Beta-tricalcium Phosphate Research Articles

Gap healing after medial open-wedge high tibial osteotomy using injectable beta-tricalcium phosphate.

The study aim was to evaluate gap healing after medial open-wedge high tibial osteotomy (MOWHTO) using novel injectable beta-tricalcium phosphate (β-TCP) as gap filler. We also aimed to evaluate radiographic and clinical outcome of MOWHTO using injectable β-TCP. Consecutive 28 patients underwent MOWHTO using anatomical locking plate fixation, and β-TCP was injected as gap filler. Serial radiographs and computed tomography were taken at postoperative 3 and 12 months, and gap healing was assessed. Lower extremity alignment was measured on radiographs, and clinical outcome was evaluated by determining International Knee Documentation Committee, Western Ontario and McMaster Universities Arthritis Index, and visual analogue scales for pain scores. Progress of bone union was found on plain radiographs, and the mean ratio (β-TCP/host bone) of computed tomography attenuation values significantly changed from postoperative 3 months to 12 months, which indicates maturation of β-TCP. The average mechanical femoro-tibial angle changed from 4.1° varus (preoperative) to 4.8° valgus (3 months) and maintained until 12 months (4.3° valgus). All clinical outcome scores were significantly improved and no significant complication occurred. Using injectable β-TCP as gap filler for MOWHTO resulted in satisfactory gap healing without complication. Radiographic and clinical results were satisfactory. The injectable β-TCP can be a safe and effective option for gap filling after MOWHTO.

Maxillary Sinus Elevation Surgery with ChronOS and Autogenous Bone Graft: Immunohistochemical Assessment of RUNX2, VEGF, TRAP, and Osteocalcin.

The purpose of this study was to evaluate a composite graft of ChronOS, a beta-tricalcium phosphate (β-TCP), mixed 1:1 with an autogenous bone graft in human maxillary sinus augmentation. A total of 12 maxillary sinuses were grafted with an autogenous bone graft (control group), and 9 maxillary sinuses were grafted with ChronOS mixed 1:1 with an autogenous bone graft (test group). After 6 months, biopsy samples were obtained concurrent to the placement of dental implants and were subjected to histomorphometric and immunohistochemical analyses for Runt-related transcription factor 2 (RUNX2), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase, and osteocalcin. Histologic analysis of samples obtained from the test group revealed the presence of immature bone, while samples from the control group indicated lamellar bone formation. However, both types of bone grafts were well vascularized. The new bone formation averaged 25.4% ± 6.4% in the test group and 38.6% ± 10.5% in the control group (P = .001). Immunostaining of samples in the test group showed high cellular turnover. The outcomes of this study demonstrate a delay in bone formation but intense cellular differentiation after 6 months of bone graft healing in the test group. The amount of immature bone and the immunostaining for RUNX2 and VEGF provide evidence of an osteogenic pathway that can improve the bone formation rate.

Radiographic and computed tomographic evaluation of bone union after medial opening wedge high tibial osteotomy with filling gap

BackgroundWe evaluated bone union and remodelling in patients undergoing opening-wedge high tibial osteotomy (OWHTO) with bone gaps filled with beta-tricalcium phosphate. We examined the effectiveness of radiography and computed tomography (CT) for the evaluation of bone union and remodelling, and investigated whether lateral hinge fractures affected bone union. MethodsSixty-six cases underwent OWHTO with a combination of a TomoFix plate and a bone substitute. Bone union and remodelling were assessed using the rating system for OWHTO at three and six months, postoperatively. ResultsRadiographic evaluation showed that bone union of the lateral hinge was 85% and 100% at three and six months, respectively. Based on CT evaluation, bone union of the lateral hinge and the flange was achieved in all cases at six months, and the bone union of the posterior cortex reached Zone 3 in 83% at six months. Based on radiographic evaluation, bone remodelling phases of bone substitute had progressed in each zone in six months compared with three months. Radiographic and CT analyses identified a Takeuchi type I hinge fracture in fourteen (21.2%) and five (7.6%) knees at two weeks postoperatively, respectively. There were no differences in bone union with and without the lateral hinge fracture. ConclusionsThe use of CT enabled us to evaluate the bone union of the flange and the extent of the bone union of the posterior cortex. Plain radiographs are useful to evaluate bone union of the lateral hinge similar to CT analysis. The presence of a Takeuchi type I hinge fracture did not affect bone union.

Multimodal analysis of in vivo resorbable CaP bone substitutes by combining histology, SEM, and microcomputed tomography data.

This study introduced and demonstrated a new method to investigate the repair process of bone defects using micro- and macroporous beta-tricalcium phosphate (β-TCP) substitutes. Specifically, the new method combined and aligned histology, SEM, and preimplantation microcomputed tomography (mCT) data to accurately characterize tissue phases found in biopsies, and thus better understand the bone repair process. The results included (a) the exact fraction of ceramic remnants (CR); (b) the fraction of ceramic resorbed and substituted by bone (CSB); and (c) the fraction of ceramic resorbed and not substituted by bone (CNSB). The new method allowed in particular the detection and quantification of mineralized tissues within the 1-10 µm micropores of the ceramic ("micro-bone"). The utility of the new method was demonstrated by applying it on biopsies of two β-tricalcium phosphate bone substitute groups with two differing macropore sizes implanted in an ovine model for 6weeks. The total bone deposition and ceramic resorption of the two substitute groups, having macropore sizes of 510 and 1220 μm, were 25.1 ± 8.1% and 67.5 ± 3.2%, and 24.4 ± 4.1% and 61.4 ± 6.5% for the group having the larger pore size. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1567-1577, 2018.

Clinical Study of Bone Regeneration by Conditioned Medium From Mesenchymal Stem Cells After Maxillary Sinus Floor Elevation.

This clinical study was undertaken to evaluate the safety of use of the secretome of bone marrow-derived mesenchymal stem cells (MSC-CM) for maxillary sinus floor elevation (SFE). MSC-CM was prepared from conditioned medium from human bone marrow-derived MSCs. Six partially edentulous patients were enrolled in the study. MSC-CM was mixed with porous beta-tricalcium phosphate (β-TCP) and implanted in 4 patients (experimental group), whereas only β-TCP was implanted in the other 2 patients (control group). Six months after SFE, bone biopsies and histological assessments were performed. Bone formation was clinically confirmed in all cases. Although Hounsfield units in computed tomography images were not significantly different between the groups, histological analysis revealed a significant difference in newly formed bone area between the groups. In particular, bone volume in the center of the augmented area was significantly greater in the MSC-CM group. Newly formed bone consisted of lamellar bone in the MSC-CM group but woven bone in the β-TCP group. The secretome of bone marrow-derived mesenchymal stem cells (MSC-CM) was used safely and has great osteogenic potential for regenerative medicine of bone.

Fracture toughness and R-curve behavior of BCP/YTZP nanocomposites produced using the spark plasma sintering process

The aim of this study is to evaluate the fracture toughness and R-curve behavior of synthesized biphasic calcium phosphate (BCP) and yttria-tetragonal zirconia polygonal (YTZP) nanocomposites produced by spark plasma sintering (SPS) method. BCP comprising of 30 wt% hydroxyapatite and 70 wt% betatricalcium phosphate, was mixed with various amounts of YTZP nanopowder and sintered using SPS at different processing conditions (e.g. various pressures, times, temperatures, cooling and heating rates). Fracture toughness (KIC) of the samples was calculated by the indentation-strength method and the phase composition of the samples was evaluated by x-ray diffractometry (XRD). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) analyses were also utilized to study the powder morphology, microstructure and fractured surfaces of the samples. According to the results, the bulk density can reach to about 97% of the theoretical density using SPS process. The maximum fracture toughness of 3.04 MPa m0.5 was obtained for the sample containing 3 vol% of YTZP (BCP-3SZ) in optimum conditions of the SPS process. The obtained fracture toughness value was approximately triple of the pure BCP (1.07 MPa m0.5) and was comparable with that of the cortical human bone. Rising crack growth resistance (R-curve) behavior of the sample BCP-3SZ at different indentation loads was also observed due to the martensitic phase transformation. Furthermore, YTZP nanoparticles persuade HA to β-TCP phase transformation during the SPS process.

Influence of sol–gel derived strontium–cerium co-substitution in fluorohydroxyapatite and its in-vitro bioactivity

The present study is to investigate the influence of Sr2+ and Ce3+ ions in the structure of fluorohydroxyapatite (FHA) (Ca10(PO4)6F0.5(OH)1.5), a partial substitution of fluorine ion in hydroxyapatite. Co-substitution of Sr2+ and Ce3+ ions improves the osteoblast cell response, an important factor which stimulates the bone formation surrounding the implant material. Sol–gel derived fluorohydroxyapatite samples were co-substituted with Sr2+ and Ce3+ ions [xSr/yCe-FHA, where x = 5–40 mol% of Sr2+ and y = 5–20 mol% of Ce3+]. The intensity variation and shift of Fourier transform infrared bands observed after the co-substitution of Sr2+ and Ce3+ ions confirmed the doping. The X-ray diffraction shows the decrease in crystallite size with Ce3+ concentration and aids in forming beta-tri calcium phosphate and cerium-oxide (CeO) phases. Co-substitution of Sr2+ and Ce3+ increases the microhardness and fracture toughness, while micro structural analysis reveals the decrease in grain size. In-vitro bioactivity studies were conducted on samples using human osteosarcoma MG63 cells to investigate the osteoblast cell response. Co-substitution of cations in fluorohydroxyapatite by sol–gel method influenced the structure, phase formation, mechanical property, and grain size. These factors due to addition of Sr2+ and Ce3+ ions in fluorohydroxyapatite are attributed to the improvement of cell viability and alkaline phosphatase (ALP) activity.

Influence of aluminum substitutions on phase composition and morphology of β - tricalcium phosphate nanopowders

Abstract Al-substituted beta-tricalcium phosphate (β-TCP) nanopowders containing 0–20 mol.% of Al were obtained via precipitation method. The effect of Al content on the phase composition, lattice parameters, crystallite size, specific surface area and morphology of powders was established. Over the substitution range 0 – 1 mol.% the synthesis products consist of single whitlokite-like phase. For 5 – 20 mol.% two separate whitlokite-like phases were indentified: Al enriched Ca 9 Al(PO 4 ) 7 and β-TCP solid solution. For both phases, the general trend is a reduction of cell parameters, as well as decrease of crystalline and particle size with an increase of Al content. Powder with 20 mol.% of Al consists of 84 wt% of Ca 9 Al(PO 4 ) 7 and 16 wt% of β-TCP solid solution and is formed by spherical particles with average size of 20–30 nm and specific surface area of 129 m 2 /g.

Resorption of calcium phosphate materials: Considerations on the in vitro evaluation

Literature is quite abundant concerning the resorption of calcium phosphates. However, articles on in vitro acellular dissolution tests are scarcer, although these immersion experiments are often considered a first step in establishing a predictive dissolution test and understanding the resorption mechanisms. Also, the comparison of results obtained after immersion in model fluids reveals large discrepancies.The first part of this paper is a literature review focused on in vitro aging of apatite, dicalcium phosphate dihydrate (DCPD) and beta tricalcium phosphate (β-TCP). In the second part, experimental findings obtained by immersing DCPD and β-TCP samples in TRIS and PBS solutions for different times demonstrate the influence of the immersion conditions and possible artefacts induced by the experimental protocols. Suggestions are provided to improve the design of in vitro experiments. In addition, the interest to follow-up at the same time and at a local scale physico-chemical, microstructural and mechanical properties is discussed.

Influence of surface acid and base sites on the Guerbet coupling of ethanol to butanol over metal phosphate catalysts

Hydroxyapatite (HAP; Ca10(PO4)6(OH)2) is a well-recognized catalyst for the Guerbet coupling of ethanol to butanol. In an effort to explore the role of the anion components of the catalyst, steady-state, gas phase catalytic coupling of ethanol to butanol was investigated at 633K and atmospheric pressure over beta tricalcium phosphate (β-TCP; β-Ca3(PO4)2) and fluorine-substituted hydroxyapatite (FAP; Ca10(PO4)6F2). Both β-TCP and FAP catalysts were catalytically active for butanol formation, leading to ∼35% selectivity at low conversion, suggesting that the PO43− group contributes to the active acid-base site pair for butanol formation during ethanol coupling over HAP. Co-feeding water, a product of ethanol coupling, revealed weaker inhibition of the rate over HAP relative to MgO, confirming the potential negative influence of strong base sites on coupling catalysts. Catalytic reactions of ethanol over Mg3(PO4)2, β-TCP, and Sr3(PO4)2 catalysts demonstrated the importance of Lewis acidity of the metal phosphates on the reaction. Relatively strong Lewis acid sites on the Mg3(PO4)2 surface (Mg2+ cations) favored undesired ethanol dehydration to ethene (36% selectivity) and diethyl ether (52% selectivity) whereas the Sr3(PO4)2 catalyst predominantly catalyzed ethanol dehydrogenation to acetaldehyde (91% selectivity) at a rate significantly higher than that observed over the other catalysts. Evidently, the β-TCP exposes intermediate-strength Lewis acid sites provided by surface Ca2+ cations that enable the material to effectively convert ethanol to butanol with 35% selectivity.

<b>Analysis of indicators of osteogenesis, cytotoxicity and genotoxicity of an experimental β-TCP compared to other bone substitutes

The aim of this study was to evaluate the indicators of osteogenesis, cytotoxicity and genotoxicity of an experimental beta tri-calcium phosphate (experimental β-TCP) compared with two other bone substitutes: bovine hydroxyapatite (HA) (Bio-Oss ® - Geistlich) and beta tri-calcium phosphate (β-TCP - Bionnovation). The cell viability and genotoxicity were measured by MTT and MNT assay, respectively. The indicators of osteogenesis were analyzed by alkaline phosphatase activity, total protein content, and calcium deposition. The MTT and MNT assay showed that none of the tested materials was cytotoxic nor genotoxic. Concerning the indicators of osteogenesis, it was observed that cells in contact with all the materials were able to induce the osteogenesis and this process was influenced by the period of the cell culture in contact with bone substitutes. Based on the results of this study, it was concluded that this experimental β-TCP appears to be a promising material as a bone substitute.

Induced membrane technique using beta-tricalcium phosphate for reconstruction of femoral and tibial segmental bone loss due to infection: technical tips and preliminary clinical results.

This study aimed to provide preliminary evidence regarding effectiveness of grafting beta-tricalcium phosphate (β-TCP) combined with a cancellous autograft for treating nonunion of long bones in the lower extremity due to infection by evaluating clinical and radiological outcomes. We retrospectively reviewed the clinical and radiological results in seven patients (six men, one woman; median age 39years) treated by the induced membrane technique for nonunion of the femur or tibia due to infection. In the second stage of the procedure, the bony defect was filled with a combination of autologous cancellous bone and β-TCP, which were mixed in approximately the same proportions. The time interval between the second stage of the procedure and bone healing was investigated. Radiographic characteristics including maximum bone gap and radiographic apparent bone gap were evaluated. The median follow-up period was 14months. Bone healing was achieved in a median of sixmonths after the second procedure. The median maximum bone gap and radiographic apparent bone gap were 55mm and 34mm, respectively. Use of β-TCP, which has osteoconductive ability, with an autograft provided good clinical and radiological outcomes. The findings of this preliminary study suggest the potential of β-TCP as a useful bone substitute for autografts in the induced membrane technique. Our findings suggest that β-TCP may be an effective extender when using the induced membrane technique.

Fabrication and characterization of two-layered nanofibrous membrane for guided bone and tissue regeneration application

Membranes used in dentistry act as a barrier to prevent invasion of intruder cells to defected area and obtains spaces that are to be subsequently filled with new bone and provide required bone volume for implant therapy when there is insufficient volume of healthy bone at implant site. In this study a two-layered bioactive membrane were fabricated by electrospinning whereas one layer provides guided bone regeneration (GBR) and fabricated using poly glycerol sebacate (PGS)/polycaprolactone (PCL) and Beta tri-calcium phosphate (β-TCP) (5, 10 and 15%) and another one containing PCL/PGS and chitosan acts as guided tissue regeneration (GTR). The morphology, chemical, physical and mechanical characterizations of the membranes were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), tensile testing, then biodegradability and bioactivity properties were evaluated. In vitro cell culture study was also carried out to investigate proliferation and mineralization of cells on different membranes.Transmission electron microscope (TEM) and SEM results indicated agglomeration of β-TCP nanoparticles in the structure of nanofibers containing 15% β-TCP. Moreover by addition of β-TCP from 5% to 15%, contact angle decreased due to hydrophilicity of nanoparticles and bioactivity was found to increase. Mechanical properties of the membrane increased by incorporation of 5% and 10% of β-TCP in the structure of nanofibers, while addition of 15% of β-TCP was found to deteriorate mechanical properties of nanofibers. Although the presence of 5% and 10% of nanoparticles in the nanofibers increased proliferation of cells on GBR layer, cell proliferation was observed to decrease by addition of 15% β-TCP in the structure of nanofibers which is likely due to agglomeration of nanoparticles in the nanofiber structure. Our overall results revealed PCL/PGS containing 10% β-TCP could be selected as the optimum GBR membrane in view point of physical and mechanical properties along with cell behavior. PCL/PGS nanofibers containing 10% β-TCP were electrospun on the GTR layer for fabrication of final membrane. Addition of chitosan in the structure of PCL/PGS nanofibers was found to decrease fiber diameter, contact angle and porosity which are favorable for GTR layer. Two-layered dental membrane fabricated in this study can serve as a suitable substrate for application in dentistry as it provides appropriate osteoconductivity and flexibility along with barrier properties.

Cranioplasty with Adipose-Derived Stem Cells, Beta-Tricalcium Phosphate Granules and Supporting Mesh: Six-Year Clinical Follow-Up Results.

Several alternative techniques exist to reconstruct skull defects. The complication rate of the cranioplasty procedure is high and the search for optimal materials and techniques continues. To report long‐term results of patients who have received a cranioplasty using autologous adipose‐derived stem cells (ASCs) seeded on beta‐tricalcium phosphate (betaTCP) granules. Between 10/2008 and 3/2010, five cranioplasties were performed (four females, one male; average age 62.0 years) using ASCs, betaTCP granules and titanium or resorbable meshes. The average defect size was 8.1 × 6.7 cm2. Patients were followed both clinically and radiologically. The initial results were promising, with no serious complications. Nevertheless, in the long‐term follow‐up, three of the five patients were re‐operated due to graft related problems. Two patients showed marked resorption of the graft, which led to revision surgery. One patient developed a late infection (7.3 years post‐operative) that required revision surgery and removal of the graft. One patient had a successfully ossified graft, but was re‐operated due to recurrence of the meningioma 2.2 years post‐operatively. One patient had an uneventful clinical follow‐up, and the cosmetic result is satisfactory, even though skull x‐rays show hypodensity in the borders of the graft. Albeit no serious adverse events occurred, the 6‐year follow‐up results of the five cases are unsatisfactory. The clinical results are not superior to results achieved by conventional cranial repair methods. The use of stem cells in combination with betaTCP granules and supporting meshes in cranial defect reconstruction need to be studied further before continuing with clinical trials. Stem Cells Translational Medicine 2017;6:1576–1582

Beta-tricalcium phosphate for orthopedic reconstructions as an alternative to autogenous bone graft

A total of 50 patients were enrolled in a controlled, non-inferiority clinical trial to compare the safety and efficacy of β-TCP (25 patients) with those of autograft (25 patients) in indications requiring usually autograft. These 50 patients were categorized according to the etiology and morphology of the 54 bone defects resulting from elective surgical procedures, such as 34 open-wedge high tibial osteotomies, and 20 osteonecrosis treatments with core decompression. Radiographic (healing process with or without integration of β-TCP), clinical (no other surgical procedure), functional outcomes and safety (with or without complications) were assessed through fifty-two weeks postoperatively. With regard to the primary endpoint (radiographic evolution), the fusion rate of the 34 open-wedge osteotomies was 100% (17 among 17) for patients in the group with β-TCP compared with 94% (16 among 17) for patients in the autograft group. For the 20 cavitary defects (osteonecrosis), the radiographic union rates, as determined by the presence of osseous bridging, were 100% for patients in the group with β-TCP and 100% for those in the autograft group. Clinically at one year, all quality-of-life and functional outcome data supported non-inferiority of β-TCP compared with autograft, and patients in the β-TCP group were found to have less pain and an improved safety profile. Treatment with β-TCP resulted in comparable fusion rates, less pain and fewer side effects as compared with treatment with autograft. This study established clinical parameters where the β-TCP alone can successfully support the osteogenic process.

In vitro osteoblast gene expression and differentiation atop of titanium blocks laser coated with multilayer biphasic calcium phosphate/titanium nanocomposites

In this paper, we presented a comprehensive and complete study of the biological behavior of the bone forming cells, osteoblasts, on the graded nano-biphasic calcium-phosphate/Ti coatings of different compositions by investigating bone cell proliferation, bone cell viability, markers for bone cell differentiation and key genes that encode for known proteins which are important for de novo extracellular matrix and osteoid production. We prepared the gradient nano hydroxyapatite and titanium nanoparticles (nanoTi) composite coating on Ti-6Al-4V implants. Due to the size effects of nano-Ti, this process could be used to sinter nano HA/nanoTi composite coating at low temperature. The gradient coating with different concentration of HA could be prepared by controlling the composition of the nanoparticles, and the composition of nanoHA and beta-tricalcium phosphate in the coating could be varied by controlling the laser power. The coating was characterized with XRD and SEM, and exhibited excellent biocompatibility as well as bioactivity to UMR-106 cells.

Histological and Histomorphometrical Determination of the Biogradation of β-Tricalcium Phosphate Granules in Maxillary Sinus Floor Augmentation: A Prospective Observational Study.

We have recently used highly pure β-TCP (beta-tricalcium phosphate) as the bone grafting material to avoid highly invasive autogenous bone grafting. We evaluated the osseoconduction potential of highly pure β-TCP in sinus augmentation surgery treatment. The study group comprised 13 patients who underwent maxillary sinus floor augmentation with β-TCP alone. Seven patients underwent sinus augmentation and implant placement simultaneously. Six patients were treated with a staged approach. Six months after surgery, specimens were obtained from 7 patients (for lateral biopsy) and 6 patients (for vertical biopsy). Histological and histomorphometrical analysis showed a mean bone proportion of 30.8% (vertical) and 12.0% (lateral) for new bone formation and good integration of the β-TCP. New bone formation was lower in the lateral biopsy specimens than in the vertical. Highly pure β-TCP is a safe bone-grafting material with superior osteoconductive properties. Histologic and radiographic examinations indicate that β-TCP is slowly resorbed, which results in unresorbed graft material remaining even 6 months after the procedure, and that new bone replacement occurs slowly for approximately 1 year.

Chitosan/gelatin/platelet gel enriched by a combination of hydroxyapatite and beta-tricalcium phosphate in healing of a radial bone defect model in rat

This study compared the regeneration potentials of the hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) alone or in combination with a HA:TCP ratio of 30:70 in the critical-sized radial bone defects of rats. Bilateral 60 radial bone defects created were randomly divided into six equal groups (n=10 defects/group) including autograft, untreated or defect, chitosan-gelatin-platelet gel (CGP), CGP-HA, CGP-TCP and CGP-HA/TCP. The defects were evaluated by radiography, morphology, histopathology, histomorphometry, CT scan, scanning electron microscopy and biomechanical testing after eight weeks. Compared with the untreated and CGP-HA groups, the CGP and CGP-HA/TCP groups showed significantly higher new bone formation, bone volume, and mechanical properties. The CGP-HA and CGP-TCP scaffolds showed low biodegradability, whereas the CGP scaffolds were completely degraded. Osteoconductivity and osteoinductivity of the CGP and CGP-HA/TCP scaffolds were superior to the CGP-HA ones. The untreated and CGP-HA groups repaired mostly through fibrosis, while there were evidence of higher bone formation in the autograft, CGP and CGP-HA/TCP groups. In conclusion, addition of HA or β-TCP alone into the CGP scaffolds impaired bone regeneration, while bone regeneration with the CGP and CGP-HA/TCP scaffolds was comparable with the autograft. Therefore, the CGP-HA/TCP scaffold can be a possible option to substitute the autologous bone grafting.

Anterior cervical fusion with interbody cage containing beta-tricalcium phosphate: Clinical and radiological results

AimBeta tricalcium phosphate (beta-TCP) is an osteoconductive, resorbable material. Its clinical effectiveness has been proved in many indications. This study was clinical and radiographic study report obtained in patients undergoing anterior cervical discectomy and fusion ACDF in which PEEK cages were filled beta-TCP in an injectable form. Material and methodsBetween January 2010 and June 2011, 16 consecutive patients underwent ACDF using PEEK cages with beta-TCP. The cohort compromised 10 men and 6 women with a mean age of 45.2 years. The surgery was performed when the patient had myelopathy or radiculopathy with progressive neurological deficit, or failure of conservative treatment (a minimum of 3 months). The patients were evaluated by Odom criteria preoperatively and postoperative 3rd, 6th, 12th and 24th months. Preop and postop pain was evaluated with visual analogue scala (VAS). Disc height and fusion success rates were evaluated. ResultsPreoperative average VAS score was 7.9 (7–10) for neck pain and 8 (7–10) for arm pain. At the final follow-up, these scores became 1.5 and 1.4 for neck and arm pain, respectively. The average improvement rate was 81% for neck pain and 82.5% for arm pain. Postop ODOM's criteria main rate was 3.4. Bone fusion was achieved in 14 segments (70%) at 3rd month, 19 segments (95%) at 12th month follow-up assessment. ConclusionClinical and radiological results revealed that B-TCP is a good alternative synthetic fusion material for cervical interbody fusion.Level of evidence: Level IV, therapeutic study.

Controlled Release of Vanadium from a Composite Scaffold Stimulates Mesenchymal Stem Cell Osteochondrogenesis.

Large bone defects often require the use of autograft, allograft, or synthetic bone graft augmentation; however, these treatments can result in delayed osseous integration. A tissue engineering strategy would be the use of a scaffold that could promote the normal fracture healing process of endochondral ossification, where an intermediate cartilage phase is later transformed to bone. This study investigated vanadyl acetylacetonate (VAC), an insulin mimetic, combined with a fibrous composite scaffold, consisting of polycaprolactone with nanoparticles of hydroxyapatite and beta-tricalcium phosphate, as a potential bone tissue engineering scaffold. The differentiation of human mesenchymal stem cells (MSCs) was evaluated on 0.05 and 0.025wt% VAC containing composite scaffolds (VAC composites) in vitro using three different induction media: osteogenic (OS), chondrogenic (CCM), and chondrogenic/osteogenic (C/O) media, which mimics endochondral ossification. The controlled release of VAC was achieved over 28days for the VAC composites, where approximately 30% of the VAC was released over this period. MSCs cultured on the VAC composites in C/O media had increased alkaline phosphatase activity, osteocalcin production, and collagen synthesis over the composite scaffold without VAC. In addition, gene expressions for chondrogenesis (Sox9) and hypertrophic markers (VEGF, MMP-13, and collagen X) were the highest on VAC composites. Almost a 1000-fold increase in VEGF gene expression and VEGF formation, as indicated by immunostaining, was achieved for cells cultured on VAC composites in C/O media, suggesting VAC will promote angiogenesis in vivo. These results demonstrate the potential of VAC composite scaffolds in supporting endochondral ossification as a bone tissue engineering strategy.