TY - JOUR A1 - Xin, L. A1 - Bungartz, M. A1 - Maenz, S. A1 - Horbert, V. A1 - Hennig, M. A1 - Illerhaus, Bernhard A1 - Günster, Jens A1 - Bossert, J. A1 - Bischoff, S. A1 - Borowski, J. A1 - Schubert, H. A1 - Jandt, K. A1 - Kunisch, E. A1 - Kinne, R. A1 - Brinkmann, O. T1 - Decreased extrusion of calcium phosphate cement versus high viscosity PMMA cement into spongious bone marrow—an ex vivo and in vivo study in sheep vertebrae N2 - Vertebroplasty or kyphoplasty of osteoporotic vertebral fractures bears the risk of pulmonary cement embolism (3.5%–23%) caused by leakage of commonly applied acrylic polymethylmethacrylate (PMMA) cement to spongious bone marrow or outside of the vertebrae. Ultraviscous cement and specific augmentation systems have been developed to reduce such adverse effects. Rapidly setting, resorbable, physiological calcium phosphate cement (CPC) may also represent a suitable alternative. PURPOSE: This study aimed to compare the intravertebral extrusion of CPC and PMMA cement in an ex vivo and in vivo study in sheep. STUDY DESIGN/SETTING: A prospective experimental animal study was carried out. METHODS: Defects (diameter 5 mm; 15 mm depth) were created by a ventrolateral percutane-ous approach in lumbar vertebrae of female Merino sheep (2–4 years) either ex vivo (n = 17) or in vivo (n = 6), and injected with: (1) CPC (L3); (2) CPC reinforced with 10% poly(l-lactide-co-glycolide) (PLGA) fibers (L4); or (3) PMMA cement (L5; Kyphon HV-R). Controls were untouched (L1) or empty defects (L2). The effects of the cement injections were assessed in vivo by blood gas analysis and ex vivo by computed tomography (CT), micro-CT (voxel size: 67 µm), histology, and biomechanical testing. KW - Bone marrow extrusion KW - Brushite-forming calcium phosphate cement KW - Cement injection KW - Ex vivo KW - High- viscosity PMMA cement KW - In vivo KW - Large animal model KW - Sheep KW - Vertebroplasty PY - 2016 U6 - https://doi.org/10.1016/j.spinee.2016.07.529 SN - 1529-9430 SN - 1878-1632 VL - 16 IS - 12 SP - 1468 EP - 1477 PB - Elsevier Inc. AN - OPUS4-38058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bungartz, M. A1 - Maenz, S. A1 - Kunisch, E. A1 - Horbert, V. A1 - Xin, L. A1 - Gunella, F. A1 - Mika, J. A1 - Borowski, J. A1 - Bischoff, S. A1 - Schubert, H. A1 - Sachse, A. A1 - Günster, Jens A1 - Illerhaus, Bernhard A1 - Bossert, J. A1 - Jandt, K. D. A1 - Kinne, R. W. A1 - Brinkmann, O. T1 - First-time systematic postoperative clinical assessment of a minimally invasive approach for lumbar ventrolateral vertebroplasty in the large animal model sheep N2 - Large animal models are highly recommended for meaningful preclinical studies, including the optimization of cement augmentation for vertebral body defects by vertebroplasty/kyphoplasty. The aim of this study was to perform a systematic characterization of a strictly minimally invasive in vivo large animal model for lumbar ventrolateral vertebroplasty. This is a prospective experimental animal study. Lumbar defects (diameter 5 mm; depth approximately 14 mm) were created by a ventrolateral percutaneous approach in aged, osteopenic, female sheep (40 Merino sheep; 6–9 years; 68–110 kg). L1 remained untouched, L2 was left with an empty defect, and L3 carried a defect injected with a brushite-forming calcium phosphate cement (CPC). Trauma/functional impairment, surgical techniques (including drill sleeve and working canula with stop), reproducibility, bone defects, cement filling, and functional cement augmentation were documented by intraoperative incision-to-suture time and X-ray, postoperative trauma/impairment scores, and ex vivo osteodensitometry, microcomputed tomography (CT), histology, static/fluorescence histomorphometry, and biomechanical testing. Minimally invasive vertebroplasty resulted in short operation times (28±2 minutes; mean±standard error of the mean) and X-ray exposure (1.59±0.12 minutes), very limited local trauma (score 0.00±0.00 at 24 hours), short postoperative recovery (2.95±0.29 hours), and rapid decrease of the postoperative impairment score to 0 (3.28±0.36 hours). Reproducible defect creation and cement filling were documented by intraoperative X-ray and ex vivo conventional/micro-CT. Vertebral cement augmentation and osteoconductivity of the CPC was verified by osteodensitometry (CPC>control), micro-CT (CPC>control and empty defect), histology/static histomorphometry (CPC>control and empty defect), fluorescence histomorphometry (CPC>control; all p<.05 for 3 and 9 months), and compressive strength measurements (CPC numerically higher than control; 102% for 3 months and 110% for 9 months). This first-time systematic clinical assessment of a minimally invasive, ventrolateral, lumbar vertebroplasty model in aged, osteopenic sheep resulted in short operation times, rapid postoperative recovery, and high experimental reproducibility. This model represents an optimal basis for standardized evaluation of future studies on vertebral augmentation with resorbable and osteoconductive CPC. KW - Computed tomography KW - Calcium phosphate cement KW - Large animal model KW - Minimal-invasive KW - Vertebroplasty KW - Void defect PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S152994301630273X U6 - https://doi.org/10.1016/j.spinee.2016.06.015 VL - 16 IS - 10 SP - 1263 EP - 1275 PB - Elsevier Inc. AN - OPUS4-38429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Illerhaus, Bernhard A1 - Maenz, S. A1 - Bischoff, S. A1 - Bungartz, M. A1 - Bossert, J. A1 - Kunisch, E. A1 - Kinne, R. ED - Maenz, S. T1 - Micro computer tomography (μCT) set-up for long-term serial measurements, image evaluation, and subsequent compressive strength tests on frozen sheep vertebrae for osteoporosis research N2 - Injection of poly(methyl methacrylate) cements, one standard Treatment for osteoporotic vertebral body fractures, may lead to critical loads and subsequent fractures in adjacent vertebral bodies. Biodegradable calcium phosphate cements (CPC) with bioinductive growth factors may be an alternative, since they have a Young’s modulus comparable to that of cancellous bone. Non-destructive tests with μCT and quantitative Image evaluation are used to assess new bone growth and material resorption following intravertebral injection of CPC. Immediate deep-freezing of excised bone prevents shrinkage or tissue disintegration and the samples have to be kept frozen for all following steps, including transport, μCT measurements, and subsequent biomechanical tests. Here we will report on a set-up to preserve the frozen state of the material and allow stable long-term serial μCT measurements. In addition, the image processing technique for the evaluation of bone growth and selected results on subsequently carried out compressive strength tests will be presented. T2 - WCNDT2016 CY - München, Germany DA - 13.6.2016 KW - Computed tomography KW - Osteoporosis KW - CT PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-366410 UR - https://www.ndt.net/?id=19382 VL - BB 158 SP - 1 EP - 7 PB - DGZfP CY - Berlin AN - OPUS4-36641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -