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Muscle graft as a substitute for peripheral nerve graft in rats
Palhares, Aristides;Viterbo, Fausto;Cardoso, Ricardo Galesso;
Acta Cirurgica Brasileira , 2009, DOI: 10.1590/S0102-86502009000300011
Abstract: purpose: to evaluate the applicability of the use of autogenous muscle treated in various ways, as a substitute of the nerve grafts. methods: rats were divided into seven groups that received, as a treatment for a standard nerve injury, the following types of grafts: fresh muscle, muscle fixed with 10% formaldehyde, muscle frozen in a freezer, muscle frozen in refrigerator, nerveless muscle, peripheral nerve and a group was without any treatment. it assessed the histological appearance of the nerve fibers in the segment repaired. results: the evaluation of the segment nervous repaired showed nerve fibers through the graft in almost all groups, but the methodology employed has not adequately characterized the differences between the groups. conclusion: this study showed the migration of nerves fibers through all grafts used.
A paradigm for a skin graft substitute  [PDF]
Denis E. Solomon
Open Journal of Regenerative Medicine (OJRM) , 2013, DOI: 10.4236/ojrm.2013.22005
Abstract:

Skin grafts have remained relatively unchanged since their introduction as a medical treatment for burns/wounds. This paper seeks to open an academic discussion as to whether their use-by date has now been passed. A skin graft substitute is described in a paradigm using fine leaf gelatine sheets which inherently possess several distinct advantages including, discarding the harvest of autologous tissue from patient donor sites. A clinical study will be needed to determine its suitability taken together with the understanding that experimental animal studies may not provide unequivocal answers to its in situ modus operandi.

Hydroxyapatite as a bone graft substitute: Use in cortical and cancellous bone  [cached]
Agarwala Sanjay,Bhagwat Abhijit
Indian Journal of Orthopaedics , 2005,
Abstract: Background : Autogenous bone is regarded as the best bone graft material. Various grafting materials have been advocated to fill bony defects. Our purpose was to study the utility of amorphous hydroxyapatite as an autogenous bone graft substitute in cancellous and cortical bone. Methods : A prospective study was undertaken over a period of five years. Patients included were those which would otherwise require bone grafting in cancellous and cortical bone fractures (15 in each group). Hydroxyapatite (HA) ceramic blocks of standard size (5mm x10m) were either used alone or mixed with autogenous cancellous graft in metaphyseal locations, along with bone marrow (derived from reaming or drilling) in intertrochanteric regions and mixed with cancellous graft in cortical areas. The results were assessed on standard radiographs. Biopsy of hydroxyapatite regenerated bone was taken at implant removal. Results: In cancellous areas as graft incorporation ensues over months the intrinsic structure of the hydroxyapatite blocks blurred with blunting of the sharp edges (on radiographs). Biopsy confirmed bone in-growth. In cortical areas the blocks did not show evidence of bone in-growth. Conclusion: Hydroxyapatite alone or when mixed with cancellous bone marrow is an effective adjuvant for autogenous bone grafts, especially in cancellous areas of bone. Mixing it with host marrow provides osteoinductive stimulus. It is biocompatible, osteoconductive but not osteogenic.
The use of hydroxyapatite as a bone graft substitute in orthopaedic conditions  [cached]
Reddy Renuka,Swamy MKS
Indian Journal of Orthopaedics , 2005,
Abstract: Background: The procedure of harvesting autologous bone graft has its own complications and morbidity, so there is search for alternative substances. G- Bone is a natural calcium phosphate hydroxyapatite in crystalline ceramic form derived from bovine. Methods: From August 1997 to Dec 2003, we operated 12 cases of benign bone tumours and 3 cases of scoliosis in which curettage and hydroxyapatite appatite filling was done. Clinico-radiological follow up was minimum 6 months to maximum 6 years. Results: We observed good bone formation and healing of lesion in all cases. In small lesion of hand and scoliosis, hydroxyapatite got incorporated by three months but in larger lesions of long bones incorporation of hydroxyapatite was partial even after 18 - 24 months. There was no collapse of graft on weight bearing. There was no complications like graft disintegration, recurrence of lesion, foreign body reaction to hydroxyapatite. Conclusion: Hydroxyapatite is an excellent bone graft substitute in orthpaedic surgeries. It facilities bone formation and is a biocompatible, slow remodeling material.
Evaluation of hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute for posterolateral spinal fusion  [cached]
Bansal Sanjay,Chauhan Vijendra,Sharma Sansar,Maheshwari Rajesh
Indian Journal of Orthopaedics , 2009,
Abstract: Background: Autologous cancellous bone is the most effective biological graft material. However, harvest of autologous bone is associated with significant morbidity. Since porous hydroxyapatite and beta-tricalcium phosphate are biodegradable materials and can be replaced by bone tissue, but it lacks osteogenic property. We conducted a study to assess their use as a scaffold and combine them with bone marrow aspirate for bone regeneration using its osteogenic property for posterolateral spinal fusion on one side and autologous bone graft on the other side and compare them radiologically in terms of graft incorporation and fusion. Materials and Methods: Thirty patients with unstable dorsal and lumbar spinal injuries who needed posterior stabilization and fusion were evaluated in this prospective study from October 2005 to March 2008. The posterior stabilization was done using pedicle screw and rod assembly, and fusion was done using hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute over one side of spine and autologous bone graft obtained from iliac crest over other side of spine. The patients were followed up to a minimum of 12 months. Serial radiographs were done at an interval of 3, 6, and 12 months and CT scan was done at one year follow-up. Graft incorporation and fusion were assessed at each follow-up. The study was subjected to statistical analysis using chi-square and kappa test to assess graft incorporation and fusion. Results: At the end of the study, radiological graft incorporation and fusion was evident in all the patients on the bone graft substitute side and in 29 patients on the autologous bone graft side of the spine ( P > 0.05). One patient showed lucency and breakage of distal pedicle screw in autologous bone graft side. The interobserver agreement (kappa) had an average of 0.72 for graft incorporation, 0.75 for fusion on radiographs, and 0.88 for the CT scan findings. Conclusion: Hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate seems to be a promising alternative to conventional autologous iliac bone graft for posterolateral spinal fusion.
The use of beta-tricalcium phosphate bone graft substitute in dorsally plated, comminuted distal radius fractures
Michael G Jakubietz, Joerg G Gruenert, Rafael G Jakubietz
Journal of Orthopaedic Surgery and Research , 2011, DOI: 10.1186/1749-799x-6-24
Abstract: The study was thus conducted as a prospective randomized clinical trial. 39 patients with unilateral, intraarticular fractures of the distal radius were included and randomized to 2 groups, one being treated with internal fixation only, while the second group received an additional bone graft substitute.There was no statistical significance between both groups in functional and radiological results. The occurrence of complications did also not show statistical significance.No advantage of additional granular bone graft substitutes could be seen in this study. Granular bone graft substitutes do not seem to provide extra stability if dorsal angle stable implants are used. Dorsal plates have considerable complication rates such as extensor tendon ruptures and development of CRPS.Fractures of the distal radius are the most common fractures in the upper extremity and treatment options have been controversially discussed throughout the literature. Closed reduction is almost always easy to achieve but is difficult to maintain, resulting in a loss of reduction. Therefore, treatment aims to prevent radial shortening, malunion, and articular incongruity as these factors are associated with poor outcomes [1]. Treatment varies from splinting and minimally invasive percutaneous pinning to open reduction with external or internal fixation [2]. Internal fixation can be done through a volar, dorsal or combined approach. While volar fixed angle implants could be the future for treatment of most Colles' fractures, the dorsal approach remains a good choice in highly comminuted fractures with a metaphyseal defect, and when a bone graft is also required [2]. Open reduction of dorsally dislocated fractures is often done through a dorsal approach because of the advantages it offers: fracture reduction under direct vision with the possibility of dorsal capsulotomy to directly visualize the articular surface and small fragments. It also offers the possibility to repair associated intercarpa
Growth and Characterization of Agar Gel Grown Brushite Crystals  [PDF]
V. B. Suryawanshi,R. T. Chaudhari
Indian Journal of Materials Science , 2014, DOI: 10.1155/2014/189839
Abstract: Brushite [CaHPO4·2H2O] or calcium hydrogen phosphate dihydrate (CHPD) also known as urinary crystal is a stable form of calcium phosphate. The brushite crystals were grown by single and double diffusion techniques in agar-agar gel at room temperature. Effects of different growth parameters were discussed in single diffusion and double diffusion techniques. Good quality star, needle, platy, rectangular, and prismatic shaped crystals in single diffusion and nuclei with dendritic growth were obtained in double diffusion. These grown nuclei were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). SEM has shown the different morphologies of crystals; FTIR has confirmed the presence of functional groups; crystalline nature was supported by XRD, whereas the TGA indicates total 24.68% loss in weight and formation of stable calcium pyrophosphate (Ca2P2O7) at 500°C. 1. Introduction Calcium oxalates, phosphates, and their hydrates are very common in calcium renal stones. Some of the oxalates are found in either pure or in mixed form with phosphate and also reported with uric acid or ammonium urates [1, 2]. Calcium oxalate monohydrate [3, 4] and calcium oxalate dihydrate [5] are common constituents of calcium urinary crystal while hydroxypatite [6], carbonate apatite [7], and brushite [8–11] are in calcium phosphate crystals. Brushite [CaHPO4·2H2O] provides a medium to grow octacalcium phosphate [12] and hydroxypatite [13–16] urinary crystals, however used as a precursor to form apatite, which has an important application in bone formation [17, 18]. Gel method is the most versatile and simple technique for growing urinary crystals [19–21]. In this method, gel acts as an inert and viscous medium for the growth of these crystals [22, 23]. The growth inhibition study of brushite crystals are reported in silica gel by adding tamarind, tartaric acid, and citric acid [24, 25] and in the presence of sodium fluoride [26]. Lim et al. [27] have grown three-dimensional flower like brushite crystals from high internal phase emulsion processing route; whereas Kumar and Kalainathan [28] have grown in the presence of magnetic field and observed the effect on growth of these crystals. Parekh et al. [29] have also observed the growth inhibition and dissolution of urinary type micro-CHPD crystals. Most of the brushite crystals reported are grown in silica hydrogel; however the growth of these crystals is not reported in agar-agar gel. In the present work, the brushite
Strontium Ions Substitution in Brushite Crystals: The Role of Strontium Chloride  [PDF]
Mohammad H. Alkhraisat,Carmen Rueda,Enrique López Cabarcos
Journal of Functional Biomaterials , 2011, DOI: 10.3390/jfb2020031
Abstract: The incorporation of strontium chloride to brushite cement was successful to introduce strontium ions within the lattice of brushite crystals. The effect of strontium ions on brushite cement properties was concentration dependent; such that, the addition of 5% and 10% (w/w) SrCl 2 significantly increased the cement FST and the addition of 10% SrCl 2 decreased the cement tensile strength. Further, cement weight loss was shown to be increased by cement modification with SrCl 2. The combination of ionic substitution and the degradability of brushite cements would constitute a system for the local delivery of strontium ions in the treatment of osteoporosis.
Histological Analysis of the Effect of Accelerated Portland Cement as a Bone Graft Substitute on Experimentally-Created Three-Walled Intrabony Defects in Dogs  [cached]
Saeed Dokami,Saeed Raoofi,Mohamad Javad Ashraf,Hooman Khorshidi
Journal of Dental Research, Dental Clinics, Dental Prospects , 2007,
Abstract: Background and aims. Recent literature shows that accelerated Portland cement (APC) is a non-toxic material that may have potential to promote bone healing. The objective of this study was to histologically evaluate periodontal healing focusing on new bone regeneration following implantation of APC into intra-bony defects in dogs. Materials and methods. Three-wall intra-bony periodontal defects were surgically created at the mesial aspect of the first molar in both sides of mandible in six dogs. One side was randomly filled with the material and other received a flap operation only. The animals were euthanized eight weeks post-surgery when block sections of the defect sites were collected and prepared for qualitative histological analysis. Results. Compared to control group, stimulation of growth of new bone tissue in the cavity containing APC was significantly prominent in three of six cases, showing osteoid formation with osteoblastic rimming and new bone trabeculla. New bone formation was observed just close to cavity containing APC. Connective tissue proliferation and downgrowth of epithelium were significantly less than those of control group. Conclusion. Our results are encouraging for the use of APC as a bone substitute, but more comprehensive study are necessary before warranting clinical use.
Brushite-Forming Mg-, Zn- and Sr-Substituted Bone Cements for Clinical Applications  [PDF]
Sandra Pina,José M.F. Ferreira
Materials , 2010, DOI: 10.3390/ma3010519
Abstract: Calcium phosphate cements have been in clinical use for the last 10 years. Their most salient features include good biocompatibility, excellent bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping to accomodate any complicated geometry. They are commonly used in filling bone defects and trauma surgeries as mouldable paste-like bone substitute materials. Substitution of trace elements, such as Mg, Sr and Zn ions, into the structure of calcium phosphates is the subject of widespread investigation nowadays, because of their impending role in the biological process. Subtle differences in composition and structure of these materials may have a profound effect on their in vivo behaviour. Therefore, the main goal of this paper is to provide a simple, but comprehensive overview of the present achievements relating to brushite-forming cements doped with Mg, Zn and Sr, and to identify new developments and trends. In particular, the influence of ionic substitution on the chemical, physical and biological properties of these materials is discussed.
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