Paediatric bone and joint infection

Case Report: Atypical acute compartment syndrome of the forearm in a child following minor trauma with consecutive osteomyelitis

Introduction

Forearm compartment syndrome (CS) in children is above all a clinical diagnosis whose main cause is traumatic. However, rarer causes such as infection can alter its clinical presentation.

Clinical case

An 8-year-old boy has been seen in the emergency department complaining of severe forearm pain under a splint in a mild traumatic context. The previous radiological imaging examination three days before had not revealed any fractures. On admission, he presented with major signs of skin inflammation, loss of mobility, paresthesia and a significant biological inflammatory syndrome. The acute CS diagnosis has been made and was treated, but its atypical presentation raised a series of etiological hypotheses, in particular infectious, even if it remains rare. Complementary imaging examinations confirmed the presence of osteomyelitis of the distal radius as well as an occult Salter-Harris II fracture.

Discussion

Beyond the classic "five P's of CS" -pain, paresthesia, paralysis, pallor and pulselessness-, CS's clinical presentations are multiple, especially in pediatric patients. In children, severe pain and increasing analgesic requirement must be indicators of a CS. We hypothesize that this patient sustained a nondisplaced Salter-Harris II fracture with a hematoma colonized by hematogenous osteomyelitis explaining its initial clinical presentation.

Conclusion

Hematogenous osteomyelitis complicated by CS is rare and may be accompanied by a traumatic history. It's atypical presentation in pediatric patients requires vigilance and prompt diagnosis given the disastrous and irreversible complications.

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.

Exploring the role of bacterial virulence factors and host elements in septic arthritis: insights from animal models for innovative therapies

Septic arthritis, characterized as one of the most aggressive joint diseases, is primarily attributed to Staphylococcus aureus (S. aureus) and often results from hematogenous dissemination. Even with prompt treatment, septic arthritis frequently inflicts irreversible joint damage, leading to sustained joint dysfunction in a significant proportion of patients. Despite the unsatisfactory outcomes, current therapeutic approaches for septic arthritis have remained stagnant for decades. In the clinical context, devising innovative strategies to mitigate joint damage necessitates a profound comprehension of the pivotal disease mechanisms. This entails unraveling how bacterial virulence factors interact with host elements to facilitate bacterial invasion into the joint and identifying the principal drivers of joint damage. Leveraging animal models of septic arthritis emerges as a potent tool to achieve these objectives. This review provides a comprehensive overview of the historical evolution and recent advancements in septic arthritis models. Additionally, we address practical considerations regarding experimental protocols. Furthermore, we delve into the utility of these animal models, such as their contribution to the discovery of novel bacterial virulence factors and host elements that play pivotal roles in the initiation and progression of septic arthritis. Finally, we summarize the latest developments in novel therapeutic strategies against septic arthritis, leveraging insights gained from these unique animal models.

Exploring Nanotechnology as a Strategy to Circumvent Antimicrobial Resistance in Bone and Joint Infections

Bone and joint infections (BJIs) are difficult to treat, necessitating antimicrobial therapy at high doses for an extended period of time, in some cases different from our local guidelines. As a consequence of the rise in antimicrobial-resistant organisms, drugs that were previously reserved for last-line defense are now being used as first line treatment, and the pill burden and adverse effects on patients are leading to nonadherence, encouraging antimicrobial resistance (AMR) to these last-resort medicines. Nanodrug delivery is the field of pharmaceutical sciences and drug delivery which combines nanotechnology with chemotherapy and/or diagnostics to improve treatment and diagnostic outcomes by targeting specific cells or tissues affected. Delivery systems based on lipids, polymers, metals, and sugars have been used in an attempt to provide a way around AMR. This technology has the potential to improve drug delivery by targeting the site of infection and using the appropriate amount of antibiotics to treat BJIs caused by highly resistant organisms. This Review aims to provide an in-depth examination of various nanodrug delivery systems used to target the causative agents in BJI.

Subacute Bacterial Infection Mimicking a Slipped Capital Femoral Epiphysis in an Obese Adolescent Male - A Case Report and Review of Literature

Introduction

Atypical and subacute presentations of pediatric bacterial septic arthritis are difficult to diagnose due to lack of systemic manifestations and inadequate laboratory data. Furthermore, they may mimic certain well-documented pediatric disorders to confound the diagnosis and management.

Case Report

The authors present a case of an adolescent obese male with features suggestive of a slipped capital femoral epiphysis (SCFE). Further investigations revealed bacterial septic arthritis which may have contributed to the slip. He was treated with an initial debridement followed by a definitive pelvic support osteotomy (PSO) with a compensatory distal femoral varus osteotomy. At 12 months, he had a satisfactory clinical and radiological outcome.

Conclusion

Clinicians should have a high degree of suspicion for infection in patients presenting with atypical clinical or radiological signs of SCFE. A thorough investigation in such cases is a must, to aid in correct management. PSO is an effective salvage procedure in adolescents with septic hip sequelae.

A Child With Acute Hematogenous Osteomyelitis of the Distal Fibula and Infective Endocarditis

Acute hematogenous osteomyelitis (AHO) commonly interests the pediatric population. It typically affects the metaphyses of long tubular bones. However, the fibula is rarely involved. Regarding the hematogenous inoculation, this infection may be associated with distant foci. Herein, we present the case of a 10-year-old girl who was initially diagnosed with atypical AHO of the distal fibula complicated by a subperiosteal abscess. Upon admission, the child showed a severe septic condition, including embolic infective endocarditis (IE), which was responsible for multiple cerebral, renal, and splenic loci. AHO was successfully resolved with appropriate intravenous antimicrobial treatment targeting Staphylococcus aureus, surgical drainage, and debridement. Due to the complexity of the lesions and the embolic nature, the IE was also managed operatively with a mechanical prosthesis. The distal fibula is a rare and challenging location for AHO. EI co-infection should always be sought and suspected because, in such instances, it will genuinely complicate diagnostic and therapeutic management.

Analysis of the epidemiological status, microbiology, treatment methods and financial burden of hematogenous osteomyelitis based on 259 patients in Northwest China

Background

The incidence of hematogenous osteomyelitis is on the rise, and the prognosis is poor. There has been no large-scale epidemiological analysis of hematogenous osteomyelitis in the world, and the treatment method is still controversial.

Methods

A retrospective case study method was used to collect and analyze clinical data obtained from patients with hematogenous osteomyelitis in a tertiary hospital in Northwest China from January 1, 2011, to December 31, 2020. The aim of this study was to investigate the epidemiological status, microbiological characteristics, treatment and financial burden of hematogenous osteomyelitis in Northwest China to explore the therapeutic effects of different treatment methods, elucidate the epidemiological characteristics of hematogenous osteomyelitis and to provide a basis for the choice of treatment.

Results

We included 259 patients with hematogenous osteomyelitis, including 96 patients with acute hematogenous osteomyelitis and 163 patients with chronic hematogenous osteomyelitis. The cause of the disease was not obvious in most patients, the sex ratio of males to females was 1.98, and the three most common infected sites were the tibia, femur and phalanx. Regarding preoperative serum inflammatory markers, the rate of positivity for ESR was the highest at 67.58%. Among pathogenic microorganisms, Staphylococcus aureus was the most common. Regarding the financial burden, the median total cost per patient was 25,754 RMB, and medications accounted for the largest proportion of the main costs.

Conclusions

The most common pathogen associated with HO infection was MSSA. Oxacillin has good PK and PD and is recommended as the first-line drug. Some blood-borne bone infections may lead to complications, such as pulmonary infection through bacteremia, which requires early detection to avoid a missed diagnosis. Regarding surgical intervention, debridement plus absorbable calcium sulfate bone cement and calcium sulfate calcium phosphate bone cement exclusion have achieved good therapeutic effects, but they are worthy of further in-depth research. Regarding the financial burden, the median total cost per patient was 25,754 RMB. The financial burden of blood-borne osteomyelitis was lower than that of traumatic osteomyelitis. Among the main costs, drugs accounted for the largest proportion.

Fever and Knee Effusion in the Pediatric Patient

ABSTRACT

The pediatric patient with fever and knee effusion is always a cause for clinical concern. A thorough history and physical examination is required to guide appropriate diagnostic evaluation and management. Although pediatric knee effusions are common in the setting of trauma, the presence of fever should prompt consideration of infectious, rheumatologic, vasculitic, and malignant etiologies. This review covers the key components of the history, physical examination, diagnostic strategies, common etiologies, and initial management of the pediatric patient with fever and knee effusion.

Acute Hematogenous Osteomyelitis Resulting in Atraumatic Pediatric Forearm Compartment Syndrome

Acute hematogenous osteomyelitis is well described after minor trauma in the pediatric population, with an incidence of 1 to 13 cases per 100,000 individuals. Compartment syndrome (CS) in children is a rare, but potentially devastating disease, classified as “cannot miss diagnosis.” Compared with adults, CS may exhibit a variable presentation with a wide range of symptoms in children, often leading to delayed diagnosis. Expeditious diagnosis and treatment of CS is paramount in minimizing adverse sequelae and maximizing potential functional outcome, regardless of etiology. Here, we present a rare case of atraumatic CS resulting from ruptured subperiosteal abscess secondary to acute hematogenous osteomyelitis in a pediatric male patient with 2 weeks of forearm pain and evolving neurologic deficits with initial delay in presentation to our facility. The ramifications of delayed diagnosis or misdiagnosis of CS emphasize the importance of a high index of suspicion despite atypical presentations in the pediatric patient.

Bilateral hip septic arthritis caused by nontyphoidal Salmonella group D in a 16-year-old girl with COVID-19: A case report

Introduction and importance

Nontyphoidal Salmonella infection can lead to gastroenteritis, enteric fever, and bacteremia. However, joint infections due to this bacterium are rare, and usually associated with immunosuppressive disorders.

Case presentation

A 16-year-old girl, with a recent history of acute lymphocytic leukemia (ALL) presented with bacteremia, and bilateral hip pain after COVID-19 symptoms. Clinical presentation, laboratory features and imaging showed bilateral nontyphoidal Salmonella septic arthritis. We administered antibiotics, based on antibiotics susceptibility pattern of the isolated Salmonella.

Clinical discussion

The case is presented because reports of bilateral hip joint infection due to nontyphoidal Salmonella are rare especially after COVID-19. When the patient presents with joint discomfort, the clinician should think infection especially in immunocompromised hosts.

Conclusion

It illustrates successful management of septic arthritis requires prompt clinical diagnosis, microorganism identification, administration of appropriate systemic antibiotics and hip joint surgery.

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Nontyphoidal Salmonella is one of the most important organisms involved in septic shock and arthritis.

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Acute lymphocytic leukemia (ALL) is a type of cancer that affects white blood cells (WBC).

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COVID-19 is a contagious disease caused by severe acute respiratory syndrome coronavirus.

Is Early Surgical Intervention Necessary for Acute Neonatal Humeral Epiphyseal Osteomyelitis: A Retrospective Study of 31 Patients

Objective: To review the treatment experience of neonatal humeral epiphyseal osteomyelitis retrospectively. Study design: Retrospective cohort study of infants with neonatal humeral epiphyseal osteomyelitis. Patients were divided into conservative group and surgical group, and the surgical group was subdivided into early and delayed surgical group. Results: In total, there were 7 patients in the conservative group and 24 in the surgical group. The length of hospital stay and intravenous course of antibiotic therapy were both significantly shorter in the surgical group (p < 0.001). The full recovery rate was also higher in the surgical group (83.3%) than the conservative group (14.3%) (p < 0.001). Early surgery group (n = 14) had an insignificantly higher positive rate of pus/aspirate culture and full recovery rate than delayed surgery group (n = 10). Conclusion: Surgical treatment for neonatal humeral epiphyseal osteomyelitis demonstrated significantly higher rates of positive culture for the pathogen, a shorter course of intravenous oral antibiotics, and lower incidence of growth abnormality than conservative treatment. In our institution, most of culture outcome Gram-positive bacteria, and early surgical treatment was recommended with better outcome than delayed surgical group. Empirical antibiotics should be tailored to the epidemiological characteristics of local virulent bacteria.

Paediatric Osteomyelitis and Septic Arthritis Pathogen Distribution and Antimicrobial Resistance in a Single Centre: A 15-Year Retrospective Analysis

BACKGROUND

The epidemiological characteristics of the common pathogens underlying acute haematogenous osteoarticular infection (AHOI) and their resistance to drugs have temporal and regional differences.

AIMS

To determine the antimicrobial treatment most effective for culture-negative AHOI patients and those without bacterial cultures.

METHODS

Retrospective analysis of clinical data of children with AHOI who were culture positive from January 2007 to December 2021. And the distribution of the main pathogens and the drug resistance Staphylococcus aureus were analysed in different time periods, age groups and infection types.

RESULTS

A total of 188 cases met the inclusion criteria, including 97 cases of acute haematogenous osteomyelitis (AHO), 75 cases of septic arthritis (SA) and 16 cases of AHO concomitant with SA. The commonest causative pathogen in local children was S. aureus of Gram-positive cocci, followed by Streptococcus, and occasionally Gram-negative bacilli. The distribution of S. aureus had no significant correlation with age or infection type. Staphylococcus aureus accounted for 81.82%, 90.91% and 96.15% of all pathogens, and methicillin-resistant S. aureus (MRSA) accounted for 24.22%, 53.33% and 76.00% of S. aureus in 2007-11, 2012-16 and 2017-21, respectively. The frequency of MRSA infection showed an increasing trend over time.

CONCLUSION

Staphylococcus aureus is still the main pathogen of AHOI in local children. The proportion of MRSA in S. aureus has also increased over time to 76% in the last 5 years, and the increased proportion of MRSA can affect the choice of initial empirical medication.

Real time monitoring of Staphylococcus aureus biofilm sensitivity towards antibiotics with isothermal microcalorimetry

Biofilm-associated infections with Staphylococcus aureus are difficult to treat even after administration of antibiotics that according to the standard susceptibility assays are effective. Currently, the assays used in the clinical laboratories to determine the sensitivity of S. aureus towards antibiotics are not representing the behaviour of biofilm-associated S. aureus, since these assays are performed on planktonic bacteria. In research settings, microcalorimetry has been used for antibiotic susceptibility studies. Therefore, in this study we investigated if we can use isothermal microcalorimetry to monitor the response of biofilm towards antibiotic treatment in real-time. We developed a reproducible method to generate biofilm in an isothermal microcalorimeter setup. Using this system, the sensitivity of 5 methicillin-sensitive S. aureus (MSSA) and 5 methicillin-resistant S. aureus (MRSA) strains from different genetic lineages were determined towards: flucloxacillin, cefuroxime, cefotaxime, gentamicin, rifampicin, vancomycin, levofloxacin, clindamycin, erythromycin, linezolid, fusidic acid, co-trimoxazole, and doxycycline. In contrast to conventional assays, our calorimetry-based biofilm susceptibility assay showed that S. aureus biofilms, regardless MSSA or MRSA, can survive the exposure to the maximum serum concentration of all tested antibiotics. The only treatment with a single antibiotic showing a significant reduction in biofilm survival was rifampicin, yet in 20% of the strains, emerging antibiotic resistance was observed. Furthermore, the combination of rifampicin with flucloxacillin, vancomycin or levofloxacin was able to prevent S. aureus biofilm from becoming resistant to rifampicin. Isothermal microcalorimetry allows real-time monitoring of the sensitivity of S. aureus biofilms towards antibiotics in a fast and reliable way.

The spectrum and burden of in-patient paediatric musculoskeletal diseases in Northern Tanzania

BACKGROUND

Musculoskeletal diseases (MSD) are a major contributor to the global burden of disease and disability, and disproportionally affect low- and middle-income countries; however, there is a dearth of epidemiological data. Affected children often face increased morbidity, social isolation and economic hardship.

AIM

To assess the spectrum and burden of paediatric MSD in children aged 5-18 years admitted to a major referral hospital in Tanzania.

METHODS

This was a retrospective cohort study of children aged 5-18 years admitted to Kilimanjaro Christian Medical Centre (KCMC) whose initial diagnosis was recognised as a musculoskeletal condition by the International Classification of Diseases-10 between 1 January and 31 December 2017.

RESULTS

During 2017, 163 cases of confirmed paediatric MSD were admitted to KCMC, representing 21.2% of all admissions of children aged 5-18 years (n = 769). Bone disease was the most common diagnosis. They comprised 106 (65.0%) traumatic fractures, 31 (19.0%) osteo-articular infections, 9 (5.5%) malunions and 3 (1.8%) pathological fractures. Congenital defects and rheumatic disease were relatively uncommon, accounting for only 6 (3.7%) and 4 (2.5%) MSD admissions, respectively.

CONCLUSION

The majority of cases of MSD were related to fractures, followed by osteo-articular infections, while recognised cases of rheumatic disease were rare. The study, although small, identified the sizeable burden and spectrum of paediatric MSD admitted to a hospital in Tanzania over a 12-month period and highlights the need for larger studies to inform the optimal allocation of health resources.

ABBREVIATION

CI: confidence interval; HIC: high-income countries; HIV: human immunodeficiency virus; ICD-10: International Classification of Diseases 10; IQR: interquartile range; JIA: juvenile idiopathic arthritis; KCMC: Kilimanjaro Christian Medical Centre; LMIC: low- and middle-income countries; MSD: musculoskeletal diseases: NAI: non-accidental injury; NIHR: National Institute for Health Research; PAFLAR: Paediatric Society of the African League Against Rheumatism; RTA: road traffic accidents; SCD: sickle cell disease; SLE: systemic lupus erythematosus; SSA: sub-Saharan Africa.

The Utility of Routine Radiographic Monitoring in Pediatric Osteoarticular Infections

BACKGROUND

Pediatric musculoskeletal (MSK) infections broadly include isolated osteomyelitis (OM), septic arthritis (SA), and combined infections (OM+SA). These diagnoses are often monitored with serum inflammatory markers and serial radiographs to monitor treatment response and development of negative sequelae, despite limited data supporting these practices. The purpose of this study is to evaluate the utility of obtaining serial radiographic follow-up for pediatric osteoarticular infections.

METHODS

An institutional review board-approved retrospective review was completed. Children 18 years and below admitted to a single institution with a culture/biopsy-proven diagnosis of OM, SA, or OM+SA. All postdischarge radiographs were reviewed and retrospectively categorized as either routine (scheduled) or reactive. Routine radiographs were obtained regardless of clinical presentation. Reactive radiographs were obtained in patients presenting with the sign of an altered clinical course. Negative sequelae, defined as growth arrest/disturbance, pathologic fracture, recurrent MSK infection, and underlying neoplastic process, were recorded and tracked. Descriptive statistics were used to summarize demographic and outcome variables. Number needed to screen (NNS) was defined as the inverse of the incidence of negative sequelae detected.

RESULTS

A total of 131 patients were included for analysis, with a mean age of 11.9 years (SD: 4.96 y). Ninety (69%) patients were diagnosed and treated for OM, 25 (19%) for SA, and 16 (12%) for combined infections. A total of 329 radiographs were obtained following discharge. Of those obtained, 287 (88%) were routine, resulting in the detection of 2 (0.7%) negative sequelae and a resultant NNS of 143 radiographs (95% confidence interval: 36-573). The remaining 39 were reactive radiographs, resulting in the detection of 2 (5.1%) negative sequelae with an NNS of 20 radiographs (95% confidence interval: 5-78).

CONCLUSIONS

While radiographs remain a widely utilized tool to screen for the development of negative sequelae in pediatric osteoarticular infections, they rarely alter management in the absence of other concerning clinical signs or symptoms such as recurrent fevers, swelling of the extremity, or limb deformity. Moreover, routine radiographic surveillance should be replaced with a reactive radiographic protocol.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

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.

Surgery's role in contemporary osteoarticular infection management

The treatment paradigm for osteoarticular infections (OAIs) has changed drastically over the past 80 years, from the advent of penicillin to the use of broad-spectrum antibiotics. Before these drugs, surgery was the only available treatment for OAIs; today, antibiotic therapy is considered the primary response to them. As a result, surgical treatment of OAIs is thus far more rarely indicated, sometimes even considered outdated and obsolete. However, long experience has taught us that many OAI contexts can still benefit from surgical management, constituting an essential complement to medical treatment. The present article seeks to contextualize this discussion by providing a chronological review of the surgical treatments used in cases of OAI and describing the quality of evidence supporting their rehabilitation in well-established situations.

Early oral switch to combined cefixime therapy for management of osteoarticular infections in pediatric sickle cell disease patients: A descriptive analysis

BACKGROUND

The treatment of osteoarticular infections in pediatric patients with sickle cell disease (SCD) is a challenging task for the practitioner. The aim of this study is to evaluate cefixime for the treatment of osteoarticular infections in pediatric SCD patients by retrospective design.

METHODS

This study was done in the pediatric hospital of King Saud Medical City, Riyadh, Saudi Arabia. The data was obtained from medical records of patients aged 1-16 years admitted between January 2019 to December 2020, diagnosed with SCD and received cefixime for the treatment of OI. A descriptive study for pediatric patients admitted between January 2019 to December 2020 diagnosed with sickle cell disease and diagnosed with osteoarticular infection. All patients were treated with cefixime. Medians and interquartile ranges (IQRs) were used for the descriptive analysis.

RESULTS

A total of 260 patients were screened, and 51 cases [osteomyelitis (OM), n = 43, and septic arthritis (SA), n = 8] met the inclusion criteria. The median age of OM patients was 7 years, with males making up 67.4% of the cohort. The median length of IV antibiotics and hospital stays were 10 days and 11 days, respectively. The median total duration of antibiotic use was 37 and 25 days for OM and SA, respectively. The treatment success rate was 88% in OM cases and 100% in SA patients. Readmission was noted in 39.5% of the OM patients, while only 25% of the SA patients were recorded for reinfection.

CONCLUSION

The study's findings revealed that Cefixime is a viable oral alternative for treating osteoarticular infection in pediatric SCD patients. Nonetheless, a prospective investigation is required to corroborate the findings of this study.

The Epidemiology of Osteomyelitis in Children

Pediatric osteomyelitis remains challenging to treat. Detailed epidemiological data are required to estimate future developments. Therefore, we aimed to analyze how the incidence has changed over the last decade depending on age, gender, osteomyelitis subtype, and anatomical localization. Cases were quantified for patients aged 20 years or younger, using yearly reported ICD-10 diagnosis codes from German medical institutions for the time period 2009 to 2019. Incidence rates of osteomyelitis increased by 11.7% from 8.2 cases per 100,000 children in 2009 to 9.2 cases per 100,000 children in 2019. The age-specific incidence rate revealed the highest occurrence of osteomyelitis in patients aged 10–15 years (15.3/100,000 children), which increased by 23% over the observation period, followed by the age group 5–10 years (9.7/100,000 children). In 2019, out of all diagnoses, 39.2% were classified as acute, 38.4% as chronic, and 22.4% were unspecified, whereby chronic cases increased by 38.7%. The lower extremity was mainly affected, with 58.9% of osteomyelitis diagnoses in 2019. In conclusion, pediatric osteomyelitis is a serious issue, even in a developed and industrialized country such as Germany. Considering the recent incidence increase, the permanent need for appropriate treatment should let pediatricians and orthopedic surgeons deal with diagnosis and treatment protocols.

Characteristics of Musculoskeletal Involvement in Pediatric Patients with Disseminated Sepsis in a Tertiary Care Center

BACKGROUND

Pediatric bone and joint infections account for one of the major causes of childhood morbidity. Disseminated sepsis being a systemic disorder with multisystem involvement, overshadows the timely recognition of bone and joint infections. Hence, we did this cross sectional study to evaluate the prevalence of septic arthritis and osteomyelitis in disseminated sepsis in children, the organisms implicated, and their antibiotic sensitivities.

METHODS

We prospectively collected data from 1st July 2016 to 31st September 2017 of children aged less than 12 years with disseminated sepsis, i.e., patients with fever and two or more sites of focal infection of anatomically non-contiguous tissues.

RESULTS

Fifty-four patients of disseminated disease were included, of which 25 patients (46.3%) had osteoarticular infections. Septic arthritis was seen in 17 patients, and osteomyelitis was seen in 12 patients. The most common joint was hip (41.6%), and the most common bone involved was femur (53.8%). Blood culture showed MRSA in 28% and MSSA in 20%. Joint and bone aspirates showed S. aureus in 56% with 28% of MRSA and MSSA each. All Staphylococcus aureus organisms were found sensitive to vancomycin and teicoplanin. The mean values of CRP, duration of stay and duration of intravenous antibiotic was higher in MRSA infected patients compared to MSSA patients.

CONCLUSIONS

Staphylococcus aureus is the most prevalent organism in musculoskeletal infection in disseminated sepsis children, with vancomycin sensitivity of 100% and methicillin sensitivity of 46.2% only. Cases of osteoarticular involvement with MRSA were higher compared to MSSA among the cases of disseminated disease. The prevalence of osteoarticular involvement is high in disseminated sepsis in children and increased clinical suspicion for such must be maintained.

The role of dendritic cells derived osteoclasts in bone destruction diseases

The bone is previously considered as a dominant organ involved in the processes of locomotion. However, in the past two decades, a large number of studies have suggested that the skeletal system closely coordinated with the immune system so as to result in the emerging area of 'osteoimmunology'. In the evolution of many kinds of bone destruction-related diseases, osteoclasts could differentiate from dendritic cells, which contributed to increased expression of osteoclast-related membrane receptors and relatively higher activity of bone destruction, inducing severe bone destruction under inflammatory conditions. Numerous factors could influence the interaction between osteoclasts and dendritic cells, contributing to the pathogenesis of several bone diseases in the context of inflammation, including both immunocytes and a large number of cytokines. In addition, the products of osteoclasts released from bone destruction area serve as important signals for the differentiation and activation of immature dendritic cells. Therefore, the border between the dendritic cell-related immune response and osteoclast-related bone destruction has gradually unravelled. Dendritic cells and osteoclasts cooperate with each other to mediate bone destruction and bone remodelling under inflammatory conditions. In this review, we will pay attention to the interactions between dendritic cells and osteoclasts in physiological and pathological conditions to further understand the skeletal system and identify potential new therapeutic targets for the future by summarizing their significant roles and molecular mechanisms in bone destruction.

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.

Late sequelae of osteoarticular infections in pediatric patients: A single-center study

To review the orthopedic sequelae of pediatric patients diagnosed with osteoarticular infections (OAIs) and identify significant differences between those with and without sequelae. Medical charts between 2010 and 2016 from a tertiary-care pediatric hospital were reviewed to collect demographic and clinical data for this retrospective case series. The main inclusion criteria were: 1. age (≤10 years old); 2. absence of sickle cell anemia and immunocompromising disease or medication; 3. a minimum follow-up of 12 months with radiographs; and 4. diagnosis of osteomyelitis of long bones and/or septic arthritis. The following late sequelae were observed and aggregated: osteal deformations that led to limb-length discrepancies (LLD) superior to 5 mm, abnormal articular angulations of more than 5°, and symptomatic chondropathies visible on imaging studies after 1 year. The patients were divided into 2 subgroups: with and without sequelae. Chi-Squared tests were used for categorical variables and Mann–Whitney U tests for continuous data to identify statistically significant differences between the 2 subgroups. Among 401 patients with osteomyelitis and/or septic arthritis, 50 (12.5%) were included (24 girls and 26 boys). There were 36 (72%) cases of osteomyelitis, 8 (16%) cases of septic arthritis, and 6 (12%) cases of combined infection (3 acute/subacute and 3 chronic cases). Five (10%) patients had orthopedic sequelae at the latest follow-up. The total duration of antibiotic treatment (P = .002), infectious disease follow-up (P = .002), and the presence of sequestra (P = .005) were significantly different between subgroups. There were no statistically significant differences between the 2 subgroups for the other variables, but some trends could be discerned. Only 4/50 patients developed a sequestrum, 2 of which were in the orthopedic sequelae subgroup. Furthermore, initial C-reactive protein (CRP) values were higher in the sequelae subgroup, as were the CRP values at hospital discharge. The orthopedic follow-up was also longer in the sequelae subgroup. Finally, the delay between the onset of symptoms and the beginning of antibiotic treatment was longer in the sequelae group. Patients with orthopedic sequelae had a longer antibiotic treatment and infectious disease follow-up, and were more likely to have presented with a sequestrum. Level of evidence: IV – case series.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Acute Hematogenous Escherichia coli Osteomyelitis of the Fibula in an Adolescent Girl

Introduction: Acute hematogenous osteomyelitis (AHO) usually occurs in the first two decades of life. Evidence shows that 50% of patients with AHO are younger than five years. This infection typically affects the metaphyseal region of long tubular bones, whereas the fibula is rarely involved. Staphylococcus aureus is the causative agent of AHO in the majority of cases, while Escherichia coli is isolated rather uncommonly beyond the neonatal period. Case Presentation: Herein, we describe the case of an adolescent girl who was treated medically and surgically for AHO with an unusual location in the proximal fibula, caused by E. coli. The source of the causative agent remained unknown after the patient had been evaluated for possible urinary tract infection and underlying immune system defect. Conclusions: The fibula is a rare anatomic location for AHO, and such cases may pose a diagnostic challenge. Lack of response to empiric antibiotic treatment in patients with AHO may indicate the involvement of an uncommon pathogen, which is not susceptible to standard empiric antimicrobials aimed to target S. aureus as the most likely pathogen. In such instances, prompt surgical intervention can help determine the causative pathogen and optimize antimicrobial treatment.

Clinical features and outcomes in children with bone and joint infections of the ankle or foot

BACKGROUND

The foot and ankle are uncommon sites of bone and joint infections (BJIs) in children. The objectives of the present study were to determine the clinical and bacteriologic features of BJIs and to assess any associated complications and orthopedic sequelae.

METHODS

We performed a retrospective, single-center study of children treated for foot or ankle BJIs between 2008 and 2018 in a French university medical center. A total of 23 children were included. The median age at diagnosis was 9.1 years. Osteomyelitis was noted in 14 cases; it involved the calcaneus in seven cases, the distal fibula in four cases, the first metatarsal in two cases, and the distal tibia in one case. Arthritis affected the ankle in six cases and the cuneiform-cuboidal joint in one case. In two cases, osteoarthritis of the ankle was associated with distal osteomyelitis of the tibia. Clinical, radiological, and bacteriological parameters, surgical procedures, complications, and sequelae were recorded and analyzed.

RESULTS

The median (range) time to diagnosis was 3.18 days (0-10), and trauma was reported in four cases. Fever was present on admission in 18 cases, and the serum C-reactive protein level was elevated in 22 cases. Standard X-rays showed osteolysis in one case and bone sequestration in another. Staphylococcusaureus was identified in 10 cases. Surgery was performed in 17 cases. A subperiosteal abscess that required surgical drainage complicated 10 cases of osteomyelitis. No recurrence was observed. At the last follow-up, the median (range) age was 11.9 years (1.5-19). Sequelae (spontaneous tibia-talus fusion, first metatarsal epiphysis fusion, and varus deformity of the hindfoot) were observed in three cases, all of which were initially complicated by an abscess.

CONCLUSION

Physicians should be aware that pediatric BJIs of the lower limb may involve the foot and ankle. S. aureus is frequently involved. In cases of osteomyelitis, complications are closely associated with subperiosteal abscesses justifying an early diagnosis. These BJIs must be treated rapidly, and the risk of sequelae justifies long-term follow-up.

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

BACKGROUND

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

METHOD

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

RESULT

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

CONCLUSION

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

The Heterogeneity of Pediatric Knee Infections: A Retrospective Analysis

BACKGROUND

Musculoskeletal infection is a major cause of morbidity in the pediatric population. Despite the canonical teaching that an irritable joint and signs of infection likely represent an infected joint space, recent evidence in the pediatric hip has demonstrated that alternative diagnoses are equally or more likely and that combinations of pathologies are common. The knee is the second most commonly infected joint in children, yet there remains a paucity of available data regarding the epidemiology and workup of the infected pediatric knee. The authors hypothesize that there is heterogeneity of pathologies, including combinations of pathologies, that presents as a potentially infected knee in a child. The authors aim to show the utility of magnetic resonance imaging and epidemiologic and laboratory markers in the workup of these patients.

METHODS

A retrospective review of all consults made to the pediatric orthopaedic surgery team at a single tertiary care center from September 2009 through December 2015 regarding a concern for potential knee infection was performed. Excluded from the study were patients with penetrating trauma, postoperative infection, open fracture, no C-reactive protein (CRP) within 24 hours of admission, sickle cell disease, an immunocompromised state, or chronic osteomyelitis.

RESULTS

A total of 120 patients were analyzed in this study. There was marked variability in pathologies. Patients with isolated osteomyelitis or osteomyelitis+septic arthritis were older, had an increased admission CRP, were more likely to be infected with Staphylococcus aureus, required an increased duration of antibiotics, and had an increased incidence of musculoskeletal complications than patients with isolated septic arthritis.

CONCLUSIONS

When considering a child with an irritable knee, a heterogeneity of potential underlying pathologies and combinations of pathologies are possible. Importantly, the age of the patient and CRP can guide a clinician when considering further workup. Older patients with a higher admission CRP value warrant an immediate magnetic resonance imaging, as they are likely to have osteomyelitis, which was associated with worse outcomes when compared with patients with isolated septic arthritis.

LEVEL OF EVIDENCE

Level III-retrospective research study.

Osteoarticular infections in pediatrics

OBJECTIVE

To collect the most up-to-date information regarding pediatric osteoarticular infections, including the epidemiological and microbiological profiles, diagnosis, and treatment.

SOURCE OF DATA

A non-systematic review was performed on the search engines PubMed, SciELO, LILACS, and Google Scholar, using the keywords "bone and joint infection", "children", "pediatric", "osteomyelitis", "septic arthritis" and "spondylodiscitis" over the last ten years. The most relevant articles were selected by the authors to constitute the database.

SYNTHESIS OF DATA

Osteoarticular infections are still a major cause of morbidity in pediatrics. Their main etiology is Staphylococcus aureus, but there has been an increase in the detection of Kingella kingae, especially through molecular methods. Microbiological identification allows treatment direction, while evidence of inflammatory activity assists in treatment follow-up. Imaging tests are especially useful in the initial diagnosis of infections. Empirical treatment should include coverage for the main microorganisms according to the age and clinical conditions of the patient, while considering the local resistance profile. Surgical procedures can be indicated for diagnosis, focus control, and function preservation. Acute complications include sepsis, deep venous thrombosis, and pulmonary embolism. Deaths are rare. Late complications are uncommon but may lead to deformities that compromise motor development.

CONCLUSION

A correct and early diagnosis, prompt implementation of adequate antimicrobial therapy, and focus control, when indicated, are critical to a better prognosis.

Knee orthopedic problems in newborns and infancy: a review

PURPOSE OF REVIEW

We present the reader with insight on the most common disorders of the knee in newborns and infants. Knee issues in this population may confuse the first contact physicians due to certain peculiarities of the immature immune system, small size and underdevelopment of joint anatomy. Data presented here are recent and significant, and something to bear in mind when caring for children of this age.

RECENT FINDINGS

With the advent of new diagnostic methods, a shift in the causative agent of pediatric knee infections has been noted. Minimally invasive methods such as arthrocentesis and arthroscopy are successfully employed in treatment of knee problems in newborns and infants. A trial of conservative therapy in congenital patellar instability can give good results, and obviate the need for surgery in some cases. Various syndromes that affect the knee have specific characteristics that need to be recognized early to avoid problems in the future.

SUMMARY

Although rare, knee problems in infants can and do occur. Their cause varies significantly and good outcomes require a multidisciplinary approach. Early diagnosis, referral and initiation of treatment protocols can significantly influence the fate of the joint and with it the patients' functional status for life.

Determination of diagnostic value (validity) leukocyte esterase (urine dipstick strip) in differentiating inflammatory arthritis from bacterial arthritis

BACKGROUND

The current diagnostic cornerstone for septic arthritis contains gram stains, bacterial culture, and cell count with a differential of aspirated synovial fluid. Recently, a synovial leukocyte esterase (LE) test has been used for diagnosing septic arthritis. Since this test measures the esterase activity of leukocytes, there is always a dilemma for using this test in patients with inflammatory arthritis.

METHODS

We collected the synovial fluid specimens as part of the general diagnostic protocol for patients suspected of Juvenile Idiopathic Arthritis (JIA) or Septic Arthritis (SA). Each group included 34 patients. We compared the result of the synovial LE test with the result of the culture of each patient.

RESULTS

The mean ages of patients were 64.14 ± 31.27 and 50.88 ± 23.19 months in the JIA group and septic arthritis group, respectively. The LE test results were positive in 30 specimens, trace in 3 and negative in one in the first-time test and were positive in 31 specimens and trace in 3 in the second-time test, while it was negative in all patients with JIA. Hence, the sensitivity of the synovial LE test was 80.8%, the specificity, PPV, and NPV were 78.6, 70.0, 86.8% respectively based on a positive culture.

CONCLUSION

The leukocyte esterase strip test can be used as a rapid, bedside method for diagnosing or excluding bacterial infections in different body fluids. The synovial LE test can be used as an accurate test to rapidly rule in or out an acute articular bacterial infection, even in patients with concurrent inflammatory arthritis.

Pediatric Maxillary Osteomyelitis: A Case Report of a Rare Entity

Maxillary osteomyelitis is a rare disease, especially in the pediatric population. We present a case of maxillary osteomyelitis in an eight-year-old girl with favorable outcome. Diagnosis was based on magnetic resonance imaging as well as on direct inspection intra operatively. Treatment should be based primarily on clinical signs (e.g. loose teeth). Teeth should not been extracted if healthy.

Bone and joint infections with Staphylococcus aureus strains producing Panton-Valentine Leukocidin in French Guiana

The aim of this study was to describe the clinical features of bone and joint infections (BJI) due to Panton-Valentine Leukocidin producing (PVL+) Staphylococcus aureus (SA) in French Guiana.A multicenter study that consists of a retrospective charts review of children admitted for PVL+ S. aureus BJI between January 2010 and December 2015.Six patients with SA-PVL BJI were identified during the study period: 2 osteomyelitis, 1 septic arthritis, and 3 disseminated BJI. The median age was 11 years old (4-14 years), and fever lasted for 3.2 days (2-5 days) before diagnosis. An open skin wound preceded the BJI in 5/6 patients. One patient presented with a septic thrombophlebitis of the femoral-popliteal vein on admission. Methicillin-susceptible Staphylococcus aureus (MSSA) were identified for all patients. Three patients had complications: 2 cases of necrotizing pneumonia and 2 pericarditis, with 1 death caused by cardiac tamponade.SA-PVL BJI was not frequent. Strains were susceptible to methicillin, but responsible of severe BJI. Early diagnosis and a multidisciplinary management of these infections are essential to prevent further complications.

Acute Hematogenous Osteomyelitis in Children

Background: The epidemiology of acute hematogenous osteomyelitis (AHO) in children has changed. Methods: We reviewed the current literature regarding the epidemiology, microbiology, pathogenesis, clinical presentation, diagnosis, and antimicrobial management of AHO in children. Results: Staphylococcus aureus is the most common microorganism causing pediatric AHO, followed by group A Streptococcus (GAS). AHO due to community-associated methicillin-resistant Staphylococcus aureus (MRSA) can cause severe and complicated disease. Pathogen isolation by culture is key for targeted antibiotic therapy. Polymerase chain reaction assay in tissue sample or joint fluid may enhance the yield of Kingella kingae. C-reactive protein is useful in diagnosis and monitoring the course of AHO. Magnetic resonance imaging is the preferred diagnostic imaging study for AHO. Clindamycin or vancomycin (for serious disease) is recommended for empiric therapy of suspected AHO due to MRSA depending on the geographic prevalence. Penicillinase-stable penicillins or first-generation cephalosporins are preferred antibiotics to treat methicillin-sensitive S aureus (MSSA) infection. Beta-lactam agents are the drugs of choice for treating AHO due to K kingae, GAS, or Streptococcus pneumoniae. For uncomplicated AHO due to MSSA, a short parenteral antibiotic course followed by oral therapy for a minimum total duration of 3-4 weeks is adequate. Complicated AHO due to MRSA may warrant prolonged therapy with surgical intervention. Conclusion: Given the evolution of pathogens, the variability in clinical presentations and course ranging from simple to complex disease, and response to treatment, the management of AHO continues to evolve and warrants an individualized, multidisciplinary approach.

Production of Staphylococcal Complement Inhibitor (SCIN) and Other Immune Modulators during the Early Stages of Staphylococcus aureus Biofilm Formation in a Mammalian Cell Culture Medium

Immune modulators are known to be produced by matured biofilms and during different stages of planktonic growth of Staphylococcus aureus Little is known about immune modulator production during the early stages of biofilm formation, thus raising the following question: how does S. aureus protect itself from the innate immune responses at these stages? Therefore, we determined the production of the following immune modulators: chemotaxis inhibitory protein of staphylococci (CHIPS); staphylococcal complement inhibitor (SCIN); formyl peptide receptor-like 1 inhibitor; gamma-hemolysin component B; leukocidins D, E, and S; staphylococcal superantigen-like proteins 1, 3, 5, and 9; and staphylococcal enterotoxin A. Production was determined during in vitro biofilm formation in Iscove's modified Dulbecco's medium at different time points using a competitive Luminex assay and mass spectrometry. Both methods demonstrated the production of the immune modulators SCIN and CHIPS during the early stages of biofilm formation. The green fluorescence protein promoter fusion technology confirmed scn (SCIN) and, to a lesser extent, chp (CHIPS) transcription during the early stages of biofilm formation. Furthermore, we found that SCIN could inhibit human complement activation induced by early biofilms, indicating that S. aureus is able to modulate the innate immune system already during the early stages of biofilm formation in vitro These results form a stepping stone toward elucidating the role of immune modulators in the establishment of biofilms in vivo and present opportunities to develop preventive strategies.

Targeting intracellular Staphylococcus aureus to lower recurrence of orthopaedic infection

Staphylococcus aureus is often found in orthopaedic infections and may be protected from commonly prescribed antibiotics by forming biofilms or growing intracellularly within osteoblasts. To investigate the effect of non-antibiotic compounds in conjunction with antibiotics to clear intracellular and biofilm forming S. aureus causing osteomyelitis. SAOS-2 osteoblast-like cell lines were infected with S. aureus BB1279. Antibiotics (vancomycin, VAN; and dicloxacillin, DICLOX), bacterial efflux pump inhibitors (piperine, PIP; carbonyl cyanide m-chlorophenyl hydrazone, CCCP), and bone morphogenetic protein (BMP-2) were evaluated individually and in combination to kill intracellular bacteria. We present direct evidence that after gentamicin killed extracellular planktonic bacteria and antibiotics had been stopped, seeding from the infected osteoblasts grew as biofilms. VAN was ineffective in treating the intracellular bacteria even at 10× MIC; however in presence of PIP or CCCP the intracellular S. aureus was significantly reduced. Bacterial efflux pump inhibitors (PIP and CCCP) were effective in enhancing permeability of antibiotics within the osteoblasts and facilitated killing of intracellular S. aureus. Confocal laser scanning microscopy (CLSM) showed increased uptake of propidium iodide within osteoblasts in presence of PIP and CCCP. BMP-2 had no effect on growth of S. aureus either alone or in combination with antibiotics. Combined application of antibiotics and natural agents could help in the treatment of osteoblast infected intracellular bacteria and biofilms associated with osteomyelitis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1086-1092, 2018.