Subchondral involvement in osteonecrosis of the femoral head: insight on local composition, microstructure and vascularization.

OBJECTIVE: To determine changes of subchondral bone composition, micro-structure, bone marrow adiposity and micro-vascular perfusion in end-stage osteonecrosis of the femoral head (ONFH) compared to osteoarthritis (OA) using a combined in vivo and ex vivo approach. DESIGN: Male patients up to 70 years old referred for total hip replacement surgery for end-stage ONFH were included (n = 14). Fifteen patients with OA were controls. Pre-operative MRI was used to assess bone perfusion (dynamic contrast-enhanced (DCE) sequences) and marrow fat content (chemical shift imaging). Three distinct zones of femoral head subchondral bone - necrotic, sclerotic, distant - were compared between groups. After surgery, plugs were sampled in these zones and Raman spectroscopy was applied to characterize bone mineral and organic components (old and newly-formed), and contrast-enhanced micro-computed tomography (CE-µCT) to determine bone micro-structural parameters and volume of bone marrow adipocytes, using conventional 2D histology as a reference. RESULTS: In the necrotic zone of ONFH patients compared to OA patients: 1) the subchondral plate did not exhibit significant changes in composition nor structure; 2) the volume fraction of subchondral trabecular bone was significantly lower; 3) type-B carbonate substitution was less pronounced, 4) collagen maturity was more pronounced; and 5) bone marrow adipocytes were significantly depleted. The sclerotic zone from the ONFH group showed greater trabecular thickness, and higher DCE-MRI AUC and Ktrans. Volume fraction of subchondral bone, trabecular number, and Kep were significantly lower in the distant zone of the ONFH group. CONCLUSIONS: This study demonstrated alterations of subchondral bone microstructure, composition, perfusion and/or adipose content in all zones of the femoral head.

[Implementation of a multi-interventional approach to improve medication safety in older hospitalized patients: Feasibility and impact on 30-day rehospitalization rate]. / Mise en place d'une procédure multi-interventionnelle de prise en charge médicamenteuse chez la personne âgée hospitalisée : faisabilité et efficacité sur la réhospitalisation à 30jours.

BACKGROUND: The impact of a multi-interventional approach for medication safety (MIMS) on rehospitalization rate have been inconstant in the literature. This would be due to difficulty in implementing the interventions and insufficient information transmission at discharge. The purpose of this study was to determine the effect of a MIMS on the 30-day rehospitalization rate after discharge from an acute geriatric unit (AGU). METHOD: This was a single-center interventional randomized controlled trial that included patients hospitalized in an AGU and were at least 75 years old. The intervention group benefited from a MIMS including medication reconciliation at admission and at discharge, medication review, and standardized transmission of hospital's medication changes sent to community practitioners (general practitioners and pharmacists) at discharge. The control group benefited from the usual approach applied in the AGU. RESULTS: One hundred nine patients (mean age 87,5±6,1 years) were included. At intention-totreat analysis, the rehospitalization rate was 30% in the intervention group and 15,2% in the control group. The difference was non-significant before and after adjustments (P=0,27 and 0,28 respectively). However, the intervention protocol was not effectively completed in 40% of patients in the intervention group and no intervention was performed in 10%. CONCLUSION: The implementation of a MIMS in an AGU showed a non-significant decrease in the number of rehospitalizations. Other indicators should be analysed, such as the reason for rehospitalisation or the maintenance of treatment at 30 days.

Dual-energy computed tomography in calcium pyrophosphate deposition: initial clinical experience.

OBJECTIVE: To determine the dual-energy computed tomography (DECT) attenuation properties of meniscal calcifications in calcium pyrophosphate deposition (CPPD) in vivo, and assess whether DECT was able to discriminate meniscal CPP deposits from calcium hydroxyapatite (HA) in subchondral and trabecular bone. METHOD: Patients with clinical suspicion of crystal-related arthropathy (gout and/or CPPD) and knee DECT scans were retrospectively assigned to CPPD (n = 19) or control (n = 21) groups depending on the presence/absence of chondrocalcinosis on DECT. Two observers drew standardized regions of interest (ROI) in meniscal calcifications, non-calcified menisci, as well as subchondral and trabecular bone. Five DECT parameters were obtained: CT numbers (HU) at 80 and 140 kV, dual-energy index (DEI), electron density (ρe), and effective atomic number (Zeff). The four different knee structures were compared within/between patients and controls using linear mixed models, adjusting for confounders. RESULTS: Meniscal calcifications (n = 89) in CPPD patients had mean ± SD CT numbers at 80 and 140 kV of 257 ± 64 and 201 ± 48 HU, respectively; with a DEI of 0.023 ± 0.007, and ρe and Zeff of 140 ± 35 and 8.8 ± 0.3, respectively. Meniscal CPP deposits were readily distinguished from calcium HA in subchondral and trabecular bone (p ≤ 0.001), except at 80 kV separately (p = 0.74). Zeff and ρe both significantly differed between CPP deposits and calcium HA in subchondral and trabecular bone (p < 0.0001). CONCLUSION: This proof-of-concept study shows that DECT has the potential to discriminate meniscal CPP deposits from calcium HA in subchondral and trabecular bone in vivo, paving the way for the non-invasive biochemical signature assessment of intra- and juxta-articular calcium crystal deposits.

Preoperative assessment of idiopathic scoliosis in adolescent and young adult with three-dimensional T2-weighted spin-echo MRI.

PURPOSE: To compare tridimensional (3D) T2-weighted spin-echo MRI and CT for minimal pedicle width measurements in the preoperative assessment of adolescent idiopathic scoliosis (AIS) in adolescent and young patients. MATERIALS AND METHODS: A total of 22 adolescents/young patients suffering from AIS were retrospectively included. There were 18 females and 4 males with a mean age of 15.3±2.3 (SD) years (range: 11-21years). Preoperative lumbar spine MRI and CT examinations of the 22 patients were reviewed by two independent readers who measured the minimal width of 259 pedicles. Inter-reader agreement for CT and MRI was assessed using intra-class correlation coefficient (ICC). Intra-reader agreement and relative differences in measurements between MRI and CT were also assessed for each reader. RESULTS: Inter-reader agreement was excellent (ICC≥0.8) for both CT and MRI. Relative differences in measurements between CT and MRI was 10.3% for reader 1 and 9.4% for reader 2. CONCLUSION: 3D T2-weighted spin-echo MRI underestimates minimal pedicle width by only 9.4 - 10.3% compared to CT. 3D T2-weighted MRI appears as a valuable alternative to CT for preoperative measurements of vertebral pedicles in AIS.

Comparison between enhanced susceptibility-weighted angiography and time of flight sequences in the detection of arterial occlusion in acute ischemic stroke.

PURPOSE: Optimizing the MRI protocol in acute ischemic stroke remains a challenging issue. In this field, susceptibility-weighted sequences have proved their superiority over T2*. Besides the strengthened susceptibility effect, enhanced susceptibility-weighted angiography (eSWAN) sequence provides also a time-of-flight (TOF) effect, allowing the exploration of the intracranial arterial circulation. The objective of our study was to compare eSWAN and 3D TOF, considered as the reference, in the detection of arterial occlusion in acute stroke. METHODS: Patients who underwent MRI between March and July 2014 for suspected acute stroke with an acute ischemic lesion on diffusion-weighted imaging (DWI) were prospectively included in this study. eSWAN and TOF images were analyzed under double-blind conditions by a junior radiologist and a senior neuroradiologist for the detection of arterial occlusion. eSWAN images were assessed in order to estimate the inter-observer agreement. After a consensus, eSWAN and TOF data were compared to calculate inter-modality agreement. RESULTS: Thirty-four patients were included. Inter-observer agreement was excellent (kappa: 0.96) for eSWAN detection of occlusion. After consensus, comparison between TOF and eSWAN showed substantial agreement (kappa: 0.71). eSWAN provided better detection of distal occlusions, but poorer performance for detection of siphon occlusions. CONCLUSIONS: Shortest echoes eSWAN images enabled detection of arterial occlusion with substantial agreement with TOF images. The susceptibility vessel sign associated with the TOF effect improved the identification of distal occlusions. In acute stroke protocol, eSWAN may represent a valuable alternative to T2* and TOF sequences.

[Prevalence and risk factors of vitamin D deficiency in healthy adults aged 18-65 years in northern France]. / Prévalence et facteurs de risque de l'insuffisance en vitamine D chez l'adulte sain entre 18 et 65 ans dans le Nord de la France.

INTRODUCTION: Screening and treatment of vitamin D deficiency are the subject of several publications. A lot of recognized risk factors have increased steadily, leading to the recognition of populations at risk. Despite their exposure to the same risk factors as other populations, there are no recommendations concerning healthy adults, a population rarely studied. To determine the prevalence of vitamin D deficiency in healthy adults aged 18-65 years residing in northern France and to search for correlated risk factors at 20ng/mL. METHODS: Descriptive, prospective, single-center epidemiology study; 297 subjects studied in January and February, 2015. The prevalence of vitamin D deficiency was determined at three serum levels (10, 20 and 30ng/mL). A self-administered questionnaire was used to identify risk factors correlated with vitamin D deficiency (<20ng/mL). RESULTS: 25(OH) vitamin D serum level was strictly less than 30ng/mL in 92.3% of participants, strictly less than 20ng/mL in 75.1%, and strictly less than 10ng/mL in 27.9%. Male gender (P=0.0001), age (P=0.012), no vacations in sunny regions (P=0.03) and no intake of prescription vitamin supplements (P=0.002) were independent risk factors of vitamin D deficiency (<20ng/mL). CONCLUSION: In our population, vitamin D deficiency is frequent in healthy adults and is often severe. A systematic screening and supplementation strategy would limit the development of many pathological complications and ensure good nutritional balance.