Acute osteomyelitis of the hand is common in the pediatric population. Treatment with intravenous antibiotics is expensive and is associated with catheter-site infection and thrombosis. The purpose of this study is to investigate the efficacy of managing osteomyelitis of the hand in children with oral antibiotics. Methods: A retrospective review of cases of acute osteomyelitis of the hand at a single pediatric institution over a 4.5-year period was performed. Demographic and clinical data were reviewed, and treatment courses and outcomes were analyzed. Results: In total, 21 patients with acute osteomyelitis of the hand were included in the study. Of the 21 patients, 17 were initiated on a 6-week course of oral antibiotics upon diagnosis. Thirteen were successfully treated with oral antibiotics alone, 3 required subsequent surgical debridement, and 3 required conversion to intravenous antibiotics. Of the 21 patients, 4 were treated with surgical debridement upon diagnosis due to gross purulent drainage and then initiated on a 6-week course of oral antibiotics. All patients who underwent debridement were treated successfully with postoperative oral antibiotics. Conclusions: Most cases of osteomyelitis of the hand in children can be treated with oral antibiotics, either as the primary treatment or as postoperative therapy. Surgical debridement is indicated when purulence is present at the time of initial diagnosis or if the infection progresses during treatment with oral antibiotics. The use of oral antibiotics for treating acute osteomyelitis of the hand in children may result in decreased cost and fewer catheter-associated complications.

Rapid identification of pathogens involved in pediatric osteoarticular infections by multiplex PCR

Background

Delays in the diagnosis of pediatric osteoarticular infections (OAIs) can cause associated acute complications or long-term morbidity. This study attempts to develop a multiplex PCR-based assay that can rapidly and accurately detect the main pathogens involved in pediatric OAIs, namely, methicillin-sensitive or methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa.

Methods

A set of four gene-specific primers suitable for use in a one-tube PCR assay was designed to detect four common pathogens involved in pediatric OAIs, namely, nuc for methicillin-sensitive Staphylococcus aureus, nuc and mecA for methicillin-resistant Staphylococcus aureus, spyM for Streptococcus pyogenes and orpI for Pseudomonas aeruginosa. The multiplex PCR was first evaluated with 39 isolated clinical strains and further with 41 specimens collected from patients suspected of having OAIs.

Results

Specific primer pairs were successfully designed, and the targeted genes were simultaneously amplified. The product sizes in the assay for nuc, mecA, spyM and oprI were 233, 158, 336 and 109 bp, respectively. Evaluation of the multiplex PCR with 39 isolated clinical strains and 41 specimens revealed 100% sensitivity and 100% specificity. The limit of detection of the multiplex PCR assay was approximately 1×10³ CFU at the bacterial cell level.

Conclusions

This newly developed multiplex PCR assay, without sequencing, enables a rapid and accurate diagnosis of the major bacterial species in children with OAIs and might serve as an additional diagnostic approach for urgent pathogen determination.

Kingella kingae and Osteoarticular Infections

OBJECTIVES

In this study, we aimed to contrast the bacteriologic epidemiology of osteoarticular infections (OAIs) between 2 patient groups in successive 10-year periods, before and after the extensive use of nucleic acid amplification assays in the diagnostic process.

METHODS

Epidemiologic data and bacteriologic etiologies of all children presenting with OAIs on admission to our institution over 20 years (1997-2016) were assessed retrospectively. The population was divided into 2 cohorts, using the standardized use of polymerase chain reaction as the cutoff point (2007). The conventional cohort included children with OAIs mainly investigated by using classic cultures, whereas the molecular cohort referred to patients also investigated by using molecular assays.

RESULTS

Kingella kingae was the most frequently isolated pathogen, responsible for 51% of OAIs, whereas other classic pathogens were responsible for 39.7% of cases in the molecular cohort. A statistically significant increase in the mean incidence of OAIs was observed, as was a decrease in the mean age at diagnosis after 2007. After 2007, the pathogen remained unidentified in 21.6% of OAIs in our pediatric population.

CONCLUSIONS

Extensive use of nucleic acid amplification assays improved the detection of fastidious pathogens and has increased the observed incidence of OAI, especially in children aged between 6 and 48 months. We propose the incorporation of polymerase chain reaction assays into modern diagnostic algorithms for OAIs to better identify the bacteriologic etiology of OAIs.

Experience With a Care Process Model in the Evaluation of Pediatric Musculoskeletal Infections in a Pediatric Emergency Department

OBJECTIVES

Care process models (CPMs) for certain conditions have improved clinical outcomes in children. This study describes the implementation and impact of a CPM for the evaluation of musculoskeletal infections in a pediatric emergency department (ED).

METHODS

A retrospective pre-post intervention study was performed to analyze the impact of a musculoskeletal infection CPM. Patients were identified retrospectively through electronic order history for imaging of an extremity or joint and recommended laboratory tests. Clinical outcomes evaluated included hospital length of stay (LOS), time to magnetic resonance imaging (MRI), time to administration of antibiotics, hospital admission rate, and 30-day readmission rate.

RESULTS

Musculoskeletal infection evaluations completed in the ED were reviewed from 1 year before implementation (n = 383) and 2 years after implementation (n = 1219) of the CPM. A significant improvement in the time to antibiotic administration for all patients (4.3 vs 3.7 hours, P < 0.05) and for patients with confirmed musculoskeletal infections (9.5 vs 4.9 hours, P < 0.05) was observed after the implementation of the CPM. The overall time to MRI (13.2 vs 10.3 hours, P = 0.29) and hospital LOS (4.7 vs 3.7 days, P = 0.11) were improved for all patients but were not statistically significant. The admission rate and 30-day readmission were similar before and after the implementation of the CPM.

CONCLUSIONS

The implementation of a musculoskeletal infection CPM has standardized the approach to the evaluation and diagnosis of musculoskeletal infections resulting in a significant decrease in the time to administer antibiotics and a downward trend in time to MRI and hospital LOS.

Validation and Modification of a Severity of Illness Score for Children With Acute Hematogenous Osteomyelitis

BACKGROUND

Children with osteomyelitis demonstrate a wide spectrum of illness. Objective measurement of severity is important to guide resource allocation and treatment decisions, particularly for children with advanced illness. The purpose of this study is to validate and improve a previously published severity of illness scoring system for children with acute hematogenous osteomyelitis (AHO).

METHODS

Children with AHO were prospectively studied during evaluation and treatment by a multidisciplinary team who provided care according to evidence-based guidelines to reduce variation. A severity of illness score was calculated for each child and correlated with surrogate measures of severity. Univariate analysis was used to assess the significance of each parameter within the scoring model along with new parameters, which were evaluated to improve the model. The scoring system was then modified by the addition of band count to replace respiratory rate. The modified score was calculated and applied to the prospective cohort followed by correlation with the surrogate measures of severity.

RESULTS

One hundred forty-eight children with AHO were consecutively studied. The original severity of illness score correlated well with length of stay and other established measures of severity. Band percent of the white blood cell differential ≥1.5% was found to be significantly associated with severity and chosen to replace respiratory rate in the model. The modified calculated severity scores correlated well with the chosen surrogate measures and significantly differentiated children with osteomyelitis on the basis of causative organism, length of stay, intensive care, surgeries, bacteremia, and disseminated or multifocal disease.

CONCLUSIONS

The findings of this study validate the previously published severity of illness scoring tool in large cohort of children who were prospectively evaluated. The replacement of respiratory rate with band count improved the scoring system.

Can a Septic Hip Decision Rule Aid in the Evaluation of Suspected Pediatric Musculoskeletal Infections?

BACKGROUND

Musculoskeletal (MSK) infections can be difficult to diagnose in acute care settings. The utility of clinical decision tools for pediatric MSK infections in an emergency department has not been well studied.

OBJECTIVE

Our aim was to evaluate the performance of a septic hip clinical decision rule (CDR) in the evaluation of pediatric musculoskeletal infections.

METHODS

We performed a retrospective study of children evaluated for an MSK infection in our emergency department from 2014 to 2016. Data collection included demographics, discharge diagnoses, and clinical/laboratory predictors from the CDR. A χ² analysis and Wilcoxon rank-sum tests compared patients with and without MSK infections. Logistic regression analysis examined the predictors for MSK infections. A receiver operating characteristic (ROC) curve was calculated to evaluate the performance of the predictors.

RESULTS

Of 996 evaluations included in the final analysis, 109 (10.9%) had MSK infections. In a multivariable model, an adjusted odds ratio (OR) was significant for fever (OR 3.9, 95% confidence interval [CI] 2.4-6.4), refusal to bear weight/pseudoparalysis (OR 4.4, 95% CI 2.7-7.1), and C-reactive protein (CRP) > 2.0 mg/dL (OR 5.4, 95% CI 3.2-9.1). The probability of infection was 75.1% with five predictors present, 1.9% for zero predictors, and 5.1% if one predictor was present. An ROC curve showed an area under the curve of 0.82, indicating moderate accuracy.

CONCLUSIONS

A septic hip CDR demonstrates a low predicted probability of an MSK infection with zero or one clinical predictor present and moderate predictability with all five predictors. Fever, refusal to bear weight/pseudoparalysis, and CRP > 2.0 mg/dL performed best and should alert providers to consider other MSK infections in addition to septic arthritis.

Use of a Clinical Care Algorithm to Improve Care for Children With Hematogenous Osteomyelitis

BACKGROUND AND OBJECTIVES

Acute hematogenous osteomyelitis (AHO) causes significant morbidity in children. Quality improvement (QI) methods have been used to successfully improve care and decrease costs through standardization for numerous conditions, including pediatric AHO. We embarked on a QI initiative to standardize our approach to the inpatient management of AHO, with a global aim of reducing inpatient costs.

METHODS

We used existing literature and local consensus to develop a care algorithm for the inpatient management of AHO. We used the Model for Improvement as the framework for the project, which included process mapping, failure mode analysis, and key driver identification. We engaged with institutional providers to achieve at least 80% consensus regarding specific key drivers and tested various interventions to support uptake of the care algorithm.

RESULTS

Fifty-seven patients were included. There were 31 patients in the preintervention cohort and 26 in the postintervention cohort, of whom 19 were managed per the algorithm. Mean inpatient charges decreased from $45 718 in the preintervention cohort to $32 895 in the postintervention cohort; length of stay did not change. Adherence to recommended empirical antimicrobial agents trended upward.

CONCLUSIONS

A simple and low-cost QI project was used to safely decrease the cost of inpatient care for pediatric AHO at a tertiary care children's hospital. A robust local consensus process proved to be a key component in the uptake of standardization.

Comparison of Methicillin-resistant Versus Susceptible Staphylococcus aureus Pediatric Osteomyelitis

BACKGROUND

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) pediatric osteomyelitis has risen and been associated with a more severe clinical course than methicillin-susceptible Staphylococcus aureus (MSSA) infections. National databases have been underutilized to describe these trends. We compared demographics, clinical course, and outcomes for patients with MRSA versus MSSA osteomyelitis.

METHODS

We queried the 2009 and 2012 Healthcare Cost and Utilization Project Kids Inpatient Database for discharge records with diagnosis codes for osteomyelitis and S. aureus. We explored demographics predicting MRSA and evaluated MRSA versus MSSA as predictors of clinical outcomes including surgery, sepsis, thrombophlebitis, length of stay, and total charges.

RESULTS

A total of 4214 discharge records were included. Of those, 2602 (61.7%) had MSSA and 1612 (38.3%) had MRSA infections. Patients at Southern and Midwestern hospitals were more likely to have MRSA than those at Northeastern hospitals. Medicaid patients' odds of MRSA were higher than those with private insurance, and black patients were more likely to have MRSA compared with white patients. MRSA patients were more likely to undergo multiple surgeries compared with MSSA patients and were more likely to have complications including severe sepsis, thrombophlebitis, and pulmonary embolism. Patients with MRSA had longer lengths of stay than those with MSSA and higher total charges after controlling for length of stay.

CONCLUSION

Review of a national database demonstrates MRSA is more prevalent in the South and Midwest regions and among black patients. MRSA patients have more surgeries, complications, and longer lengths of stay.

LEVEL OF EVIDENCE

Level III.

Diagnosis and management of acute osteoarticular infections in children

Acute hematogenous osteomyelitis and septic arthritis are not uncommon infections in children and should be considered as part of the differential diagnosis of limb pain and pseudoparalysis. Most bone infections in children arise secondary to hematogenous seeding of bacteria into bone. The most common pathogens are Staphylococcus aureus and Kingella kingae. Children with septic arthritis should be evaluated promptly by orthopedic specialists for aspiration and possible debridement of concomitant osteomyelitis. Optimal empiric therapy after appropriate cultures continues to be intravenous cefazolin. In most cases, conversion to oral antimicrobials should occur when the patient has clinically improved and has decreasing inflammatory markers. For most uncomplicated cases of osteomyelitis, current recommendations are 3 to 4 weeks of antimicrobial therapy compared with the 6 weeks previously recommended.

Performance of TEM-PCR vs Culture for Bacterial Identification in Pediatric Musculoskeletal Infections

Improved diagnostics are needed for children with musculoskeletal infections (MSKIs). We assessed the performance of target-enriched multiplex polymerase chain reaction (TEM-PCR) in children with MSKI. TEM-PCR was concordant with culture in pathogen identification and antibiotic susceptibility testing, while increasing the overall yield of pathogen detection. This technology has the potential to inform judicious antimicrobial use early in the disease course.

Seasonal Variation and Weather Changes Related to the Occurrence and Severity of Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Acute hematogenous osteomyelitis (AHO) demonstrates regional variability in incidence and severity. In this study, we evaluated seasonal variations of AHO and assessed the effects of weather trends on the occurrence and severity of illness in affected children.

METHODS

National Weather Service data from the dates of symptom onset and of admission of children with AHO were gathered. Seasonal occurrence rates and the weather patterns were studied according to severity-of-illness category. Statistical analysis was performed with Pearson and Spearman correlations and analysis of variance.

RESULTS

A total of 209 children with AHO were admitted within 21 days of symptom onset (average, 5.0 ± 3.8 days). Severity-of-illness scores ranged from 0 to 10 (average, 3.2 ± 3.2). Symptom onset occurred most commonly in summer (73 [34.9%]) or spring (54 [25.8%]). We found a significant correlation between severity of illness and minimum temperature at symptom onset during the summer season (P = .020). A significant change in average humidity (21.6%) occurred during the winter between the date of symptom onset and the date of admission for children with severe illness (P = .020).

DISCUSSION

This study identified seasonal variation in the occurrence of AHO in children; summer was the most common season for occurrence. To our knowledge, this is the first detailed evaluation of weather parameters and trends in weather changes from symptom onset to admission with consideration of the effects of weather on the occurrence of infection and severity of illness.

Comparison of Empiric Antibiotics for Acute Osteomyelitis in Children

OBJECTIVES

Broad-spectrum antibiotics are commonly used for the empiric treatment of acute hematogenous osteomyelitis and often target methicillin-resistant Staphylococcus aureus (MRSA) with medication-associated risk and unknown treatment benefit. We aimed to compare clinical outcomes among patients with osteomyelitis who did and did not receive initial antibiotics used to target MRSA.

METHODS

A retrospective cohort study of 974 hospitalized children 2 to 18 years old using the Pediatric Health Information System database, augmented with clinical data. Rates of hospital readmission, repeat MRI and 72-hour improvement in inflammatory markers were compared between treatment groups.

RESULTS

Repeat MRI within 7 and 180 days was more frequent among patients who received initial MRSA coverage versus methicillin-sensitive S aureus (MSSA)-only coverage (8.6% vs 4.1% within 7 days [P = .02] and 12% vs 5.8% within 180 days [P < .01], respectively). Ninety- and 180-day hospital readmission rates were similar between coverage groups (9.0% vs 8.7% [P = .87] and 10.9% vs 11.2% [P = .92], respectively). Patients with MRSA- and MSSA-only coverage had similar rates of 72-hour improvement in C-reactive protein values, but patients with MRSA coverage had a lower rate of 72-hour white blood cell count normalization compared with patients with MSSA-only coverage (4.2% vs 16.4%; P = .02).

CONCLUSIONS

In this study of children hospitalized with acute hematogenous osteomyelitis, early antibiotic treatment used to target MRSA was associated with a higher rate of repeat MRI compared with early antibiotic treatment used to target MSSA but not MRSA. Hospital readmission rates were similar for both treatment groups.

Serologic Detection of Antibodies Targeting the Leukocidin LukAB Strongly Predicts Staphylococcus aureus in Children With Invasive Infection

BACKGROUND

Staphylococcus aureus is among the most commonly identified causes of invasive bacterial infection in children; however, reliable results from cultures of sterile-site samples often cannot be obtained, which necessitates prescription of a broad empiric antimicrobial agent(s). Children with invasive S aureus infection rapidly generate high antibody titers to the cytotoxin LukAB; therefore, the aim of this study was to assess the diagnostic utility of an anti-LukAB antibody assay for children with musculoskeletal infection (MSKI).

METHODS

We conducted a 2-year prospective study of all eligible children admitted to Vanderbilt Children's Hospital with an MSKI. Acute and convalescent sera were obtained, and antibodies that target LukAB were measured by an enzyme-linked immunosorbent assay.

RESULTS

Forty-two children were enrolled. The median concentrations of LukAB antibodies for children with S aureus infection were 130.3 U/mL in the acute phase and 455 U/mL in the convalescent phase (P < .001). The median concentrations of LukAB antibodies in children with a non-S aureus MSKI were 8.6 U/mL in the acute phase and 9.7 U/mL in the convalescent phase. The assay discriminated between S aureus and non-S aureus infection with areas under the receiver operating characteristic curve of 0.81 (95% confidence interval, 0.67-0.95; P < .001) and 0.95 (95% confidence interval, 0.86-1; P < .001) for samples tested in the acute and follow-up periods, respectively. With no false-negative results, the assay accurately ruled out S aureus in samples obtained during the convalescent phase.

CONCLUSION

Culture-independent diagnostics have the potential to improve care by narrowing antimicrobial therapy on the basis of the likelihood of S aureus infection. The results of this proof-of-concept study suggest that a LukAB serologic assay might be useful in the diagnosis of invasive bacterial infections, and larger-scale validation studies are warranted.

Patient Factors Associated With Methicillin-Resistant Staphylococcus aureus Septic Arthritis in Children

Staphylococcus aureus is the most common causative organism in pediatric septic arthritis, with methicillin-resistant Staphylococcus aureus (MRSA) being responsible for a significant portion of these infections. Early identification and initiation of proper treatment may improve outcomes by minimizing potential morbidity. The purpose of this study was to identify variables obtained on initial patient presentation associated with MRSA septic arthritis. Sixteen factors were retrospectively evaluated in 109 consecutive pediatric patients diagnosed with culture-confirmed septic arthritis. Graphical and logistical regression analyses were employed to determine factors independently predictive of MRSA septic arthritis. Twenty-seven (25%) patients had MRSA and 82 (75%) had non-MRSA septic arthritis. C-reactive protein of 13.7 mg/L or greater, duration of symptoms of 4 days or more, heart rate of 126 beats per minute or greater, and absolute neutrophil count of 8.72×10³ cells/µL or greater were associated with MRSA septic arthritis. Ultimately, 98% of patients with 1 or no risk factors had non-MRSA and 96% of patients with MRSA septic arthritis had 2 or more positive risk factors. Elevated C-reactive protein, duration of symptoms, heart rate, and absolute neutrophil count are predictive of MRSA infection in the setting of pediatric septic arthritis and can be obtained on initial evaluation. In patients for whom there is concern for MRSA infection, this may guide more expedient treatment, such as early initiation of contact precautions and appropriate antibiotic therapy before culture results become available. [Orthopedics. 2018; 41(2):e277-e282.].

The Contemporary Bacteriologic Epidemiology of Osteoarticular Infections in Children in Switzerland

OBJECTIVES

To assess the contemporary bacteriologic epidemiology of pediatric osteoarticular infection with particular regard to children's ages, because Kingella kingae has gained increasing recognition as the predominant pathogen for osteoarticular infection in young children.

STUDY DESIGN

Retrospective file review of enrolled children from 0 to 15 years of age, admitted to our institution from 2007 to 2015 for suspected osteoarticular infection (217 cases). Information on age, sex, the bone or joint infected, imaging studies, and laboratory data (including bacterial investigations) were collected for analysis.

RESULTS

Microorganism identification was possible for 138 infected children (63.6%), through blood (cultures or polymerase chain reaction [PCR]) and/or operative samples (cultures or PCR). Thirty-one patients (14.3%) were found to both have positive blood cultures and operative samples. The results of positive bacteriology specimens identified the most common causative pathogen for osteoarticular infection as K kingae (47.8% of microbiologically confirmed osteoarticular infections of all ages, and 87.7% in children between the ages of 6 and 48 months), significantly more common than Staphylococcus aureus (35.5% of microbiologically confirmed osteoarticular infections of all ages, and 78.2% in children >4 years of age).

CONCLUSIONS

Use of the appropriate PCR assays demonstrated that K kingae currently is the major bacterial cause of pediatric osteoarticular infection, especially in children <4 years of age in whom K kingae is more common than S aureus. PCR assays should be used in routine microbiologic laboratory evaluation to improve diagnostic performance. However, despite the use of molecular methods, there are many osteoarticular infections in which no microorganism is detected, which suggests that these infections may be caused by other as yet unrecognized fastidious microorganisms.

Comparative Analysis of Spontaneous Infectious Spondylitis : Pyogenic versus Tuberculous

Objective

Spondylitis is often chemotherapy resistant and requires long-term treatment. Without adequate chemotherapy, the outcome can be fatal or result in severe neurologic damage. Therefore, differentiating the etiology of spondylitis is very important, particularly in spontaneous cases. As the prevalence of tuberculosis in Korea has decreased in recent years, updated clinical research about spondylitis is warranted.

Methods

From April 2010 to March 2016, data from spondylitis patients were collected retrospectively. In total, 69 patients (51 with pyogenic spondylitis and 18 with tuberculous spondylitis) were included. Clinical data, laboratory findings including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level, measurements of Cobb angles at the initial and final follow-up, and radiologic features on magnetic resonance imaging (MRI) scans were evaluated. To test differences between the pyogenic and tuberculous groups, numerical data were compared using the student’s t-test and Mann-Whitney U test, and categorical data were compared using the chi-square test and Fisher’s exact test.

Results

The patients’ mean age was 60.0 years. Male sex was slightly predominant (56.5%). There was no difference in mean age and sex between the two groups. The pyogenic group had a relatively higher proportion of immunocompromised patients. The peak CRP value was higher in the pyogenic group than in the tuberculous group (14.08 mg/dL and 8.50 mg/dL, respectively, p=0.009), whereas the ESR was not significantly different between the groups (81.5 mm/h and 75.6 mm/h, respectively, p=0.442). Radiologically, the presence of disc space sparing and vertebral body collapse differed between the groups. In the tuberculous group, the disc was more commonly preserved on contrast-enhanced MRI (50% and 23.5%, respectively, p=0.044), and vertebral body collapse was more common (66.6% and 15.7%, respectively, p<0.001). The mean length of hospitalization was longer in the pyogenic group (56.5 days and 41.2 days, respectively, p=0.001). Four mortality cases were observed only in the pyogenic group. The most commonly isolated microorganism in the pyogenic group was Staphylococcus aureus (S. aureus) (methicillin susceptible S. aureus and methicillin resistant S. aureus [MRSA] in 8 and 4 cases, respectively).

Conclusion

The clinical and radiological manifestations of spontaneous spondylitis differ based on the causative organism. Pyogenic spondylitis patients tend to have a higher CRP level and a more severe clinical course, whereas tuberculous spondylitis patients present with destruction of the vertebral body with disc sparing more frequently. The presence of MRSA is increasing in community-acquired spondylitis cases.