scholarly journals Radiographic Assessment of Implant Failures of Titanium 3.5 LCP vs. 4.5 LCP Used for Flexible Bridging Osteosynthesis of Large Segmental Femoral Diaphyseal Defects in a Miniature Pig Model

2010 ◽  
Vol 79 (4) ◽  
pp. 599-606 ◽  
Author(s):  
Alois Nečas ◽  
Pavel Proks ◽  
Lucie Urbanová ◽  
Robert Srnec ◽  
Ladislav Stehlík ◽  
...  
Keyword(s):  
Bone Defect ◽  
Implant Failure ◽  
Radiographic Examination ◽  
Femoral Diaphysis ◽  
Proximal Fragment ◽  
Segmental Defect ◽  
Miniature Pig ◽  
Segmental Bone ◽  
Transplantation Experiments

The study describes types, absolute and relative numbers of implant failures in flexible bridging osteosynthesis using a six-hole 3.5 mm titanium Locking Compression Plate (n = 9) or a five-hole LCP 4.5 mm titanium (n = 40) selected for the fixation of segmental ostectomy of femoral diaphysis in the miniature pig used as an in vivo model in a study on the healing of a critically sized bone defect using transplantation of mesenchymal stem cells combined with biocompatible scaffolds within a broader research project. Occasional implant failure was evaluated based on radiographic examination of femurs of animals 2, 4, 8, 12 and 16 weeks after surgery. When bone defect was stabilized using 3.5 mm LCP, in 6 cases (66.7%) the screw was broken/lost in the proximal fragment of the femur 2 weeks after implantation (n = 4) and 4 weeks after implantation (n = 2). In 4 cases of these, the implant failure was accompanied also by loosening of the screw in position 3 in the proximal fragment of the femur. During ostectomy stabilization with 4.5 mm LCP, in 3 cases (7.5%) LCP was broken at the place of the empty central plate hole (without inserted screw) at the level of the segmental bone defect. Compared to the six-hole 3.5 mm LCP, the five-hole titanium 4.5 mm LCP is more suitable implant for flexible bridging osteosynthesis of a critically sized segmental defect of femoral diaphysis in the miniature pig. The results of this study will allow reducing implant failures in time- and cost-demanding transplantation experiments focused on bone healing.

scholarly journals Comparison of the Resistance to Bending Forces of the 4.5 LCP Plate-rod Construct and of 4.5 LCP Alone Applied to Segmental Femoral Defects in Miniature Pigs

2010 ◽  
Vol 79 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Lucie Urbanová ◽  
Robert Srnec ◽  
Pavel Proks ◽  
Ladislav Stehlík ◽  
Zdeněk Florian ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Femoral Diaphysis ◽  
Miniature Pig ◽  
Femoral Bone ◽  
Bone Implant ◽  
Miniature Pigs ◽  
Bone Defect Healing ◽  
Considerable Strain

The study deals with the determination of mechanical properties, namely resistance to bending forces, of flexible buttress osteosynthesis using two different bone-implant constructs stabilizing experimental segmental femoral bone defects (segmental ostectomy) in a miniature pig ex vivo model using 4.5 mm titanium LCP and a 3 mm intramedullary pin (“plate and rod” construct) (PR-LCP), versus the 4.5 mm titanium LCP alone (A-LCP). The “plate and rod” fixation (PR-LCP) of the segmental femoral defect is significantly more resistant (p < 0.05) to bending forces (200 N, 300 N, and 500 N) than LCP alone (A-LCP). Stabilisation of experimental segmental lesions of the femoral diaphysis in miniature pigs by flexible bridging osteosynthesis 4.5 mm LCP in combination with the “plate and rod” construct appears to be a suitable fixation of non-reducible fractures where considerable strain of the implants by bending forces can be assumed. These findings will be used in upcoming in vivo experiments in the miniature pig to investigate bone defect healing after transplantation of mesenchymal stem cells in combination with biocompatible scaffolds.

Bilayer nanostructure coated AZ31 magnesium alloy implants: in vivo reconstruction of critical-sized rabbit femoral segmental bone defect

2020 ◽  
Vol 29 ◽  
pp. 102232
Author(s):  
Govindaraj Perumal ◽  
Boopalan Ramasamy ◽  
Maya Nandkumar A ◽  
Sivaraman Dhanasekaran ◽  
Selvaraj Ramasamy ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Bone Defect ◽  
Az31 Magnesium Alloy ◽  
Segmental Bone Defect ◽  
Segmental Bone

Fabrication of piezoelectric porous BaTiO3 scaffold to repair large segmental bone defect in sheep

2020 ◽  
Vol 35 (4-5) ◽  
pp. 544-552 ◽  
Author(s):  
Wenwen Liu ◽  
Di Yang ◽  
Xinghui Wei ◽  
Shuo Guo ◽  
Ning Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Bone Defect ◽  
Piezoelectric Effect ◽  
Bone Defects ◽  
Segmental Bone Defect ◽  
Segmental Bone ◽  
Large Bone ◽  
Large Bone Defects

Porous titanium scaffolds can provide sufficient mechanical support and bone growth space for large segmental bone defect repair. However, they fail to restore the physiological environment of bone tissue. Barium titanate (BaTiO3) is considered a smart material that can produce an electric field in response to dynamic force. Low-intensity pulsed ultrasound stimulation (LIPUS), as a kind of micromechanical wave, can not only promote bone repair but also induce BaTiO3 to generate an electric field. In our studies, BaTiO3 was coated on porous Ti6Al4V and LIPUS was externally applied to observe the influence of the piezoelectric effect on the repair of large bone defects in vitro and in vivo. The results show that the piezoelectric effect can effectively promote the osteogenic differentiation of bone marrow stromal cells (BMSCs) in vitro as well as bone formation and growth into implants in vivo. This study provides an optional alternative to the conventional porous Ti6Al4V scaffold with enhanced osteogenesis and osseointegration for the repair of large bone defects.

scholarly journals The Role of Three-Dimensional Scaffolds in Treating Long Bone Defects: Evidence from Preclinical and Clinical Literature—A Systematic Review

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Alice Roffi ◽  
Gopal Shankar Krishnakumar ◽  
Natalia Gostynska ◽  
Elizaveta Kon ◽  
Christian Candrian ◽  
...  
Keyword(s):  
Bone Defect ◽  
Clinical Studies ◽  
Three Dimensional ◽  
Bone Defects ◽  
Long Bone ◽  
Current Evidence ◽  
Pubmed Database ◽  
Segmental Bone ◽  
Large Animals

Long bone defects represent a clinical challenge. Bone tissue engineering (BTE) has been developed to overcome problems associated with conventional methods. The aim of this study was to assess the BTE strategies available in preclinical and clinical settings and the current evidence supporting this approach. A systematic literature screening was performed on PubMed database, searching for both preclinical (only on large animals) and clinical studies. The following string was used: “(Scaffold OR Implant) AND (Long bone defect OR segmental bone defect OR large bone defect OR bone loss defect).” The search retrieved a total of 1573 articles: 51 preclinical and 4 clinical studies were included. The great amount of preclinical papers published over the past few years showed promising findings in terms of radiological and histological evidence. Unfortunately, this in vivo situation is not reflected by a corresponding clinical impact, with few published papers, highly heterogeneous and with small patient populations. Several aspects should be further investigated to translate positive preclinical findings into clinical protocols: the identification of the best biomaterial, with both biological and biomechanical suitable properties, and the selection of the best choice between cells, GFs, or their combination through standardized models to be validated by randomized trials.

scholarly journals Application of hydroxyapatite nanoparticles in tumor-associated bone segmental defect

2019 ◽  
Vol 5 (8) ◽  
pp. eaax6946 ◽  
Author(s):  
Kun Zhang ◽  
Yong Zhou ◽  
Cong Xiao ◽  
Wanlu Zhao ◽  
Hongfeng Wu ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Bone Repair ◽  
Osteolytic Lesion ◽  
Tumor Model ◽  
Antitumor Agent ◽  
Porous Titanium ◽  
Suppressive Effect ◽  
Segmental Defect ◽  
Segmental Bone

Hydroxyapatite (HA) has been widely applied in bone repair because of its superior biocompatibility. Recently, a proliferation-suppressive effect of HA nanoparticles (n-HA) against various cancer cells was reported. This study was aimed at assessing the translational value of n-HA both as a bone-regenerating material and as an antitumor agent. Inhibition of tumor growth, prevention of metastasis, and enhancement of the survival rate of tumor-bearing rabbits treated with n-HA were demonstrated. Activated mitochondrial-dependent apoptosis in vivo was confirmed, and we observed that a stimulated immune response was involved in the n-HA–induced antitumor effect. A porous titanium scaffold loaded with n-HA was fabricated and implanted into a critical-sized segmental bone defect in a rabbit tumor model. The n-HA–releasing scaffold not only showed a prominent effect in suppressing tumor growth and osteolytic lesion but also promoted bone regeneration. These findings provide a rationale for using n-HA in tumor-associated bone segmental defects.

Evaluation of Polylactic Acid/Beta-Tricalcium Phosphate Scaffolds as Segmental Bone Graft Substitutes

2008 ◽  
Author(s):  
Laura Yanoso ◽  
Justin Jacobson ◽  
Tulin Dadali ◽  
David Reynolds ◽  
Hani Awad
Keyword(s):  
Bone Formation ◽  
Polylactic Acid ◽  
Tricalcium Phosphate ◽  
Segmental Defect ◽  
Defect Region ◽  
Beta Tricalcium Phosphate ◽  
Ectopic Bone ◽  
Segmental Bone ◽  
Endothelial Growth Factor

The use of processed structural allografts for treatment of massive segmental defects in long bones can be complicated by poor incorporation and remodeling of the devitalized graft, foreign-body reaction and micro-damage accumulation which often leads to catastrophic graft failure [1]. It is therefore useful to develop a bioengineered, biodegradable scaffold that is able to stimulate healing of the defect region. The use of bioengineered scaffolds has been limited due to their poor mechanical strength that does not permit withstanding large in vivo loads and due to their poor osteoinductive properties. We therefore investigated the use of rigid polylactic acid/beta-tricalcium phosphate (PLA/βTCP) composites used in conjunction with osteoinductive factors such as growth hormones (parathyroid hormone (PTH)) and growth factors (bone morphogenic protein-2 (BMP-2) & vascular endothelial growth factor (VEGF)) to stimulate bone formation and vessel ingrowth in the segmental defect region. We examined the physical characteristics of the scaffolds, and evaluated their osteoinductive potential in a clinically-relevant mouse model of a femoral segmental defect with or without PTH treatment. Finally, we used an ectopic bone formation model to assess the efficacy of the scaffold in site-specific delivery of bone anabolic factors.

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