10 research outputs found
Fractures in myelomeningocele
BACKGROUND: In patients with myelomeningocele (MMC), a high number of fractures occur in the paralyzed extremities, affecting mobility and independence. The aims of this retrospective cross-sectional study are to determine the frequency of fractures in our patient cohort and to identify trends and risk factors relevant for such fractures. MATERIALS AND METHODS: Between March 1988 and June 2005, 862 patients with MMC were treated at our hospital. The medical records, surgery reports, and X-rays from these patients were evaluated. RESULTS: During the study period, 11% of the patients (n = 92) suffered one or more fractures. Risk analysis showed that patients with MMC and thoracic-level paralysis had a sixfold higher risk of fracture compared with those with sacral-level paralysis. Femoral-neck z-scores measured by dual-energy X-ray absorptiometry (DEXA) differed significantly according to the level of neurological impairment, with lower z-scores in children with a higher level of lesion. Furthermore, the rate of epiphyseal separation increased noticeably after cast immobilization. Mainly patients who could walk relatively well were affected. CONCLUSIONS: Patients with thoracic-level paralysis represent a group with high fracture risk. According to these results, fracture and epiphyseal injury in patients with MMC should be treated by plaster immobilization. The duration of immobilization should be kept to a minimum (<4 weeks) because of increased risk of secondary fractures. Alternatively, patients with refractures can be treated by surgery, when nonoperative treatment has failed
Radio source evolution on galactic scales
There is mounting evidence that mechanical radio source feedback is important
in galaxy evolution and in order to quantify this feedback, detailed models of
radio source evolution are required. We present an extension to current
analytic models that encompasses young radio sources with physical sizes on
sub-kiloparsec scales. This work builds on an existing young source dynamical
model to include radiative losses in a flat environment, and as such, is the
best physically-motivated Compact Symmetric Object model to date. Results
predict that young radio sources experience significant radiative loss on
length scales and spectral scales consistent with observed Compact
Steep-Spectrum sources. We include full expressions for the transition to
self-similar expansion and present this complete model of radio source
evolution from first cocoon formation to end of source lifetime around 10^8
years within the context of a simplified King profile external atmosphere.Comment: 17 pages, 2 tables, 11 figures, Accepted for publication by MNRA