Christophe Glorion

Bacterial aetiology of acute osteoarticular infections in children.

Aim: To study the bacterial aetiology of acute osteoarticular infections in children and to analyse the efficiency of culture methods. Methods: Bacteriological data of 407 cases of clinically suspected osteoarticular infections affecting 406 children hospitalized in an orthopaedic surgery department between 1999 and 2002 were retrospectively reviewed. Results: Bacterial cultures from clinical specimens were positive in 74 cases (18%): 38 cases of septic arthritis and 36 cases of bone infections (osteitis, osteomyelitis or osteoarthritis). The use of liquid medium bottles to grow bacteria from articular fluids increased the rate of positive cultures compared to the use of standard solid media (p=0.0001). The most commonly recovered pathogen was Staphylococcus aureus (44%) followed by Kingella kingae (14%), Streptococcus pyogenes (10%) and Streptococcus pneumoniae (10%). K. kingae was most frequently isolated among children under 36 mo of age (p=0.0003), whereas S. aureus was most frequently isolated among children over 36 mo (p=0.0015).

Expansion of Regulatory T Cells in Patients with Langerhans Cell Histiocytosis

Background Langerhans cell histiocytosis (LCH) is a rare clonal granulomatous disease that affects mainly children. LCH can involve various tissues such as bone, skin, lung, bone marrow, lymph nodes, and the central nervous system, and is frequently responsible for functional sequelae. The pathophysiology of LCH is unclear, but the uncontrolled proliferation of Langerhans cells (LCs) is believed to be the primary event in the formation of granulomas. The present study was designed to further investigate the nature of proliferating cells and the immune mechanisms involved in the LCH granulomas. Methods and Findings Biopsies (n = 24) and/or blood samples (n = 25) from 40 patients aged 0.25 to 13 y (mean 7.8 y), were studied to identify cells that proliferate in blood and granulomas. We found that the proliferating index of LCs was low (∼1.9%), and we did not observe expansion of a monocyte or dendritic cell compartment in patients. We found that LCH lesions were a site of active inflammation, tissue remodeling, and neo-angiogenesis, and the majority of proliferating cells were endothelial cells, fibroblasts, and polyclonal T lymphocytes. Within granulomas, interleukin 10 was abundant, LCs expressed the TNF receptor family member RANK, and CD4+ CD25high FoxP3high regulatory T cells (T-regs) represented 20% of T cells, and were found in close contact with LCs. FoxP3+ T-regs were also expanded compared to controls, in the blood of LCH patients with active disease, among whom seven out of seven tested exhibited an impaired skin delayed-type hypersensitivity response. In contrast, the number of blood T-regs were normal after remission of LCH. Conclusions These findings indicate that LC accumulation in LCH results from survival rather than uncontrolled proliferation, and is associated with the expansion of T-regs. These data suggest that LCs may be involved in the expansion of T-regs in vivo, resulting in the failure of the host immune system to eliminate LCH cells. Thus T-regs could be a therapeutic target in LCH.

Osteoarticular infections caused by Kingella kingae in children: contribution of polymerase chain reaction to the microbiologic diagnosis.

We report the cases of 18 children with osteoarticular infections caused by Kingella kingae. The bacteriologic diagnosis, mainly based on cultures of articular fluids, was significantly improved by directly inoculating the liquid medium used for hemocultures, yielding 65% of positive cultures vs. 13.5% with standard solid medium. In 5 cases infection of articular fluids was detected only by PCR of 16S ribosomal RNA.

Imaging of malignant tumours of the long bones in children: monitoring response to neoadjuvant chemotherapy and preoperative assessment

This review focuses on imaging of osteosarcoma and Ewing’s sarcoma of the long bones in children during preoperative neoadjuvant chemotherapy. Morphological criteria on plain films and conventional static MRI are insufficiently correlated with histological response. We review the contribution of dynamic MRI, diffusion-weighted MR and nuclear medicine (18FDG-PET) to monitor tumoural necrosis. MRI is currently the best method to evaluate local extension prior to tumour resection, especially to assess the feasibility of conservative surgery. Quantitative models in dynamic MRI and 18FDG-PET are currently being developed in order to find new early prognostic criteria, but for the time being, treatment protocols are still based on the gold standard of histological response.

Fractures of the odontoid process: a report of 15 cases in children younger than 6 years.

Fractures of the odontoid process are rare in children. We retrospectively reviewed 15 cases in children younger than 6 years, with an average follow-up of 4 years and 3 months. Eight of these patients had neurologic involvement; magnetic resonance imaging (MRI) changes were seen in the spinal cord at the cervicothoracic junction in six. This neurologic injury was thought to be due to the major anterior displacement of the upper spine, causing spinal cord stretch at the spinal apex of the cervical and thoracic spine. Eight patients secured in forward-facing car seats were injured as the result of motor vehicle accident. Conservatively treated fractures fused without problem. By contrast, the three cases operated on as the initial management of the fracture had complications postoperatively.

Femoral lengthening using the callotasis method : study of the complications in a series of 70 cases in children and adolescents

The authors reviewed 70 femoral lengthenings performed for limb-length discrepancy in 66 children and adolescents using gradual incremental distraction. Nine were performed using the Judet lengthener and 61, the Orthofix external fixator. Etiology of the femoral shortening was congenital in 22, posttraumatic in 17, postinfection in 13, neurologic in 12, and miscellaneous in six. There were 83 complications, which were assessed as to their relation to the etiology of shortening, amount of lengthening, and age. The incidence of joint complications did not seem to be less than that previously encountered with rapid distraction methods of lengthening. Bony consolidation was achieved without additional surgery in 88% of cases. Delayed consolidation was most commonly encountered in children younger than 8 years old with congenitally short femora. The authors believe that good results can be obtained by incremental distraction by using uniplanar fixation by aggressive physical therapy, proper fixator application, and appropriate dynamization of the fixator.

Traumatic hip dislocation in childhood.

Traumatic dislocation of the hip in childhood is uncommon and can be a consequence of minor trauma. The authors report a series of 35 dislocations in skeletally immature patients. Most were isolated posterior dislocations without acetabular lesions. In 75% of cases, reduction of the dislocation was easy. Nine children required surgery to remove interposed joint capsule and/or osteochondral fragments to achieve anatomic reduction. Outcomes were generally good, except in one patient in whom a displaced fracture of the femoral physis was followed by total head avascular necrosis. One case of partial necrosis had a satisfactory outcome. Epiphyseal necrosis, though uncommon, appeared to be inconsistent to prevent and hard to predict. Bone scan seems to be more effective than MRI for the detection of necrosis.

Mortality associated with neurofibromatosis 1: a cohort study of 1895 patients in 1980-2006 in France.

BackgroundNeurofibromatosis 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.MethodsConsecutive 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.ResultsBetween 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; P < 10-4). The excess mortality occurred among patients aged 10 to 20 years (SMR, 5.2; CI, 2.6-9.3; P < 10-4) and 20 to 40 years (SMR, 4.1; 2.8-5.8; P < 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%).ConclusionsWe 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.

Scoliosis in Patients With Prader-Willi Syndrome

OBJECTIVE. Our goals were to determine the prevalence and estimate the evolution of spinal deformities in patients suffering from Prader-Willi syndrome; find out which kind of spine deformity predominates regarding genotype and clinical patterns; and evaluate the affect of growth-hormone treatment on the onset and progression of spinal deformities. PATIENTS AND METHODS. This was a retrospective longitudinal, clinical, and radiologic study. One hundred forty-five children followed between 1980 and 2006 were studied in 2 referral centers for Prader-Willi syndrome. Genetic testing confirmed the diagnosis in 133 patients. Ninety-three patients (64%) received growth-hormone therapy. For statistical analysis, age-adjusted comparison between groups was performed by using multivariate logistic regression. RESULTS. Mean age of the patients was 10.2 ± 6.2 years. Sixty-three (43.4%) patients were afflicted with scoliosis. Scoliosis frequency steadily rose with age, and a large majority of patients were affected at skeletal maturity (66.7%). Scoliosis prevalence was not affected by the genotype or by growth-hormone treatment. Patients with higher BMI values had an increased risk of developing a kyphotic deformity in association with scoliosis. We found a statistical association between kyphotic deformity and the need for surgical treatment. CONCLUSIONS. Scoliosis is a major concern for patients with Prader-Willi syndrome, and a regular (annual) systematic back examination is mandated. The role of growth-hormone treatment on the natural history of scoliosis could not be determined, and careful monitoring during treatment is recommended.

Cementless hip arthroplasty in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children. The hip is usually affected later, and its involvement is the most common cause of disability in JIA. Failure of medical and preventive treatment, significant joint destruction, or multiarticular involvement may necessitate total hip arthroplasty (THA) to restore good function. Related clinical trials show initially good THA results in most of the series, but long-term outcomes are uncertain due to a significant arthroplasty loosening rate in the initial years, particularly with cemented stems. The authors report the results of 62 noncemented THAs in 34 children with JIA after an average follow-up of 6 years (range 3-13). Mean age at surgery was 18.3 years (range 11.8-31) and 14 of the 34 children had active disease. Clinical results were good for hip function but less for global function. There were no infections. Two acetabular cups early in the series failed due to poor primary fixation and had to be revised. Survivorship analysis was performed with the Kaplan-Meier method. At 13 years, the survival rate was 100% for the femoral component and 90.1% for the acetabular component.