Large femoral bone loss after hip revision using the uncemented proximally porous-coated Bi-Metric prosthesis: 22 hips followed for a mean of 6 years

Background and purpose Periprosthetic bone loss after uncemented femoral hip revision is a matter of concern. We have used a proximally porous- and hydroxyapatite-coated prosthesis (Bi-Metric) in revision since 1989 and now we report the bone changes. This prosthesis is intended to distribute the forces more evenly and to avoid proximal femoral unloading.Methods 22 patients were unilaterally reoperated because of aseptic loosening. Only patients with a healthy contralateral hip were included. Mean age at revision was 69 (55–80) years. Bone defects were graded by Gustilo-Pasternak and Endo-Klinik classifications. Clinical assessment was performed with Harris hip score. We used radiographs and dual-energy X-ray absorptiometry to evaluate migration, femoral remodeling, and bone mineral density after 72 (30–158) months.Results The mean Harris hip score was 74 (30–100) points at follow-up. Mild thigh discomfort was present in 1 patient and moderate thigh pain in 3 patients. There was no loosening or subsidence. Osteolysis seen at revision had diminished in 19 of the 22 hips at follow-up. We noted a large reduction in bone mineral density. It was most pronounced in Gruen regions 1, 2, 6, and 7.Interpretation Revision with this stem is a reliable procedure; however, we noted a large degree of proximal bone loss that could lead to later mechanical complications or fractures.     

Surgical treatment for acute symptomatic refractory status epilepticus: a case report

A previously healthy 10-year-old boy developed generalized convulsive status epilepticus following a mild febrile illness. Prolonged video-electroencephalographic monitoring revealed frequent right hemispheric electrographic seizures that were refractory to high-dose suppressive therapy. Ictal and interictal magnetoencephalography demonstrated dipole sources projecting from the right mesial temporal region. Diffusion-weighted imaging showed restricted diffusion involving the right hippocampus. Right anterior temporal lobectomy resulted in cessation of status epilepticus. At 1-year follow-up, he attends regular school and has infrequent nocturnal seizures on chronic antiepileptic drug therapy. Surgical treatment should be considered to stop status epilepticus in selected cases of acute symptomatic refractory status epilepticus with no preexisting epilepsy or magnetic resonance imaging abnormalities and may avoid the complications associated with prolonged high-dose suppressive therapy.     

The brain in children: is contrast enhancement really needed after obtaining normal unenhanced CT results?

PURPOSE: To retrospectively determine and compare the sensitivity and specificity of unenhanced and contrast material-enhanced computed tomography (CT) (reference standard) in the diagnosis of brain abnormalities and to evaluate any change in diagnosis that resulted from the contrast-enhanced study. MATERIALS AND METHODS: This study was approved by the local research ethics board; the requirement for informed consent was waived. The authors reviewed the unenhanced and contrast-enhanced CT scans of the brain obtained in 353 children for indications other than trauma. There were 196 boys and 157 girls aged 0 months to 17.8 years. Scans were read independently by two pediatric neuroradiologists who were blinded to clinical information. The diagnosis for each scan was recorded according to the anatomic section (supratentorial, infratentorial, ventricles, and skull). The final diagnosis was classified as normal, abnormal, or equivocal. kappa Statistics, with 95% confidence intervals, were reported, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: Interreader agreement for different anatomic regions varied between good (kappa coefficient, 0.63) and very good (kappa coefficient, 0.88) for unenhanced and contrast-enhanced scans. Sensitivity, specificity, positive predictive value, and negative predictive value for unenhanced scans were 97%, 89%, 87%, and 97%, respectively. The use of contrast material led to a change in the original normal or equivocal diagnosis to an abnormal diagnosis for only five (2.7%) of the 183 normal unenhanced scans. CONCLUSION: Unenhanced CT of developing brains has high sensitivity and specificity in the diagnosis of pathologic findings. The use of intravenous contrast material after unenhanced CT of the brain in children did not change the diagnosis frequently.     

Injection drug use among street-involved youth in a Canadian setting

Background  

Street-involved youth contend with an array of health and social challenges, including elevated rates of blood-borne infections and mortality. In addition, there has been growing concern regarding high-risk drug use among street-involved youth, in particular injection drug use. We undertook this study to examine the prevalence of injection drug use and associated risks among street-involved youth in Vancouver, Canada.     

Unstable housing and hepatitis C incidence among injection drug users in a Canadian setting

Background  

There has emerged growing recognition of the link between housing and health. Since Vancouver, Canada has had increasing concerns with homelessness brought about by urban renewal in the lead-up to the 2010 Winter Olympic Games, we evaluated hepatitis C virus (HCV) incidence among injection drug users (IDU) with and without stable housing.     

A bimodal association of vitamin D levels and vascular disease in children on dialysis

In addition to its classical role in calcium-phosphate homeostasis, vitamin D has anti-inflammatory effects that may influence vascular disease. This study examined the impact of vitamin D levels on the vascular phenotype in 61 children who had been on dialysis for >or=3 mo and in 40 age-matched control subjects. All dialysis patients were prescribed daily oral 1-alpha hydroxyvitamin D(3). 92% of patients were deficient in 25-hydroxyvitamin D [25(OH)D]. 1,25-dihydroxyvitamin D [1,25(OH)(2)D] levels were low in 36% and high in 11% of patients. There was a weak correlation between 1 alpha-hydroxyvitamin D(3) dosage and 1,25(OH)(2)D levels. Both carotid intima-media thickness and calcification scores showed a U-shaped distribution across 1,25(OH)(2)D levels: patients with both low and high 1,25(OH)(2)D had significantly greater carotid intima-media thickness (P < 0.0001) and calcification (P = 0.0002) than those with normal levels. Low 1,25(OH)(2)D levels were associated with higher high-sensitivity C-reactive protein (P < 0.0001). Calcification was most frequently observed in patients with the lowest 1,25(OH)(2)D and the highest high-sensitivity C-reactive protein. In contrast, 25(OH)D levels did not correlate with any vascular measure. In conclusion, both low and high 1,25(OH)(2)D levels are associated with adverse morphologic changes in large arteries, and this may be mediated through the effects of 1,25(OH)(2)D on calcium-phosphate homeostasis and inflammation. For optimization of strategies to protect the vasculature of dialysis patients, careful monitoring of 1,25(OH)(2)D levels may be required.