Acute osteomyelitis, septic arthritis and discitis: Differences between neonates and older children

Osteomyelitis and Septic Arthritis of the Foot and Ankle: Imaging Update

Radiography is considered the first-line screening exam for clinically suspected osteomyelitis. However, additional evaluation is generally needed. MRI is the definitive diagnostic exam with high sensitivity and specificity combined with excellent anatomic definition. Gadolinium contrast can be useful to detect areas of devitalization before surgery. Bone marrow edema on fluid-sensitive images and low signal intensity on T1-weighted images in the presence of secondary MRI findings, including ulcer, sinus tract, and cellulitis with or without abscess are typical findings of osteomyelitis. If MRI is contraindicated, three phase bone scan can be used. Early diagnosis and treatment is essential.

Pictorial review: challenges in distinguishing bilateral metaphyseal marrow abnormalities on magnetic resonance imaging

The paediatric metaphysis is afflicted by a wide range of pathological processes as it is the most metabolically active and well-vascularised part of the developing skeleton. This review focuses on metaphyseal marrow signal change detected with magnetic resonance imaging, which is most often occult on radiographs. When bilateral, these imaging appearances frequently present a diagnostic quandary. This review assists the radiologist to confidently dismiss physiological signal change and confidently work through the differential diagnosis. This is achieved by illustrating a practical method of classifying signal change into four categories: physiological red marrow, red marrow reconversion, marrow infiltration, and oedema-like marrow signal intensity. In doing so, various pathological entities are reviewed along with imaging pearls and next-step investigations.

Bacterial and Viral Infectious Disease of the Spine

Spinal infections are a diverse group of diseases affecting different compartments of the spine with variable clinical and imaging presentations. Diagnosis of spinal infections is based on a combination of clinical features, laboratory markers, and imaging studies. Imaging plays a pivotal role in the diagnosis and management of spinal infections. The characteristic imaging manifestations of bacterial and viral infections in the spine are discussed with key teaching points emphasized.

Diagnostic performance comparison of conventional radiography to magnetic resonance imaging for suspected osteomyelitis of the extremities: a multi-reader study

OBJECTIVE

To determine whether MRI provides improved diagnostic accuracy compared to radiography for the diagnosis of extremity osteomyelitis (OM) with multi-reader analysis.

METHODS

In this cross-sectional study, three musculoskeletal fellowship-trained expert radiologists evaluated cases of suspected OM in two rounds-first using radiographs (XR), then with conventional MRI. Radiologic features consistent with OM were recorded. Each reader recorded individual findings on both modalities and rendered a binary diagnosis along with certainty of final diagnosis on a confidence scale of 1-5. This was compared with the pathology-proven diagnosis of OM to determine diagnostic performance. Intraclass correlation (ICC) and Conger's Kappa were used for statistics.

RESULTS

XR and MRIs of 213 pathology proven cases (51.5 years ± 14.0 years, mean ± St.Dev.) were included in this study, with 79 tested positive for OM and 98 were positive for a soft tissue abscess, with 78 patients being negative for both. In total, 139 were males and 74 females with bones of interest in the upper and lower extremities in 29 and 184 cases, respectively. MRI showed significantly higher sensitivity and negative predictive value than XR (p < 0.001 for both metrics). Conger's Kappa for OM diagnosis were 0.62 and 0.74 on XR and MRI, respectively. Reader confidence improved slightly from 4.54 to 4.57 when MRI was used.

CONCLUSIONS

MRI is a diagnostically more effective imaging modality than XR for finding extremity osteomyelitis with better inter-reader reliability.

CLINICAL RELEVANCE STATEMENT

This study validates the diagnosis of OM with MRI over XR but adds novelty because it is the largest study of its kind with a clear reference standard to guide clinician decision making.

KEY POINTS

• Radiography is the first-line imaging modality for musculoskeletal pathology but MRI can add value for infections. • MRI shows greater sensitivity for the diagnosis of osteomyelitis of the extremities than radiography. • This improved diagnostic accuracy makes MRI a better imaging modality for patients with suspected osteomyelitis.

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.

Osteomyelitis and Septic Arthritis of the Foot and Ankle: Imaging Update

Radiography is considered the first-line screening exam for clinically suspected osteomyelitis. However, additional evaluation is generally needed. MRI is the definitive diagnostic exam with high sensitivity and specificity combined with excellent anatomic definition. Gadolinium contrast can be useful to detect areas of devitalization before surgery. Bone marrow edema on fluid-sensitive images and low signal intensity on T1-weighted images in the presence of secondary MRI findings, including ulcer, sinus tract, and cellulitis with or without abscess are typical findings of osteomyelitis. If MRI is contraindicated, three phase bone scan can be used. Early diagnosis and treatment is essential.

Septic Arthritis of the Elbow in a Premature Neonate: An Uncommon Disease in an Uncommon Location

Septic arthritis (SA) is an infrequent diagnosis in the neonate. This case illustrates the presentation of SA within the elbow, an atypical location for neonatal SA. SA should be considered in any neonate with joint swelling, as symptoms are often subtle. Constitutional symptoms of infection, including fever, may not be present in the neonate. Staphylococcus aureus is the most common etiologic organism, and neonatal SA is often caused by hematogenous spread partially due to unique neonatal intraosseous anatomy. Joint aspiration can provide a definitive diagnosis and aid in targeted antimicrobial therapy. Other laboratory tests, including C-reactive protein and erythrocyte sedimentation rate, can aid in diagnosis. Ultrasound and magnetic resonance imaging can demonstrate joint effusion along with osteomyelitis, which is often seen concurrently with neonatal SA. There are no definitive guidelines for the treatment of neonatal SA. Conservative therapy with antimicrobials along with surgical intervention are the mainstays of treatment. Prompt diagnosis and treatment are crucial to decrease permanent joint damage. [Pediatr Ann. 2023;52(8):e292-e296.].

Image-guided percutaneous bone biopsy for pediatric osteomyelitis: correlating MRI findings, tissue pathology and culture, and effect on clinical management

Bone biopsy remains the gold standard for diagnosis of osteomyelitis while MRI results in a radiologic diagnosis that generally precedes biopsy. This study's purpose is to examine the diagnostic yield and effect of biopsy results on clinical management in children with suspected osteomyelitis and positive MRI findings. A retrospective review was performed at a tertiary care children's hospital. Search of the EMR and radiology PACS identified patients below 18 years who underwent bone biopsy with interventional radiology for osteomyelitis and had positive MRI findings for osteomyelitis prior to biopsy. Data was collected on patient demographics, MRI findings, biopsy procedural details, tissue culture, histopathology results, and clinical management before and after biopsy. Changes in management were categorized as antibiotic type/quantity, duration, or diagnosis. A total of 82 biopsies in 79 patients with suspicion for osteomyelitis and positive MRIs prior to biopsy were performed over 5 years from 2014 to 2019. All biopsies were successful and sent for tissue culture. 22/82 biopsies (27%) yielded positive cultures. Of those with tissue cultures, 16/22 (72%) resulted in change in clinical management. Of all biopsies, 18/82 (22%) resulted in a change in management (15 antibiotic, 1 duration, 2 diagnosis). The 2 changes in diagnosis included one biopsy done which was positive for cancer and a second which was found to not demonstrate osteomyelitis on histology. In the pediatric population, bone biopsy is a reasonably low morbidity procedure. However, there is a relatively low rate of positive tissue cultures even with MRI findings suspicious for osteomyelitis. Approximately 1 in 5 biopsies resulted in a change in clinical management, mostly in antibiotic selection. Bone biopsy may have a higher clinical impact in pre-specified circumstances.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

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.

Magnetic resonance imaging protocols for pediatric acute hematogenous osteomyelitis

Pediatric musculoskeletal infection can be a challenging clinical diagnosis. MRI protocols should be tailored appropriately to diagnose and localize sites of infection, to determine alternative pathologies that could explain the child's presentation, and to identify complications that could alter treatment or lead to devastating consequences in growing bones. In this review, we discuss MRI protocols tailored for suspected acute appendicular musculoskeletal infection in children. These protocols are based on patient age in order to generally reflect the developmental stage of the child, the corresponding relevant anatomy and physiology, and the skeletal maturity-dependent physiopathology of musculoskeletal infections.

Elbow Septic Arthritis caused by Klebsiella pneumoniae in a Newborn - Case Report and Literature Review

Septic arthritis is a rare condition in children, especially in neonates. Early recognition and proper treatment are required to avoid serious complications. We present the case of a male newborn diagnosed with septic arthritis of the right elbow who was treated with repeated joint aspiration and i.v. antibiotics (Amikacin and Meropenem). Blood culture and joint cultures were positive for Klebsiella pneumoniae. The final outcome was good, with no apparent local or systemic complications. General considerations regarding this rare condition, etiology and treatment options are also included in the paper.

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.

Chronic Osteomyelitis of Long Bones: Imaging Pearls and Pitfalls in Pediatrics

Chronic bacterial osteomyelitis is characterized by progressive inflammatory bone destruction and apposition of new bone most often caused by pyogenic bacteria. Clinical findings are nonspecific, and serum inflammatory markers can be normal. Prompt diagnosis and treatment are essential. Left untreated, chronic infection can lead to high morbidity and mortality. Imaging's major role is to suggest the correct diagnosis, exclude other diagnoses that can mimic osteomyelitis, document extent of disease, and guide interventions such as image-guided biopsy or surgical debridement. Several conditions can mimic chronic osteomyelitis clinically and radiographically. The main differential diagnoses include an oncologic process, chronic nonbacterial or chronic recurrent multifocal osteomyelitis, bone infarct in sickle cell disease, osteoid osteoma, and stress reaction/fracture. The oncologic process to consider includes metastatic neuroblastoma and Langerhans cell histiocytosis in a child younger than five years or leukemia, Ewing sarcoma, and osteosarcoma in the older age group. However, these lesions can typically be excluded based on radiographs and magnetic resonance imaging findings. Therefore, radiologist familiarity with imaging findings and mimickers is essential. In this article, we briefly review the epidemiologic, clinical, and histopathologic features of chronic bacterial osteomyelitis and emphasize imaging pearls and pitfalls, with discussion of the most common differential diagnoses.

Distal Tibia Epiphysiodesis After Saphenous Vein Catheterization During Treatment for Prematurity

Extravasation injuries are frequent complications, especially in extremely preterm neonates treated in neonate intensive care units (NICU). Depending on the type of the extravasated substance, the duration, and the amount of the leak, extravasation may result in necrosis of the soft tissues adjacent to the leak, compartment syndrome, and limb amputation. However, in some cases, the results of extravasation may be evident years after NICU treatment. In this case report, we describe a rare case of physeal arrest of the distal tibia in a preterm and discuss the possible causes.

Osteoarticular infections in infants under 3 months of age

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pediatric Musculoskeletal Infections: Imaging Guidelines and Recommendations

Pediatric musculoskeletal infections often pose a diagnostic challenge due to their frequently vague and nonspecific clinical presentation. Imaging evaluation is a crucial component to diagnostic workup of these entities. Changed epidemiology of these infections over the past 2 decades has resulted in increases in both disease incidence and severity in the pediatric population. Prompt and accurate diagnosis is essential in order to reduce the risk of morbid sequelae, and to optimize patient management. In this article, the unique pathophysiology of musculoskeletal infections and characteristic imaging findings in children compared with adults are reviewed.

Radiological changes in the formation of Brodie's abscess by sequential magnetic resonance imaging: a case report

Brodie's abscess is a relatively rare subacute form of osteomyelitis. Early diagnosis is challenging because of its insidious onset and vague symptoms. Magnetic resonance imaging is helpful in the diagnosis of Brodie's abscess; however, to date, no study has described the imaging findings of this disease in the early stage. Here, we present the case of a 14 year-old boy with Brodie's abscess in the proximal tibia. The lesion initially presented as a bone marrow edema in the proximal metaphysis of the left tibia on MRI and was misinterpreted as a bone bruise. Further radiological examination was performed 1 month later; this revealed the formation of an abscess cavity, which suggested Brodie's abscess. The patient was referred to our hospital and underwent curettage and debridement, which led to the definitive diagnosis of Brodie's abscess on histopathological findings and bacterial culture. On careful retrospective evaluation, the initial radiological findings suggested a microabscess on the metaphyseal side of the growth plate and bone marrow edema spreading from the lesion to the epiphysis. These radiological changes could be reliable evidence proving that the metaphyseal side of the growth plate is the origin of Brodie's abscess. Moreover, bone marrow edema with suspected microabscess in the metaphysis of the long bones can be the initial stage of the formation of Brodie's abscess and should be carefully followed up.

Newborn Septic Arthritis-A Rare Presentation of Late-Onset Group B Streptococcal Disease: Case Report and Short Review of the Literature

Group B Streptococcus (GBS) disease is a leading cause of invasive bacterial infections among neonates. We present the case of an 11-day-old neonate with septic arthritis as a rare presentation of late-onset disease (LOD) with a favorable short-term outcome. GBS is a leading cause of neonatal infection. Early-onset disease (EOD) is defined as infection from birth to 6 days of age, while LOD occurs from 7 days to approximately 3 months of age. EOD is acquired through vertical transmission and can be reduced through application of intrapartum antibiotic prophylaxis (IAP). LOD can be acquired from the mother or from environmental sources, unlikely to be prevented by IAP. The most common presentation of EOD is bacteremia (83%), pneumonia (9%), and meningitis (7%). While the clinical picture in both EOD and LOD frequently resembles in LOD hamatogenous spreading may predispose neonates to present with uncommon organ manifestation other than the classic systemic signs of sepsis, for example, septic arthritis. Herein, we report on the management and outcome of a term neonate with late onset GqBS bacteremia and subtle clinical symptoms of septic monoarthritis.

Excessive extremity shortness due to septic arthritis : Case report of treatment with two surgical procedures

Septic arthritis is a common joint infection in neonates and young children. Since osteoarticular infections cause permanent disability in bones and joints, they should be treated appropriately as soon as possible. If there is a delay in starting treatment it can cause severe morbidity. It is most common in the hip and shoulder joints. In this article the surgical treatment process and postoperative clinical status of a 35-year-old patient with severe coxarthrosis and 12 cm femoral shortening due to septic arthritis are reported. To avoid damage to neurovascular structures an extremity lengthening procedure was performed first, followed by a total hip replacement. In order to complete the distraction and consolidation phase in one session and to reduce complications, a growing intramedullary nail was selected. As a result of the surgical interventions, the complaints of the patient in the hip joint and the limping due to shortness of the leg decreased and the performance of activities of daily living was improved.

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.

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.

Staphylococcus aureus Osteomyelitis: Bone, Bugs, and Surgery

Osteomyelitis, or inflammation of bone, is most commonly caused by invasion of bacterial pathogens into the skeleton. Bacterial osteomyelitis is notoriously difficult to treat, in part because of the widespread antimicrobial resistance in the preeminent etiologic agent, the Gram-positive bacterium Staphylococcus aureus Bacterial osteomyelitis triggers pathological bone remodeling, which in turn leads to sequestration of infectious foci from innate immune effectors and systemically delivered antimicrobials. Treatment of osteomyelitis therefore typically consists of long courses of antibiotics in conjunction with surgical debridement of necrotic infected tissues. Even with these extreme measures, many patients go on to develop chronic infection or sustain disease comorbidities. A better mechanistic understanding of how bacteria invade, survive within, and trigger pathological remodeling of bone could therefore lead to new therapies aimed at prevention or treatment of osteomyelitis as well as amelioration of disease morbidity. In this minireview, we highlight recent developments in our understanding of how pathogens invade and survive within bone, how bacterial infection or resulting innate immune responses trigger changes in bone remodeling, and how model systems can be leveraged to identify new therapeutic targets. We review the current state of osteomyelitis epidemiology, diagnostics, and therapeutic guidelines to help direct future research in bacterial pathogenesis.

COMPUTED TOMOGRAPHY SCAN FOR DIAGNOSIS OF OSTEOARTHRITIS: RARE LOCALIZATION IN THE SHOULDER IN A TWELVE-YEAR-OLD BOY

Acute osteomyelitis is pyogenic infection of the bone and bone marrow. We report a case of successful diagnosis and treatment in a 12-year-old boy with right shoulder joint osteoarthritis. On admission, he was febrile (39.0 ºC) with pain in his right shoulder. Laboratory and biochemistry findings were as follows: leukocytes 10.9x10⁹/L; hemoglobin 122 g/l; fibrinogen 34.7; C-reactive protein 56.8. No changes were observed using conventional radiography. Computed tomography (CT) scan was conducted on the right limb using LightSpeed 16 slices in native and contrast series. The area of interest was shown on axial section, less dense fluid within the joint cavity with a thickened capsule and joint soft tissue swelling around the joint. On bone structures, CT morphological changes were not observed. After deterioration of the condition despite antibiotic therapy, surgery had to be performed. The purulent content was removed by surgery. Prolonged antibiotic therapy and rehabilitation led to improvement of the condition. At two-month follow-up, ultrasonography and CT scan showed that there were no pathologic changes, while magnetic resonance imaging showed minimal tissue fibrosis that did no require surgical treatment.

Sonography of musculoskeletal infection in children

Musculoskeletal infection, especially in young children, often presents with non-specific clinical signs and symptoms necessitating early imaging to identify the source of infection. While MRI is the investigation of choice to demonstrate bone infection, it is expensive and often requires a general anaesthetic in the young child. Ultrasound can be a useful tool in the initial assessment due to its easy availability and portable equipment. It does not involve ionising radiation and is used to guide aspiration and drainage procedures. This review explains sonographic features of septic arthritis, osteomyelitis, pyomyositis and soft tissue infection in children and highlights advantages and limitations of sonography when assessing the child with suspected musculoskeletal infection.

An unreported case of Streptococcus cristatus septic arthritis of wrist in a neonate

Septic Arthritis of the wrist is rare in the paediatric population due to its extraarticular metaphysis. We report here a case of wrist septic arthritis in a neonate caused by an uncommon causative organism, Streptococcus cristatus. A 15 days old male child was referred with the complaint of swelling and decreased movement of the left wrist for 5 days. Local examination revealed warm, tender, erythematous and fluctuant swelling over the dorso-ulnar aspect of the left wrist. Ultrasonography of the affected region was suggestive of focal fluid collection in the wrist and periosteal elevation of the distal ulna. Aspiration followed by arthrotomy of the wrist joint was performed and multiple holes were made in the distal ulnar metaphysis using 0.8mm k-wire. The pus culture was positive for Streptococcus cristatus, sensitive to vancomycin, which was given for a total of 4 weeks. At one year follow up the child had a full, painless range of motion with no functional deficit. Final follow up x rays of the left wrist were normal. Streptococcus cristatus strains are described as Gram-positive, catalase-negative cocci, approximately 1 μm in diameter growing in chains and were originally isolated from the human throat and oral cavities. Its association with bone and joint infections has not been described in the literature. To our knowledge, this is the first case of isolated septic arthritis of wrist in a 15 days old child caused by Streptococcus cristatus. To conclude, wrist septic arthritis in a neonate is a rare entity. With the advanced diagnostics, species-level identification of rare organism like Streptococcus cristatus is possible along with antibiotic sensitivity for appropriate therapy. Early surgical decompression and intravenous culture-directed antibiotics are the mainstays of management.

Physeal separation in pediatric osteomyelitis

In children, acute osteomyelitis, an infection of the bone, is most commonly hematogeneous in origin. Osteomyelitis is most often diagnosed with magnetic resonance imaging (MRI) and findings may include marrow signal changes on T1 and T2, with abnormal enhancement after gadolinium. Imaging helps detect any associated intraosseous or subperiosteal abscesses, which may require orthopedic drainage. In this pictorial essay, we demonstrate the association of acute pediatric osteomyelitis with physeal separation, resulting in what may be confused for simple trauma, although there was no known history of trauma in any of the cases we researched. All of the cases had a large subperiosteal fluid collection with marked separation of the epiphysis from the metaphysis. It is important to recognize this potential association in osteomyelitis, as it is readily visible by radiographs and may lead to diagnostic uncertainty.

ACR Appropriateness Criteria® Acutely Limping Child Up To Age 5

Imaging plays in important role in the evaluation of the acutely limping child. The decision-making process about initial imaging must consider the level of suspicion for infection and whether symptoms can be localized. The appropriateness of specific imaging examinations in the acutely limping child to age 5 years is discussed with attention in each clinical scenario to the role of radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. Common causes of limping such as toddler's fracture, septic arthritis, transient synovitis, and osteomyelitis are discussed. 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 may supplement the available evidence to recommend imaging or treatment.

Imaging of the limping child

Limping is a challenging symptom in the pediatric patient as the diagnosis can range from traumatic, malformative, infectious/inflammatory and neoplastic diseases. In this paper, we propose a schematic imaging algorithm to the limping child in three different age groups (Toddler: 1-3years, child: 4-10 years; adolescent: 11-16 years) based on presence of signs of infection, any specific localization of pain, and history of trauma. In this setting, the most common imaging pitfalls are also summarised. Finally, a literature review of the main differential causes of limping in the pediatric patient is reported.

Duration of intravenous antibiotic therapy for children with acute osteomyelitis or septic arthritis: a feasibility study

BACKGROUND

There is little current consensus regarding the route or duration of antibiotic treatment for acute osteomyelitis (OM) and septic arthritis (SA) in children.

OBJECTIVE

To assess the overall feasibility and inform the design of a future randomised controlled trial (RCT) to reduce the duration of intravenous (i.v.) antibiotic use in paediatric OM and SA.

DESIGN

(1) A prospective service evaluation (cohort study) to determine the current disease spectrum and UK clinical practice in paediatric OM/SA; (2) a prospective cohort substudy to assess the use of targeted polymerase chain reaction (PCR) in diagnosing paediatric OM/SA; (3) a qualitative study to explore families' views and experiences of OM/SA; and (4) the development of a core outcome set via a systematic review of literature, Delphi clinician survey and stakeholder consensus meeting.

SETTING

Forty-four UK secondary and tertiary UK centres (service evaluation).

PARTICIPANTS

Children with OM/SA.

INTERVENTIONS

PCR diagnostics were compared with culture as standard of care. Semistructured interviews were used in the qualitative study.

RESULTS

Data were obtained on 313 cases of OM/SA, of which 218 (61.2%) were defined as simple disease and 95 (26.7%) were defined as complex disease. The epidemiology of paediatric OM/SA in this study was consistent with existing European data. Children who met oral switch criteria less than 7 days from starting i.v. antibiotics were less likely to experience treatment failure (9.6%) than children who met oral switch criteria after 7 days of i.v. therapy (16.1% when switch was between 1 and 2 weeks; 18.2% when switch was > 2 weeks). In 24 out of 32 simple cases (75%) and 8 out of 12 complex cases (67%) in which the targeted PCR was used, a pathogen was detected. The qualitative study demonstrated the importance to parents and children of consideration of short- and long-term outcomes meaningful to families themselves. The consensus meeting agreed on the following outcomes: rehospitalisation or recurrence of symptoms while on oral antibiotics, recurrence of infection, disability at follow-up, symptom free at 1 year, limb shortening or deformity, chronic OM or arthritis, amputation or fasciotomy, death, need for paediatric intensive care, and line infection. Oral switch criteria were identified, including resolution of fever for ≥ 48 hours, tolerating oral food and medicines, and pain improvement.

LIMITATIONS

Data were collected in a 6-month period, which might not have been representative, and follow-up data for long-term complications are limited.

CONCLUSIONS

A future RCT would need to recruit from all tertiary and most secondary UK hospitals. Clinicians have implemented early oral switch for selected patients with simple disease without formal clinical trial evidence of safety. However, the current criteria by which decisions to make the oral switch are made are not clearly established or evidence based.

FUTURE WORK

A RCT in simple OM and SA comparing shorter- or longer-course i.v. therapy is feasible in children randomised after oral switch criteria are met after 7 days of i.v. therapy, excluding children meeting oral switch criteria in the first week of i.v. therapy. This study design meets clinician preferences and addresses parental concerns not to randomise prior to oral switch criteria being met.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

In the setting of paediatric osteomyelitis do not be afraid to CAST an eye

The case commences with an innocuous right ankle injury (lateral malleolus), for which the patient, a 9-year-old boy, was placed in a temporary cast at his local hospital. Three days following this incident, the patient was diagnosed with new-onset type 1 diabetes mellitus. He was admitted to his local hospital with severe diabetic ketoacidosis appropriately treated and subsequently discharged c.1 week later clinically well. Approximately 1 week later, again he presented for a third time with a significant serosanguinous discharge from the site of the initial injury permeating through the temporary cast in place for c.2 weeks by that time. On removal of the cast, a severely invasive infection of bone and soft tissue was noted, and the patient was urgently transferred to our unit at the tertiary general hospital for further management. He underwent a series of orthopaedic and plastic surgery procedures with an eventual satisfactory outcome.

Neonatal Cervical Osteomyelitis With Bilateral Upper Limb Paresis

Neonatal cervical osteomyelitis is extremely rare, with only a few cases having been reported. We report a neonate with cervical osteomyelitis and extensive inflammation of the surrounded tissues that caused nerve root compression and upper limb paresis.

[Chronic recurrent multifocal osteomyelitis of the spine : Children and adolescent]

Chronic non-bacterial osteomyelitis (CNO) in childhood and adolescence is a non-infectious autoinflammatory disease of the bone with partial involvement of adjacent joints and soft tissue. The etiology is unknown. The disease can occur singular or recurrent. Individual bones can be affected and multiple lesions can occur. Chronic recurrent multifocal osteomyelitis (CRMO) shows the whole picture of CNO. Accompanying but temporally independent of the bouts of osteomyelitis, some patients show manifestations in the skin, eyes, lungs and the gastrointestinal tract. The article gives an overview of the clinical manifestations, diagnostic procedures, and treatment options for CRMO involvement of the spine based on the current literature and our own cases.

[Spondylodiscitis in children and adolescents]

BACKGROUND

Spondylodiscitis in children is rare. The condition has an incidence of 2 to 4 % of all infectious skeletal diseases in children.

AIM

Aim of the article is the presentation of epidemiology, the clinical signs, radiological findings as well the treatment options of non-specific and specific spondylodiscitis in children.

METHODS

The available literature was reviewed.

RESULTS

Non-specific spondylodiscitis in children is caused by haematogenous spread of pathogens. Staphylococcus aureus is the most frequently detected bacterium. The clinical signs are unspecific and an Magnetic Resonance Imaging of the spine is the standard radiological procedure to detect spondylodiscitis. In general, the treatment is conservative and includes an antibiotic therapy as well an immobilization of the spine. In endemic areas of the world, specific spondylodiscitis is more common and is caused by Mycobacterium tuberculosis or Brucellae. The treatment is also conservative. For all entities of spondylodiscitis in children, a surgical intervention is only necessary in the case of severe deformities due to the infection or in the case of neurological symptoms.

CONCLUSION

Elevated infectious laboratory values and back pain or other unspecific symptoms can indicate spondylodiscitis in children. MRI of the spine is necessary to rule out spondylodiscitis.

Osteomyelitis of the Odontoid Process in Children: Two Cases and Review of the Literature

OBJECTIVE

To report clinical, laboratory and radiologic manifestations in 2 infants with osteomyelitis of the odontoid process (dens).

BACKGROUND

Vertebral osteomyelitis is uncommon, and osteomyelitis of the dens has rarely been reported in the pediatric population.

METHODS

The medical records of 2 infants diagnosed with dens osteomyelitis were reviewed.

RESULTS

Both infants had fever, which resolved spontaneously before admission. Both were nontoxic appearing with persistent neck stiffness and torticollis. White blood count and C-reactive protein were only mildly elevated in both cases. Blood cultures were sterile. Magnetic resonance imaging revealed the diagnosis. They both fully recovered.

CONCLUSIONS

We report 2 cases of dens osteomyelitis. These cases emphasize the need to consider C1-C2 osteomyelitis in the differential diagnosis of neck stiffness and torticollis.

Multifocal bone and bone marrow lesions in children - MRI findings

Polyostotic bone and bone marrow lesions in children may be due to various disorders. Radiographically, lytic lesions may become apparent after loss of more than 50% of the bone mineral content. Scintigraphy requires osteoblastic activity and is not specific. MRI may significantly contribute to the correct diagnosis and management. Accurate interpretation of MRI examinations requires understanding of the normal conversion pattern of bone marrow in childhood and of the appearances of red marrow rests and hyperplasia. Differential diagnosis is wide: Malignancies include metastases, multifocal primary sarcomas and hematological diseases. Benign entities include benign tumors and tumor-like lesions, histiocytosis, infectious and inflammatory diseases, multiple stress fractures/reactions and bone infarcts/ischemia.

Epidemiology and Management of Acute, Uncomplicated Septic Arthritis and Osteomyelitis: Spanish Multicenter Study

BACKGROUND

Acute osteoarticular infection (OAI) is a potentially severe disease. The aim of this study was to evaluate the etiology, clinical characteristics and therapeutic approach of OAI in children in Spain.

METHODS

Medical records from children <14 years with OAI from 25 hospitals between 2008 and 2012 were reviewed. Confirmed osteomyelitis (OM) and septic arthritis (SA) required a positive bacterial isolate; otherwise, they were considered probable. Probable SA with <40,000 cells/mm in joint fluid was not included.

RESULTS

A total of 641 children were evaluated. Two hundred and ninety-nine cases (46%) were OM, 232 (36%) SA, 77 (12%) osteoarthritis and 33 (5%) spondylodiscitis. Children with OM were older (63 vs. 43 months for SA; P < 0.001). Magnetic resonance imaging and bone scintigraphy had the highest yield for OM diagnosis (94%). Arthrocentesis was performed in 96% of SA. A microorganism was isolated in 246 patients (38%: 33% OM vs. 55% SA; P < 0.001): Staphylococcus aureus was the most common (63%), followed by Kingella kingae (15%) and Streptococcus pyogenes (9%). Ninety-five percent of children initially received IV antibiotics, mostly cefotaxime + cloxacillin (60%) or cloxacillin (40%). Total treatment duration was 38 (±31) days for OM and 28 (±16) days for SA (P < 0.0001). Twenty percent of children with OM (46% because of complications) and 53% with SA (95% initial arthrotomy) underwent surgery. Patients with SA were compared according to initial arthrotomy (n = 123) versus arthrocentesis (n = 109), and no clinical differences were observed, except for higher rate of hip SA in the former (50% vs. 9%; P < 0.001). Children with arthrocentesis had less sequelae [6.6% vs. 1%; P = 0.03, odds ratio = 0.58 (95% confidence interval: 0.45-0.76)], but not in the multivariate analysis.

CONCLUSIONS

This is the largest pediatric cohort of OAI in Spain. S. aureus was the most common isolate, although K. kingae was recovered in a high proportion of cases. Conservative management was applied in half of the patients. There was a low rate of sequelae, even with nonsurgical approaches.

Delayed treatment of septic arthritis in the neonate: A review of 52 cases

There is still controversy on the management of septic arthritis in neonates. This study aims to investigate the treatment of septic arthritis in neonates.We reviewed 52 neonates (37 males and 15 females) with septic arthritis in our hospital during 2004 to 2015. The mean age at onset of infection was 17.5 ± 7.6 days, mean age at admission was 32.6 ± 10.7 days. A total of 56 joints were involved (22 knees, 18 shoulders, 13 hips, and 3 other joints). Thiryt-six patients underwent surgical drainage, 14 patients were treated nonoperatively, 2 families refused treatment. Forty-four patients (48 joints) were followed for 4.5 ± 1.2 years. Based on treatment, these 48 joints were divided into an operative group and a nonoperative group. Clinical presentations, imaging examination results, treatments, and outcomes were analyzed.Among the patients who were followed-up, the time from onset to treatment in the operatively managed group (12.7 ± 8.1 days) was significantly shorter than that in the conservatively managed group (20.0 ± 8.2 days). There were no significant differences between both groups on the age at onset, age at admission, imaging score, length of hospital stay, WBC counts, and intravenous medication time. Thirty-five sites (72.9%) recovered completely. There was no significant difference on recovery rate between operative and nonoperative group. Only 33.3% of the hips recovered, this was significantly lower than that of knee/ankle (85.0%) and shoulder/elbow (78.9%). Sequels were found in 13 joints. Logistic regression indicated that sex, imaging score, and hip joint involvement were predictors of sequel. One point of imaging score increased the risk of sequels by a factor of 2.960, and hip joint involvement increased the risk of sequels by a factor of 12.712. Females were more likely to have sequels than males.Surgical drainage is recommended for early diagnosed neonatal septic arthritis and hip infections. A conservative approach may be more efficient for patients whose diagnosis and treatment had been delayed for more than 2 weeks. Antibiotics should be administered intravenously for 2 weeks and then orally for another 2 weeks. First-generation cephalosporin and clindamycin are recommended empirical antibiotics before causative agent and its resistance pattern are known.

Sepsis, parenteral vaccination and skin disinfection

ASBSTRACT Disinfection should be required for all skin penetrative procedures including parenteral administration of vaccines. This review analyses medically attended infectious events following parenteral vaccination in terms of their microbiological aetiology and pathogenesis. Like 'clean' surgical site infections, the major pathogens responsible for these events were Staphylococcal species, implicating endogenous con-tamination as a significant source of infection. As 70% isopropyl alcohol swabbing has been shown to effectively disinfect the skin, it would be medico-legally difficult to defend a case of sepsis with the omission of skin disinfection unless the very low risk of this event was adequately explained to the patient and documented prior to vaccination. There was a significant cost-benefit for skin disinfection and cellulitis. Skin disinfection in the context of parenteral vaccination represents a new paradigm of medical practice; the use of a low cost intervention to prevent an event of very low prevalence but of significant cost.

Septic arthritis in children in resource limited and non-resource limited countries: an update on diagnosis and treatment

INTRODUCTION

Septic arthritis (SA) is an orthopedic emergency in childhood. It is uncommon in high resource settings. However, an incidence of 5-20 per 100,000 children has been reported in low-income countries. Area covered: The predictive value of serum markers is still under debate and the proposed diagnostic algorithms for SA are not sufficiently validated in children. Recent data suggest that short-course intravenous treatment, followed by oral therapy, is as effective as traditional long-term treatment. Results from three randomized controlled trials suggest that the addition of systemic steroids may accelerate clinical improvement. Minimally invasive surgical techniques have been proposed for treatment in recent years. Expert commentary: The causes and the epidemiology of septic arthritis will continue to mutate according to the changes in immunization practices, bacterial resistance patterns and the implementation of PCR techniques. Future research should focus on the assessment of appropriate antibiotic regimens and surgical procedures.

Bone and Joint Infections in Children: Acute Hematogenous Osteomyelitis

Acute hematogenous osteomyelitis (AHO) is one of the commonest bone infection in childhood. Staphylococcus aureus is the commonest organism causing AHO. With use of advanced diagnostic methods, fastidious Kingella kingae is increasingly becoming an important organism in etiology of osteoarticular infections in children under the age of 3 y. The diagnosis of AHO is primarily clinical. The main clinical symptom and sign in AHO is pain and tenderness over the affected bone especially in the metaphyseal region. However, in a neonate the clinical presentation may be subtle and misleading. Laboratory and radiological investigations supplement the clinical findings. The acute phase reactants such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are frequently elevated. Ultrasonography and MRI are key imaging modalities for early detection of AHO. Determination of infecting organism in AHO is the key to the correct antibiotic choice, treatment duration and overall management and therefore, organism isolation using blood cultures and site aspiration should be attempted. Several effective antibiotics regimes are available for managing AHO in children. The choice of antibiotic and its duration and mode of delivery requires individualization depending upon severity of infection, causative organism, regional sensitivity patterns, time elapsed between onset of symptoms and child's presentation and the clinical and laboratory response to the treatment. If pus has been evidenced in the soft tissues or bone region, surgical decompression of abscess is mandatory.

The imaging of osteomyelitis

Osteomyelitis is an important cause of morbidity and mortality in children and adults. Imaging plays a crucial role in establishing a timely diagnosis and guiding early management, with the aim of reducing long-term complications. Recognition of the imaging features of osteomyelitis requires a good understanding of its pathogenesis. In this review, the key imaging findings in osteomyelitis are correlated with the underlying pathological processes. There is a particular emphasis on magnetic resonance imaging (MRI), which is the best available imaging modality owing to its high sensitivity for detecting early osteomyelitis, excellent anatomical detail and superior soft tissue resolution. However, other modalities such as nuclear medicine and computed tomography (CT) are also useful in many clinical contexts, and will also be described in this review.

Pediatric Emergency Magnetic Resonance Imaging: Current Indications, Techniques, and Clinical Applications

MR imaging plays an important role in the detection and characterization of several pediatric disease entities that can occur in the emergent setting because of its cross-sectional imaging capability, lack of ionizing radiation exposure, and superior soft tissue contrast. In the age of as low as reasonably achievable, these advantages have made MR imaging an increasingly preferred modality for diagnostic evaluations even in time-sensitive settings. In this article, the authors discuss the current indications, techniques, and clinical applications of MR imaging in the evaluation of pediatric emergencies.

A Rare Full-Term Newborn Case of Rib Osteomyelitis with Suspected Preceding Fracture

Acute osteomyelitis is uncommon in full-term neonates and occurs most frequently in those with critical illnesses, often following episodes of sepsis, skin infection, umbilical catheterization, urinary tract anomalies, or a complicated delivery. Here, we report a very rare case of acute rib osteomyelitis due to Staphylococcus aureus in a 13-day-old full-term male neonate. Ultrasonography (US) enabled diagnosis and revealed a coexisting costochondral junction rib fracture, which was not detected on routine chest radiography. Following a 29-day course of intensive parenteral antibiotic therapy, the patient was discharged in good health at 42 days of age without any scar formation. Due to its accessibility and safety, US can be a promising modality for detecting acute osteomyelitis in neonates with clinically highly suspected conditions in the neonatal intensive care unit setting, particularly those involving thin and mobile bones subject to respiratory motion. However, further studies are required to assess the utility of US in these cases and negative results. In low-risk neonates with osteomyelitis, an accompanying fracture should be considered.