Prediction of Adverse Outcomes in Pediatric Acute Hematogenous Osteomyelitis

Acute Hematogenous Osteomyelitis in Pediatric Patients

This article focuses on the advancements made in diagnostic techniques and drug interventions of acute hematogenous osteomyelitis. A diagnosis necessitates a combination of factors, including inflammatory markers and imaging findings, as well as the collection of specimens for culture when feasible. Subsequently, treatment should be based on epidemiology, mechanisms of resistance, and susceptibility findings. A brief course of intravenous (IV) antibiotics, followed by oral antibiotics, may be employed for uncomplicated infections if there is improvement in the clinical condition and a decline in C-reactive protein levels. However, for complex infections caused by methicillin-resistant Staphylococcus aureus, prolonged administration of IV antibiotics is recommended, along with surgical intervention if necessary. [Pediatr Ann. 2024;53(10):e392-e395.].

Early Bone Ischemia in Pediatric Acute Hematogenous Osteomyelitis and its Association With Progression to Chronic Osteomyelitis: New Insights From Gadolinium-enhanced Subtraction MRI

BACKGROUND

Acute hematogenous osteomyelitis (AHO), the most common osteoarticular infection in children, carries a significant risk for chronic complications. Predicting chronic complications early in the course of disease is challenging. The underlying pathogenesis of complications is not fully understood.

METHODS

Children who presented to Sultan Qaboos University Hospital, Muscat, Oman between January 2015 and April 2022 for AHO were identified by a search of magnetic resonance imaging (MRI) records. Children between 1 month and 18 years of age who did not meet exclusion criteria, and whose MRI also included gadolinium-enhanced subtraction (GES) sequences were included in the analysis. Outcomes were compared between patients who showed early evidence of bone ischemia and those who did not.

RESULTS

The analysis included 11 children who had GES MRI sequences from among 18 AHO cases in total. Median age was 5 years (IQR, 4-9), and 82% were males. Median duration of symptoms at presentation was 5 days (IQR, 3-7). GES sequences showed early bone ischemia in 6 of 11 (55%) patients. Patients with early bone ischemia were treated with significantly longer durations of IV antibiotics (median 23 vs. 10 days, P = 0.017) and oral antibiotics (median 134 vs. 29 days, P = 0.004), and required more surgical debridements (median 3 vs. 0 debridements, P = 0.017). Chronic osteomyelitis only developed among patients with early bone ischemia (5/6 vs. 0/5, P = 0.015).

CONCLUSIONS

In pediatric AHO, GES MRI sequences revealed early bone ischemia in a significant proportion of patients. Early bone ischemia was strongly associated with progression to chronic osteomyelitis.

Accelerated Severity of Illness Score Enhances Prediction of Complicated Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Severity of illness determination for children with acute hematogenous osteomyelitis should be accomplished during the earliest stages of evaluation to guide treatment and establish prognosis. This study objectively defines an outcome of complicated osteomyelitis and explores an illness severity-based model with an improved ability to predict this outcome as soon and accurately as possible, comparing it to existing models.

METHODS

Children with Staphylococcus aureus acute hematogenous osteomyelitis (n = 438) were retrospectively studied to identify adverse events and predictors of severity. The outcome of complicated osteomyelitis was ultimately defined as the occurrence of any major or at least 3 minor adverse events, which occurred in 52 children. Twenty-four clinical and laboratory predictors were evaluated through univariate and stacked multivariable regression analyses of chronologically distinct groups of variables. Receiver operating characteristic curve analyses were conducted to compare models.

RESULTS

Accelerated Severity of Illness Score included: triage tachycardia [odds ratio: 10.2 (95% confidence interval: 3.48-32.3], triage tachypnea [6.0 (2.4-15.2)], C-reactive proteininitial ≥17.2 mg/dL [4.5 (1.8-11.8)], white blood cell count band percentageinitial >3.8% [4.6 (2.0-11.0)], hemoglobininitial ≤10.4 g/dL [6.0 (2.6-14.7)], methicillin-resistant S. aureus [3.0 (1.2-8.5)], septic arthritis [4.5 (1.8-12.3)] and platelet nadir [7.2 (2.7-20.4)]. The receiver operating characteristic curve of Accelerated Severity of Illness Score [area under the curve = 0.96 (0.941-0.980)] were superior to those of Modified Severity of Illness Score = 0.903 (0.859-0.947), Acute Score for Complications of Osteomyelitis Risk Evaluation = 0.878 (0.830-0.926) and Chronic Score for Complications of Osteomyelitis Risk Evaluation = 0.858 (0.811-0.904). Successive receiver operating characteristic curve analyses established an exponentially increasing risk of complicated osteomyelitis for children with mild (0/285 or 0%), moderate (4/63 or 6.3%), severe (15/50 or 30.0%) and hyper-severe (33/40 or 82.5%) acute hematogenous osteomyelitis (P<0.0001).

CONCLUSIONS

This study improves upon previous severity of illness models by identifying early predictors of a rigorously defined outcome of complicated osteomyelitis.

Clinical characteristics of and risk factors for poor outcomes in children with bacterial culture-negative septic arthritis of the hip

BACKGROUND

Septic arthritis of the hip is a serious infection in children. However, blood and joint fluid cultures are often negative, which makes the diagnosis and treatment challenging. We analyzed the clinical features of children with septic arthritis of the hip with negative bacterial cultures and identified the risk factors for poor outcomes.

METHODS

The clinical data of children with septic arthritis of the hip with negative bacterial cultures who were treated at our hospital from January 2010 to December 2020 were retrospectively analyzed. The clinical characteristics and outcomes of the culture-negative cohort were compared with those of children with positive bacterial cultures treated during the same period. Culture-negative patients were divided into a group with good outcomes and a group with poor outcomes. The differences between the two groups were compared.

RESULTS

Thirty-nine children with culture-negative septic arthritis of the hip were compared with 37 children with culture-positive sepsis. Compared with the culture-positive group, the culture-negative group had a significantly younger mean age and a significantly lower mean serum C-reactive protein concentration. Logistic regression analysis of culture-negative patients with good versus poor outcomes revealed that the independent risk factors for poor outcomes were an increased serum C-reactive protein concentration and prolonged time from onset to surgery. The cut-off values for predicting a poor outcome in the culture-negative group were a time from onset to surgery of greater than 21 days and a C-reactive protein concentration of greater than 23 mg/L.

CONCLUSIONS

Culture-negative septic arthritis of the hip has similar clinical features to culture-positive septic arthritis of the hip and can result in sequelae of varying severity. Therefore, active anti-infective and hip drainage therapy should be performed when children present with clinical symptoms, inflammatory marker concentrations, and imaging findings that are clinically diagnostic for septic arthritis of the hip.

LEVEL OF EVIDENCE

Level II, retrospective study.

Predictive value of PAR and PNI for the acute complicated course of pediatric acute hematogenous osteomyelitis

OBJECTIVE

Platelet to albumin ratio (PAR) and prognostic nutritional index (PNI) are potential indicators for evaluating nutritional and inflammatory status. This study aimed to examine the relationship between PAR and PNI and the acute complicated course of acute hematogenous osteomyelitis (AHO).

METHODS

AHO patients were divided into the simple course group and the acute complicated course group. The patient's gender, age, site of infection, body temperature, laboratory results, and pathogen culture results were collected and compared. Multivariate logistic regression analysis was used to determine the independent risk factors of the acute complicated course group. The receiver operating characteristic curve was applied to determine the optimal cut-off value.

RESULTS

In total, 101 AHO patients with a median age of 7.58 years were included. There were 63 cases (62.4 %) in the simple course group and 38 cases (37.6 %) in the complicated course group. Binary logistic regression analysis revealed that PAR and PNI were independent risk factors for predicting the acute complicated course of AHO (p = 0.004 and p < 0.001, respectively). Receiver operating characteristic curve analysis demonstrated that the combination of PAR and PNI had an area under the curve of 0.777 (95 % CI: 0.680-0.873, p < 0.001) with a cut-off value of 0.51.

CONCLUSIONS

The incidence of acute complicated courses was significantly higher in patients with high PAR and low PNI. A combined factor greater than 0.51, derived from PAR and PNI measurements within 24 h of admission, may be useful for predicting AHO patients who are likely to develop severe disease.

Developing a nomogram for predicting acute complicated course in pediatric acute hematogenous osteomyelitis

BACKGROUND

The objective of this study was to develop and validate a nomogram for predicting the risk of an acute complicated course in pediatric patients with Acute Hematogenous Osteomyelitis (AHO).

METHODS

A predictive model was developed based on a dataset of 82 pediatric AHO patients. Clinical data, imaging findings, and laboratory results were systematically collected for all patients. Subsequently, biomarker indices were calculated based on the laboratory results to facilitate a comprehensive evaluation. Univariate and multivariate logistic regression analyses were conducted to identify factors influencing early adverse outcomes in AHO. A nomogram model was constructed based on independent factors and validated internally through bootstrap methods. The discriminative ability, calibration, and clinical utility of the nomogram model were assessed using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA), respectively. The developed nomogram model was compared with previously published A-score and Gouveia scoring systems.

RESULTS

Logistic regression analysis identified delayed source control, suppurative arthritis, albumin on admission, and platelet to lymphocyte ratio (PLR) as independent predictors of early adverse outcomes in pediatric AHO patients. The logistic regression model was formulated as: Log(P) = 7. 667-1.752 × delayed source control - 1.956 × suppurative arthritis - 0.154 × albumin on admission + 0.009 × PLR. The nomogram's AUC obtained through Bootstrap validation was 0.829 (95% CI: 0.740-0.918). Calibration plots showed good agreement between predictions and observations. Decision curve analysis demonstrated that the model achieved net benefits across all threshold probabilities. The predictive efficacy of our nomogram model for acute complicated course in pediatric AHO patients surpassed that of the A-score and Gouveia scores.

CONCLUSIONS

A predictive model for the acute complicated course of pediatric AHO was established based on four variables: delayed source control, suppurative arthritis, albumin on admission, and PLR. This model is practical, easy to use for clinicians, and can aid in guiding clinical treatment decisions.

Analysis of poor prognostic factors for septic arthritis of the hip in children: a case series of 76 patients

The clinical characteristics, treatment and outcomes of children with septic arthritis of the hip in our hospital were analyzed to identify the risk factors for a poor prognosis. The clinical data of 76 children with septic arthritis of the hip who were treated at our hospital from January 2010 to December 2020 were retrospectively analyzed. According to the most recent follow-up data, the patients were classified as good prognosis or poor prognosis. The differences between the two groups were analyzed. From January 2010 to December 2020, a total of 76 children with septic arthritis of the hip were admitted to our hospital, comprising 52 (68.4%) with a good prognosis and 24 (31.6%) with a poor prognosis. The risk of a poor prognosis was significantly higher in the group with time from onset to surgery >22 days than in the group with time from onset to surgery <11 days. The risk of poor prognosis in the group with C-reactive protein (CRP) > 100 mg/L was significantly higher than that in the group with CRP < 20 mg/L. Time from onset to surgery >14 days and CRP > 93 mg/L were the cutoff values for a poor prognosis. Significant elevation of CRP and prolonged time from onset to surgery in children with septic arthritis of the hip are risk factors for a poor prognosis. Early diagnosis and effective treatment are very important because delays in these factors can lead to a poor prognosis. Level of Evidence: Level II, retrospective study.

Acute Hematogenous Osteomyelitis of the Pelvis in Children

BACKGROUND

Pelvic involvement has been reported in 3%-14% of acute hematogenous osteomyelitis (AHO) cases in children. One guideline suggests need for a longer antibiotic course in pelvic AHO, however, recent data are lacking. We describe the clinical course of children with pelvic AHO and compare it to nonpelvic AHO.

METHODS

A retrospective review of patients with a diagnosis of AHO admitted to Texas Children's Hospital from January 2012 to December 2020 was conducted. Patients 6 months-<19 years old and with ≤14 days of symptoms at admission were eligible. Patients with sickle cell disease or immunocompromised were excluded. Wilcoxon rank-sum test assessed for differences between continuous variables and Fisher exact for categorical variables using STATA 17.

RESULTS

We compared 104 cases of pelvic AHO to 314 cases of nonpelvic AHO. Patients had similar microbiology, length of stay and length of antibiotic therapy. Patients with pelvic AHO had pyomyositis identified by magnetic resonance imaging more often (28.8 vs. 9.4%, P < 0.001) and bone abscess less often (22.1 vs. 46.5%, P < 0.001). Rates of chronic complications were comparable between patients with pelvic AHO and nonpelvic AHO (8.4% vs. 15.1%, P = 0.1). Nineteen patients (18.3%) with pelvic AHO received ≤30 antibiotic days without complications, but they had less need for intensive care or bone abscesses than patients treated longer.

CONCLUSIONS

Pelvic AHO in children may be more frequent than previously reported but is not associated with more complications. Four weeks of therapy may be sufficient in selected patients. Prospective studies to compare outcomes with different lengths of therapy are needed.

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.

CRP Predicts the Need to Escalate Care After Initial Debridement for Musculoskeletal Infection

BACKGROUND

Musculoskeletal infections (MSKIs) are a major cause of morbidity in the pediatric population and account for nearly 1 in every 10 consultations with a pediatric orthopaedic provider at a tertiary care center. To prevent or deescalate the risk of adverse medical and musculoskeletal outcomes, timely medical intervention in the form of antibiotics and potential surgical debridement is required. While there have been numerous studies indicating the value of laboratory testing during the initial workup of a child with MSKI, few studies to date have examined the utility of longitudinal assessment of laboratory measures in the acute setting to monitor the efficacy of antibiotic therapy and/or surgical intervention. The purpose of this investigation was to retrospectively determine whether measuring changes in the inflammatory response could indicate the need for escalated care. Specifically, this study examined the hypothesis that serial measurements of C-reactive protein (CRP), immediately preoperatively and 2 days after surgical debridement, could predict the need for medical (change in antibiotics) or surgical (additional debridement) escalation.

METHODS

Retrospective review of pediatric patients undergoing operative debridement for the treatment of MSKI between September 2009 and December 2015 from whom laboratory data (CRP) was obtained preoperatively and at postoperative day (POD) 2. Patient demographics, the need for escalated care, and patient outcomes were evaluated.

RESULTS

Across 135 pediatric patients, preoperative CRP values >90 mg/L and a positive change in CRP at POD2 effectively predicted the need for escalation of care after initial surgical debridement (Area under the Receiver Operator Curve: 0.883). For each 10-unit increase in preoperative CRP or postoperative change in CRP, there was a 21% or 22% increased risk of needing escalated care, respectively. Stratification by preoperative CRP >90 mg/L and change in CRP postoperatively likewise correlated with increased rates of disseminated disease, percent tissue culture positivity, length of stay, and rate of adverse outcomes.

CONCLUSIONS

This study demonstrates the utility of serial CRP to assess the need for escalated care in patients being treated for MSKI. As serial CRP measurements become standard of practice in the acute setting, future prospective studies are needed to optimize the timing of CRP reassessment during inpatient hospitalization to prognosticate patient outcomes, weighing both improvements of patient care and clinical burden.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Predictors of Developing a Complex Course of Osteomyelitis in Patients with Sickle Cell Anaemia

Objectives

Despite the numerous advances in management strategies, treating osteomyelitis in individuals with sickle cell disease (SCD) remains a significant challenge, leading to severe long-term consequences. This study aimed to assess the key factors potentially linked to a complex progression of osteomyelitis in patients diagnosed with SCD.

Methods

A cohort of 34 patients was identified and their progress was monitored over a span of 12 months during a 10-year period (2010-2020). The variables under investigation encompassed demographic and clinical traits, laboratory analyses and imaging data, as well as the treatment strategies employed.

Results

The risk prediction model pinpointed 5 factors (severity of SCD, involvement of lower limbs, presence of bacteraemia, magnetic resonance image [MRI] findings and utilisation of surgical debridement) that exhibited an area under the curve (AUC) exceeding 0.7. Causative organisms were identified in 9 out of the total 34 patients (26.47%). A total of 17 patients displayed a severe course of SCD (AUC = 7.88), with MRI being highlighted as a valuable contributing factor (AUC = 7.88). Furthermore, 13 patients (38.2%) underwent surgical debridement, a procedure that yielded a statistically significant P value of 0.012 and an AUC of 0.714.

Conclusion

Osteomyelitis within the context of severe SCD, particularly when accompanied by lower extremity infection, bacteraemia, positive MRI findings and the need for surgical debridement, emerges as a cluster of risk factors predisposing individuals to osteomyelitis relapse and a more complex disease course.

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.

Assessing Risk for Complications in Acute Hematogenous Osteomyelitis in Children: Validation of 2 Predictive Scores

BACKGROUND

Acute hematogenous osteomyelitis (AHO) can be associated with severe complications which can be difficult to predict in the clinical setting. The previously published predictive acute complication score ("A-SCORE") and chronic complication score ("C-SCORE") show promise, however, further external validation is needed.

METHODS

We performed a retrospective study of 418 children with AHO and analyzed the performance of A-SCORE (variables included bone abscess, fever after 48 h of starting antibiotics, suppurative arthritis, disseminated disease, and delayed source control) to predict risk for acute complicated course (treatment failure, prolonged admission, and/or need for ≥2 bone debridements) and C-SCORE (includes disseminated disease, bone debridement, and CRP ≥10 mg/dL at 2-4 days after starting antibiotics) to predict chronic complications (growth restriction, pathologic fracture, chronic osteomyelitis, avascular necrosis, joint deformity, and/or frozen joint).

RESULTS

An acute complicated course occurred in 106/418 (25.4%); 51/380 (13.5%) with complete follow-up data had a chronic complication. The A-SCORE performed with similar specificity (78%) and negative predictive value (NPV) (92%), and higher sensitivity (81%) and increased area under the receiver operating curve (AUC) (0.87) in our population. The C-SCORE performed with similar sensitivity (64%) and NPV (94%) but had lower specificity (86%) and AUC (0.71) than originally reported. Other variables associated with development of complications such as tibia involvement and bacteremia ≥2 days were identified but did not result in significantly improved predictive scores.

CONCLUSIONS

Predictive A-SCORE and C-SCORE for AHO complications in children may help guide acute management and long-term follow-up decisions. Prospective studies are needed to determine their applicability.

Osteoarticular Infections: Younger Children With Septic Arthritis and Low Inflammatory Patterns Have a Better Prognosis in a European Cohort

BACKGROUND

Osteoarticular infections (OAI) are associated with complications and sequelae in children, whose prediction are of great importance in improving outcomes. We aimed to design risk prediction models to identify early complications and sequelae in children with OAI.

METHODS

This observational study included children (>3 months-17 years old) with acute OAI admitted to a tertiary-care pediatric hospital between 2008 and 2018. Clinical treatment, complications and sequelae were recorded. We developed a multivariable logistic predictive model for an acute complicated course (ACC) and another for sequelae.

RESULTS

A total of 240 children were identified, 17.5% with ACC and 6.0% and 3.6% with sequelae at 6 and 12 months of follow-up, respectively. In the multivariable logistic predictive model for ACC, predictors were fever at admission [adjusted odds ratio (aOR): 2.98; 95% confidence interval (CI): 1.10-8.12], C-reactive protein ≥100 mg/L (aOR: 2.37; 95% CI: 1.05-5.35), osteomyelitis (aOR: 4.39; 95% CI: 2.04-9.46) and Staphylococcus aureus infection (aOR: 3.50; 95% CI: 1.39-8.77), with an area under the ROC curve of 0.831 (95% CI: 0.767-0.895). For sequelae at 6 months, predictors were age ≥4 years (aOR: 4.08; 95% CI: 1.00-16.53), C-reactive protein ≥110 mg/L (aOR: 4.59; 95% CI: 1.25-16.90), disseminated disease (aOR: 9.21; 95% CI: 1.82-46.73) and bone abscess (OR: 5.46; 95% CI: 1.23-24.21), with an area under the ROC curve of 0.887 (95% CI: 0.815-0.959).

CONCLUSIONS

In our model we could identify patients at low risk for complications and sequelae, probably requiring a less aggressive approach.

Quality of life in children up to 13 years following acute haematogenous osteomyelitis

Acute haematogenous osteomyelitis (AHO) remains a cause of severe illness among children with the possibility of long-term consequences for growth and development. Previous research on sequelae from AHO rarely considers outcomes more than 2 years following treatment. This study aims to establish the quality of life of patients diagnosed with AHO in childhood up to 13 years after diagnosis, evaluating the impact on social, emotional, physical, and school function. Children treated for AHO between 2008 and 2018 at a tertiary referral centre in New Zealand were identified. Paediatric Quality of Life Inventory (PedsQL) questionnaires were conducted via phone with either the child or primary caregiver and responses analysed. Forty patients met inclusion criteria, were contactable by phone, and consented to participate. The mean age was 7 years (range 0-15) and most were female (60%). Health-related quality of life (HRQOL) was scored as a percentage with most participants scoring >80% ( n  = 27). Those who do experience reduced quality of life following treatment for AHO were likely to complain of pain, stiffness, or anxiety. The impact of significant childhood illness on mental health was not adequately captured by the PedsQL but was highlighted in qualitative feedback. The majority of children treated for AHO reported excellent HRQOL up to 13 years following treatment although a negative impact on mental health was reported using qualitative analysis. A refined scoring system is needed to assess the long-term impact of musculoskeletal infection. Patient case series, Level IV.

Pediatric musculoskeletal infections

PURPOSE OF REVIEW

The aim of this article is to review the recent guidelines and literature regarding the diagnosis and the treatment of common pediatric musculoskeletal infections: septic arthritis, osteomyelitis, pyomyositis, and Lyme disease.

RECENT FINDINGS

In the last decade, a better understanding of the causative organisms of common bacterial infections, including Kingella , leads to prompt targeted antimicrobial coverage in all musculoskeletal infections. Prompt diagnosis and treatment continues to be the mainstay in the treatment of children with osteoarticular infections. Efforts to improve early detection have lead to improving rapid lab diagnostic testing; however, more advanced diagnostics such as arthrocentesis for septic arthritis and MRI for osteomyelitis and pyomyositis, remain the gold standard. Shorter and narrowed antibiotic courses, with appropriate transition to outpatient oral treatment provide effective infection clearance and reduction in complications of disease.

SUMMARY

Advances in diagnostics, including pathogen identification as well as imaging continues to improve our ability to diagnose and treat these infections, although still lack ability to provide definitive diagnosis without more invasive nor advanced techniques.

Ten-year Review of Acute Pediatric Hematogenous Osteomyelitis at a New Zealand Tertiary Referral Center

BACKGROUND

Acute hematogenous osteomyelitis (AHO) remains a cause of severe illness among children with the possibility of long-term consequences for growth and development. Recent research has highlighted an unusually high burden of disease in the New Zealand population compared with other Western regions. We have sought to identify trends in presentation, diagnosis, and management of AHO, with added focus on ethnicity and access to health care.

METHODS

A 10-year retrospective review of all patients <16 years with presumed AHO presenting to a tertiary referral center between 2008 and 2018 was performed.

RESULTS

One hundred fifty-one cases met inclusion criteria. The median age was 8 years with a male predominance (69.5%). Staphylococcus aureus was the most common pathogen using traditional laboratory culture method (84%). The number of cases per year decreased from 2008 to 2018. Assessment using New Zealand deprivation scores showed Māori children were most likely to experience socioeconomic hardship ( P ≤0.01). Median distance traveled by families to first hospital consult was 26 km (range 1 to 178 km). Delayed presentation was associated with need for prolonged antibiotic therapy. Incidence of disease varied by ethnicity with 1:9000 cases per year for New Zealand European, 1:6500 for Pacific, and 1:4000 for Māori. Overall recurrence rate was 11%.

CONCLUSIONS

The incidence of AHO in New Zealand is concerningly high within Māori and Pacific populations. Future health interventions should consider environmental, socioeconomic, and microbiological trends in the burden of disease.

LEVEL OF EVIDENCE

Retrospective study, Level III.

Predictive Factors to Guide Empiric Antimicrobial Therapy of Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Acute hematogenous osteomyelitis (AHO) is a serious infection in children. Pediatric Infectious Diseases Society guidelines recommend empiric methicillin-resistant Staphylococcus aureus (MRSA) therapy in regions where MRSA accounts for more than 10-20% of all staphylococcal osteomyelitis. We sought to examine factors present at the time of admission which may predict etiology and guide empiric treatment for pediatric AHO in a region with endemic MRSA.

METHODS

We reviewed admissions with International Classification of Diseases 9/10 codes for AHO from 2011 to 2020 in otherwise healthy children. Medical records were reviewed for clinical and laboratory parameters present on the day of admission. Logistic regression was used to determine clinical variables independently associated with (1) MRSA infection and (2) non-Staphylococcus aureus infection.

RESULTS

A total of 545 cases were included. An organism was identified in 77.1% of cases and S. aureus was the most common (66.2%); 18.9% of all AHO cases were MRSA. Organisms besides S. aureus were identified in 10.8% of cases. CRP >7 mg/dL, subperiosteal abscess, history of any prior skin or soft tissue infection (SSTI) and need for intensive care unit admission were independently associated with MRSA infection. Vancomycin was used as an empiric treatment in 57.6% of cases. If the above criteria were relied upon to predict MRSA AHO, empiric vancomycin use could have been reduced by 25%.

CONCLUSIONS

Critical illness, CRP >7 mg/dL at the time of presentation, subperiosteal abscess and history of SSTI are suggestive of MRSA AHO, and could be considered when planning empiric therapy. Further work is needed to validate these findings before wider implementation.

Early CRP Trends in Childhood Osteomyelitis Predict Complicated Disease

BACKGROUND

Acute hematogenous osteomyelitis (AHO) remains a cause of severe illness among children. Contemporary research aims to identify predictors of acute and chronic complications. Trends in C-reactive protein (CRP) after treatment initiation may predict disease course. We have sought to identify factors associated with acute and chronic complications in the New Zealand population.

METHODS

A retrospective review of all patients younger than16 years with presumed AHO presenting to a tertiary referral centre between 2008 and 2018 was performed. Multivariate was analysis used to identify factors associated with an acute or chronic complication. An "acute" complication was defined as the need for 2 or more surgical procedures, a hospital stays longer than 14 days, or recurrence despite intravenous antibiotics. A "chronic" complication was defined as growth or limb length discrepancy, avascular necrosis, chronic osteomyelitis, pathologic fracture, frozen joint, or dislocation.

RESULTS

One hundred fifty-one cases met the inclusion criteria. The median age was 8 years (69.5% male). Within this cohort, 53 (34%) experienced an acute complication and 18 (12%) a chronic complication. Regression analysis showed that contiguous disease, delayed presentation, and failure to reduce CRP by 50% at day 4/5 predicted an acutely complicated disease course. Chronic complication was predicted by the need for surgical management and failed CRP reduction by 50% at day 4/5.

CONCLUSIONS

CRP trends over 96 hours after the commencement of treatment differentiate patients with AHO likely to experience severe disease.

LEVEL OF EVIDENCE

Level II, retrospective study.

Surveillance of osteoarticular infections caused by Staphylococcus aureus in a paediatric hospital in Mexico City

Staphylococcus aureus is the main aetiologic agent of osteoarticular infections (OAIs) in paediatric patients. The aim of this prospective unicenter study was to describe the phenotypic and genotypic characteristics of S. aureus isolates obtained from OAIs in paediatric patients admitted to tertiary care hospital. Through a surveillance program called OsteoCode, a multidisciplinary team was created and we identified 27 patients with OAIs caused by S. aureus from 2019 to 2021. The susceptibility profile, virulence factors, biofilm formation, pulsed-field gel electrophoresis (PFGE), clonal complex (CC) and sequence type (ST) were determined. In addition, the clinical characteristics and evolution of the patients presented six months after the diagnosis of OAIs were described. Ninety-two percent of the isolates were methicillin-sensitive S. aureus (MSSA). In methicillin-resistant S. aureus (MRSA), SCCmec-II and SCCmec-V were detected. The pvl gene was only observed in MSSA (18.5%) and was associated with highest fever (p=0.015), multiple localization (p=0.017), and soft tissue sites of infection beyond the bone (pyomyositis, pulmonary abscess) (p=0.017). Biofilm formation was detected in 55.6% of isolates. The most common CC were CC5 and CC30 which represent the most common linages for bone and joint infections worldwide. The isolates were distributed in different STs, and ST672 was predominant. MRSA were associated with a longer duration of intravenous treatment and a prolonged hospital stay (p=0.023). Recurrent infection occurred in five children and orthopaedic complications in 33.3% of patients. This is the first study that reflects the epidemiology of S. aureus in OAIs in paediatric patients in Mexico; a clear predominance of MSSA distributed in different STs was observed. Our findings highlight that a multidisciplinary team is required for the diagnosis and treatment of OAIs.

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.

Clinical Scores Predict Acute and Chronic Complications in Pediatric Osteomyelitis: An External Validation

BACKGROUND

Pediatric acute hematogenous osteomyelitis (AHO) outcomes are highly dependent on the disease severity. Recently, the A-SCORE and C-SCORE, were proposed as predictors of an acute complicated course and chronic morbidity, respectively. The purpose of this study was to externally validate the A-SCORE and C-SCORE at a single institution.

METHODS

This IRB-approved retrospective chart review included AHO patients admitted at a tertiary referral hospital between October 1, 2015 and December 31, 2019. The inclusion criteria were ages 0 to 18 and clinical response to treatment. The exclusion criteria were immunocompromised status or penetrating inoculation.

RESULTS

The A-SCORE demonstrated an area under the receiver operator curve (ROC area) of >86% with regards to all acute complications. It also demonstrated sensitivities >85% and specificities >92% at the cut-off of 4 (Youden index) for all acute complications. The C-SCORE demonstrated an ROC area of 100% with regards to chronic osteomyelitis. It also demonstrated sensitivities >70% and specificities >93% for the chronic morbidity variables seen in our population at the cut-off of 3 (Youden index.).

CONCLUSIONS

These novel composite clinical scores, in combination with clinical judgment, could help guide early care decisions. The A-SCORE and C-SCORE are useful risk stratification tools in the management of pediatric AHO and in predicting acute complicated courses or chronic sequelae of AHO, respectively. These scoring systems, if integrated into standardized pediatric AHO guidelines, can allow clinicians to stratify the AHO population and guide clinical decision making.

LEVEL OF EVIDENCE

Level III (prognostic study, retrospective chart review).

Distinguishing Kingella kingae from Pyogenic Acute Septic Arthritis in Young Portuguese Children

(1) Background: We aim to identify clinical and laboratorial parameters to distinguish Kingella kingae from pyogenic septic arthritis (SA). (2) Methods: A longitudinal, observational, single-centre study of children < 5 years old with microbiological positive SA admitted to a paediatric hospital from 2013−2020 was performed. Clinical and laboratorial data at admission and at 48 h, as well as on treatment and evolution, were obtained. (3) Results: We found a total of 75 children, 44 with K. kingae and 31 with pyogenic infections (mostly MSSA, S. pneumoniae and S. pyogenes). K. kingae affected younger children with low or absent fever, low inflammatory markers and a favourable prognosis. In the univariate analyses, fever, septic look, CRP and ESR at admission and CRP at 48 h were significantly lower in K. kingae SA. In the multivariate analyses, age > 6 months ≤ 2 years, apyrexy and CRP ≤ 100 mg/L were significative, with an overall predictive positive value of 86.5%, and 88.4% for K. kingae. For this model, ROC curves were capable of differentiating (AUC 0.861, 95% CI 0.767−0.955) K. kingae SA from typical pathogens. (4) Conclusions: Age > 6 months ≤ 2 years, apyrexy and PCR ≤ 100 mg/L were the main predictive factors to distinguish K. kingae from pyogenic SA < 5 years. These data need to be validated in a larger study.

Practice Variation in the Surgical Management of Children With Acute Hematogenous Osteomyelitis

INTRODUCTION

The surgical indications to manage children with acute hematogenous osteomyelitis (AHO) remain poorly defined. The purpose of this study was to identify if practice pattern variation exists in the surgical management of pediatric AHO among tertiary pediatric medical centers across the United States. A secondary purpose was to evaluate variables that may impact the rate of surgical intervention among these institutions.

METHODS

Children with AHO were retrospectively analyzed between January 1, 2010, and December 31, 2016, from 18 pediatric medical centers throughout the United States. The rates of surgery were identified. Admission vitals, labs, weight-bearing status, length of stay, and readmission rates were compared between those who did and did not undergo surgery. Multivariate regression and classification and regression tree analyses were performed to identify the variables that were associated with surgical intervention.

RESULTS

Of the 1003 children identified with AHO in this retrospective, multicenter database, 619/1003 (62%) were treated surgically. Multivariate analysis revealed institution, inability to ambulate, presence of multifocal infection, elevated admission C-reactive protein, increased admission platelet count, and location of the osteomyelitis were significant predictors of surgery (P<0.01). Patients who underwent surgery were more than twice as likely to have a recurrence or readmission and stayed a median of 2 days longer than those who did not have surgery. In the classification and regression tree analysis, 2 distinct patterns of surgical intervention were identified based on institution, with 12 institutions operating in most cases (72%), regardless of clinical factors. A second cohort of 6 institutions operated less routinely, with 47% receiving surgery overall. At these 6 institutions, patients without multifocal infection only received surgery 26% of the time, which increased to 74% with multifocal infection and admission erythrocyte sedimentation rate >37.5 mm/h.

CONCLUSIONS

This study is the first to objectively identify significant differences in the rates of surgical management of pediatric AHO across the United States. Variation in the surgical management of AHO appears to be driven primarily based on institutional practice. Twelve institutions operated on 72% of patients, regardless of the severity of disease, indicating that the institution custom or dogma may drive the surgical indications. Six institutions relied more on clinical judgment with significant variability in rates of surgical intervention (26% vs. 74%), depending on the severity of the disease. Surgical intervention is associated with increased recurrence, readmission, and hospital length of stay. As a result of these findings, it is essential to prospectively study the appropriate surgical indications and measure the outcomes in children with pediatric AHO.

LEVEL OF EVIDENCE

Level III.

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.

Management and Prevention of Staphylococcus aureus Infections in Children

Staphylococcus aureus is a common skin commensal with the potential to cause severe infections resulting in significant morbidity and mortality. Up to 30% of individuals are colonized with S aureus, though infection typically does not occur without skin barrier disruption. Infection management includes promptly addressing the source of infection, including sites of metastatic infection, and initiation of effective antibiotics, which should be selected based on local antibiotic susceptibility patterns. Given that S aureus colonization is a risk factor for infection, preventive strategies are aimed at optimizing hygiene measures and decolonization regimens for outpatients and critically ill children with prolonged hospitalizations.

Clinical Outcome and Antibiotic Dosing Differences by Weight in Children With Acute Osteomyelitis

OBJECTIVES

To evaluate for weight-based differences in clinical outcomes and antibiotic dosing variability for children hospitalized with acute hematogenous osteomyelitis (AHO).

METHODS

We performed a retrospective cohort study of children aged 2 to 17 years and hospitalized with a primary AHO International Classification of Diseases, Ninth Revision or International Classification of Diseases, 10th Revision diagnosis code between 2010 and 2017 using the Cerner Health Facts database. Weight categories (healthy, overweight, obesity) were determined by using Centers for Disease Control and Prevention age- and sex-specific BMI percentiles. Rates of procedures, complications, and length of stay (LOS) were compared between groups. Dosing variability between groups was assessed by comparing the initial milligrams per kilogram per day of prescribed antibiotics.

RESULTS

We identified 755 children with AHO for inclusion. Children with overweight and obesity were more likely to undergo surgical procedures (19% and 17%, respectively) compared with children with a healthy weight (10%; P = .009). They also had a longer LOS (5.7 and 5.8 days) than children with a healthy weight (4.9 days; P = .03). There were no differences in complication rates between weight categories. Mean weight-adjusted daily dose for the most frequently prescribed antibiotics was different by weight category, with children in higher weight categories more likely to receive lower weight-based doses.

CONCLUSIONS

Children with overweight and obesity hospitalized for AHO were more likely to undergo procedures, have longer LOS, and receive lower weight-based antibiotic dosing compared with children with a healthy weight. Our findings suggest that weight should be carefully considered when treating children with AHO.

Clinical Epidemiology and Outcomes of Pediatric Musculoskeletal Infections

OBJECTIVES

To understand the epidemiology of acute hematogenous osteomyelitis and septic arthritis, including clinical and demographic features, microbiology, treatment approaches, treatment-associated complications, and outcomes.

STUDY DESIGN

Retrospective cohort study of 453 children with acute hematogenous osteomyelitis and/or septic arthritis from 2009 to 2015.

RESULTS

Among the 453 patients, 218 (48%) had acute hematogenous osteomyelitis, 132 (29%) had septic arthritis, and 103 (23%) had concurrent acute hematogenous osteomyelitis/septic arthritis. Treatment failure/recurrent infection occurred in 41 patients (9%). Patients with concurrent acute hematogenous osteomyelitis/septic arthritis had longer hospital stays, longer duration of antibiotic therapy, and were more likely to have prolonged bacteremia and require intensive care. Staphylococcus aureus was identified in 228 (51%) patients, of which 114 (50%) were methicillin-resistant S aureus. Compared with septic arthritis, acute hematogenous osteomyelitis and concurrent acute hematogenous osteomyelitis/septic arthritis were associated with higher odds of treatment failure (OR, 8.19; 95% CI, 2.02-33.21 [P = .003]; and OR, 14.43; 95% CI, 3.39-61.37 [P < .001], respectively). The need for more than 1 surgical procedure was also associated with higher odds of treatment failure (OR, 2.98; 95% CI, 1.18-7.52; P = .021). Early change to oral antibiotic therapy was not associated with treatment failure (OR, 0.64; 95% CI, 0.24-1.74; P = .386). Most (73%) medically attended treatment complications occurred while on parenteral therapy.

CONCLUSIONS

Musculoskeletal infections are challenging pediatric infections. S aureus remains the most common pathogen, with methicillin-resistant S aureus accounting for 25% of all cases. Concurrent acute hematogenous osteomyelitis/septic arthritis is associated with more severe disease and worse outcomes. Fewer treatment-related complications occurred while on oral therapy. Early transition to oral therapy was not associated with treatment failure.

Prospective Observational Study to Determine Kinetics of Procalcitonin in Hospitalized Children Receiving Antibiotic Therapy for Non-Critical Acute Bacterial Infections

INTRODUCTION

The kinetics of procalcitonin in pediatric patients with non-critical acute bacterial infections receiving appropriate antibiotic therapy are not well described.

METHODS

We performed a single-center, prospective observational pilot study of children admitted to a tertiary care children's hospital who were receiving antibiotics for treatment of a non-critical acute bacterial infection, and we prospectively measured serial procalcitonin levels daily for 4 days during hospitalization.

RESULTS

Among the 46 children with baseline procalcitonin levels enrolled in the study, procalcitonin kinetics followed a half-life of approximately 24 h in most patients. Procalcitonin declined faster than C-reactive protein over the first 48 h of appropriate antibiotic treatment. There was variation in biomarker levels among participants with the same infection type, especially in participants with bacteremia, musculoskeletal infection and skin/soft tissue infection.

CONCLUSION

Utility of procalcitonin as a biomarker to follow every 24-48 h in non-critically ill children receiving antibiotic therapy for bacterial infections as an objective measure of clinical improvement is promising.