Nele Herregods

Bone size and bone strength are increased in obese male adolescents.

CONTEXT Controversy exists on the effect of obesity on bone development during puberty. OBJECTIVE Our objective was to determine differences in volumetric bone mineral density (vBMD) and bone geometry in male obese adolescents (ObAs) in overlap with changes in bone maturation, muscle mass and force development, and circulating sex steroids and IGF-I. We hypothesized that changes in bone parameters are more evident at the weight-bearing site and that changes in serum estradiol are most prominent. DESIGN, SETTING, AND PARTICIPANTS We recruited 51 male ObAs (10-19 years) at the entry of a residential weight-loss program and 51 healthy age-matched and 51 bone-age-matched controls. MAIN OUTCOME MEASURES vBMD and geometric bone parameters, as well as muscle and fat area were studied at the forearm and lower leg by peripheral quantitative computed tomography. Muscle force was studied by jumping mechanography. RESULTS In addition to an advanced bone maturation, differences in trabecular bone parameters (higher vBMD and larger trabecular area) and cortical bone geometry (larger cortical area and periosteal and endosteal circumference) were observed in ObAs both at the radius and tibia at different pubertal stages. After matching for bone age, all differences at the tibia, but only the difference in trabecular vBMD at the radius, remained significant. Larger muscle area and higher maximal force were found in ObAs compared with controls, as well as higher circulating free estrogen, but similar free testosterone and IGF-I levels. CONCLUSIONS ObAs have larger and stronger bones at both the forearm and lower leg. The observed differences in bone parameters can be explained by a combination of advanced bone maturation, higher estrogen exposure, and greater mechanical loading resulting from a higher muscle mass and strength.

Sex Steroids in Relation to Sexual and Skeletal Maturation in Obese Male Adolescents

BACKGROUND Childhood obesity is associated with an accelerated skeletal maturation. However, data concerning pubertal development and sex steroid levels in obese adolescents are scarce and contrasting. OBJECTIVES To study sex steroids in relation to sexual and skeletal maturation and to serum prostate specific antigen (PSA), as a marker of androgen activity, in obese boys from early to late adolescence. METHODS Ninety obese boys (aged 10-19 y) at the start of a residential obesity treatment program and 90 age-matched controls were studied cross-sectionally. Pubertal status was assessed according to the Tanner method. Skeletal age was determined by an x-ray of the left hand. Morning concentrations of total testosterone (TT) and estradiol (E2) were measured by liquid chromatography-tandem mass spectrometry, free T (FT) was measured by equilibrium dialysis, and LH, FSH, SHBG, and PSA were measured by immunoassays. RESULTS Genital staging was comparable between the obese and nonobese groups, whereas skeletal bone advancement (mean, 1 y) was present in early and midadolescence in the obese males. Although both median SHBG and TT concentrations were significantly (P < .001) lower in obese subjects during mid and late puberty, median FT, LH, FSH, and PSA levels were comparable to those of controls. In contrast, serum E2 concentrations were significantly (P < .001) higher in the obese group at all pubertal stages. CONCLUSION Obese boys have lower circulating SHBG and TT, but similar FT concentrations during mid and late puberty in parallel with a normal pubertal progression and serum PSA levels. Our data indicate that in obese boys, serum FT concentration is a better marker of androgen activity than TT. On the other hand, skeletal maturation and E2 were increased from the beginning of puberty, suggesting a significant contribution of hyperestrogenemia in the advancement of skeletal maturation in obese boys.

Diagnostic value of MRI features of sacroiliitis in juvenile spondyloarthritis.

AIM To determine the diagnostic utility of magnetic resonance imaging (MRI) features of sacroiliitis in juvenile spondyloarthritis (JSpA). MATERIALS AND METHODS This was a prospective study of 80 paediatric patients who underwent MRI of the sacroiliac joints that were clinically suspected to have sacroiliitis. The prevalence of MRI features of active and structural lesions of sacroiliitis was recorded. Patients were classified according to the International League of Association for Rheumatology criteria. The MRI findings were compared to the final clinical diagnosis. RESULTS Sacroiliitis was seen in 25/80 (31%) patients. MRI showed active inflammation in 23 patients (29%): synovial enhancement (28%), high short tau inversion recovery (STIR)-signal in the joint space (29%), bone marrow oedema (BMO; 20%), and capsulitis (8%). Structural changes were present in 14 patients (18%): erosion (14%), fat infiltration (13%), sclerosis (8%), and ankylosis (1%). Of all MRI features, ankylosis (100%), capsulitis (98%), BMO (96%), and erosion (96%) had the highest specificity for JSpA; global diagnostic impression (55%) and synovial enhancement (52%) were the MRI features with the highest sensitivity. The likelihood ratios (LR+) for diagnosis of JSpA were high for BMO (10.5), capsulitis (7.5), global diagnostic impression (6.9), and erosions (6.75), but greater for BMO concomitant with synovial enhancement (LR+ 19.5) and for erosion concomitant with BMO (LR+ 12) or synovial enhancement (LR+ 13.5). CONCLUSION There are multiple features of active inflammation and structural damage visible at MRI of the sacroiliac joints that can provide a specific diagnosis of JSpA when present in children with suspected sacroiliitis. Synovial enhancement is the MRI feature with the highest sensitivity for JSpA. If BMO is seen concomitant with synovial enhancement or erosion, the diagnosis of JSpA is very likely. Ankylosis, capsulitis, bone marrow oedema, and erosion all have a high specificity for JSpA. Absence of MRI findings of sacroiliitis does not exclude the diagnosis of JSpA.

ASAS definition for sacroiliitis on MRI in SpA: applicable to children?

BackgroundThe Assessment of Spondyloarthritis International Society (ASAS) definition for a ‘positive’ Magnetic Resonance Imaging (MRI) for sacroiliitis is well studied and validated in adults, but studies about the value of this definition in children are lacking. The aim of this study is to evaluate whether the adult ASAS definition of a positive MRI of the sacroiliac joints can be applied to children with a clinical suspicion of Juvenile Spondyloarthritis (JSpA).MethodsTwo pediatric musculoskeletal radiologists blinded to clinical data independently retrospectively reviewed sacroiliac (SI) joint MRI in 109 children suspected of sacroiliitis. They recorded global impression (sacroiliitis yes/no) and whether the adult ASAS definition for sacroiliitis was met at each joint. This was compared to gold-standard clinical diagnosis of JSpA. Additionally, MRI were scored according to’adapted’ ASAS definitions including other features of sacroiliitis on MRI.ResultsJSpA was diagnosed clinically in 47/109 (43%) patients. On MRI, sacroiliitis was diagnosed by global assessment in 30/109 patients, of whom 14 also fulfilled ASAS criteria. No patients with negative global assessment for sacroiliitis fulfilled ASAS criteria. Sensitivity (SN) for JSpA was higher for global assessment (SN = 49%) than for ASAS definition (SN = 26%), but the ASAS definition was more specific (SP = 97% vs. 89%). Modifying adult ASAS criteria to allow bone marrow edema (BME) lesions seen on only one slice, synovitis or capsulitis, increased SN to 36%, 32% and 32% respectively, only slightly lowering SP. Including structural lesions increased SN to 28%, but lowered specificity to 95%.ConclusionThe adult ASAS definition for sacroiliitis has low sensitivity in children. A pediatric-specific definition of MRI-positive sacroiliitis including BME lesions visible on one slice only, synovitis and/or capsulitis may improve diagnostic utility, and increase relevance of MRI in pediatric rheumatology practice.

Diagnostic value of MRI of the sacroiliac joints in juvenile spondyloarthritis

Early diagnosis of spondyloarthritis (SpA) is becoming more important as new medical treatment options have become available to treat inflammation and delay progression of the disease. Increasingly, magnetic resonance imaging (MRI) of the sacroiliac joints is obtained for early detection of inflammatory changes, as it shows active inflammatory and structural lesions of sacroiliitis long before radiographic changes become evident. MRI of the sacroiliac joints in children is a useful tool for suspected juvenile spondyloarthritis (JSpA), even though it is not yet included in the current pediatric classification systems. Recognizing MRI features of pediatric sacroiliitis is a challenge. As most radiologists are not familiar with the normal MRI appearance of the pediatric sacroiliac joint, clear definitions are mandatory. Actually, the adult Assessment of Spondyloarthritis International Society (ASAS) definition for sacroiliitis needs some adaptations for children. A proposal for a possible pediatric-specific definition for active sacroiliitis on MRI is presented in this review. Furthermore, MRI without contrast administration is sufficient to identify bone marrow edema (BME), capsulitis, and retroarticular enthesitis as features of active sacroiliitis in JSpA. In selected cases, when high short tau inversion recovery (STIR) signal in the joint is the only finding, gadolinium-enhanced images may help to confirm the presence of synovitis. Lastly, we found a high correlation between pelvic enthesitis and sacroiliitis on MRI of the sacroiliac joints in children. As pelvic enthesitis indicates active inflammation, it may play a role in assessment of the inflammatory status. Therefore, it should be carefully sought and noted when examining MRI of the sacroiliac joints in children.

Update on Pediatric Hip Imaging

Abstract Hip disorders are common in children. Prompt diagnosis and treatment are important because of the potential complications. Symptoms are frequently nonspecific, and clinical examination can be difficult and unreliable, especially in smaller children. Therefore, imaging can be valuable. Radiography and ultrasound remain the initial imaging modalities of choice. Increasingly, magnetic resonance imaging is obtained for assessing the pediatric hip, although the long imaging time and need for sedation may limit its use in daily practice. Because of the exposure to ionizing radiation, the use of computed tomography and bone scintigraphy in children is limited to selected cases. Pediatric hip pathology varies depending on patient age. This article provides an overview of common hip pathologies in children including congenital and developmental pathologies, trauma, infectious processes, inflammatory disease, and neoplasm. The age of the child, history, and clinical examination are essential to narrow down the differential diagnosis and subsequent selection of the appropriate imaging modality.

‘Backfill’ of the sacroiliac joint space in spondlyloarthritis

Three patients of the outpatient rheumatology clinic of our hospital with inflammatory type low back pain suggestive for spondyloarthritis were referred for MRI of the sacroiliac joints. MRI showed high T1 signal within the SI joint (arrows) in all three patients, filling the extended erosions of the iliac bone in two patients (Figs. A and B) whereas a more petechial appearance in the sacroiliac joint space was seen in the third patient (Fig. C). The diagnosis of ‘backfill’ of erosions and of the sacroiliac joint space in spondyloarthritis was made.

Anal Canal Duplication in an 11-Year-Old-Child

Anal canal duplication (ACD) is the least frequent digestive duplication. Symptoms are often absent but tend to increase with age. Recognition is, however, important as almost half of the patients with ACD have concomitant malformations. We present the clinical history of an eleven-year-old girl with ACD followed by a review of symptoms, diagnosis, treatment, and prognosis based on all the reported cases in English literature.