A Case of Acute Osteomyelitis: An Update on Diagnosis and Treatment

Clinical characteristics of neonatal and infant osteomyelitis and septic arthritis: a multicenter retrospective study

OBJECTIVE

Signs and symptoms of osteomyelitis or septic arthritis in neonates and infants are often nonspecific and early-stage bone infections in infants may often go unnoticed. The objective of this study was to analyze the clinical characteristics of newborns and infants with osteomyelitis and septic arthritis to improve understanding of the disorder and to assist clinicians with diagnosis.

METHODS

A retrospective multicenter study was conducted on neonates (0-28 days old, n = 94) and infants (1-12 months old, n = 415) with osteoarticular infections. Data consisting of clinical characteristics, complications, laboratory outcomes, and the pathogenic microorganisms causing osteomyelitis were tabulated. The statistics were further broken down into two regions and the significant differences between neonates and infants were evaluated and compared to the literature.

RESULTS

Compared to infants, neonates had significantly lower incidences of fever (p < 0.0001), higher incidences of localized swelling (p = 0.0021), higher rate of infection at the humerus (p = 0.0016), higher percentage of Escherichia coli (p < 0.0001) and Klebsiella pneumoniae (p = 0.0039) infections, lower percentage of Staphylococcus aureus infections (p < 0.0001) and were more likely to develop septic arthritis (p < 0.0001).

CONCLUSION

Distinct differences were found between neonatal and infants with osteoarticular infections. Future studies should focus on improving diagnosis and subsequent treatment regimens for younger age groups.

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

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

Acute Primary Epiphyseal Osteomyelitis of Proximal Tibia - A Case Report and Review of the Literature

Introduction

Acute pyogenic epiphyseal osteomyelitis is a rare condition, mostly affecting children. This case report discusses the importance of clinical suspicion and the role of adjuncts in the diagnosis of these cases.

Case Presentation

A 12-year-old female presented with pain in the right knee for 1 week and difficulty in walking for 4 days. Diagnosis was made with the help of magnetic resonance imaging MRI and guided biopsy. Pseudomonas aeruginosa was isolated from culture. She was treated with intravenous antibiotics with a good response.

Discussion

Despite being a rarely reported entity, primary epiphyseal osteomyelitis should be kept as one of the differentials of the painful swollen knee in a child. Early diagnosis with the help of proper radiological investigations is the key to prevent the sequelae of this disease.

Italian consensus on the therapeutic management of uncomplicated acute hematogenous osteomyelitis in children

BACKGROUND

Acute hematogenous osteomyelitis (AHOM) is an insidious infection of the bone that more frequently affects young males. The etiology, mainly bacterial, is often related to the patient's age, but it is frequently missed, owing to the low sensitivity of microbiological cultures. Thus, the evaluation of inflammatory biomarkers and imaging usually guide the diagnosis and follow-up of the infection. The antibiotic treatment of uncomplicated AHOM, on the other hand, heavily relies upon the clinician experience, given the current lack of national guidelines for the management of this infection.

METHODS

A systematic review of the studies on the empirical treatment of uncomplicated AHOM in children published in English or Italian between January 1, 2009, and March 31, 2020, indexed on Pubmed or Embase search engines, was carried out. All guidelines and studies reporting on non-bacterial or complicated or post-traumatic osteomyelitis affecting newborns or children older than 18 years or with comorbidities were excluded from the review. All other works were included in this study.

RESULTS

Out of 4576 articles, 53 were included in the study. Data on different topics was gathered and outlined: bone penetration of antibiotics; choice of intravenous antibiotic therapy according to the isolated or suspected pathogen; choice of oral antibiotic therapy; length of treatment and switch to oral therapy; surgical treatment.

CONCLUSIONS

The therapeutic management of osteomyelitis is still object of controversy. This study reports the first Italian consensus on the management of uncomplicated AHOM in children of pediatric osteomyelitis, based on expert opinions and a vast literature review.

Epidemiology and Management of Acute Hematogenous Osteomyelitis, Neonatal Osteomyelitis and Spondylodiscitis in a Third Level Paediatric Center

Acute hematogenous osteomyelitis (AHOM) is a rare pathology in pediatric population. The aim of this study is to analyse the epidemiological data and the management, compared to European Society for Paediatric Infectious Disease (ESPID, European Society for Pediatric Infectious Diseases) guidelines 2017 of 216 children with AHOM, divided in three cohorts (neonatal-onset osteomyelitis, those with vertebral involvement and other types of osteomyelitis). We conducted a retrospective single center study, evaluating data from all the children (aged 0–18 years) consecutively admitted to the Meyer Children’s Hospital, during a period of ten years (1 January 2010–31 December 2019). Isolation of pathogen was possible in 65 patients and S. aureus was the most frequently involved (43/65 children). Magnetic Resonance Imaging (MRI, magnetic resonance imaging) was performed in 201/216 cases and was compatible with osteomyelitis in 185/201 of these children (92.03%). In the neonatal-onset osteomyelitis group the percentage of diagnostic ultrasound for osteomyelitis was 36.36% significantly higher than the other groups. The median duration of total antibiotic therapy was 37.5 days. In total, 186/199 children recovered without complications. The present study delineates three heterogeneous cohorts of patients. S. aureus is confirmed as the first pathogen for isolation in all three groups analysed. MRI represent a gold standard for diagnosis. Longer duration of antibiotics treatment was performed in neonatal and spondylodiscitis group, compared to the other types of osteomyelitis.

Amoxicillin-Clavulanic Acid Empirical Oral Therapy for the Management of Children with Acute Haematogenous Osteomyelitis

According to the Guidelines of the European Society of Pediatric Infectious Diseases (ESPID), in low methicillin-resistant Staphylococcus aureus (MRSA) prevalence settings, short intravenous therapy is recommended in uncomplicated cases of acute haematogenous osteomyelitis (AHOM), followed by empirical oral therapy, preferentially with first/second-generation cephalosporin or dicloxacillin or flucloxacillin. However, several practical issues may arise using some of the first-line antibiotics such as poor palatability or adherence problems. Clinical, laboratory and therapeutic data from children with AHOM hospitalized in one Italian Paediatric Hospital between 2010 and 2019 were retrospectively collected and analyzed. The aim of the study was to highlight the extent of the use and the possible role of amoxicillin-clavulanic acid in the oral treatment of children with AHOM. Two hundred and ten children were included. S.aureus was identified in 42/58 children (72.4% of identified bacteria); 2/42 S.aureus isolates were MRSA (4.8%). No Kingella kingae was identified. Amoxicillin-clavulanic acid was the most commonly used oral drug (60.1%; n = 107/178) and it was associated with clinical cure in all treated children. Overall, four children developed sequelae. One (0.9%) sequela occurred among the 107 children treated with amoxicillin-clavulanic acid. Our results suggest that amoxicillin-clavulanic acid might be an option for oral antibiotic therapy in children with AHOM.

Oral Flucloxacillin for Treating Osteomyelitis: A Narrative Review of Clinical Practice

Flucloxacillin (FLU) administered by the oral route is widely used for treating various infections, but there are no published retrospective or prospective trials of its efficacy, or its advantages or disadvantages compared to parenteral treatment or other antibiotics for treating osteomyelitis. Based on published in vitro data and expert opinions, other non-β-lactam oral antibiotics that have better bone penetration are generally preferred over oral FLU. We reviewed the literature for studies of oral FLU as therapy of osteomyelitis (OM), stratified by acute versus chronic and pediatric versus adult cases. In striking contrast to the prevailing opinions and the few descriptive data available, we found that treatment of OM with oral FLU does not appear to be associated with more clinical failures compared to other oral antibiotic agents. Because of its narrow antibiotic spectrum, infrequent severe adverse effects, and low cost, oral FLU is widely used in clinical practice. We therefore call for investigators to conduct prospective trials investigating the effectiveness and potential advantages of oral FLU for treating OM.

Diagnostic errors in pediatric bacterial osteomyelitis

BACKGROUND

Clinical evidence for improving diagnostic accuracy in pediatric medicine is still scarce. Septic osteomyelitis is sometimes challenging for physicians to diagnose. The aim of this study was to improve patient care through identifying the incidence and reasons for errors in the diagnosis of bacterial osteomyelitis in pediatric patients.

METHODS

We retrospectively identified patients younger than 16 years with acute or chronic osteomyelitis at Tokyo Metropolitan Children's Medical Center between April 2010 and September 2017. We extracted data on patient demographics, clinical course, symptoms, locus of the lesions, and diagnosis at presentation and discharge. The patients were categorized into the misdiagnosis and non-misdiagnosis groups following a review by two pediatricians. Misdiagnosis was defined as a difference between the initial and discharge diagnosis. The factors in the two groups were compared, and the types of error in the misdiagnosis group were examined.

RESULTS

In total 71 patients were enrolled. The median age and proportion of boys was 7.6 years (IQR, 1.4-11.2 years) and 66%, respectively. Misdiagnosis occurred in 27 patients (38.0%). Precedent antibiotic use was independently associated with misdiagnosis (P = 0.044). A cognitive error was observed in 88.3% of the misdiagnosis group. The median number of types of error per case was 2.0 (IQR, 2.0-3.0).

CONCLUSIONS

The misdiagnosis of septic osteomyelitis in pediatric patients was common and chiefly caused by cognitive errors. Eliminating cognitive errors in diagnosis is highly likely to improve the care of patients with osteomyelitis.

Antisense yycG Regulation of Antibiotic Sensitivity of Methicillin-Resistant Staphylococcus aureus in Chronic Osteomyelitis

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an urgent medical problem in osteomyelitis. The YycFG two-component regulatory system (TCS) allows bacteria to adapt rapidly to physical, chemical, and biological stresses. The recombinant plasmid shuttle vector was used to overexpress an antisense RNA (asRNA) to inhibit target gene expression by sequence-specific double-stranded RNA complex degradation. In the current study, antisense yycG RNA (ASyycG)-overexpression MRSA clinical isolates were constructed. Methods: Bacterial growth was monitored, and biofilm biomass was determined by crystal violet microtiter assay. Quantitative reverse transcription polymerase chain reaction analysis was used to identify expression of yycF/G/H and icaA/D in MRSA and ASyycG strains. The expression of YycG protein was quantified by Western blot assays. The antibiotic resistance of ASyycG strains was compared with that of the MRSA strains. Results: The ASyycG strains showed a decrease in growth rate compared with the MRSA strains. Of note, overexpression of ASyycG led to a reduction in biofilm formation and adhesion force. ASyycG strains had decreased expressions of the yycF/G/H and icaA/D. Furthermore, Western blot data showed that expression of the YycG protein decreased by 40% in ASyycG strains compared with MRSA strains. In addition, the effect of yycG asRNA improved the susceptibility of ASyycG strains to cefoxitin. Conclusions: The ASyycG strains inhibited biofilm organization and increased antibiotic sensitivity, which may be attributed to altered intracellular polysaccharide construction.

Clinical analysis of 17 cases of neonatal osteomyelitis: A retrospective study

Although acute osteomyelitis is rare in neonates, it might result in severe sequelae such as joint destruction and growth failure if it is not diagnosed and treated early. However, few studies have focused on the clinical features and treatment of this disease.A retrospective review of 17 cases of neonatal osteomyelitis, for which the patients underwent medical treatment alone or combined with surgery at the Children's Hospital of Zhejiang University School of Medicine between January 2009 and September 2016, was conducted. Medical treatment included the use of antibiotics and supportive care. Surgery was performed in cases with subperiosteal abscess (>1 cm) or clinical deterioration despite antibiotic therapy.All of the patients (11 men and 6 women) were term neonates. The main complaints were redness or swelling around the affected bone and fever. The most common sites were the femur (29.4%) and humerus (23.5%). There were 14 (82.35%) cases with positive cultures: Staphylococcus accounted for 71.43% (n = 10), followed by Salmonella (n = 1), Streptococcus pneumoniae (n = 1), Klebsiella pneumoniae (n = 1), and Escherichia coli (n = 1). X-rays (n = 14), ultrasound (n = 6), computed tomography (CT) (n = 5), or magnetic resonance imaging (MRI) (n = 7) were performed. Three of 14 x-rays were not pathological at the onset of the disease, while the positive rate of MRI in detecting osteomyelitis was 100%. Eleven of 17 cases underwent surgical drainage, and higher white blood cell (WBC) counts were found in patients requiring surgery (P < .05). The prognosis for all patients was good without severe sequelae with a mean follow-up period of 49.47 ± 23.43 months.In conclusion, the prognosis of neonatal osteomyelitis with early active treatment is good. MRI is advocated for detecting early osteomyelitis. Additionally, neonates with higher WBC count together with osteomyelitis have an increased risk for surgery.

Evaluation and Management of Septic Arthritis and its Mimics in the Emergency Department

Septic arthritis is a dangerous medical condition associated with significant morbidity and mortality. However, the differential diagnosis can be broad with conditions that mimic this disease and require different evaluation and treatment. This narrative review presents the emergency medicine evaluation and management, as well as important medical conditions that may mimic this disease. Septic arthritis commonly presents with monoarticular joint pain with erythema, warmth, swelling, and pain on palpation and movement. Fever is present in many patients, though most are low grade. Blood testing and imaging may assist with the diagnosis, but the gold standard is joint aspiration. Management includes intravenous antibiotics and orthopedic surgery consult for operative management vs. serial aspirations. Clinicians should consider mimics, such as abscess, avascular necrosis, cellulitis, crystal-induced arthropathies, Lyme disease, malignancy, osteomyelitis, reactive arthritis, rheumatoid arthritis, and transient synovitis. While monoarticular arthritis can be due to septic arthritis, other medical and surgical conditions present similarly and require different management. It is essential for the emergency clinician to be aware how to diagnose and treat these mimics.

Distinguishing Ewing sarcoma and osteomyelitis using FTIR spectroscopy

The differential diagnosis of Ewing sarcoma and osteomyelitis can be challenging and can lead to delays in treatment with possibly devastating results. In this retrospective, small-cohort study we demonstrate, that the Fourier Transformed Infrared (FTIR) spectra of osteomyelitis bone tissue can be differentiated from Ewing sarcoma and normal bone tissue sampled outside tumour area. Significant differences in osteomyelitis samples can be seen in lipid and protein composition. Supervised learning using a quadratic discriminant analysis classifier was able to differentiate the osteomyelitis samples with high accuracy. FTIR spectroscopy, alongside routine radiological and histopathological methods, may offer an additional tool for the differential diagnosis of osteomyelitis and ES.

Osteomyelitis of the Thumb in a 21-Year-Old Chiropractic Patient: A Case Report

OBJECTIVE

The purpose of this case report is to describe the presentation of a patient with osteomyelitis of the thumb.

CLINICAL FEATURES

A 21-year-old man presented with painful, red, and edematous thumb pain over the anterior and posterior surface for a duration of 4 days. The patient reported no trauma or recent operation. The patient was treated conservatively for capsulitis. The patient's symptoms worsened within 2 days, and he was referred for additional imaging consisting of a bone scan. The bone scan showed increased uptake, resulting in a change of diagnosis to suspected osteomyelitis. The patient was referred to a medical doctor for care that consisted of antibiotics and physiotherapy.

INTERVENTION AND OUTCOME

Despite treatment, the patient had some mild permanent damage to the range of motion of the joint and soft tissue volume loss.

CONCLUSION

This case demonstrates the importance of considering osteomyelitis as a differential diagnosis. Amputation was avoided for this patient because of the early recognition and referral.

Biomimetic 3D in vitro model of biofilm triggered osteomyelitis for investigating hematopoiesis during bone marrow infections

In this work, we define the requirements for a human cell-based osteomyelitis model which overcomes the limitations of state of the art animal models. Osteomyelitis is a severe and difficult to treat infection of the bone that develops rapidly, making it difficult to study in humans. We have developed a 3D in vitro model of the bone marrow, comprising a macroporous material, human hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). Inclusion of biofilms grown on an implant into the model system allowed us to study the effects of postoperative osteomyelitis-inducing bacteria on the bone marrow. The bacteria influenced the myeloid differentiation of HSPCs as well as MSC cytokine expression and the MSC ability to support HSPC maintenance. In conclusion, we provide a new 3D in vitro model which meets all the requirements for investigating the impact of osteomyelitis.

STATEMENT OF SIGNIFICANCE

Implant-associated osteomyelitis is a persistent bacterial infection of the bone which occurs in many implant patients and can result in functional impairments or even entire loss of the extremity. Nevertheless, surprisingly little is known on the triangle interaction between implant material, bacterial biofilm and affected bone tissue. Closing this gap of knowledge would be crucial for the fundamental understanding of the disease and the development of novel treatment strategies. For this purpose, we developed the first biomaterial-based system that is able to mimic implant-associated osteomyelitis outside of the body, thus, opening the avenue to study this fatal disease in the laboratory.

Risk factors associated with complications/sequelae of acute and subacute haematogenous osteomyelitis: an Italian multicenter study

BACKGROUND

Acute/subacute haematogenous osteomyelitis (AHOM/SAHOM) are potentially devastating diseases. Updated information about the epidemiology, management and outcome of AHOM/SAHOM is needed to minimize the risk of complications and sequelae.

METHODS

A multicenter study was performed to evaluate retrospectively the management and outcome of AHOM/SAHOM in Italy. Data from children aged >1 month, and hospitalized between 2010 and 2016, in 19 pediatric centers, were analyzed.

RESULTS

300 children with AHOM and 98 with SAHOM were included. Median age was 6.0 years (IQR: 2.0-11.0). No clinical difference was observed with the exception of fever at onset (63.0% vs. 42.9%; P < 0.0001), and a more common spinal involvement in SAHOM (6.7% vs 20.4%; P < 0.001). Fifty-Eight Staphylococcus aureus strains were isolated; 5 (8.6%) were MRSA. No Kingella kingae infection was documented. No different risk for complication/sequela was observed between AHOM and SAHOM (38.3% vs. 34.7%; OR:0.85; 95%CI: 0.53-1.38; P = 0.518). Duration and type of antibiotic therapy were not associated with risk of complication/sequelae.

CONCLUSION

AHOM and SAHOM displayed some differences, however occurrence and risk factors for complications and sequelae are similar, and the same empiric treatment might be recommended.

Pneumolysin-induced autophagy contributes to inhibition of osteoblast differentiation through downregulation of Sp1 in human osteosarcoma cells

BACKGROUND INFORMATION

The 53kDa protein pneumolysin (PLY) is the main virulence factor of Streptococcus pneumoniae, a leading cause of invasive pneumococcal diseases. PLY forms pores in cholesterol-containing membranes, thereby interfering with the function of cells. Bone destruction is a serious matter in chronic inflammatory diseases such as septic arthritis and osteomyelitis. S. pneumoniae is increasingly being recognized as a common cause of septic arthritis, but its pathogenesis is poorly defined.

METHOD

We examined the effect of PLY on osteoblast differentiation and its mechanisms of action. The effect of PLY on osteoblast differentiation was evaluated by qRT-PCR, ALP activity assay, flow cytometric analysis, and Western blotting. We also examined the role of PLY-induced autophagy in osteoblast differentiation using RNA interference analysis.

RESULTS

PLY inhibited osteoblast differentiation by decreasing the expression of osteoblast marker genes such as Runx2 and OCN, along with ALP activity. ROS production was increased by PLY during osteoblast differentiation. PLY induced autophagy through ROS-mediated regulation of AMPK and mTOR, which downregulated the expression of Sp1 and subsequent inhibition of differentiation. Treatment with autophagy inhibitors or Atg5 siRNA alleviated the PLY-induced inhibition of differentiation.

CONCLUSION

The results suggest that PLY inhibits osteoblast differentiation by downregulation of Sp1 accompanied by induction of autophagy through ROS-mediated regulation of the AMPK/mTOR pathway.

GENERAL SIGNIFICANCE

This study proposes a molecular mechanism for inhibition of osteoblast differentiation in response to PLY.

Xanthogranulomatous osteomyelitis of the humerus in a pediatric patient with Alagille syndrome: a case report and literature review

Xanthogranulomatous osteomyelitis (XO) is an exceedingly rare disease characterized by infiltration of histiocytes and foamy macrophages. Both on gross examination and on radiographs, XO can mimic malignancy. We describe the case of a 5-year-old female with Alagille syndrome who presented with a pathologic fracture of the right humerus. Initial radiographs revealed multiple osteolytic lesions in the distal humerus while MRI showed a large soft tissue mass. Biopsy confirmed the diagnosis of XO, which has hitherto not been described in a patient with Alagille syndrome. The patient was admitted for IV antibiotics and taken to the operating room for an incision and debridement. Tissue cultures were obtained and grew Salmonella. Antibiotic therapy was tapered, and the patient responded to treatment. She was doing well at her 6-month follow-up visit. In the discussion section, we explore how osteopenia and immune dysregulation caused by Alagille syndrome can affect the development of XO. We summarize all previously reported cases of XO and conclude that XO presents as an osteolytic lesion that expands rapidly over the course of a few weeks. We highlight that XO can mimic sarcoma because of its mass effect but can be distinguished radiographically by the presence of surrounding sclerosis. Given the rapid onset of XO, we classify it as an acute osteomyelitis. We discuss how leukemia and Ewing sarcoma can present similarly to acute osteomyelitis. We then emphasize key features that can be used to distinguish these malignancies from acute osteomyelitis.

Epidemiology and Management of Acute Haematogenous Osteomyelitis in a Tertiary Paediatric Center

Background: Paediatric acute hematogenous osteomyelitis (AHOM) is a serious disease requiring early diagnosis and treatment. To review the clinical presentation, management and organisms responsible for AHOM, and to explore risk factors for complicated AHOM, a large cohort referring to a single center over a 6-year period was evaluated. Methods: Data from children with AHOM, hospitalized between 2010 and 2015, and aged > 1 month, were retrospectively collected and analyzed. Results: 121 children (median age 4.8 years; 55.4% males) were included. Fever at onset was present in 55/121 children (45.5%); the lower limb was most frequently affected (n = 68/121; 56.2%). Microbiological diagnosis (by culture and/or polymerase chain reaction (PCR)) was reached in 33.3% cases. Blood and pus/biopsy culture sensitivities were 32.4% and 46.4%, respectively. PCR sensitivity was 3.6% (2/55) on blood, and 66.6% (16/24) on pus/biopsy sample. Staphylococcus aureus was the most commonly identified pathogen (n = 20); no methicillin-resistant Staphylococcus aureus (MRSA) was isolated, 10.0% (n = 2) strains were Panton-Valentine-Leukocidin (PVL) producer; 48.8% (59/121) cases were complicated. At univariate analysis, factors associated with complicated AHOM were: recent fever episode, fever at onset, upper limb involvement, white blood count (WBC) ≥ 12,000/µL, C reactive protein (CRP) ≥ 10 mg/L, S. aureus infection. At multivariate analyses S. aureus infection remained the only risk factor for complicated AHOM (aOR = 3.388 (95%CI: 1.061–10.824); p-value = 0.039). Conclusions: In this study microbiological diagnosis was obtained in over one third of cases. Empiric treatment targeting methicillin-sensitive Staphylococcus aureus seems to be justified by available microbiological data.