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woven bone [keywords]
- Effects of Wnt5a haploinsufficiency on bone repair. [JOURNAL ARTICLE]
- J Orthop Trauma 2013 Dec 13.
Wnt5a expression is up-regulated during fracture repair and has previously been implicated as a potential regulator of skeletal development, as well as bone mass accrual and maintenance. Our objective was to evaluate the function of Wnt5a in fracture healing.Femoral fracture experiments on Wnt5a and Wnt5a mice were carried out. To better understand the effect of the Wnt5a on bone repair, we evaluated radiographs using a previously validated, qualitative scoring system and performed micro-CT analyses. Histomorphometric analyses determined the temporal distribution of stroma, cartilage matrix, and woven bone in the fracture callus. Finally, we performed tartrate resistant acid phosphatase (TRAP) immunohistochemical staining to visualize and quantify bone resorbing cells.Radiographic evaluations at day 21 demonstrated significantly higher cortical remodeling and bridging parameters for the Wnt5a group, compared to the Wnt5a group. The bone volume fraction by micro-CT was also significantly increased in Wnt5a mice. Histological and histomorphometric analyses showed that while Wnt5a mice exhibit decreased cartilage matrix production at day 7 post-fracture, they displayed increased residual cartilaginous callus at days 14 and 21, compared to the Wnt5a group. In addition, the total number of multinucleated TRAP cells was significantly lower in the Wnt5a group, than in the Wnt5a group.The data indicates that decreased Wnt5a signaling impaired proper fracture healing, possibly through decreased cartilaginous callus formation, and delayed cartilage matrix and mineralized tissue remodeling within the fracture callus.
- A Clinicopathologic Analysis of 207 Cases of Benign Fibro-Osseous Lesions of the Jaws. [JOURNAL ARTICLE]
- Int J Surg Pathol 2013 Dec 10.
Benign fibro-osseous lesion (BFOL) is a distinct group of jaw entities composed of fibrocellular tissue and mineralized materials. In this study, we examined the epidemiological, clinical, and pathological features of patients with BFOL. Records and microslides of 207 BFOLs submitted to pathology service were retrospectively reviewed. Overall, fibrous dysplasia (FD) was the most prevalent (36.7%), followed by ossifying fibroma (OF; 32.4%), osseous dysplasia (OD; 24.6%), and juvenile ossifying fibroma (JOF; 6.3%). Female predilection was noted. FD and JOF were common in maxilla, whereas most OF and OD affected the mandible. Most patients with FD and OF presented with painless swelling, while patients with OD were symptomless. The majority of FD specimens showed woven bone, while a mixture of woven bone and cementum-like materials was often noted in OF and OD. Our data show variations in the clinicopathologic features of BFOLs. A thorough examination of all aspects of BFOL patients is imperative for accurate diagnosis.
- Failure of cement-augmented pedicle screws in the osteoporotic spine: a case report. [Journal Article]
- Geriatr Orthop Surg Rehabil 2013 Sep; 4(3):84-8.
The treatment of patients with osteoporosis and spinal abnormalities that require surgical intervention is difficult because of the challenge of achieving fixation in osteoporotic bone. As the population ages, this challenge is becoming a common problem in the field of spinal surgery. Although numerous publications exist about the biomechanical benefits of various fixation devices and techniques, no standard of care has emerged that offers a clear method for accomplishing spinal stabilization in such patients. This case presents the failure mode of cement-augmented pedicle screws in a patient with severe osteoporosis, a description of the methods used to attain fixation and spinal stability during the revision surgery, and the outcome achieved for the patient 1 year after surgery. An 82-year-old female with a T9 burst fracture and a history of osteoporosis underwent minimally invasive instrumentation from T5 to T12, fusion from T7 to T11, and decompression from T8 to T10. Four weeks after surgery, the patient returned to the hospital because of back pain. Imaging studies showed that the pedicle screws at T11 and T12, which were augmented with polymethylmethacrylate (PMMA), had pulled out of the vertebral bodies. The pedicle screws failed by disengaging from the PMMA and displacing posteriorly and inferiorly. The PMMA did not appear to move during this process. A revision surgery was performed, in which the posterior construct was extended caudally and cephalad, the pedicle screws were augmented with PMMA, and a titanium hook and woven polyester band were used to increase the points of fixation. At 1-year follow-up after revision, our patient showed radiographic evidence of fusion, and the construct continued to maintain stability in the osteoporotic spine.
- Filling of extraction sockets of feline maxillary canine teeth with autogenous bone or bioactive glass. [Journal Article]
- Acta Cir Bras 2013 Dec; 28(12):856-62.
To evaluate bone healing in the extraction socket of the feline maxillary canine tooth after grafting.Eighteen adult cats were submitted to unilateral extraction of maxillary canine tooth and divided into three groups. In group 1 (n=6), control, the extraction socket was left empty. In group 2 (n=6), the extraction socket was filled with autogenous cancellous bone from the iliac crest and in group 3 (n=6), with bioactive glass particulate material. Cats were euthanized at four weeks postoperative.The radiographic examinations performed four weeks after surgery showed that in all groups the healing process converged to a radiopacity similar to that observed in the surrounding bones. Histological examination showed formation of woven bone within the extraction socket. The percentage of newly formed bone within the extraction socket, measured by the histometry, showed no statistically significant difference among the values of the three groups (Kruskal-Wallis'test p>0.05) (group 1: 63.96 ± 5.85, group 2: 66.84 ± 11.67, group 3: 59.28 ± 15.50).The bone regeneration observed in the extraction sockets filled with autogenous cancellous bone or bioactive glass was similar to that observed in the control sites, given an observation period of four weeks after extraction of the maxillary canine tooth.
- Investigation of rat bone fracture healing using pulsed 1.5MHz, 30mW/cm(2) burst ultrasound - Axial distance dependency. [JOURNAL ARTICLE]
- Ultrasonics 2013 Nov 1.
This study investigated the effect of LIPUS on fracture healing when fractures were exposed to ultrasound at three axial distances: z=0mm, 60mm, and 130mm. We applied LIPUS to rat fracture at these three axial distances mimicking the exposure condition of human fractures at different depths under the soft tissue. Measurement of LIPUS shows pressure variations in near field (nearby transducer); uniform profile was found beyond it (far field). We asked whether different positions of the fracture within the ultrasound field cause inconsistent biological effect during the healing process. Closed femoral fractured Sprague-Dawley rats were randomized into control, near-field (0mm), mid-near field (60mm) or far-field (130mm) groups. Daily LIPUS treatment (plane, but apodized source, see details in the text; 2.2cm in diameter; 1.5MHz sine waves repeating at 1kHz PRF; spatial average temporal average intensity, ISATA=30mW/cm(2)) was given to fracture site at the three axial distances. Weekly radiographs and endpoint microCT, histomorphometry, and mechanical tests were performed. The results showed that the 130mm group had the highest tissue mineral density; and significantly higher mechanical properties than control at week 4. The 60mm and 0mm groups had significantly higher (i.e. p<0.05) woven bone percentage than control group in radiological, microCT and histomorphometry measurements. In general, LIPUS at far field augmented callus mineralization and mechanical properties; while near field and mid-near field enhanced woven bone formation. Our results indicated the therapeutic effect of LIPUS is dependent on the axial distance of the ultrasound beam. Therefore, the depth of fracture under the soft tissue affects the biological effect of LIPUS. Clinicians have to be aware of the fracture depth when LIPUS is applied transcutaneously.
- Enrichment isolation of adipose-derived stem/stromal cells from the liquid portion of liposuction aspirates with the use of an adherent column. [JOURNAL ARTICLE]
- Cytotherapy 2013 Nov 12.
Adipose-derived stem/progenitor cells (ASCs) are typically obtained from the lipoaspirates; however, a smaller number of ASCs can be isolated without enzymatic digestion from the infranatant liposuction aspirate fluid (LAF). We evaluated the effectiveness of an adherent column, currently used to isolate mesenchymal stromal cells from bone marrow, to isolate LAF cells.We applied peripheral blood (PB), PB mixed with cultured ASCs (PB-ASC), and LAF solution to the column and divided it into two fractions, the adherent (positive) and the non-adherent (negative) fractions. We compared this method with hypotonic hemolysis (lysis) for the red blood cell count, nucleated cells count and cell compositions as well as functional properties of isolated mesenchymal cells.The column effectively removed red blood cells, though the removal efficiency was slightly inferior to hemolysis. After column processing of PB-ASC, 60.5% of ASCs (53.2% by lysis) were selectively collected in the positive fraction, and the negative fraction contained almost no ASCs. After processing of LAF solution, nucleated cell yields were comparable between the column and hemolysis; however, subsequent adherent culture indicated that a higher average ASC yield was obtained from the column-positive samples than from the lysis samples, suggesting that the column method may be superior to hemolysis for obtaining viable ASCs. Mesenchymal differentiation and network formation assays showed no statistical differences in ASC functions between the lysis and column-positive samples.Our results suggest that a column with non-woven rayon and polyethylene fabrics is useful for isolating stromal vascular fraction cells from LAF solutions for clinical applications.
- Novel biologically-inspired rosette nanotube PLLA scaffolds for improving human mesenchymal stem cell chondrogenic differentiation. [Journal Article]
- Biomed Mater 2013 Dec; 8(6):065003.
Cartilage defects are a persistent issue in orthopedic tissue engineering where acute and chronic tissue damage stemming from osteoarthritis, trauma, and sport injuries, present a common and serious clinical problem. Unlike bone, cartilage repair continues to be largely intractable due to the tissue's inherently poor regenerative capacity. Thus, the objective of this study is to design a novel tissue engineered nanostructured cartilage scaffold via biologically-inspired self-assembling rosette nanotubes (RNTs) and biocompatible non-woven poly (l-lactic acid) (PLLA) for enhanced human bone marrow mesenchymal stem cell (hMSC) chondrogenic differentiation. Specifically, RNTs are a new class of biomimetic supramolecular nanomaterial obtained through the self-assembly of low-molecular-weight modified guanine/cytosine DNA base hybrids (the G∧C motif) in an aqueous environment. In this study, we synthesized a novel twin G∧C-based RNT (TB-RGDSK) functionalized with cell-favorable arginine-glycine-aspartic acid-serine-lysine (RGDSK) integrin binding peptide and a twin G∧C based RNT with an aminobutane linker molecule (TBL). hMSC adhesion, proliferation and chondrogenic differentiation were evaluated in vitro in scaffold groups consisting of biocompatible PLLA with TBL, 1:9 TB-RGDSK:TBL, and TB-RGDSK, respectively. Our results show that RNTs can remarkably increase total glycosaminoglycan, collagen, and protein production when compared to PLLA controls without nanotubes. Furthermore, the TB-RGDSK with 100% well-organized RGDSK peptides achieved the highest chondrogenic differentiation of hMSCs. The current in vitro study illustrated that RNT nanotopography and surface chemistry played an important role in enhancing hMSC chondrogenic differentiation thus making them promising for cartilage regeneration.
- Bone Preservation in Dehiscence-Type Defects Using Composite Biphasic Calcium Sulfate Plus Biphasic Hydroxyapatite/β-Tricalcium Phosphate Graft: A Histomorphometric Case Series in Canine Mandible. [Journal Article]
- Implant Dent 2013 Dec; 22(6):590-5.
To examine bone formation in dehiscence defects using biphasic hydroxyapatite/β-tricalcium phosphate plus biphasic calcium sulfate (BCP/BCS).After extractions, 24 mandibular buccal dehiscence defects (3 × 3 mm) were treated with BCP/BCS (E), membrane (MC), or control (NC). Histology and histomorphometric analysis were performed.After 6 weeks, bone formation was noticeable in most sites. In subsequent phases, the woven bone was gradually remodeled into lamellar bone and marrow. Vertical new bone height in the E and MC groups (1.06 and 0.85 mm.) was substantially greater than that in the NC group (-0.28 mm). For all groups, there was an overall increase in the height of the newly formed bone through the observation. At week 12, the vertical bone height was 1.95, 2.07, and 0.29 mm, respectively. The mean new bone area in the E and MC groups was much greater than that in the NC group (2.85, 2.80, and -0.20 mm, respectively). Percent new bone in all 3 groups was similar (36.25%, 34.84%, and 28.34%, respectively).This study demonstrates the efficacy of BCP/BCS graft for bone augmentation in dehiscence-type extraction socket defect.
- Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids. [Journal Article]
- PeerJ 2013.:e182.
The tube-crested hadrosaurid dinosaur Parasaurolophus is remarkable for its unusual cranial ornamentation, but little is known about its growth and development, particularly relative to well-documented ontogenetic series for lambeosaurin hadrosaurids (such as Corythosaurus, Lambeosaurus, and Hypacrosaurus). The skull and skeleton of a juvenile Parasaurolophus from the late Campanian-aged (∼75.5 Ma) Kaiparowits Formation of southern Utah, USA, represents the smallest and most complete specimen yet described for this taxon. The individual was approximately 2.5 m in body length (∼25% maximum adult body length) at death, with a skull measuring 246 mm long and a femur 329 mm long. A histological section of the tibia shows well-vascularized, woven and parallel-fibered primary cortical bone typical of juvenile ornithopods. The histological section revealed no lines of arrested growth or annuli, suggesting the animal may have still been in its first year at the time of death. Impressions of the upper rhamphotheca are preserved in association with the skull, showing that the soft tissue component for the beak extended for some distance beyond the limits of the oral margin of the premaxilla. In marked contrast with the lengthy tube-like crest in adult Parasaurolophus, the crest of the juvenile specimen is low and hemicircular in profile, with an open premaxilla-nasal fontanelle. Unlike juvenile lambeosaurins, the nasal passages occupy nearly the entirety of the crest in juvenile Parasaurolophus. Furthermore, Parasaurolophus initiated development of the crest at less than 25% maximum skull size, contrasting with 50% of maximum skull size in hadrosaurs such as Corythosaurus. This early development may correspond with the larger and more derived form of the crest in Parasaurolophus, as well as the close relationship between the crest and the respiratory system. In general, ornithischian dinosaurs formed bony cranial ornamentation at a relatively younger age and smaller size than seen in extant birds. This may reflect, at least in part, that ornithischians probably reached sexual maturity prior to somatic maturity, whereas birds become reproductively mature after reaching adult size.
- Periostin deficiency increases bone damage and impairs injury response to fatigue loading in adult mice. [Journal Article, Research Support, Non-U.S. Gov't]
- PLoS One 2013; 8(10):e78347.
Bone damage removal and callus formation in response to fatigue loading are essential to prevent fractures. Periostin (Postn) is a matricellular protein that mediates adaptive response of cortical bone to loading. Whether and how periostin influences damage and the injury response to fatigue remains unknown. We investigated the skeletal response of Postn(-/-) and Postn(+/+) mice after fatigue stimulus by axial compression of their tibia. In Postn(+/+) mice, cracks number and surface (CsNb, CsS) increased 1h after fatigue, with a decrease in strength compared to non-fatigued tibia. At 15 days, CsNb had started to decline, while CtTV and CtBV increased in fatigued vs non-fatigued tibia, reflecting a woven bone response that was present in 75% of the fatigued bones. Cortical porosity and remodelling also prominently increased in the fatigued tibia of Postn(+/+) mice. At 30 days, paralleling a continuous removal of cortical damage, strength of the fatigued tibia was similar to the non-fatigue tibia. In Postn(-/-) mice, cracks were detectable even in the absence of fatigue, while the amount of collagen crosslinks and tissue hardness was decreased compared to Postn(+/+). Fatigue significantly increased CsNb and CsS in Postn(-/-), but was not associated with changes in CtTV and CtBV, as only 16% of the fatigued bones formed some woven bone. Cortical porosity and remodelling did not increase either after fatigue in Postn(-/-), and the level of damage remained high even after 30 days. As a result, strength remained compromised in Postn(-/-) mice. Contrary to Postn(+/+), which osteocytic lacunae showed a change in the degree of anisotropy (DA) after fatigue, Postn(-/-) showed no DA change. Hence periostin appears to influence bone materials properties, damage accumulation and repair, including local modeling/remodeling processes in response to fatigue. These observations suggest that the level of periostin expression could influence the propensity to fatigue fractures.