Can procalcitonin measurement help the diagnosis of osteomyelitis and septic arthritis? A prospective trial

<p>Abstract</p> <p>Objectives</p> <p>Procalcitonin (PCT) is an accurate marker for differentiating bacterial infection from non-infective causes of inflammation or viral infection. However, there is only one study in children which tested procalcitonin as a diagnostic aid in skeletal infections. With this study we sought to evaluate the sensitivity, specificity and predictive values of procalcitonin for identifying bone and joint infection in children evaluated in the emergency department for non traumatic decreased active motion of a skeletal segment.</p> <p>Methods</p> <p>Patients aged 1 month to 14 years were prospectively included in the emergency department when suspected for osteomyelitis or septic arthritis. Procalcitonin levels, C reactiv protein, white blood cell count were measured and bacteriological samples were collected before initiation of antibiotic treatment. Patients were assigned to 3 groups according to the degree of suspected infection: group 1 confirmed infection, group 2 presumed infection and group 3 non infected patients.</p> <p>Results</p> <p>Three hundred thirty nine patients were included (118 girls and 221 boys). Group 1 comprised 8 patients (2 had PCT levels > 0.5 ng/ml). Two had osteomyelitis and 6 septic arthritis. Forty children were incuded in group 2 (4 had PCT levels > 0.5 ng/ml). Eighteen had presumed osteomyelitis and 22 presumed septic arthritis. Group 3 comprised 291 children (9 PCT levels > 0.5 ng/ml) who recovered without antibiotic treatment. The specificity of the PCT as a marker of bacterial infection (comparing Group 1 and Group 3) was 96.9% [95% CI, 94.2-98.6], the sensitivity 25% [95% CI, 3.2-65.1], the positive predictive value (PPV) 18.2% [95% CI, 2.3-51.8] and the negative predictive value (NPV) 97.9% [95% CI, 95.5-99.2].</p> <p>Conclusion</p> <p>PCT is not a good screening test for identifying skeletal infection in children. Larger studies are needed to evaluate still more the place of PCT measurements in the diagnosis of osteomyelitis and septic arthritis.</p

Biomechanical cadaver study of proximal fixation in a minimally invasive bipolar construct

Study design Biomechanical human cadaver study. Objective To determine the three-dimensional intervertebral ranges of motion (ROMs) of intact and hook-instrumented tho- racic spine specimens subjected to physiological loads, using an in vitro experimental protocol with EOS biplane radiography. Summary of background data Pedicle screws are commonly used in thoracic instrumentation constructs, and their biome- chanical properties have been widely studied. Promising clinical results have been reported using a T1–T5 thoracic hook–claw construct for proximal rod anchoring. Instrumentation stability is a crucial factor in minimizing mechanical complications rates but had not been assessed for this construct in a biomechanical study. Methods Six fresh-frozen human cadaver C6–T7 thoracic spines were studied. The first thoracic vertebrae were instrumented using two claws of supra-laminar and pedicle hooks, each fixed on two adjacent vertebrae, on either side of a single free vertebra. Quasi-static pure-moment loads up to 5 Nm were applied to each specimen before and after instrumentation, in flexion–extension, right and left bending, and axial rotation. Five steel beads impacted in each vertebra allowed 3D tracking of vertebral movements on EOS biplanar radiographs acquired after each loading step. The relative ranges of motion (ROMs) of each pair of vertebras were computed. Results Mean ROMs with the intact specimens were 17° in flexion–extension, 27.9° in lateral bending, and 29.5° in axial rotation. Corresponding values with the instrumented specimens were 0.9°, 2.6°, and 7.3°, respectively. Instrumentation sig- nificantly (P < 0.05) decreased flexion–extension (by 92–98%), lateral bending (by 87–96%), and axial rotation (by 68–84%). Conclusion This study establishes the biomechanical stability of a double claw–hook construct in the upper thoracic spine, which may well explain the low mechanical complication rate in previous clinical studies. Level of evidence Not applicable, experimental cadaver study

Mortality Associated with Neurofibromatosis 1: A Cohort Study of 1895 Patients in 1980-2006 in France

<p>Abstract</p> <p>Background</p> <p>Neurofibromatosis 1 (NF1), a common autosomal dominant disorder, was shown in one study to be associated with a 15-year decrease in life expectancy. However, data on mortality in NF1 are limited. Our aim was to evaluate mortality in a large retrospective cohort of NF1 patients seen in France between 1980 and 2006.</p> <p>Methods</p> <p>Consecutive NF1 patients referred to the National French Referral Center for Neurofibromatoses were included. The standardized mortality ratio (SMR) with its 95% confidence interval (CI) was calculated as the ratio of observed over expected numbers of deaths. We studied factors associated with death and causes of death.</p> <p>Results</p> <p>Between 1980 and 2006, 1895 NF1 patients were seen. Median follow-up was 6.8 years (range, 0.4-20.6). Vital status was available for 1226 (65%) patients, of whom 1159 (94.5%) survived and 67 (5.5%) died. Overall mortality was significantly increased in the NF1 cohort (SMR, 2.02; CI, 1.6-2.6; <it>P </it>< 10^-4). The excess mortality occurred among patients aged 10 to 20 years (SMR, 5.2; CI, 2.6-9.3; <it>P </it>< 10^-4) and 20 to 40 years (SMR, 4.1; 2.8-5.8; <it>P </it>< 10^-4). Significant excess mortality was found in both males and females. In the 10-20 year age group, females had a significant increase in mortality compared to males (SMR, 12.6; CI, 5.7-23.9; and SMR, 1.8; CI, 0.2-6.4; respectively). The cause of death was available for 58 (86.6%) patients; malignant nerve sheath tumor was the main cause of death (60%).</p> <p>Conclusions</p> <p>We found significantly increased SMRs indicating excess mortality in NF1 patients compared to the general population. The definitive diagnosis of NF1 in all patients is a strength of our study, and the high rate of death related to malignant transformation is consistent with previous work. The retrospective design and hospital-based recruitment are limitations of our study. Mortality was significantly increased in NF1 patients aged 10 to 40 years and tended to be higher in females than in males.</p

Prolonged dialysis during ex vivo lung perfusion promotes inflammatory responses

Ex-vivo lung perfusion (EVLP) has extended the number of transplantable lungs by reconditioning marginal organs. However, EVLP is performed at 37°C without homeostatic regulation leading to metabolic wastes’ accumulation in the perfusate and, as a corrective measure, the costly perfusate is repeatedly replaced during the standard of care procedure. As an interesting alternative, a hemodialyzer could be placed on the EVLP circuit, which was previously shown to rebalance the perfusate composition and to maintain lung function and viability without appearing to impact the global gene expression in the lung. Here, we assessed the biological effects of a hemodialyzer during EVLP by performing biochemical and refined functional genomic analyses over a 12h procedure in a pig model. We found that dialysis stabilized electrolytic and metabolic parameters of the perfusate but enhanced the gene expression and protein accumulation of several inflammatory cytokines and promoted a genomic profile predicting higher endothelial activation already at 6h and higher immune cytokine signaling at 12h. Therefore, epuration of EVLP with a dialyzer, while correcting features of the perfusate composition and maintaining the respiratory function, promotes inflammatory responses in the tissue. This finding suggests that modifying the metabolite composition of the perfusate by dialysis during EVLP can have detrimental effects on the tissue response and that this strategy should not be transferred as such to the clinic

Expansion of Regulatory T Cells in Patients with Langerhans Cell Histiocytosis

Frederic Geissmann and colleagues find that Langerhans cell accumulation in Langerhans cell histiocytosis results from survival rather than uncontrolled proliferation, and is associated with the expansion of regulatory T cells

Herpes-Virus Infection in Patients with Langerhans Cell Histiocytosis: A Case-Controlled Sero-Epidemiological Study, and In Situ Analysis

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare disease that affects mainly young children, and which features granulomas containing Langerhans-type dendritic cells. The role of several human herpesviruses (HHV) in the pathogenesis of LCH was suggested by numerous reports but remains debated. Epstein-barr virus (EBV, HHV-4), & Cytomegalovirus (CMV, HHV-5) can infect Langerhans cells, and EBV, CMV and HHV-6 have been proposed to be associated with LCH based on the detection of these viruses in clinical samples. METHODOLOGY: We have investigated the prevalence of EBV, CMV and HHV-6 infection, the characters of antibody response and the plasma viral load in a cohort of 83 patients and 236 age-matched controls, and the presence and cellular localization of the viruses in LCH tissue samples from 19 patients. PRINCIPAL FINDINGS: The results show that prevalence, serological titers, and viral load for EBV, CMV and HHV-6 did not differ between patients and controls. EBV was found by PCR in tumoral sample from 3/19 patients, however, EBV small RNAs EBERs -when positive-, were detected by in situ double staining in bystander B CD20+ CD79a+ lymphocytes and not in CD1a+ LC. HHV-6 genome was detected in the biopsies of 5/19 patients with low copy number and viral Ag could not be detected in biopsies. CMV was not detected by PCR in this series. CONCLUSIONS/SIGNIFICANCE: Therefore, our findings do not support the hypothesis of a role of EBV, CMV, or HHV-6 in the pathogenesis of LCH, and indicate that the frequent detection of Epstein-barr virus (EBV) in Langerhans cell histiocytosis is accounted for by the infection of bystander B lymphocytes in LCH granuloma. The latter observation can be attributed to the immunosuppressive micro environment found in LCH granuloma

TRAITEMENT DE LA LUXATION DE ROTULE CHEZ L'ENFANT TRISOMIQUE 21 (A PROPOS DE 31 CAS CHEZ 20 PATIENTS)

PARIS6-Bibl. St Antoine CHU (751122104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Maladie de Legg-Perthes-Calvé (analyse en fin de croissance de patients âgés de 8 ans et plus au début de la maladie)

La maladie de Legg-Perthes-Calvé ou ostéochondrite primitive de hanche est une pathologie affectant la hanche en croissance. Elle se traduit par une atteinte épiphysaire fémorale supérieure d origine ischémique encore mal expliquée de nos jours. Sa gravité potentielle vient des déformations séquellaires qui vont évoluer, à plus ou moins long terme selon leur importance, vers une coxarthrose. Le principal facteur pronostique communément admis est l âge de l enfant au début de la maladie. Au-delà de 8 ou 9 ans selon les auteurs, le pronostic devient moins favorable. Cette étude a revu 36 hanches chez 33 enfants âgés d au moins 8 ans lors de la survenue de la maladie avec un recul moyen de 14,2 ans (extrêmes allant de 5,7 ans à 28,8 ans). Au dernier recul, 22 hanches (61,1 %) étaient classées parmi les bons résultats, 4 hanches (11,1 %) parmi les résultats moyens et 10 hanches (27,8 %) parmi les mauvais résultats. Malgré la sélection de la population étudiée en fonction de l âge, l étude statistique a fait ressortir l âge au début de la maladie comme le facteur pronostic principal. En divisant la population étudiée en deux groupes selon ce critère (> 8 ans et = 9 ans : 21 hanches) des tendances très nettes se sont dégagées sans preuve statistique du fait de la faiblesse des échantillons : les enfants les plus âgé avait des résultats cliniques et radiologiques moins bons que ceux plus jeunes.Au total, la littérature est pauvre sur cette population particulière. La revue de la littérature est rendue difficile par la variété des moyens d évaluation utilisés et par l importance de l éventail thérapeutique disponible. Notre étude met en évidence l âge de survenue de la maladie comme un facteur pronostic statistiquement prouvé avec un seuil à 9 ans. Au-delà, il s agit d une population à risques qu il faut traiter de façon agressive, très souvent chirurgicalement et parmi les techniques employées la triple ostéotomie pelvienne nous semble la plus efficace et la moins délétère.PARIS13-BU Serge Lebovici (930082101) / SudocSudocFranceF