Concurrent septic arthritis and osteomyelitis in children

Predicting the presence of adjacent septic arthritis in children with acute hematogenous osteomyelitis

INTRODUCTION

This study conducted statistical analysis of clinical data from cases of acute hematogenous osteomyelitis (AHO) with or without concomitant septic arthritis, with the objective of identifying factors that are indicative of concomitant septic arthritis. Predictive models will be developed to predict coexisting infections, with one that is independent of MR findings and another that incorporates MRI data.

METHODS

A retrospective review of 127 children (132 cases of AHO) treated for AHO was performed. All patients underwent MRI. The data encompassed various demographic, clinical, and diagnostic factors. Graphical and logistical regression analysis was used to determine variables independently predictive of adjacent infection. Optimal cutoff values were determined for each variable and a prediction model was created. Finally, the model was applied to our patient database and each patient with isolated AHO, or concomitant infection was stratified based upon the number of positive predictive factors.

RESULTS

The overall incidence of coexisting septic arthritis in patients with AHO was 52.2% (69/132). Four risk factors (age below 4 years, a history of preceding infection, platelet count > 390.5 × 10^9/L, and absolute neutrophil count < 5.45 × 10^3 cells/ml) were found to be predictive of concomitant infection and were included in the algorithm. Patients with ≥ 2 risk factors were classified as high risk for AHO with concomitant infection (Sensitivity: 79.41% (95% CI: [64.10%, 94.71%]), Specificity: 76.56% (95% CI: [58.61%, 94.51%]), Positive Predictive Value (PPV): 78.26% (95% CI: [63.43%, 93.09%]), and Negative Predictive Value (NPV): 77.78% (95% CI: [61.02%, 94.54%]). In MRI, joint effusion was the primary indicator of concomitant septic arthritis in patients with AHO, followed by the absence of subperiosteal abscess. The presence of subperiosteal abscess in the absence of joint effusion was highly correlated with isolated AHO, showing a 100% occurrence rate (39/39).

CONCLUSIONS

Our study successfully identified several risk factors and radiologic signs associated with concomitant septic arthritis in patients with AHO. These findings can assist clinicians in early recognition and management of coexisting infections, especially in situations where MRI is not readily available or when its findings are inconclusive. Timely identification of these factors is crucial for appropriate treatment planning and improved patient outcomes.

Does rickets carry an increased risk of osteomyelitis and septic arthritis? An aggregated electronic health record data study

To investigate the prevalence of osteomyelitis and septic arthritis in pediatric patients with rickets, compared to the general population. A retrospective cohort study was conducted using the TriNetX analytics network, which aggregates deidentified electronic health record data from over 105 million US patients. We queried pediatric patients with rickets, based on ICD-10-CM (International Classification of Diseases, Tenth Revision, Clinical Modification) encounter diagnoses. Patients with any ICD-10-CM encounter diagnoses of osteomyelitis or septic arthritis were reported. We established a control cohort of pediatric patients without rickets. Of 7337 pediatric patients (≤18 years old) with a rickets diagnosis, 96 [1.31%, 95% confidence interval (CI): 1.05%-1.57%] had a diagnosis of osteomyelitis and 28 (0.38%, 95% CI: 0.24%-0.52%) had a diagnosis of septic arthritis. In comparison, of the 17 240 604 pediatric patients without a rickets diagnosis, 16 995 (0.10%, 95% CI: 0.10%-0.10%) had a diagnosis of osteomyelitis and 8521 (0.05%, 95% CI: 0.05%-0.05%) had a diagnosis of septic arthritis. The relative risk for an osteomyelitis diagnosis in pediatric patients with a rickets diagnosis was 13.27 (95% CI: 10.86-16.23), while the relative risk for a septic arthritis diagnosis was 7.72 (95% CI: 5.33-11.18). Pediatric patients with a diagnosis of rickets have over 10- and 5-times higher relative risks for having a diagnosis of osteomyelitis and septic arthritis, respectively, compared to those without a diagnosis of rickets. This is the first study to explore musculoskeletal infections in rickets patients, highlighting the importance of clinicians being vigilant about these conditions.

Comparison Between Septic Arthritis Alone and Coexisting with Other Bone and Joint Infections in Pediatric Patients: A Retrospective Review

Background

It is unclear whether coexisting septic arthritis and osteomyelitis (CSAO) differs from septic arthritis (SA) alone in terms of susceptible age groups, clinical and paraclinical presentations, and prevalence. This study aimed to compare patients with isolated SA with those presenting with CSAO, determine the efficacy of different parameters used to distinguish those diagnoses, and investigate the prevalence of CSAO due to Kingella kingae.

Methods

The study retrospectively included all patients treated for SA over a 17-year period at Geneva University Hospitals. Clinical, biological, and bacteriological data were analyzed. Magnetic resonance imaging (MRI) was reviewed for all patients to identify those with coexisting osteomyelitis. Comparisons between patients with isolated SA and those with CSAO were performed using the unpaired Mann-Whitney U for continuous outcomes (reported with median [interquartile range]) and the Pearson χ2 tests for dichotomous outcomes (reported with n [%]).

Results

Of 247 patients with osteoarticular infections, 177 with SA fulfilled our inclusion criteria. Of these, 124 had SA alone, and 53 (29.9%) had a CSAO. There were no statistically significant differences between the 2 groups regarding sex, age, and clinical and paraclinical results. When coexisting osteomyelitis was present, 51% of cases were acute and 49% were subacute. Bone infection was found in the metaphyses of 21 patients (39.6%), the epiphyses of 11 (20.8%), and was transphyseal in 10 (18.9%). Whatever the infection location, K. kingae was the most common pathogen found in both groups (48% of SA, 43% of CSAO, p = 0.651).

Conclusions

This study showed that CSAO is common in children, especially among those younger than 4 years, with an unexpectedly high prevalence of subacute osteomyelitis. This should encourage caregivers to use MRI more extensively in diagnostic processes. Clinical and paraclinical data did not contribute to differentiate CSAO from SA. The widespread presence of K. kingae as a pathogen in both groups supports the advice to systematically use polymerase chain reaction techniques in children younger than 4 years of age.

Level of Evidence

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

The Price for Delayed Diagnosis of Pediatric Septic Hip: Increased Cost and Poor Outcomes

BACKGROUND

Most authors agree that early diagnosis and treatment of pediatric septic hip, within 4 days of onset of symptoms, is crucially important for good outcomes. In healthcare, value is a function of outcome over cost. The purpose of this study was to determine the clinical outcome and cost, therefore value, associated with early versus delayed treatment of pediatric septic arthritis of the hip.

METHODS

A retrospective review was performed at a single pediatric hospital. Hospital records over 6 years (2011 to 2016) were examined to identify patients who had undergone treatment for primary septic arthritis of the hip. Patient demographics, clinical data at presentation, treatment information, and follow-up data were recorded. Hospital charges at account level were calculated and compared between groups.

RESULTS

Forty-three subjects were identified for analysis. Twelve presented more than 4 days after the onset of symptoms (delayed diagnosis). There was no difference in patient demographics, Kocher criteria, or initial imaging performed between those with early versus delayed diagnosis. The delayed group had significantly longer length of hospital stay (17 vs. 9 d, P =0.003), follow-up needed (56 vs. 19 wk P =0.001), long-term complications (50% vs. 3%, P =0.000), duration of antibiotics (8 vs. 5.5 wk, P= 0.043), greater number of I&Ds (2 vs. 1, P =0.04), more tissue cultures and blood draws (6 vs. 2, P =0.002; and 3 vs. 2 P =0.009, respectively) and more radiographs taken as outpatients (4 vs. 2, P =0.001, respectively). The average total hospital charge (inpatient and outpatient) was $102,774 in the early diagnosis group and $243,411 in the delayed group ( P =0.012).

CONCLUSIONS

Delayed diagnosis of pediatric septic hip correlated with longer length of hospital stay, duration of follow-up, and more long-term complications. These factors contributed to higher total hospital costs and therefore decreased healthcare value.

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.

Bone and joint infection complicated with sepsis in neonates and infants under three months of age

OBJECTIVE

Studies focusing on bone and joint infections (BJIs) in young infants are rare. Some cases of BJI are accompanied by sepsis. This study aimed to identify the clinical and bacteriological features of sepsis in neonates and young infants with BJIs.

METHODS

Neonates and infants younger than 3 months diagnosed with BJI in the present institution from 2014 to 2021 were retrospectively reviewed. Patient characteristics, clinical data, and outcomes were documented and compared between those with and without sepsis.

RESULTS

Twenty-five patients with a mean age of 34.8 days were included. Nine BJI cases had concomitant sepsis (group A), and 16 had BJI without sepsis (group B). Within group A, staphylococcus aureus was the major pathogenic germ (5 cases, of which 4 were of the methicillin-resistant staphylococcus aureus (MRSA) type). There was no statistical difference in male-to-female ratio, age, history of hospitalization, anemia, birth asphyxia, peripheral leukocyte counts, C-reactive protein on admission, and sequelae between groups. Univariate analyses indicated a significant difference in the incidence of septic arthritis (SA) combined with osteomyelitis (OM) (88.9% vs 37.5%), congenital deformities (44.4% vs 0%), and mean duration of symptoms (2.83 days vs 9.21 days) in comparisons between groups A and B.

CONCLUSION

Staphylococcus aureus is the main pathogenic bacteria in BJI cases complicated with sepsis in neonates and young infants. Among infants younger than 3 months diagnosed with BJI, those with concurrent SA and OM, MRSA infection, or congenital deformities are more likely to develop sepsis.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA): 2023 Guideline on Diagnosis and Management of Acute Bacterial Arthritis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute bacterial arthritis (ABA) in children was developed by a multidisciplinary panel representing the 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 ABA, including specialists in pediatric infectious diseases and orthopedics. The panel's recommendations for the diagnosis and treatment of ABA are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of ABA 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 approach (Grading of Recommendations Assessment, Development and Evaluation) (see Figure 1). 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.

What's New in Pediatric Septic Arthritis? A Review of Pertinent Clinical Questions

BACKGROUND

The evaluation and treatment of children with septic arthritis (SA) is challenging and requires an organized approach to address the spectrum of pathogens which appear to aggregate in age-specific groups. Although evidence-based guidelines have recently been published for the evaluation and treatment of children with acute hematogenous osteomyelitis, there is a relative dearth of literature devoted exclusively to SA.

METHODS

Recently published guidance for the evaluation and treatment of children with SA was reviewed and evaluated with respect to pertinent clinical questions to summarize what is new in this area of practice for pediatric orthopaedic surgeons.

RESULTS

Evidence suggests that there is a profound difference between children with primary SA and those who have contiguous osteomyelitis. This disruption of the commonly accepted paradigm of a continuum of osteoarticular infections has important implications in the evaluation and treatment of children with primary SA. Clinical prediction algorithms have been established to help determine the applicability of magnetic resonance imaging during the evaluation of children suspected to have SA. Antibiotic duration for SA has been recently studied with some evidence in favor of short-course parenteral followed by short-course oral therapy may be successful if the pathogen is not methicillin-resistant Staphylococcus aureus .

CONCLUSION

Recent studies of children with SA have provided better guidance for evaluation and treatment to improve diagnostic accuracy, processes of evaluation, and clinical outcomes.

LEVEL OF EVIDENCE

Level 4.

High-resolution ultrasound in the evaluation of musculoskeletal infections

Soft tissue and osseous musculoskeletal infections are common but can be difficult to diagnose clinically. Signs, symptoms, and physical examination findings may be nonspecific, and laboratory values can be inconclusive. The extent of disease may also be underestimated on physical examination. Soft tissue infections most commonly occur secondary to direct inoculation from broken skin and less frequently due to the seeding of the soft tissues from hematogenous spread, while osseous infections are more commonly due to hematogenous seeding. Infections may also be iatrogenic, following surgery or other procedural interventions. High-resolution ultrasound is an extremely useful imaging modality in the evaluation of musculoskeletal soft tissue and joint infections, and can occasionally be used to evaluate osseous infections as well. Ultrasound can aid in the early diagnosis of musculoskeletal infections, allowing for prompt treatment, decreased risk of complications, and treatment optimization. Ultrasound is sensitive and specific in evaluating soft tissue edema and hyperemia; soft tissue abscesses; joint, bursal and tendon sheath effusions/synovitis; and subperiosteal abscesses. This article describes the typical high-resolution grayscale as well as color and power Doppler ultrasound imaging findings of soft tissue infections including cellulitis, fasciitis, necrotizing deep soft tissue infection, pyomyositis, soft tissue abscess, infectious bursitis, and infectious tenosynovitis. Ultrasound findings of septic arthritis as well as osteomyelitis, such as subperiosteal spread of infection (subperiosteal abscess). are also reviewed. In addition, the use of ultrasound to guide fluid and tissue sampling is discussed.

Disseminated Staphylococcus aureus Infection in an Adolescent Patient Following a Traditional Phlebotomy Procedure

Al-Fashdu is a well-known Islamic medicine-based alternative treatment, and it has been widely practiced with the aim of treating certain health issues in various countries. Unfortunately, this therapy can lead to certain complications, including life-threatening infections. We report a case of a 12-year-old male patient who developed a disseminated Staphylococcus aureus infection following Al-Fashdu therapy. He was treated with surgical drainage and intravenous antibiotics. To our knowledge, this is the first report of a disseminated Staphylococcus aureus infection following Al-Fashdu therapy in an adolescent patient.

Osteochondroma after acute skeletal infection: a primary or a secondary lesion?

Secondary or acquired osteochondroma may develop following radiation exposure, trauma or surgery, and osteomyelitis. This report presents a 15-year-old patient with an osteochondroma of the anterolateral left distal tibial metaphysis, who received surgical treatment for an acute suppurative arthritis of the left ankle joint at the age of 4 years. The purpose of this paper is to present the challenging diagnostic enigma of the osteochondroma's etiology in our patient between a primary versus a secondary lesion. After analysing retrospectively the available information in the patient's files, we concluded that the osteochondroma was likely a primary lesion with modified presentation due to infection.

Pediatric Emergency MRI

There is an overall increase in the use of imaging in the pediatric emergency room setting, which is accompanied by a reduction in computed tomography examinations performed mainly due to the increased awareness of the risks of ionizing radiation. Advances in MRI technology have led to shortened scan time, decreased motion sensitivity, and improved spatial resolution. With increased access to MRI in the emergency room setting, the goal of this article is to review major applications of MR in pediatric emergency room patients.

ACR Appropriateness Criteria® Osteomyelitis or Septic Arthritis-Child (Excluding Axial Skeleton)

Imaging plays an integral role in the evaluation of suspected musculoskeletal infections in children, not only in the accurate identification of infection such as osteomyelitis or septic arthritis, but also in guiding management. Various diagnostic modalities serve different purposes in the assessment of suspected pediatric musculoskeletal infections. The purpose of this document is to provide imaging guidance in the most frequently encountered clinical scenarios in which osteomyelitis and/or septic arthritis are suspected, outside of the axial skeleton. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion.

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.

Osteoarticular Infections in Pediatric Hospitals in Europe: A Prospective Cohort Study From the EUCLIDS Consortium

BACKGROUND

Pediatric osteoarticular infections (POAIs) are serious diseases requiring early diagnosis and treatment.

METHODS

In this prospective multicenter cohort study, children with POAIs were selected from the European Union Childhood Life-threatening Infectious Diseases Study (EUCLIDS) database to analyze their demographic, clinical, and microbiological data.

RESULTS

A cohort of 380 patients with POAIs, 203 with osteomyelitis (OM), 158 with septic arthritis (SA), and 19 with both OM and SA, was analyzed. Thirty-five patients were admitted to the Pediatric Intensive Care Unit; out of these, six suffered from shock, one needed an amputation of the right foot and of four left toes, and two had skin transplantation. According to the Pediatric Overall Performance Score, 36 (10.5%) showed a mild overall disability, 3 (0.8%) a moderate, and 1 (0.2%) a severe overall disability at discharge. A causative organism was detected in 65% (247/380) of patients. Staphylococcus aureus (S. aureus) was identified in 57.1% (141/247) of microbiological confirmed cases, including 1 (0.7%) methicillin-resistant S. aureus (MRSA) and 6 (4.2%) Panton-Valentine leukocidin (PVL)-producing S. aureus, followed by Group A Streptococcus (18.2%) and Kingella kingae (8.9%). K. kingae and PVL production in S. aureus were less frequently reported than expected from the literature.

CONCLUSION

POAIs are associated with a substantial morbidity in European children, with S. aureus being the major detected pathogen. In one-third of patients, no causative organism is identified. Our observations show an urgent need for the development of a vaccine against S. aureus and for the development of new microbiologic diagnostic guidelines for POAIs in European pediatric hospitals.

Predicting adjacent infections in pediatric septic arthritis: Do predictive criteria extrapolate across geographic regions?: Predicting Periarticular Infection in the Southeast

Purpose

This study aims to assess previously determined predictive criteria for presence of adjacent infection in septic arthritis within a Southeastern United States (US) pediatric population.

Results

The sensitivity, specificity, positive predictive value, and negative predictive value of the Rosenfeld criteria were: 91.7%, 22.7%, 39.3%, and 83.3%, respectively. The patients with periarticular infection were more likely to have positive blood cultures than those with isolated septic arthritis. There was no difference in likelihood of secondary surgical intervention.

Conclusions

Previously defined criteria to predict adjacent infection in pediatric septic arthritis did not demonstrate external validity in a Southeastern US pediatric population.

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.

Kingella kingae Displaced S. aureus as the Most Common Cause of Acute Septic Arthritis in Children of All Ages

BACKGROUND

Acute septic arthritis (SA) still remains a challenge with significant worldwide morbidity. In recent years, Kingella kingae has emerged and treatment regimens have become shorter. We aim to analyze trends in SA etiology and management and to identify risk factors for complications.

METHODS

Longitudinal observational, single center study of children (<18 years old) with SA admitted to a tertiary care pediatric hospital, from 2003 to 2018, in 2 cohorts, before and after implementation of nucleic acid amplification assays (2014). Clinical, treatment and disease progression data were obtained.

RESULTS

A total of 247 children were identified, with an average annual incidence of 24.9/100,000, 57.9% males with a median age of 2 (1-6) years. In the last 5 years, a 1.7-fold increase in the annual incidence, a lower median age at diagnosis and an improved microbiologic yield (49%) was noticed. K. kingae became the most frequent bacteria (51.9%) followed by MSSA (19.2%) and S. pyogenes (9.6%). Children were more often treated for fewer intravenous days (10.7 vs. 13.2 days, P = 0.01) but had more complications (20.6% vs. 11.4%, P = 0.049) with a similar sequelae rate (3.7%). Risk factors for complications were C-reactive protein ≥80 mg/L and Staphylococcus aureus infection, and for sequelae at 6 months, age ≥4 years and CRP ≥ 80 mg/L.

CONCLUSIONS

The present study confirms that K. kingae was the most common causative organism of acute SA. There was a trend, although small, for decreasing antibiotic duration. Older children with high inflammatory parameters might be at higher risk of sequelae.

Pain for Greater Than 4 Days Is Highly Predictive of Concomitant Osteomyelitis in Children With Septic Arthritis

BACKGROUND

There is no evidence-based consensus on the risk factors for concomitant osteomyelitis and septic arthritis. The purpose of this study was to investigate clinical parameters predictive of concomitant osteomyelitis in children with septic arthritis.

METHODS

A retrospective review was conducted on patients with septic arthritis with magnetic resonance imaging (MRI) between January 2004 and October 2016 at a tertiary care pediatric hospital. Medical charts were reviewed for information including symptoms, diagnosis of osteomyelitis, serum laboratory studies, joint fluid analyses, imaging results, and treatment. Positive diagnosis of osteomyelitis was defined as a hyperintense signal of osseous structures on T2-weighted MRI consistent with infection per attending pediatric radiologist final read.

RESULTS

A total of 71 patients with 73 septic joints were included. The mean age was 6±4 (0.1 to 17) years and the mean follow-up was 14.9±24.1 (1.0 to 133.1) months. Septic arthritis with concomitant osteomyelitis occurred in 43 of 71 (61%) patients, whereas 28 of 71 (39%) patients had septic arthritis alone. Inflammatory markers such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein on admission were not associated with concomitant osteomyelitis. Multivariate logistic regression revealed that positive joint fluid bacterial culture (P=0.021) and pain for >4 days before admission (P=0.004) are independent risk factors for concomitant osteomyelitis in children with septic arthritis. Among the 24 septic arthritis patients with pain for >4 days before presentation, 96% (23/24) had concomitant osteomyelitis, whereas 43% (20/47) of patients with pain for ≤4 days had concomitant osteomyelitis.

CONCLUSION

Pain for >4 days before presentation is an independent predictor of osteomyelitis in children with septic arthritis. In pediatric septic arthritis, MRI should be considered, particularly in patients presenting with pain for >4 days as 96% of these patients had concomitant osteomyelitis.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Septic Arthritis of the Knee in Children: A Critical Analysis Review

» Septic arthritis of the knee is the most common type of septic arthritis in children, and it may result in irreversible joint damage. » Staphylococcus aureus is the most common pathogen associated with septic arthritis, but other causative pathogens are possible in children with certain risk factors. » The diagnosis of septic arthritis of the knee is based on history and physical examination, blood tests, and arthrocentesis. » Empiric treatment with anti-staphylococcal penicillin or a first-generation cephalosporin is usually recommended but may be tailored according to local resistance patterns and clinical culture data. » Open or arthroscopic surgical debridement including extensive lavage is effective in eradicating infection, and most patients do not require additional surgical intervention.

[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.

Current Concepts in Pediatric Septic Arthritis

Septic arthritis continues to present challenges regarding the clinical diagnosis, workup, and definitive management. Urgent management is essential, so treating surgeons must efficiently work through differential diagnoses, identify concomitant infections, and do a timely irrigation and débridement. The incidence of methicillin-resistant Staphylococcus aureus is increasing, typically resulting in a more rapid progression of symptoms with more severe clinical presentation. The diagnostic utility of MRI has resulted in improved detection of concomitant septic arthritis and osteomyelitis, although MRI must not substantially delay definitive management. Early diagnosis followed by urgent irrigation and débridement and antibiotic therapy are essential for satisfactory long-term outcomes. Antibiotics should not be administered until blood cultures and arthrocentesis fluid are obtained, except in rare cases of a septic or toxic patient. Once cultures are obtained, empiric antibiotic therapy should commence and provide coverage for the most likely pathogens, given the patient's age. Laboratory markers, especially C-reactive protein, should be followed until normalization and correlate with resolution of clinical symptoms. Definitive antibiotic selection should be shared with a pediatric infectious disease specialist, who can help guide the duration of treatment.

Current Variation in Joint Aspiration Practice for the Evaluation of Pediatric Septic Arthritis

Pediatric septic arthritis (SA) is a condition that can be associated with significant morbidity. Although previous research has been on predictive care pathways, scrutiny of the literature continues to reveal wide differences in the patient evaluation and management. The purpose of this study was to define the differences in joint aspiration for the evaluation of pediatric SA across pediatric tertiary care institutions in the United States.

Septic Arthritis: An Evidence-Based Review of Diagnosis and Image-Guided Aspiration

OBJECTIVE. The purpose of this evidence-based review is to equip radiologists to discuss and interpret findings obtained with various imaging modalities, guide patient selection for percutaneous aspiration, and safely perform arthrocentesis to assess for infection in both native and prosthetic joints. CONCLUSION. Septic arthritis is an emergency that can lead to rapidly progressive, irreversible joint damage. Despite the urgency associated with this diagnosis, there remains a lack of consensus regarding many aspects of the management of native and periprosthetic joint infections.

Septic Arthritis of the Hip in Children: A Critical Analysis Review

Septic arthritis of the hip is a common and potentially devastating condition in children. Septic arthritis is most commonly caused by Staphylococcus aureus, but other pathogens should be considered on the basis of patient age and presence of risk factors. Diagnosis of septic arthritis is based on history and physical examination, laboratory tests, radiographs, ultrasound, and arthrocentesis. Treatment comprises empiric antibiotics and joint debridement, and antibiotics are subsequently tailored on the basis of culture data, local resistance patterns, and clinical response. Late sequelae of septic arthritis include osteonecrosis, chondrolysis, growth disturbance, subluxation or dislocation, and progressive ankylosis. Surgical treatments to address these issues have been described.

The Introduction of a Preoperative MRI Protocol Significantly Reduces Unplanned Return to the Operating Room in the Treatment of Pediatric Osteoarticular Infections

BACKGROUND

Pediatric osteoarticular infection can cause severe morbidity. Some infectious loci may be difficult to identify clinically, and there may be more than one. There is little agreement regarding the appropriate use of preoperative magnetic resonance imaging (MRI) in this setting. After noting an unacceptably high rate of unplanned returns to the operating room for recurrent infection, clinicians at a tertiary care children's hospital noticed many patients had adjacent foci of infection on postoperative MRI. As a result, patients experienced prolonged treatment courses and multiple surgeries. An interdisciplinary team instituted practice guidelines whereby all patients with suspected osteoarticular infection underwent MRI for planned debridement during a reserved morning slot with a surgical suite on hold to proceed directly to surgery if indicated. Images were reviewed in real time to form the surgical plan. Young patients that required sedation for MRI were taken to surgery under the same anesthetic used for MRI without being awakened. The purpose of our retrospective study is to determine if implementing the practice guidelines for acute management of osteoarticular infection reduced unplanned returns to the operating room.

METHODS

A total of 93 patients with osteoarticular infection were included in this study. A total of 40 cases, group A, were treated before implementing practice guidelines; 53 cases, group B, were treated after implementing practice guidelines. Our primary outcomes of interest were the identification of adjacent infections prior to surgery and need for repeat surgery, either planned or unplanned.

RESULTS

Implementation of these guidelines reduced repeat surgery from 50% of patients to <27% (P=0.0099). Of patients requiring repeat surgery, 85% (n=17) were unplanned in group A versus 60% (n=9) in group B (P=0.0099). Adjacent infections were identified in 47.5% (n=19) of patients in group A, versus 60% (n=32) in group B. Adjacent infections were known before surgery in 32% (n=6) of patients in group A versus 72% (n=23) in group B. There were no statistically significant differences in initial patient characteristics or sites of infection.

CONCLUSIONS

Implementing these guidelines reduced the need for repeat surgery in this population. It is difficult to predict with sufficient accuracy which patients need preoperative MRI. While resource intensive, preoperative MRI appears to offer substantial benefit in preoperative planning.

Pseudo paralysis of the shoulder and increased C-reactive protein are predictive factors for septic shoulder in children superior to other clinical symptoms: a retrospective case series of 25 patients

PURPOSE

The aim of the study was to evaluate predictable parameters with the highest sensitivity used in the diagnosis of children septic shoulder arthritis.

METHODS

All children treated in our paediatric orthopaedic hospital between 2000 and 2017 with intraoperative verified septic arthritis of the shoulder were included in this retrospective study. Diagnostic procedures e.g. ultrasound, MRI, radiograph or blood samples as well as typical clinical symptoms were evaluated as predictable parameters for septic shoulder arthritis in paediatric patients. Descriptive statistics as well as sensitivity analysis were performed.

RESULTS

In all, 25 children, 20 boys and five girls, aged from eight days to 15 years, were included for further statistical analysis. All parameters included were tested for sensitivity with binomial confidence intervals (Cis) of 95%. Predictive parameters with highest sensitivity were pseudo paralysis (100%, CI 0.86 to 1.00) and C-reactive protein (CRP) (96%, CI 0.79 to 0.99) superior to temperature (52%, CI 0.3 to 0.73), white blood count (11%, CI 0.01 to 0.34), radiograph (21%, CI 0.04 to 0.50), ultrasound (71%, CI 0.47 to 0.88) or MRI (100%, CI 0.78 to 1.00).

CONCLUSION

The diagnosis of a septic arthritis of the shoulder in children can be challenging for the clinician and especially for the resident doctor. Clinical symptoms such as pseudo paralysis and increased CRP level must be considered as predictive markers not to delay further diagnostics and treatment.

LEVEL OF EVIDENCE

IV.

Pediatric Septic Arthritis: An Update

Septic arthritis in children is a surgical emergency, and prompt diagnosis and treatment are mandatory. If diagnosed quickly and treated correctly, the outcomes can be good. With delay in diagnosis and without proper treatment, outcomes often are quite devastating, with growth disturbance and joint destruction.

Current Approach to the Evaluation and Management of Septic Arthritis

Septic arthritis is an emergent condition caused by bacterial infection of a joint space. The most common etiology is hematogenous spread from bacteremia, but it can also occur from direct inoculation from bites, injection injuries, cellulitis, abscesses, or local trauma. Septic arthritis occurs most frequently in the lower extremities, with the hips and knees serving as the most common locations. The most sensitive findings include pain with motion of the joint, limited range of motion, tenderness of the joint, new joint swelling, and new effusion. Laboratory testing and imaging can support the diagnosis, but the criterion standard is diagnostic arthrocentesis. Treatment involves intravenous antibiotics and joint decompression.

Clinical Features and Outcomes of Children with Culture-Negative Septic Arthritis

BACKGROUND

Septic arthritis is a serious infection, but the results of blood and joint fluid cultures are often negative in children. We describe here the clinical features and management of culture-negative septic arthritis in children at our hospital and their outcomes.

METHODS

We performed a retrospective review of a cohort of children with septic arthritis who were hospitalized at Children's Hospital of Philadelphia between January 2002 and December 2014. Culture-negative septic arthritis was defined as a joint white blood cell count of >50000/μL with associated symptoms, a clinical diagnosis of septic arthritis, and a negative culture result. Children with pretreatment, an intensive case unit admission, Lyme arthritis, immunodeficiency, or surgical hardware were excluded. Treatment failure included a change in antibiotics, surgery, and/or reevaluation because of a lack of improvement/worsening.

RESULTS

We identified 157 children with septic arthritis. The patients with concurrent osteomyelitis (n = 28) had higher inflammatory marker levels at presentation, had a longer duration of symptoms (median, 4.5 vs 3 days, respectively; P < .001), and more often had bacteremia (46.4% vs 6.2%, respectively; P < .001). Among children with septic arthritis without associated osteomyelitis, 69% (89 of 129) had negative culture results. These children had lower C-reactive protein levels (median, 4.0 vs 7.3 mg/dL, respectively; P = .001) and erythrocyte sedimentation rates (median, 39 vs 51 mm/hour, respectively; P = .01) at admission and less often had foot/ankle involvement (P = .02). Among the children with culture-negative septic arthritis, the inpatient treatment failure rate was 9.1%, and treatment failure was more common in boys than in girls (17.1% vs 3.8%, respectively; P = .03). We found no association between treatment failure and empiric antibiotics or patient age. No outpatient treatment failures occurred during the 6-month follow-up period, although 17% of the children discharged with a peripherally inserted central catheter line experienced complications, including 3 with bacteremia.

CONCLUSIONS

The majority of septic arthritis infections at our institution were culture negative. Among patients with culture-negative infection, empiric antibiotics failed for 9% and necessitated a change in therapy. More sensitive diagnostic testing should be implemented to elucidate the causes of culture-negative septic arthritis in children.

Predicting Periarticular Infection in Children With Septic Arthritis of the Hip: Regionally Derived Criteria May Not Apply to All Populations

BACKGROUND

The management of septic arthritis of the hip in children can be complicated by the presence of additional coexisting periarticular infections (PAIs). Criteria predicting the presence of PAI have recently been proposed by Rosenfeld and colleagues with the goal of using magnetic resonance imaging (MRI) efficiently in the workup of septic arthritis. The purpose of this study was to determine the applicability of recently published predictive criteria for PAI (developed in the Southwestern United States using a variety of joints) to septic arthritis of the hip treated at a large Northeastern tertiary care center.

METHODS

We studied patients treated for septic arthritis of the hip with irrigation and debridement in a large Northeastern tertiary care center over a 10-year period. Laboratory and clinical variables related to presentation, treatment, and outcome were collected. Subjects with and without a perioperative MRI were compared with published criteria by Rosenfeld and colleagues.

RESULTS

Fifty-one subjects (53 hips) were identified with a mean age of 7.0 years (range, 1.2 to 19.3 y) and mean follow-up was 16 months (range, 2 to 85 mo). MRIs were obtained in 20 subjects (43%). Coexisting osteomyelitis was revealed in 7/20 of these studies (35% of MRIs); 4 of which showed coexisting intramuscular abscesses. Within our MRI cohort, the Rosenfeld criteria were found to have a sensitivity of 86%, a specificity of 54%, and a false-positive rate of 50% for the hip (compared with originally reported sensitivity of 90%, specificity of 67%, and false-positive rate of 33%). Overall, advanced imaging changed management in 5/51 patients (9%) by influencing the need for further treatment, whereas the remainder underwent isolated treatment of the septic hip joint with no adverse outcomes. One patient in the MRI cohort (without PAI) developed osteonecrosis of the femoral head.

CONCLUSIONS

We found lower sensitivity and specificity and higher false-positive rates for the Rosenfeld criteria in the hip for our geographically distinct population. Using the Rosenfeld criteria, MRIs would have been ordered unnecessarily in half of our series. Because of potential differences in regional microbiology and anatomic-specific factors, general predictive criteria for coexisting PAI based a single geographic region may be less generalizable to cases of hip sepsis in other geographic areas such as the Northeastern United States.

LEVEL OF EVIDENCE

Level 4-retrospective cohort study.

Septic Arthritis of the Hip-Risk Factors Associated With Secondary Surgery

INTRODUCTION

Septic arthritis of the hip (SAH) is a common condition encountered by pediatric orthopaedic surgeons and is treated with arthrotomy and irrigation. Depending on the response to initial treatment, some patients require surgical treatment beyond the index procedure. The purpose of this study was to investigate risk factors for repeat surgical intervention after initial arthrotomy for presumed SAH.

METHODS

A multicenter retrospective review of all children who underwent surgical arthrotomy for presumed SAH over a ten-year period was conducted. Variables queried included demographics, clinical presentation, laboratory parameters, imaging, infecting organism, presence of osteomyelitis, and surgical interventions performed. Logistic regression was used to predict the risk of a second procedure. Chi-square was used to compare patients who required further surgery and those who did not.

RESULTS

One hundred and thirty-eight patients (139 hips) qualified for inclusion. The average age at initial surgery was 6.1 years (range, zero to 17 years), and 57% of the patients were male. Concomitant osteomyelitis was diagnosed in 55 cases (40%). An infecting organism was identified from 70 (50%) index intraoperative cultures, with Staphylococcus aureus infections (methicillin-resistant Staphylococcus aureus [MRSA], 27; methicillin-sensitive Staphylococcus aureus, 25) being the most frequent. Fifty-six patients (41%) underwent subsequent surgical intervention, at an average of 5.5 days (range, 2 to 95) from the index procedure. Independent risk factors for repeat surgical procedures included presenting C-reactive protein >10 mg/dL (P = 0.002) and presenting erythrocyte sedimentation rate >40 (P = 0.011). The odds of repeat surgical intervention were significantly increased by the presence of concomitant osteomyelitis (odds ratio, 3.4; P = 0.001) and positive index intraoperative cultures for MRSA (odds ratio, 1.19; P = 0.001). Preoperative MRI before the index procedure was not universal (73/138; 53%), and acquisition of preoperative MRI was not associated with secondary surgical intervention (P = 0.389).

DISCUSSION

Forty-one percent of children in this multicenter cohort underwent at least one repeat surgical procedure after the index arthrotomy for management of presumed SAH. Risk factors for return to the operating room include elevated initial erythrocyte sedimentation rate and C-reactive protein, infection with MRSA, and presence of osteomyelitis.

LEVEL OF EVIDENCE

Level 3, case-cohort series. Type of evidence, therapeutic.

Clinical experience of debridement combined with resorbable bone graft substitute mixed with antibiotic in the treatment for infants with osteomyelitis

BACKGROUND

Osteomyelitis (OM) is an uncommon disease that originates from many different mechanisms in children. Treatment often involves a combination of surgical debridement combined and antibiotic therapy. The purpose of this article is to evaluate the effect of debridement combined with a new resorbable bone graft substitute (RBGS) mixed with antibiotics in the treatment of infants with OM.

METHODS

Twenty-two patients diagnosed with OM at our institution underwent debridement combined with implantation of RBGS mixed with vancomycin within 48 h after admission. Clinical and epidemiological factors, preoperative and postoperative radiographs, and laboratory parameters, including white blood cell (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and neutrophil percentage (NEU%), were documented. The function of the involved extremity was evaluated at the final follow-up.

RESULTS

The mean age was 6.3 ± 4.8 months (range, 0.5 to 12 months). The mean duration of the symptoms was 14.5 ± 8.4 days (range, 2 to 30 days). The average length of hospitalization was 13.7 ± 6.2 days (range, 6 to 28 days). 13.64% (3/22) had positive results of purulent material obtained at the time of open biopsy and 18.18% (4/22) had positive blood cultures. The most common sites were located in the proximal femur (12), the distal femur (3), and the proximal humerus (3). Ten patients presented with concurrent pyogenic arthritis, while another 12 infants suffered from simple isolated hematogenous OM. The mean follow-up time was 3.0 ± 1.6 years (range, 1.0 to 6.0 years). Seven of 22 patients (31.82%) had complications such as limb length deformity (LLD), avascular necrosis (AVN), and pathologic subluxation of the hip. Fifteen out of 22 (68.18%) patients achieved good results. Additionally, patients who had concomitant pyogenic arthritis were more likely to develop complications than those with isolated OM (p = 0.02).

CONCLUSIONS

Early debridement combined with implantation of RBGS mixed with vancomycin in the treatment of infants with OM achieved acceptable results in this series. Compared to those with simple isolated OM, patients with secondary pyogenic arthritis had a more virulent course.

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.].

Validating an Algorithm to Predict Adjacent Musculoskeletal Infections in Pediatric Patients With Septic Arthritis

BACKGROUND

Septic arthritis is frequently associated with adjacent infections including osteomyelitis and subperiosteal and intramuscular abscesses. While often clinically indiscernible from isolated septic arthritis, the diagnosis of adjacent infections is important in determining the need for additional surgical intervention. MRI has been used as the diagnostic gold standard for assessing adjacent infection. Routine MRI, however, can be resource-intensive and delay surgical treatment. In this context, there is need for additional diagnostic tools to assist clinicians in determining when to obtain preoperative MRI in children with septic arthritis. In a previous investigation by Rosenfeld et al., an algorithm, based on presenting laboratory values and symptoms, was derived to predict adjacent infections in septic arthritis. The clinical applicability of the algorithm was limited, however, in that it was built from and applied on the same population. The current study was done to address this criticism by evaluating the predictive power of the algorithm on a new patient population.

QUESTIONS/PURPOSES

(1) Can a previously created algorithm used for predicting adjacent infection in septic arthritis among pediatric patients be validated in a separate population?

METHODS

Records for all pediatric patients (1-18 years old) surgically treated for suspected septic arthritis during a 3-year period were retrospectively reviewed (109 patients). Of these patients, only those with a diagnosis of septic arthritis confirmed by synovial fluid analysis were included in the study population. Patients without confirmation of septic arthritis via synovial fluid analysis, Gram stain, or culture were excluded (34 patients). Patients with absence of MRI, younger than 1 year, insufficient laboratory tests, or confounding concurrent illnesses also were excluded (18 patients), resulting in a total of 57 patients in the study population. Five variables which previously were shown to be associated with risk of adjacent infection were collected: patient age (older than 4 years), duration of symptoms (> 3 days), C-reactive protein (> 8.9 mg/L), platelet count (< 310 x 10 cells/µL), and absolute neutrophil count (> 7.2 x 10 cells/µL). Adjacent infections were determined exclusively by preoperative MRI, with all patients in this study undergoing preoperative MRI. MR images were read by pediatric musculoskeletal radiologists and reviewed by the senior author. According to the algorithm we considered the presence of three or more threshold-level variables as a "positive" result, meaning the patient was predicted to have an adjacent infection. Comparing against the gold standard of MRI, the algorithm's accuracy was evaluated in terms of sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

In the new population, the sensitivity and specificity of the algorithm were 86% (95% CI, 0.70-0.95) and 85% (95% CI, 0.64-0.97), respectively. The positive predictive value was determined to be 91% (95% CI, 0.78-0.97), with a negative predictive value of 77% (95% CI, 0.61-0.89). All patients meeting four or more algorithm criteria were found to have septic arthritis with adjacent infection on MRI.

CONCLUSIONS

Critical to the clinical applicability of the above-mentioned algorithm was its validation on a separate population different from the one from which it was built. In this study, the algorithm showed reproducible predictive power when tested on a new population. This model potentially can serve as a useful tool to guide patient risk stratification when determining the likelihood of adjacent infection and need of MRI. This better-informed clinical judgement regarding the need for MRI may yield improvements in patient outcomes, resource allocation, and cost.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Septic Arthritis, Osteomyelitis, and Pyomyositis in a Previously Healthy Infant

Septic arthritis of the shoulder is rare in the pediatric population. In younger children and infants, it can be very difficult to diagnose. Septic arthritis of the shoulder is more commonly associated with concurrent osteomyelitis when compared to septic arthritis of the lower extremity. We describe a case of a 9-month-old patient with septic arthritis, osteomyelitis, and pyomyositis of the shoulder, and a discussion of diagnosis and management of pediatric bone and joint infection in the emergency department setting.

Analysis of colostrum IgA against bacteria involved in neonatal infections

OBJECTIVE

To describe e compare the specificity of IgA antibodies against bacteria extract of Klebsiella pneumoniae , Staphylococcus aureus , Escherichia coli , and Salmonella enteritidis .

METHODS

Colostrum samples were aseptically collected in the first 12 hours after C-section delivery. The specificity of IgA against bacteria extracts was analyzed by the Western blot.

RESULTS

The findings showed proteins of high molecular weight frequently detectable in the samples. S. aureus was the most frequently found bacterium in the samples (p<0.05). Approximately 93.8, 56.3, 62.5 and 60.4% of samples presented IgA reactive to S. aureus , K. pneumoniae , S. enteritidis, and E. coli, respectively. Roughly 40% of samples showed no IgA reactive to K. pneumoniae, S. enteritidis and E. coli .

CONCLUSION

Clinical evidence of the importance of breastfeeding for the immune protection of neonates was consistent with the observed immunological findings, since most samples showed IgA reactive against the species tested. The application and development of immunotherapies during pregnancy, focused on frequently detected antigens, could be an important tool to enhance the presence of IgA in colostrum.

Osteomyelitis is Commonly Associated With Septic Arthritis of the Shoulder in Children

PURPOSE

To describe the clinical presentation, management, and outcomes of surgically treated septic arthritis of the shoulder in a pediatric population.

METHODS

A retrospective chart review over 5 years of children with operatively managed septic arthritis of the shoulder was completed. Demographics, clinical presentation, symptoms duration, antibiotic regimen and duration, number of surgical procedures, and evaluation of laboratory value improvements were collected. Pretreatment and final radiographs were assessed. Causative organisms were reviewed. Patients were stratified in age groups to determine clinical variability based upon patient age.

RESULTS

A total of 22 children, ages 15 days to 14 years (average 37.3 mo), were treated for septic arthritis of the shoulder from 2006 to 2010 at a single pediatric institution. All patients were managed with open anterior arthrotomy at an average of 1.95 days after initial orthopaedic consultation (range, 0 to 15 d). Multiple presenting signs were noted; the most common was decreased use (59%). Average admission laboratory values include C-reactive protein 10.6 (range, 0.3 to 41.6), erythrocyte sedimentation rate 62.8 (range, 11 to 107), and white blood cell count 14.9 (range, 5.9 to 31.7). Initial radiographs were read as normal in 12 patients, concern for osteomyelitis in 5, cortical irregularity in 4, effusion in 3, and neoplasm in a single child. Nineteen patients had a preoperative magnetic resonance imaging and 15 demonstrated an effusion, 15 had evidence of humeral osteomyelitis, 5 had a subperisoteal abscess, and 4 had soft tissue abscesses. Eight patients remained culture negative. The most commonly identified organism was methcillin-resistant Staphylococcus aureus (MRSA) (22.7%). The patients under 12 months of age revealed more diverse organisms at culture and were less likely to have MRSA. All patients averaged 1.55 (range, 1 to 5) surgical procedures and had an average hospital stay of 13.5 days. Intravenous antibiotics averaged 16.3 days followed by an average of 34 days of oral treatment. MRSA patients were significantly more likely to require multiple operations to eradicate the infection (P<0.02) and had a longer duration of intravenous antibiotic use (P<0.003). MRSA patients were more likely to have abnormal radiographs at final follow-up (P<0.03).

CONCLUSIONS

Septic arthritis of the shoulder in children is commonly associated with adjacent osteomyelitis. Pediatric septic arthritis of the shoulder due to MRSA bacteria can have a more virulent course than other bacterial causes, but is a less commonly identified organism in the youngest patients.

SIGNIFICANCE

To our knowledge, this is one of the largest series published concerning the treatment, course, and outcomes of pediatric septic arthritis of the shoulder.

LEVEL OF EVIDENCE

Level III-therapeutic.

Acute osteomyelitis and septic arthritis in children : A referral hospital-based study in Iran

Information concerning the epidemiology of acute osteomyelitis (OM), septic arthritis (SA) and concurrent OM and SA in children is limited. The aim of this study was to describe the epidemiology of OM, SA and concurrent OM and SA in children. During the 4 years of the study, 63,999 patients were admitted to the Children's Hospital, Tehran, Iran. We identified 111 patients with OM and/or SA during the 4‑year period. There were 72 cases of OM (11 cases per 10,000 children) and 90 cases of SA (11 cases per 10,000 children). Concurrent OM and SA accounted for 0.17% of all cases (n = 51). The erythrocyte sedimentation rate and C‑reactive protein were elevated in the majority of both infections. Staphylococcus aureus was the most frequent pathogen responsible for both OM and SA in any age group. The lower limb was the most frequently affected (femur: 33/72, 46%; tibia or fibula: 22/72, 31%; foot: 5/72, 7%). The most frequent involved joints were hips (n = 31, 34%) and knees (n = 31, 34%). The present study showed high frequency of patients with concurrent SA and OM. Therefore, prompt recognition and proper diagnosis of pediatric OM and SA is highly recommended.

Kocher Criteria Revisited in the Era of MRI: How Often Does the Kocher Criteria Identify Underlying Osteomyelitis?

BACKGROUND

The Kocher criteria are established clinical parameters that predict hip septic arthritis (SA) with a 93% or greater positive-predictive value when 3 or 4 variables are present. The incidence of osteomyelitis (OM) in these patients has not been reported. The purpose of this study is to evaluate the incidence of OM in patients who have 3 or 4 positive Kocher criteria.

METHODS

A total of 71 consecutive patients (mean age, 4.7 y) treated between January 2007 and July 2013 for suspected hip SA who had 3 or 4 positive Kocher criteria were retrospectively reviewed. The Kocher criteria variables include: non-weight-bearing status, fever>38.5°C, white blood cell>12 K, and erythrocyte sedimentation rate>40 mm/h. All patients underwent ultrasound (US) and magnetic resonance imaging as part of their workup.

RESULTS

There were a total of 71 patients with 3 or 4 positive Kocher criteria. Of these, 22.5% (n=16) had a diagnosis of SA and 47.9% (n=34) had a diagnosis of OM. Of the 71 patients, 52.1% (37/71) had a hip effusion on US. When an effusion was identified, 18.9% (7/37) had isolated SA, 18.9% (7/37) had isolated OM, and 24.3% (9/37) had combined SA and OM. When no effusion was identified, a total of 18/34 (52.9%) had underlying OM.

CONCLUSIONS

Patients with 3 or 4 Kocher criteria have a high incidence (47.9%) of OM. Even in patients with a hip effusion on US, the incidence of OM was equal to that of SA. These results suggest that the combination of Kocher criteria and US alone is not sufficient to make a diagnosis in patients presenting with hip irritability and consideration should be given to adding magnetic resonance imaging to their workup.

LEVEL OF EVIDENCE

Level III-retrospective chart review.

The Contemporary Microbiology and Rates of Concomitant Osteomyelitis in Acute Septic Arthritis

BACKGROUND

Septic arthritis (SA) and acute osteomyelitis (AO) are among the most common serious bacterial infections of childhood. Knowledge of the microbiology of SA is critical to treatment. Awareness of the presence of attendant AO is also important to guide clinical management. We sought to describe the current microbiology of SA in children and clinical features associated with coexisting AO.

MATERIALS AND METHODS

Patients with SA were identified from the infectious diseases consult service records from 2010 to 2014. Patients with penetrating/open trauma and orthopedic hardware in situ were excluded.

RESULTS

A total of 168 patients with SA were included. The most common causative organism was Staphylococcus aureus accounting for 47.7% of cases (29.1% were methicillin-susceptible S. aureus and 18.5% were methicillin-resistant S. aureus), followed by group A streptococcus (GAS, 8.9%). The proportion of cases due to GAS increased from 2011 to 2014 (3.3%-16.7%; P = 0.1). One hundred eight (64.3%) patients had concurrent AO. The presence of osteomyelitis was associated with older median age (5.9 vs. 2.4 years; P = 0.04), a longer duration of symptoms (5 vs. 2.5 days; P < 0.001), S. aureus (62.1% vs. 21.7%; P < 0.001), bacteremia (46.2% vs. 20.3%; P = 0.001), a longer duration of fever after admission (5 vs. 2 days; P < 0.001) and a longer length of stay (10 vs. 6 days; P < 0.001).

CONCLUSIONS

Methicillin-resistant S. aureus continues to be an important cause of SA though GAS may be increasing in frequency. The presence of concomitant osteomyelitis is higher than previously reported and associated with older age, a longer duration of symptoms and fever, bacteremia and S. aureus.

Passive acquisition of anti-Staphylococcus aureus antibodies by newborns via transplacental transfer and breastfeeding, regardless of maternal colonization

OBJECTIVE:

To investigate the transmission of anti-Staphylococcus aureus (Sa) IgG, IgG1 and IgG2 via placental transfer and the transfer of IgA via the colostrum according to maternal Sa carrier status at delivery.

METHODS:

We evaluated anti-Sa IgG, IgG1 and IgG2 in maternal and cord sera and IgA in colostrum from a case (n=49, Sa+) and a control group (n=98, Sa-).

RESULTS:

Of the 250 parturients analyzed for this study, 49 were nasally colonized with S. aureus (prevalence of 19.6%). Ninety-eight non-colonized subjects were selected for the control group. The anti-Sa IgG, IgG1 and IgG2 levels and the IgG avidity indexes in the maternal and cord sera did not differ between the groups, with a low transfer ratio of anti-Sa IgG to the newborns in both groups. The anti-Sa IgG2 titers were significantly higher than the IgG1 titers in the maternal and cord sera. Inversely, the transfer ratios were higher for anti-Sa IgG1 compared with IgG2; however, no differences between the groups were detected. The Sa-specific IgA levels and avidity indexes in the colostrum were equivalent between groups.

CONCLUSIONS:

Maternal Sa nasal colonization at delivery is not associated with higher antibody levels in the mother or newborns. The high titers of anti-Sa IgG2 found in the cord serum indicate a greater reactivity with non-protein antigens, which may further contribute to the susceptibility to staphylococcal infections at birth. The presence of IgA in the colostrum with avidity to S. aureus reinforces the importance of breastfeeding shortly after birth.

Indicative Knee Posture in Children with Osteomyelitis of the Proximal Part of the Tibia with or without an Associated Subperiosteal Abscess: A Report of 3 Cases

CASE

Three patients with documented osteomyelitis of the proximal part of the tibia are described. On examination, all of the patients had an indicative finding of knee flexion to 90°. Because of the concern for septic arthritis, each patient underwent knee aspiration as part of the evaluation.All recovered with conventional infection treatment protocols.

CONCLUSION

High knee flexion beyond what is typical in patients with septic arthritis may indicate osteomyelitis of the proximal part of the tibia. Consideration of this diagnosis may lead to more expedient and efficient care.