Review article: Paediatric bone and joint infection

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.

Rapid identification of pathogens involved in pediatric osteoarticular infections by multiplex PCR

Background

Delays in the diagnosis of pediatric osteoarticular infections (OAIs) can cause associated acute complications or long-term morbidity. This study attempts to develop a multiplex PCR-based assay that can rapidly and accurately detect the main pathogens involved in pediatric OAIs, namely, methicillin-sensitive or methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa.

Methods

A set of four gene-specific primers suitable for use in a one-tube PCR assay was designed to detect four common pathogens involved in pediatric OAIs, namely, nuc for methicillin-sensitive Staphylococcus aureus, nuc and mecA for methicillin-resistant Staphylococcus aureus, spyM for Streptococcus pyogenes and orpI for Pseudomonas aeruginosa. The multiplex PCR was first evaluated with 39 isolated clinical strains and further with 41 specimens collected from patients suspected of having OAIs.

Results

Specific primer pairs were successfully designed, and the targeted genes were simultaneously amplified. The product sizes in the assay for nuc, mecA, spyM and oprI were 233, 158, 336 and 109 bp, respectively. Evaluation of the multiplex PCR with 39 isolated clinical strains and 41 specimens revealed 100% sensitivity and 100% specificity. The limit of detection of the multiplex PCR assay was approximately 1×10³ CFU at the bacterial cell level.

Conclusions

This newly developed multiplex PCR assay, without sequencing, enables a rapid and accurate diagnosis of the major bacterial species in children with OAIs and might serve as an additional diagnostic approach for urgent pathogen determination.

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.

Is Climate Associated With Revision for Prosthetic Joint Infection After Primary TKA?

BACKGROUND

Climate factors have been shown to be associated with spontaneous musculoskeletal and some surgical site infections with increased rates of infection during warmer periods. To date, little research has been performed to determine if this phenomenon is associated with differences in the risk of revision for prosthetic joint infection (PJI) in primary TKA.

QUESTIONS/PURPOSES

(1) Does the rate of revision for early PJI within the first year after primary TKA differ between tropical and nontropical regions? (2) Is there a seasonal variation in the rate of revision for PJI? (3) Is the geographic and seasonal variation (if present) associated with the sex, age, and/or American Society of Anesthesiologists (ASA) grade of the patient?

METHODS

All 219,983 primary TKAs performed for osteoarthritis over a 5-year period (2011-2015) in the Australian Orthopaedic Association National Joint Replacement Registry were examined based on the month of the primary procedure to determine the rate of revision for PJI within 12 months. The data were analyzed to determine the differences in the risk of revision for PJI based on geographic region and season of the primary procedure adjusting for sex, age, and ASA grade of the patient.

RESULTS

The early revision rate for PJI was higher in the tropical compared with the nontropical region of Australia (0.73% versus 0.37%; odds ratio [OR], 1.87; 95% confidence interval [CI], 1.44-2.42; p < 0.001). The tropical region of Australia demonstrated a seasonal variation in the rate of revision for PJI with a higher rate during the warmer monsoon wet season of summer and fall (summer/fall 0.98% versus winter/spring 0.51%; OR, 1.88; 95% CI, 1.12-3.16; p = 0.02). A seasonal variation was not seen in the nontropical region (OR, 1.03; 95% CI, 0.90-1.19; p = 0.64). The regional and seasonal changes were independent of sex, age, and ASA grade.

CONCLUSIONS

Climate factors are associated with the risk of early revision for PJI in patients undergoing primary TKA with rates of such revisions approximately double in tropical regions compared with nontropical regions. Additionally, tropical regions demonstrate a seasonal variation with the risk of PJI doubling during the warmer, monsoonal wet season of summer and fall. These findings should be confirmed in further studies that can better control for possible confounding variables. The mechanism for this phenomenon is not clear, and further research into this subject is also indicated.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Panton-Valentine leukocidin-positive Staphylococcus aureus osteomyelitis of the tibia in a 10-year-old child

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasing in prevalence among asymptomatic carriers and in cases of paediatric soft-tissue infections alike. CA-MRSA may express virulence factors such as Panton-Valentine leukocidin, which makes soft-tissue and hard-tissue infections due to such organisms challenging to treat. We report a case of osteomyelitis of the proximal tibia in a 10-year-old boy and discuss its management in what is to the authors' knowledge the first case report of Panton-Valentine leukocidin-positive CA-MRSA osteomyelitis in a child in the UK.

Kingella kingae infections of the skeletal system in children: diagnosis and therapy

As the result of improved bacteriological techniques, Kingella kingae is emerging as an important cause of infections of the skeletal system in children younger than 2 years of age. This review details the bacteriological features and detection methods of this pathogen, as well as the epidemiology, clinical presentation, treatment and prognosis of septic arthritis, osteomyelitis and diskitis caused by the organism.

Lancing of a boil leading to severe invasive methicillin-sensitive Staphylococcus aureus infection in an adolescent

A 10-year-old boy presented to the emergency department with chief symptoms of fever and right leg pain for 3 days. Also of note, he reported that he had a boil on his neck 2 weeks prior to admission. This lesion was lanced by his mother with a hot needle. An X-ray, CT scan and MRI of the right knee showed no evidence of osteomyelitis. He was placed on intravenous vancomycin for empiric treatment. Blood culture grew methicillin-susceptible Staphylococcus aureus (MSSA), susceptible to vancomycin and clindamycin. He continued to spike fever with the development of erythema, and swelling of the distal thigh. Repeat MRI of the right knee showed osteomyelitis and subperiosteal abscess in the distal femur shaft with surrounding intramuscular abscesses and pyomyositis. He was taken to the operating room where 50 mL of fluid was drained from the periosteal abscess and a bone biopsy was obtained. Bone marrow culture also grew MSSA, susceptible to clindamycin.

Magnetic resonance imaging of the immature skeleton

Magnetic resonance (MR) is unique in its ability to allow assessment of bone marrow, epiphyseal, physeal, and articular cartilage as well as tendons and ligaments. An understanding of skeletal maturation and the accompanying changes on MR is of utmost importance in pediatric radiology. In particular, it is important to recognize the normal spectrum related to ossification and marrow transformation. This review will include a brief description of main indications and common pitfalls in musculoskeletal MR in children. Also, we will focus on the MR appearance of the growing pediatric skeleton on the most commonly used sequences.

Systematic review of duration and choice of systemic antibiotic therapy for acute haematogenous bacterial osteomyelitis in children

AIM

Historically, children with acute osteomyelitis received 4-6 weeks of parenteral antibiotics; however, evidence to guide optimal duration of therapy is limited. This study aims to summarise the available evidence on the duration and choice of antimicrobial therapy for acute haematogenous osteomyelitis in children.

METHODS

We systematically reviewed the literature on children with acute osteomyelitis to determine if shorter durations of antibiotic treatment compared with protracted treatment gave different cure rates. We also analysed studies for choice of antibiotics to determine differences in success rates. Randomised controlled trials, cohort studies, case-control studies and case series were eligible for inclusion.

RESULTS

We identified six randomised controlled trials, three of which addressed duration of antibiotic use and three choice of antibiotic for acute osteomyelitis in children. We found 28 observational studies, 20 of which focused on duration and 22 of which allowed analysis of choice of antibiotic. A range of therapy durations and types of antibiotics were assessed. Only one small study looked at treatment of neonates.

CONCLUSIONS

The quality of evidence on antibiotic treatment for acute osteomyelitis is limited, allowing only weak (GRADE 2B) recommendations. Our review suggests that early transition from intravenous to oral therapy, after 3-4 days in patients responding well, followed by oral therapy to a total of 3 weeks may be as effective as longer courses for uncomplicated acute osteomyelitis. This recommendation does not apply to neonates.

A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a)

The critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including Tickborne Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

Community-associated, methicillin-susceptible, and methicillin-resistant Staphylococcus aureus bone and joint infections in children: experience from India

Previously, the treatment of Staphylococcus aureus infections was less complex, as most of those isolated were susceptible to β-lactam antibiotics. In recent years, there has been a marked increase in the incidence of invasive community-acquired (CA) methicillin-resistant S. aureus (MRSA) among children worldwide. However, data on the clinical characteristics and outcomes related to pediatric bone and joint infections caused by CA-S. aureus are very limited in India. In this tertiary hospital-based study, 74 patients with invasive S. aureus less than 18 years of age were identified between January 2004 and December 2008. All patients fulfilled the case definition of CA-S. aureus with evidence of infection before admission; they presented to our hospital without previous antibiotic use and were culture positive for S. aureus within 48 h of admission. All data including demographics, clinical features, treatment protocol, laboratory findings, and antimicrobial susceptibilities were recorded and compared using the SPSS 11.5 statistical software. Of the 74 patients with culture-positive S. aureus bone and joint infection, 41 had MRSA (55%). Forty-nine patients (66.2%) had osteomyelitis, of whom 29 (59.18%) had MRSA and 25 (33.7%) had septic arthritis, of whom 12 (48%) had MRSA. The MRSA group had a significantly higher erythrocyte sedimentation rate, C-reactive protein value, neutrophil count, and white blood cell count (P<0.05). The MRSA group also had longer duration of febrile days, hospital stay, and antibiotic course compared with the methicillin-susceptible S. aureus (MSSA) group (P<0.05). A clinical predictive algorithm was developed using seven significant independent multivariate predictors, with the probability of MRSA being 94% if all seven predictors were positive and 9% if five predictors were positive. Resistance to many classes of antibiotics was noted among S. aureus isolates including trimethoprim-sulfamethoxazole (MRSA 80%, MSSA 24%), erythromycin (MRSA 83%, MSSA 67%), clindamycin (MRSA 54%, MSSA 34%), and ciprofloxacin (MRSA 61%, MSSA 48%). No vancomycin resistance was observed. The morbidity associated with MRSA bone and joint infection in children is significantly higher than that caused by MSSA. Early diagnosis at the primary healthcare level and treatment with appropriate antistaphylococcal therapy are crucial to achieve optimal clinical outcomes. High levels of antimicrobial resistance of both MSSA and MRSA isolates to several classes of antibiotics are a major concern warranting the need for antimicrobial stewardship and ongoing surveillance.

Infection of orthopedic implants with emphasis on bacterial adhesion process and techniques used in studying bacterial-material interactions

Staphylococcus comprises up to two-thirds of all pathogens in orthopedic implant infections and they are the principal causative agents of two major types of infection affecting bone: septic arthritis and osteomyelitis, which involve the inflammatory destruction of joint and bone. Bacterial adhesion is the first and most important step in implant infection. It is a complex process influenced by environmental factors, bacterial properties, material surface properties and by the presence of serum or tissue proteins. Properties of the substrate, such as chemical composition of the material, surface charge, hydrophobicity, surface roughness and the presence of specific proteins at the surface, are all thought to be important in the initial cell attachment process. The biofilm mode of growth of infecting bacteria on an implant surface protects the organisms from the host immune system and antibiotic therapy. The research for novel therapeutic strategies is incited by the emergence of antibiotic-resistant bacteria. This work will provide an overview of the mechanisms and factors involved in bacterial adhesion, the techniques that are currently being used studying bacterial-material interactions as well as provide insight into future directions in the field.

Haematogenous acute and subacute paediatric osteomyelitis: a systematic review of the literature

A delay in the diagnosis of paediatric acute and subacute haematogenous osteomyelitis can lead to potentially devastating morbidity. There are no definitive guidelines for diagnosis, and recommendations in the literature are generally based on expert opinions, case series and cohort studies. All articles in the English literature on paediatric osteomyelitis were searched using MEDLINE, CINAHL, EMBASE, Google Scholar, the Cochrane Library and reference lists. A total of 1854 papers were identified, 132 of which were examined in detail. All aspects of osteomyelitis were investigated in order to formulate recommendations. On admission 40% of children are afebrile. The tibia and femur are the most commonly affected long bones. Clinical examination, blood and radiological tests are only reliable for diagnosis in combination. Staphylococcus aureus is the most common organism detected, but isolation of Kingella kingae is increasing. Antibiotic treatment is usually sufficient to eradicate the infection, with a short course intravenously and early conversion to oral treatment. Surgery is indicated only in specific situations. Most studies were retrospective and there is a need for large, multicentre, randomised, controlled trials to define protocols for diagnosis and treatment. Meanwhile, evidence-based algorithms are suggested for accurate and early diagnosis and effective treatment.

Blistering Digital Dactylitis Complicated by Osteomyelitis and Amputation in an HIV-Positive Infant

HIV infection is rapidly emerging as a predominant cause of morbidity and mortality in children from developing countries. This probably accounts for the many reports that have emanated from resource-limited settings in the last decade. Reports highlighting bone infections and untoward complications in HIV-infected children are rare. This informed our decision to report the case of a 9-month-old HIV-positive Nigerian girl who presented with blistering dactylitis of the right middle finger. Plain radiograph of the right hand showed amputation of the terminal phalanx and changes consistent with osteomyelitis in the middle phalanx of the third finger. The case is discussed with a view of highlighting this rare complication and the challenges associated with management in a resource-limited setting.

Interaction of staphylococci with bone

Staphylococci, in particular Staphylococcus aureus, are the predominant cause of bone infections worldwide. These infections are painful, debilitating and with the rise in antibiotic-resistant forms, increasingly difficult to treat. The growth in the number of prosthetic joint replacement procedures also provides new opportunities for these infections to take hold. Comprehending the mechanisms by which staphylococci interact with and damage bone is critical to the development of new approaches to meet this challenge. This review summarises current understanding of the mechanisms by which staphylococci infect and damage bone. We address the role of the inflammatory response to staphylococcal infection in disrupting the homeostatic balance of bone matrix deposition and resorption and thereby mediating bone destruction. A number of virulence factors that have been shown to contribute to bone infection and pathology are discussed, however no single factor has been defined as being specific to bone infections. Although traditionally considered an extracellular pathogen, there is increasing evidence that staphylococci are able to invade host cells, and that an intracellular lifestyle may facilitate long-term persistence in bone tissue, enabling evasion of antimicrobials and host immune responses. ‘Small colony variant’ strains, with mutations disabling the electron transport pathway appear particularly adept at invading and persisting within host cells, and exhibit enhanced antimicrobial resistance, and may represent a further complication in the treatment and management of staphylococcal bone disease.

Acute haematogenous osteomyelitis in children: is there any evidence for how long we should treat?

PURPOSE OF REVIEW

Despite diagnostic and therapeutic advances, acute haematogenous osteomyelitis in children continues to cause significant morbidity and disease burden. The molecular epidemiology of causal organisms has wide geographic variation, but regardless of cause children often require several weeks of inpatient parenteral antibiotic therapy. This review focuses on antibiotic treatment and length of antibiotic therapy.

RECENT FINDINGS

Currently there is no international and little local consensus regarding the route or duration for antibiotic treatment of acute haematogenous osteomyelitis in children. Although there are encouraging data from review papers and case series, no randomized controlled trial has been conducted to show good evidence for shorter courses of parenteral antibiotic treatment. Prospective studies show effective treatment for a wide variety of antibiotic agents, but there are few comparative studies. Overall treatment for 4-6 weeks is considered standard therapy, but the laboratory or clinical parameters that would determine the decision to switch to oral therapy remain undefined.

SUMMARY

Evidence-based data about the route and duration of intravenous antibiotic treatment for acute haematogenous osteomyelitis in children are still limited to observational and retrospective studies. A randomized controlled trial will provide much needed data.

Community-associated Staphylococcus aureus infections and nasal carriage among children: molecular microbial data and clinical characteristics

An increasing number of infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carrying the Panton-Valentine leukocidin (PVL) genes was recently identified in Greece. In the present study, 170 patients with S. aureus infections and 123 uninfected children (<15 years old) who had been tested for nasal carriage were evaluated during a 2-year period. The MecA, PVL and superantigen family genes, and MRSA clones, were investigated by molecular methods. Sites of infection and laboratory findings for patients were recorded. The results were compared and statistically analysed. Among 123 uninfected children 73 (59%) carried S. aureus, including four MRSA strains. Of these, three MRSA and three methicillin-sensitive S. aureus (MSSA) strains were PVL-positive (p <0.0001). Ninety-six patients (96/170) exhibited skin and soft-tissue infections (SSTIs), and 74 exhibited invasive infections. The incidence of staphylococcal infections increased during July to September each year. In total, 110 S. aureus isolates were PVL-positive (81 from SSTIs and 29 from invasive infections, p <0.0001). Ninety-nine out of 106 MRSA (93%) isolates from 170 patients carried the PVL genes (p <0.0001); 97 belonged to the clonal complex CC80. Leukocyte and polymorphonuclear cell counts were higher among children with MRSA infections (p <0.005). MSSA predominated among patients with invasive infections (43/74), and carried mainly genes of the superantigen family. Children <5 years of age showed a higher risk of MRSA infection. The present study demonstrates that infections due to PVL-positive CA-MRSA spread easily among children, and SSTIs can lead to invasive infections. Nasal colonization may be an additional factor contributing to the emergence of CA-MRSA.

Specific real-time polymerase chain reaction places Kingella kingae as the most common cause of osteoarticular infections in young children

BACKGROUND

The use of universal 16S rDNA polymerase chain reaction (PCR) has recently shown that the place of Kingella kingae in osteoarticular infections (OAI) in young children has been underestimated, but this technique is not the most sensitive or the most rapid method for molecular diagnosis. We developed a specific real-time PCR method to detect K. kingae DNA and applied it to the etiologic diagnosis of OAI.

PATIENTS AND METHODS

All children admitted to a pediatric unit for OAI between January 2004 and December 2005 were enrolled in this prospective study. Culture-negative osteoarticular specimens were tested by 16S rDNA PCR and by K. kingae-specific real-time PCR when sufficient sample remained.

RESULTS

By culture alone, a pathogen was identified in 45% of the 131 specimens tested (Staphylococcus aureus, n = 25; K. kingae, n = 17; others, n = 18). 16S rDNA PCR and K. kingae-specific PCR were both applied to 61 of the culture-negative samples. The combination of culture and 16S rDNA PCR identified a pathogen in 61% of cases (K. kingae DNA, n = 16; DNA of other microorganisms, n = 5). Specific real-time PCR identified a further 6 cases caused by K. kingae and confirmed all 16 universal PCR-positive cases, bringing the overall documentation rate to 66%. K. kingae was the leading cause of OAI in this pediatric series (n = 39, 45%), followed by S. aureus (n = 25, 29%)

CONCLUSION

The K. kingae-specific real-time PCR places K. kingae as the leading cause of OAI in children at our hospital.

Imaging of osteomyelitis: current concepts

Osteomyelitis frequently requires more than one imaging technique for an accurate diagnosis. Conventional radiography still remains the first imaging modality. MRI and nuclear medicine are the most sensitive and specific methods for the detection of osteomyelitis. MRI provides more accurate information regarding the extent of the infectious process. Ultrasound represents a noninvasive method to evaluate the involved soft tissues and cortical bone and may provide guidance for diagnostic or therapeutic aspiration, drainage, or tissue biopsy. CT scan can be a useful method to detect early osseous erosion and to document the presence of sequestra. PET and SPECT are highly accurate techniques for the evaluation of chronic osteomyelitis, allowing differentiation from soft tissue infection.

High-pressure pulsatile lavage propagates bacteria into soft tissue

Initial wound treatment is critical in the treatment of open fractures, contaminated wounds, and abscesses. Ample evidence suggests that high-pressure pulsatile lavage damages bone structure and disrupts soft tissue. We compared the depth of penetration and amount of retention of bacteria in contaminated soft tissue subjected to one of two lavage methods: high-pressure pulsatile and low-pressure gravity flow. Fresh ovine muscle was harvested, contaminated with fluorescently stained Staphylococcus aureus, and subjected to lavage treatment. Specimens in each lavage method group were subdivided based on orientation across or in line with the muscle fibers. High-pressure lavage causes increased depth of bacterial penetration (across: 3,835 microm; in line: 4,220 microm) when compared with low-pressure lavage (across: 1,680 microm; in line: 2,095 microm). Furthermore, both high-pressure treatment groups had higher numbers of retained bacteria as counted in 50 mum x 7,500 microm x 5 microm sections of tissue after lavage (across: 197; in line: 188) when compared with the low-pressure groups (across: 94; in line: 40). These results show that high-pressure pulsatile lavage causes deeper penetration of bacteria and results in greater bacterial retention in soft tissue when compared with low-pressure lavage.

Osteomyelitis in children

Osteomyelitis is one of the more common invasive bacterial infections in children leading to hospitalization and prolonged antibiotic administration. Over the past decade, increasing microbial virulence, diminishing antibiotic susceptibility, and advances in diagnostic molecular microbiology and imaging techniques have led to changes in the clinical management of children with suspected osteomyelitis, which are reviewed in this article.

Contribution of a broad range polymerase chain reaction to the diagnosis of osteoarticular infections caused by Kingella kingae: description of twenty-four recent pediatric diagnoses

BACKGROUND

Microbiologic diagnosis of septic arthritis and osteomyelitis in children is hindered by the less than optimal yield of blood and osteoarticular fluid cultures.

PATIENTS AND METHODS

All patients admitted to a pediatric unit for osteoarticular infections (OAI) between January 2001 and February 2004 were enrolled in this prospective study. Osteoarticular fluid and biopsy samples that were negative by conventional culture were tested by polymerase chain reaction (PCR) with universal 16S ribosomal DNA primers.

RESULTS

We enrolled 171 children. Culture was positive in 64 cases (37.4%), yielding Kingella kingae in 9 cases. The 107 culture-negative specimens were tested by 16S ribosomal DNA PCR. Fifteen samples (14%) were positive, all for Kingella DNA sequences. K. kingae was the second cause of OAI in this population (30.4%), after Staphylococcus aureus (38%). Patients with Kingella infection diagnosed by culture (9 cases) did not differ from those diagnosed by PCR (15 cases) in terms of their clinical characteristics (including prior antibiotic therapy). The characteristics of the 24 children with arthritis (n = 17) or osteomyelitis (n = 7) were similar to those reported elsewhere. Fever (>38 degrees C) and symptom onset shortly before hospitalization (median, 4.5 days) were significantly associated with arthritis.

CONCLUSION

Use of molecular diagnostic methods increases the identification of K. kingae in osteoarticular infections.

[Acute osteomyelitis and septic arthritis in children: one year experience]

To describe bacteriologic epidemiology of bone and joint infections, a total of 52 osteomyelitis, 52 arthritis and 20 osteoarthritis of children aged one month to 15 years during a one-year period (2001) were included in a retrospective unicentric review. The mean age was 3,9 +/-3,6 years. Fever and pain were the most common clinical symptoms. The site of infection was single in 95%, involving lower extremities in 80%. Bone scintigraphy was abnormal in 71% of osteomyelitis. Positive cultures was obtained in 29% of all cases (blood cultures: 20%, aspiration cultures: 29%), but in 42% of cases which have both blood and aspiration cultures. Thirty-six bacteria were identified: 19 Staphylococcus (14 aureus), ten Streptococcus (four pneumoniae), three Salmonella, three Kingella kingae, one Moraxella. All the isolates were susceptible to the empiric antibiotic therapy. Outcome was good in 100% of osteomyelitis and in 96% of arthritis.

Two decades of acute hematogenous osteomyelitis in children: are there any changes?

Our purpose was to compare the clinical course of acute hematogenous osteomyelitis (AHO) 20 years ago and today in the Department of Paediatric Surgery, Kaunas Medical University Hospital, Lithuania. Retrospective data analysis from patients aged 1-16 years with confirmed diagnosis of AHO was performed. The data were collected from 1982 to 2003. The incidence of AHO per year for 1,00,000 children (0-16 years) was analyzed for that period. The patients were divided into two groups-group A, treated in 1982-1983, and group B, treated in 2002-2003. The number of patients, patient age, duration of illness, complications, and length of hospital stay were compared using statistical methods for nonparametric data analysis (Mann-Whitney U test, chi-square criterion). Linear regression was used for incidence analysis. Population data were obtained from the Lithuanian Statistics Department. From 1982-2003, 758 patients were treated. The incidence of AHO increased from 1982. There was no statistically significant difference between the periods 1982-1983 and 2002-2003 in median patient age (10.36 and 10.72 years, respectively), in gender proportion (20.4% and 29.8% of the cases were girls), or in median duration of symptoms until admission (4 days and 3 days, respectively, p=0.058). Median hospital stay and duration of antibiotic therapy were longer in the period 1982-1983 (50 days and 43 days) than during 2002-2003 (29 days and 29 days). The differences in frequency of positive blood cultures (36.4% in group A and 64.9% in group B, p=0.046) and frequency of periosteal abscess (40.8% in group A and 19.3% in group B, p=0.015) were statistically significant. An increase in AHO incidence is seen when comparing contemporary data and the data from two decades ago, but nowadays the clinical course is less complicated and is marked by shorter hospital stays and shorter duration of antibiotic therapy.