Bone and joint infections

Evaluation of the current use of imaging modalities and pathogen detection in children with acute osteomyelitis and septic arthritis

Diagnostic tools for the management of acute osteomyelitis (OM) and septic arthritis (SA) have improved over the last decade. To investigate the influence and availability of magnetic resonance imaging (MRI) and nucleic acid testing (NAT), a retrospective cohort study was done. Patients admitted with acute OM or SA between 2005 and 2014 were identified using ICD-10 discharge codes. Ninety-six children were identified: OM, n = 45; SA, n = 42; and OM + SA, n = 9. Diagnostic imaging was performed in 100% of OM or OM + SA and 95% of SA patients. MRI was performed in 85% of OM patients, 26% of SA patients and 100% OM + SA patients. In patients with OM or SA, concomitant joint/bone involvement was detected in 24 and 36% of patients, respectively. In 58% of patients, a pathogen was detected (Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae being most common). Blood and tissue culture were positive in 41 and 86% for OM patients and in 14 and 41%, respectively, for SA patients. In 42% of patients, no pathogen was identified, of which 40% had no material for blood or tissue culture/NAT taken.

CONCLUSION

Optimal use of imaging modalities including MRI and systematic pathogen detection including NAT should be advocated to limit use of broad spectrum antibiotics and treatment duration. What is Known: • Magnetic resonance imaging and sonography have the best sensitivity for detection of acute osteomyelitis and septic arthritis in children. • Systematic use of blood cultures, tissue cultures and nucleic acid testing improves pathogen detection in children with acute osteomyelitis and septic arthritis. What is New: • The added value of imaging modalities other than magnetic resonance and sonography for detection of osteomyelitis and septic arthritis is limited, and their routine use should be questioned. • Despite availability of optimal pathogen detection methods, missed opportunities to improve pathogen detection are frequent.

Association of vitamin D receptor gene TaqI, BsmI, FokI and ApaI polymorphisms and susceptibility to extremity chronic osteomyelitis in Chinese population

Previous studies have indicated that vitamin D receptor (VDR) TaqI, BsmI, FokI and ApaI gene polymorphisms are associated with the risk of several inflammatory diseases. However, potential association of the VDR gene polymorphisms with susceptibility to extremity chronic osteomyelitis remains unclear. The present study aimed to investigate link between VDR gene polymorphisms and the risk of extremity chronic osteomyelitis in Chinese population. A total of 233 patients with chronic osteomyelitis and 200 healthy controls were genotyped for the 4 single-nucleotide polymorphisms (SNPs) (TaqI, BsmI, FokI and ApaI) in VDR gene using the SNaPshot genotyping method. The frequencies of mutant allele C in rs731236 (P=0.044, OR=1.830, 95% CI 1.009 - 3.319) and rs2228570 (P=0.029, OR=1.347, 95% CI 1.031 - 1.761) were significantly higher in patients than those in healthy controls. In addition, outcomes of the logistic regression analysis adjusted by gender and age revealed that significant links were found between rs731236 (P=0.05, OR=1.887, 95% CI 1.001 - 3.558), rs2228570 (P=0.042, OR=1.594, 95% CI 1.016-2.500) and the risk of developing chronic osteomyelitis by dominant genetic model. In addition, significant association was also found between rs2228570 and the risk of developing the disease by homozygous model (P=0.034, OR=1.803, 95% CI 1.046 - 3.106). However, no significant correlations were found between BsmI (rs1544410) or ApaI (rs7975232) gene polymorphisms and the susceptibility to the disease. To our knowledge, we reported for the first time that VDR gene TaqI (rs731236) and FokI (rs2228570) polymorphisms may contribute to the increased risk of chronic osteomyelitis in Chinese population.

Clinical Characteristics and Treatment of Extremity Chronic Osteomyelitis in Southern China: A Retrospective Analysis of 394 Consecutive Patients

Although extremity chronic osteomyelitis is common in China, updated data were still limited regarding its characterizations. The present study aimed to review clinical features of extremity chronic osteomyelitis in Southern China.A retrospective analysis was conducted in the patients who had sought medical attention from January 2010 to April 2015 for extremity chronic osteomyelitis in Nanfang Hospital in Southern China. Clinical data were collected and analyzed.A total of 394 patients (307 males and 87 females) were included, giving a gender ratio of 3.53. The median age at first diagnosis was 42 years for all. The most frequent type was traumatic osteomyelitis (262 cases, 66.50%), which was mainly caused by open injury (166 cases, 63.36%) and during a road accident (91 cases, 34.73%). Single-site infection accounted for 81.98% (323 cases), with tibia (126 cases), femur (79 cases), calcaneus (37 cases), and toes (37 cases) as the top sites. The positive rate of intraoperative culture was 70.63% (214/303), 78.97% (169/214) of which was monomicrobial infection. Staphylococcus aureus (59 cases) was the most frequent bacteria for monomicrobial infection, followed by Pseudomonas aeruginosa (29 cases) and Escherichia coli (11 cases). The positive ratios of preoperative serum white blood cell (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were 21.63%, 64.92%, 53.27%, 42.25%, 72.82%, and 66.67%, respectively. The most frequently used intravenous antibiotic was cephalosporins. The overall cure rate was 77.74%, with a total amputation rate of 16.75%.In this representative Chinese cohort, extremity chronic osteomyelitis was mostly caused by open injury and during a road accident, predominated in males and favored the tibia. S. aureus was the most frequent pathogenic organism. Preoperative elevated levels of serum IL-6, TNF-α, and ESR may be helpful diagnostic indicators of the disease. Most patients achieved a favorable clinical efficacy after appropriate treatment.

Prosthetic joint infections-a clinico-microbiological perspective: Review article

Prosthetic joint infections (PJIs), although not very common, currently pose a very significant threat since they are associated with severe complications, high morbidity rates and substantial costs. PJIs are most commonly caused by Staphylococcus aureus and coagulase-negative staphylococci. The diagnosis of implant-associated infections is very challenging since no single routinely used laboratory or clinical test has been shown to demonstrate adequate results with respect to sensitivity, specificity and accuracy. In most cases, a sum of clinical signs and symptoms, histopathology, blood tests, radiography, bone scans and microbiological testing is considered to arrive at an accurate diagnosis. Treatment of PJIs is also very difficult since most of the infections are caused by biofilm-producing microorganisms which are significantly more resistant to the hosts natural defense mechanisms and antibiotic treatment. For successful management, a combination of both antibiotic and surgical treatment is most often required, and early diagnosis is of the utmost importance. Thus, a multidisciplinary approach is potentially the best option in dealing with PJI, and should include the involvement of microbiologists, orthopedic specialists, clinicians, pathologists and radiologists in order to improve decision-making processes and ensure overall success. The following review aims at briefly outlining the microbiology, diagnostic and treatment options, and preventive measures associated with such infections.