Summary
The study was undertaken to evaluate the feasibility of a simple, inexpensive model of circular external fixator (CEF) for use in large ruminants. A simple model of CEF frames consisting of ...four full rings (13–19 cm diameter, 4 cm wide and 4 mm thick with 18–24 holes) connected by threaded rods (8 mm diameter, 10–15 cm long) and nuts was developed using mild (low carbon) steel and were nickel‐plated. In the first phase of the study, three male cow calves were utilized to study the feasibility of application of the fixators in the metatarsus, tibia and radius, in reference of adaptation and tolerance by animals. In the second phase, the fixators were tested in osteotomized bones. Six bull calves of 1.5–2 years of age weighing about 200–250 kg were utilized for this purpose. After preparing the area for aseptic surgery, under xylazine (at 0.1 mg/kg, i.m.)‐ketamine (i.v. till effect) general anaesthesia, the test bone (metatarsus, radius and tibia in two animals each) was approached through the medial surface and an osteotomy was created with a saw and chisel at the mid‐diaphysis. The pre‐constructed 4‐ring CEF was mounted on the limb around the test bone in such a way that it formed a cylinder with the axis of the limb at the centre. Each ring was then fixed to the bone with a pair of beaded wires (316 SS) of 3.5 mm diameter. During the post‐operative period, the animals were observed for any change in behaviour, tolerance of the fixators, the weight bearing on the test limb, the status of the fixator, and the level of reduction of the osteotomy, alignment and healing at different intervals.
The fixation of CEF was easier in the metatarsus and radius than in the tibia. The inner ring diameters found adequate for metatarsus, radius and tibia were 13–15 cm, 15–17 cm and 17–19 cm, respectively. The fixators applied to different bones were well‐tolerated, and the animals could lay down, stand and walk freely with the fixator without any problems. All the animals showed good weight bearing in the immediate post‐operative period. Weight bearing, however, slightly reduced in the inflammatory period and showed improvement after about 4 weeks. Wire tract infection was seen in all the animals, which was more on proximal wire tracts on lateral aspect of limbs. Circular fixators were well‐tolerated by all the animals, and there was no breaking/bending of connecting rods, slotted bolts or the rings at any stage of observation. Slight bowing of some wires was noticed in cases of tibia and radius (in phase II) and bending of some wires was noticed from first week in two animals one each in radius and tibia. Bone fragments were well maintained until healing occurred (appearance of bridging periosteal callus) at 60–70 days. The functional results were good in all but one case of tibia, where a mal‐union was recorded. From this study, it can be concluded that CEF are well‐tolerated by large ruminants and can be used to treat long bone fractures. The fixator assembly using mild steel is sufficiently strong to maintain fracture fixation and is inexpensive. The simple design of the CEF appears to be sufficient to treat simple diaphyseal fractures of the metatarsus and radius. Improvement in the technique of fixation and design‐like coupling of linear and circular fixator components into hybrid constructs may help to provide greater rigidity in treating tibial and open long bone fractures.
The aim of this study was to evaluate epoxy-pin external skeletal fixation technique for the treatment of open fractures in calves and foals.
Twenty-eight calves and four foals (weighing 45-105 kg) ...with fractures distal to the stifle or elbow made the subject for the retrospective study. The pins (2.0-3.0-mm Kirschner wires, crossed at 60-90°) were fixed at least at two locations in both proximal and distal bone fragments as per the case situation. The pins in the same plane were bent (∼2 cm from the skin) towards the fracture site or joint and were joined using an adhesive tape (additional pins used when required) to make a temporary scaffold of connecting bars or rings. Thoroughly mixed epoxy putty was applied along the pin scaffold (the epoxy columns were 20-25 mm diameter) and allowed to set for 45 to 60 minutes. All animals were evaluated based on various clinical and radiographic observations made at regular intervals.
The epoxy-pin fixation was easy to apply and provided stable fixation of bone as indicated by early weight bearing, and fracture healing within 45 to 60 days (17/32 cases). The functional recovery was good to very good in 14 animals and satisfactory in nine cases by 12 months after removal of the fixator.
The multiplanar epoxy-pin external skeletal fixation provides stable fixation of unstable open fractures distal to the stifle or elbow joint; hence, it can be used to treat a variety of fractures in calves and foals weighing up to approximately 100 kg, especially open infected fractures of lower limb, which are difficult to treat by conventional techniques.
Objective
Quantitation of mechanical properties of a novel locking compression plate (LCP) for bovine tibia.
Study design
Prospective in vitro study.
Sample population
Adult Murrah buffalo (250‐350 ...kg) tibiae.
Methods
Forty tibiae were randomly assigned to five treatment groups (n = 8/group): intact bone and bone constructs with a standard nonlocking plate, single LCP, double LCP, and novel LCP. During implant application, a mid‐diaphyseal, oblique osteotomy was performed in all constructs, which were subsequently tested in axial compression (n = 4 each) or three‐point craniocaudal bending (n = 4 each). Novel LCP alone (n = 4) was tested only in bending. Stiffness, yield load, ultimate failure load, and bending moment were determined from the load deformation curves and compared among different treatment groups (P < .05).
Results
Under compression, yield load of the novel LCP (24.07 ± 3.45 kN) was greater than that of the nonlocking plate (11.10 ± 2.46 kN) and the single LCP (18.01 ± 2.07 kN) but less than that of the double LCP (30.61 ± 1.95 kN), and ultimate failure load of the novel LCP (25.85 ± 4.32 kN) was greater than that of the nonlocking plate (13.18 ± 2.91 kN) but similar to that of the single LCP (21.17 ± 2.33 kN) and the double LCP (32.40 ± 1.46 kN). Bending moment, yield load, and ultimate failure load of the novel LCP were 565.37 ± 79.30 Nm, 7.90 ± 1.14 kN, 9.83 ± 1.38 kN, respectively, which were greater than those of the nonlocking plate and the single LCP but comparable to those of the double LCP.
Conclusion
The novel LCP developed for bovine tibia was mechanically superior to the standard nonlocking plate or the single LCP and comparable to the double LCP.
Clinical significance
The novel LCP may provide rigid fixation of tibial diaphyseal fractures in buffaloes and cattle weighing 250 to 350 kg.
The current study was designed to study the persistence and distribution of caprine bone marrow derived mesenchymal stem cells (cBM-MSCs) when administered intra-dermally in experimentally induced ...cutaneous wounds in rabbits. MSC’s from goat bone marrow were isolated and their differentiation potential towards adipogenic and osteogenic lineages were assayed in vitro. The isolated cells were phenotypically analysed using flow cytometry for the expression of MSC specific matrix receptors (CD73, CD105 and Stro-1) and absence of hematopoietic lineage markers. Further, these in vitro expanded MSCs were stained with PKH26 lipophilic cell membrane red fluorescent dye and prepared for transplantation into cutaneous wounds created on rabbits. Five, 2 cm linear full thickness skin incisions were created on either side of dorsal midline of New Zealand white rabbits (n = 4). Four wounds in each animal were implanted intra-dermally with PKH26 labelled cBM-MSCs suspended in 500 µl of Phosphate Buffer Saline (PBS). Fifth wound was injected with PBS alone and treated as negative control. The skin samples were collected from respective wounds on 3, 7, 10 and 14 days after the wound creation, and cryosections of 6 µM were made from it. Fluorescent microscopy of these cryosections showed that the PKH26 labelled transplanted cells and their daughter cells demonstrated a diffuse pattern of distribution initially and were later concentrated towards the wound edges and finally appeared to be engrafted with the newly developed skin tissues. The labelled cells were found retained in the wound bed throughout the period of 14 days of experimental study with a gradual decline in their intensity of red fluorescence probably due to the dye dilution as a result of multiple cell division. The retention of transplanted MSCs within the wound bed even after the complete wound healing suggests that in addition to their paracrine actions as already been reported, they may have direct involvement in various stages of intricate wound healing process which needs to be explored further.
To evaluate the in vitro biomechanical properties of four different configurations of acrylic external skeletal fixator constructs.
Simulated bone constructs were prepared using two segments of 20 mm ...ultra-high-density polyethylene rods with a gap of 5 mm. The full pins (1.5 mm) were passed through the proximal and distal segments of ultra-high-density polyethylene rods, in the same plane, parallel to each other in configuration U, and were crossed in the M1, M2 and C configurations at a 90° angle to each other. Configuration U was a single bilateral uniplanar construct, M1 was a double orthogonal bilateral construct, M2 was a double orthogonal bilateral construct with proximal and distal connecting articulations, and C was a double orthogonal bilateral construct with proximal and distal circumferential articulations. Temporary scaffolds of different external skeletal fixator configurations were constructed using commercially available polyvinyl chloride pipes (20 mm) connected and secured to the fixation pins at a fixed distance from the rods. Acrylic powder (polymer) mixed with liquid (monomer) was poured into the pipes and allowed to solidify to form the side bars and rings. The external skeletal fixator constructs were then subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters, namely stress, strain, modulus of elasticity, stiffness and bending moment of fixator constructs, were determined from load-displacement curves.
Configuration U was the weakest and configuration C was the strongest under all the testing modes. Under compression, the M1, M2 and C configurations were similar. Under bending, a significant difference was observed among the uniplanar, multiplanar and circular configurations with no difference between M1 and M2. However, under torsion, all the external skeletal fixator configurations differed significantly.
The freeform external skeletal fixator using acrylic as a replacement for a metallic bar may be useful to treat bone fractures and luxations in small animals, as it is mechanically strong, lightweight, economical, and pins can be passed from any direction depending upon the clinical situation.
Caprine amniotic fluid (cAF) and bone marrow cells (cBM) were isolated, expanded and phenotypically characterized by mesenchymal stem cells (MSCs) specific cell surface markers. Both cell types were ...compared for multilineage differentiation potential by flow cytometry using specific antibodies against lineage specific markers. Furthermore, in vitro expanded cAF-MSCs showed higher expression of trophic factors viz. VEGF and TGF-β1 as compared to cBM-MSCs. Full-skin thickness excisional wounds created on either side of the dorsal midline (thoracolumbar) of New Zealand White rabbits were randomly assigned to subcutaneous injection of either fetal origin cAF-MSCs (n=4) or adult cBM-MSCs (n=4) or sterile PBS (control, n=4). The rate of wound closure was found faster (p<0.05) in cAF-MSCs treated wounds as compared with cBM-MSCs and PBS treated wounds especially on 21st day post-skin excision. Histomorphological examination of the healing tissue showed that wound healing was improved (p<0.05) by greater epithelialization, neovascularization and collagen development in cAF-MSCs as compared to cBM-MSCs and PBS treated wounds.
•Differentiation potential of stem cells derived from AF and BM was similar.•Stem cells derived from amniotic fluid had increased expression of VEGF and TGF.•Amniotic fluid derived stem cells had demonstrated accelerated wound contraction.•AF derived stem cell's treatment had improved the histology of healing wounds.
A response to "Comments on torsional testing" Aithal, H P; Tyagi, S K; Kinjavdekar, P ...
Veterinary and comparative orthopaedics and traumatology,
01/2015, Letnik:
28, Številka:
6
Journal Article
Contents
Immune privileged mesenchymal stem cells (MSCs) can differentiate into multiple cell types and possess great potential for human and veterinary regenerative therapies. This study was ...designed with an objective to isolate, expand and characterize buffalo bone marrow‐derived MSCs (BM‐MSCs) at molecular and cellular level. Buffalo BM‐MSCs were isolated by Ficoll density gradient method and cultured in Dulbecco’s modified Eagle’s medium supplemented with fetal bovine serum (FBS). These cells were characterized through alkaline phosphatase (AP) staining, colony‐forming unit (CFU) assay, mRNA expression analysis (CD 73, CD 90, CD 105, Oct4 and Nanog), immunolocalization along with flow cytometry (Stro 1, CD 73, CD 105, Oct4, Sox2 and Nanog) and in situ hybridization (Oct4 and Sox2). Multilineage differentiation (osteogenic, adipogenic and chondrogenic) was induced in vitro, which was further assessed by specific staining. Buffalo BM‐MSCs have the capacity to form plastic adherent clusters of fibroblast‐like cells and were successfully maintained up to 16th passage. These cells were AP positive, and further CFU assay confirmed their clonogenic property. RT‐PCR analysis and protein localization study showed that buffalo BM‐MSCs are positive for various cell surface markers and pluripotency markers. Cytoplasmic distribution of mRNA for pluripotency markers in buffalo BM‐MSCs and multilineage differentiation were induced in vitro, which was further assessed by specific staining. To the best of our knowledge, this is the first report of buffalo BM‐MSCs, which suggests that MSCs can be derived and expanded from buffalo bone marrow and can be used after characterization as a novel agent for regenerative therapy.
Aim of the present study was in vitro expansion and characterization of caprine wharton’s jelly derived mesenchymal stem cells (cWJ-MSCs) to investigate their tissue healing potential in xenogenic ...animal model. Plastic adherent fibroblastoid cell populations with distinctive homogeneous morphology were isolated from caprine wharton’s jelly explants. These wharton’s jelly derived cells were found positive for the surface markers CD-73, STRO-1 and CD-105, whereas they were negative for hematopoetic stem cell marker CD-34. In vitro cultured cWJ-MSCs also showed differentiation properties into osteogenic, adipogenic and chondrogenic lineages as demonstrated by von Kossa, Oil Red- O and Alcian blue staining respectively, which was further confirmed and quantified by flow cytometric analysis. Furthermore, these well characterized cWJ-MSCs were evaluated for the wound-healing potential in full-thickness skin wounds in rabbit model for 28 days. Caprine WJ- MSCs treated skin wounds showed significantly (
P
< 0.05) higher percentage of wound contraction especially at the 21
st
day post transplantation when compared to PBS treated control group animals. Further, we observed better healing potential of cWJ-MSCs in terms of histo-morphological evaluation, epithelialisation and collagenization with matured vascularization stage by day 28 as compared to control. In conclusion, cWJ- MSCs provide an alternative inexhaustible source of mesenchymal stem cells and also unravel new perspectives pertaining to the therapeutic use of these cells in different species.
A 48-year-old woman presented with severe acute heart failure of 7 days duration. Because of her rapidly worsening clinical condition, anatomical diagnosis of aortopulmonary fistula was made by ...urgent cardiac catheterization, and she successfully underwent immediate surgical closure. Retrospectively, the diagnosis of syphilitic aortitis complicated with aortopulmonary fistula was made by clinical profile, serology, and histopathology.
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