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Heuberer P.,St. Vincent Hospital Vienna | Kranzl A.,Orthopaedic Hospital Speising | Laky B.,St. Vincent Hospital Vienna | Anderl W.,St. Vincent Hospital Vienna | Wurnig C.,Orthopaedic Hospital Speising
Archives of Orthopaedic and Trauma Surgery | Year: 2015

Introduction: Restoring optimal strength and biomechanics of a pathologic shoulder knowledge of activity patterns of healthy glenohumeral muscles is mandatory. Yet, data on normal shoulder muscle activity are not always conclusive. The study was undertaken (a) to evaluate muscle activity patterns in the healthy shoulder using surface and fine-wire electromyography (EMG), and (b) to assess method’s suitability in the clinical setting especially regarding painfulness and practicability.Materials and methods: Surface and fine-wire EMG was performed on 11 healthy subjects (2f/9m, Ø age 28 years) to assess 14 muscles including rotator cuff muscles during 8 planar standardised shoulder movements (abduction, forward flexion, internal and external rotation in neutral, 45° and 90° abduction). Pain was assessed using the visual analogue scale before testing, after inserting the fine-wire electrodes, after maximal voluntary contraction, before and after exercises, and after electrode removal.Results: The most important finding regarding EMG activity patterns in the healthy shoulder was that the subscapularis activity was found to play a major role in abduction and forward flexion. Furthermore, this study was able to show that EMG measurements, especially fine-wire EMG, is prone to high failure rates (up to 32 %); however, pain was not a limiting factor.Conclusion: The present study (1) revealed a new insight, especially finding the subscapularis activity playing a major role in abduction and forward flexion of the healthy shoulder; and (2) motion analysis system and the use of fine-wire electrodes were prone to failure; however, pain was not a limiting factor.Level of evidence: Basic Science, Electrodiagnostic Study. © 2015, Springer-Verlag Berlin Heidelberg.

Valentinitsch A.,Medical University of Vienna | Patsch J.M.,Medical University of Vienna | Patsch J.M.,University of California at San Francisco | Deutschmann J.,Medical University of Vienna | And 5 more authors.
Bone | Year: 2012

The quantitative assessment of metabolic bone diseases relies on tissue properties such as bone mineral density (BMD) and bone microarchitecture. In spite of an increasing number of publications using high-resolution peripheral quantitative computed-tomography (HR-pQCT), the accurate and reproducible separation of cortical and trabecular bone remains challenging. In this paper, we present a novel, fully automated, threshold-independent technique for the segmentation of cortical and trabecular bone in HR-pQCT scans. This novel post-processing method is based on modeling appearance characteristics from manually annotated cases. In our experiments the algorithm automatically selected texture features with high differentiating power and trained a classifier to separate cortical and trabecular bone. From this mask, cortical thickness and tissue volume could be calculated with high accuracy. The overlap between the proposed threshold-independent segmentation tool (TIST) and manual contouring was 0.904 ± 0.045 (Dice coefficient). In our experiments, TIST obtained higher overall accuracy in our measurements than other techniques. © 2012.

Patsch J.M.,Center for Pathophysiology | Patsch J.M.,Medical University of Vienna | Kohler T.,B cube AG | Berzlanovich A.,Medical University of Vienna | And 5 more authors.
Journal of Bone and Mineral Research | Year: 2011

Male idiopathic osteoporosis (MIO) is a metabolic bone disease that is characterized by low bone mass, microstructural alterations, and increased fracture risk in otherwise healthy men. Although the detailed pathophysiology of MIO has yet to be clarified, evidence increasingly suggests an osteoblastic defect as the underlying cause. In this study we tested the hypothesis that the expression profile of certain osteoblastic or osteoblast-related genes (ie, WNT10B, RUNX2, Osterix, Osteocalcin, SOST, RANKL, and OPG) is different in iliac crest biopsies of MIO patients when compared with healthy controls. Furthermore, we investigated the relation of local gene expression characteristics with histomorphometric, microstructural, and clinical features. Following written informed consent and diligent clinical patient characterization, iliac crest biopsies were performed in nine men. While RNA extraction, reverse-transcription, and real-time polymerase chain reactions (PCRs) were performed on one biopsy, a second biopsy of each patient was submitted for histomorphometry and micro-computed tomography (μCT). Age-matched bone samples from forensic autopsies served as controls. MIO patients displayed significantly reduced WNT10B, RUNX2, RANKL, and SOST expression. Performing μCT for the first time in MIO biopsies, we found significant decreases in trabecular number and connectivity density. Trabecular separation was increased significantly, but trabecular thickness was similar in both groups. Histomorphometry revealed decreased BV/TV and osteoid volume and fewer osteoclasts in MIO. By providing evidence for reduced local WNT10B, RUNX2, and RANKL gene expression and histomorphometric low turnover, our data support the osteoblast dysfunction model discussed for MIO. Further, MIO seems to lead to a different microstructural pathology than age-related bone loss. Copyright © 2011 American Society for Bone and Mineral Research.

Muschitz C.,Medical University of Vienna | Kocijan R.,Medical University of Vienna | Fahrleitner-Pammer A.,Medical University of Graz | Pavo I.,University of Szeged | And 4 more authors.
Journal of Bone and Mineral Research | Year: 2014

Nine month teriparatide (TPTD) monotherapy followed by co-administration of raloxifene (RAL) or alendronate (ALN) for another nine 9 months resulted in incremental bone mineral density (BMD) increase. The aim of this study was to investigate the effects of continued antiresorptive treatments for 12 months in the extension phase. Postmenopausal women (n=125) with severe osteoporosis on ongoing TPTD treatment for 9 months were randomized into three open-label groups for another 9 months: ALN (70 mg/week, n=41), RAL (60mg/d, n=37) in addition to TPTD or no additional medication (n=47) except Ca and vitamin D. After discontinuation of TPTD the respective antiresorptives were continued for a further 12 months, while patients in the TPTD monotherapy group received Ca and vitamin D. Amino-terminal propeptide of type I procollagen (P1NP) and cross-linked C-telopeptide (CTX), areal and volumetric BMD at the lumbar spine (LS) and hip were assessed. ALN resulted in continued BMD increase in LS (4.3±1.5%; mean±SD), femoral neck (4.2±1.6%) and total hip (4±1.6%; p<0.001 for all), while RAL was only effective at the LS (2.4±1.7%, p<0.001) but no changes at the femoral neck (0.4±1.4%) or total hip (-0.8±1.5%) were observed. Cortical bone only increased in the ALN group (femoral neck 6.7±2.7% and -1.3±2.5%; total hip 13.8±2.9% and -2.3±2.5% for ALN and RAL, p<0.001 for all; respectively). Analyzing the entire 30 months of therapy, the ALN group revealed the largest BMD increase in all regions. Our results suggest that the addition of ALN to ongoing TPTD and continuing ALN after TPTD was stopped may be beneficial for patients in terms of areal and volumetric BMD increase. Further research is warranted to determine the optimal timing of the initiation of the combination treatment, the respective antiresorptive medication and the potential benefit of this BMD increase regarding fracture prevention. © 2014 American Society for Bone and Mineral Research © 2014 American Society for Bone and Mineral Research.

Fratzl-Zelman N.,Ludwig Boltzmann Research Institute | Roschger P.,Ludwig Boltzmann Research Institute | Misof B.M.,Ludwig Boltzmann Research Institute | Nawrot-Wawrzyniak K.,Ludwig Boltzmann Research Institute | And 6 more authors.
Calcified Tissue International | Year: 2011

The pathogenesis of primary osteoporosis in younger individuals is still elusive. An important determinant of the biomechanical competence of bone is its material quality. In this retrospective study we evaluated bone material quality based on quantitative backscattered electron imaging to assess bone mineralization density distribution (BMDD) in bone biopsies of 25 male patients (aged 18-61 years) who sustained fragility fractures but were otherwise healthy. BMDD of cancellous bone was compared with previously established adult reference data. Complementary information was obtained by bone histomorphometry. The histomorphometric results showed a paucity of osteoblasts and osteoclasts on the bone surface in the majority of patients. BMDD revealed a significant shift to lower mineralization densities for cancellous bone values: CaMean (weighted mean Ca content, -5.9%), CaPeak (mode of the BMDD, -5.6%), and CaHigh (portion of fully mineralized bone, -76.8%) were decreased compared to normative reference; CaWidth (heterogeneity in mineralization, +18.5%) and CaLow (portion of low mineralized bone, +68.8; all P < 0.001) were significantly increased. The shift toward lower mineral content in the bone matrix in combination with reduced indices of bone formation and bone resorption suggests an inherent mineralization defect leading to undermineralized bone matrix, which might contribute to the susceptibility to fragility fractures of the patients. The alteration in bone material might be related to osteoblastic dysfunction and seems fundamentally different from that in high bone turnover osteoporosis with a negative bone balance. © 2011 Springer Science+Business Media, LLC.

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