Bioactive Bone Cement Research Articles

Analyzing the Bioactivity of a Novel Bone Cement: An In Vitro Study.

To analyze the effect of bioactivebone cement (BBC) placed in a phosphate buffer saline solution in comparison to mineral trioxide aggregate (MTA). Ten samples each of BBC (group 1) and MTA (group 2) were prepared and stored in a phosphate buffer saline solution. After three days of storage, white precipitates were formed on the surface of the samples. The solution with precipitates from each sample was analyzed for the presence of calcium and phosphate ions with coupled plasma atomic spectroscopy. BBC showed a significant amount of calcium and phosphate release after a seven-day storage period in phosphate buffer saline solution. Calcium release was significantly higher in group 1 (MTA) (p < 0.001) compared to that in group 2 (BBC), while group 2 (BBC) (p < 0.001) exhibited greater phosphate release compared to group 1 (MTA). BBC (group 2) retains its bioactivity when it comes into contact with a stimulated oral environment (STF). This demonstrates that BBC is bioactive in a simulated oral environment. Moreover, it retainedgood handling properties and could be easily manipulated into a dough form. Clinically, in cases of apical surgery, internal resorption or perforation repair where material placement poses difficulty, BBC will prove to be beneficial.

Effect of blood and artificial saliva contamination on marginal adaptation and sealing ability of different retrograde filling materials: A comparative analysis.

The objective of this study was to evaluate the effect of blood and artificial salivary contamination of different root-end filling materials on microleakage using a confocal laser scanning microscope and on marginal adaptation using a scanning electron microscope. Eighty noncarious single-rooted teeth with mature apices were taken. After retro-cavity preparation, they were randomly assigned into two major groups (n = 40). They were contaminated with blood and artificial saliva, respectively. Each major group was divided randomly into four subgroups (n = 10) and filled as follows: Subgroup A, Biodentine; Subgroup B, bioactive bone cement; Subgroup C, Cention N; and Subgroup D, Bio-C Repair. The samples were sectioned transversely at 1 and 2 mm from the root apex and checked under a confocal laser scanning microscope for microleakage and under an scanning electron microscope for marginal adaptation. The average mean values were calculated. Independent samples t-tests, paired t-tests, and one-way analysis of variance with Tukey's post hoc tests were done to analyze the data. All the tested materials showed marginal gaps and dye leakage. The Bio-C Repair group showed the least mean marginal gap and dye leakage values, followed by bioactive bone cement, Biodentine, and Cention N, respectively, in both blood and artificial saliva contamination. However, the mean marginal gaps and dye leakage between the major groups were statistically insignificant. In an overall comparison, Bio-C Repair was found to be superior in terms of marginal adaptation and sealing ability under the test conditions.

Intelligent and Bioactive Osseointegration of the Implanted Piezoelectric Bone Cement with the Host Bone Is Realized by Biomechanical Energy.

Poly methyl methacrylate (PMMA) bone cement is widely used in orthopedic surgeries, including total hip/knee arthroplasty and vertebral compression fracture treatment. However, loosening due to bone resorption is a common mid-to-late complication. Therefore, developing bioactive bone cement that promotes bone growth and integration is key to reducing aseptic loosening. In this study, we developed a piezoelectric bone cement comprising PMMA and BaTiO3 with excellent electrobioactivity and further analyzed its ability to promote bone integration. Experiments demonstrate that the PMMA and 15 wt % BaTiO3 cement generated an open-circuit voltage of 37.109 V under biomimetic mechanical stress, which effectively promoted bone regeneration and interfacial bone integration. In vitro experiments showed that the protein expression levels of ALP and RUNX-2 in the 0.65 Hz and 20 min group increased by 1.74 times and 2.31 times. In vivo experiments confirmed the osteogenic ability of PMMA and 15 wt % BaTiO3, with the increment of bone growth in the non-movement and movement groups being 4.67 and 4.64 times, respectively, at the second month after surgery. Additionally, Fluo-4 AM fluorescence staining and protein blotting experiments verified that PMMA and 15 wt % BaTiO3 electrical stimulation promoted osteogenic differentiation of BMSCs by activating calcium-sensitive receptors and increasing calcium ion inflow by 1.41 times when the stimulation reached 30 min. Therefore, piezoelectric bioactive PMMA and 15 wt % BaTiO3 cement has excellent application value in orthopedic surgery systems where stress transmission is prevalent.

Radiological evaluation of cemented acetabular component in primary total hip arthroplasty with or without interface bioactive bone cement technique

PurposeWe evaluated the medium-term radiological outcomes of the interface bioactive bone cement (IBBC) technique used in the acetabular component in primary cemented total hip arthroplasty (THA). MethodsIn total, 79 patients (88 hips) who underwent primary THA at our hospital between January 2004 and April 2009 were divided into the non-IBBC (NIBBC; n ​= ​39 patients, 44 hips) and IBBC (n ​= ​40 patients, 44 hips) groups. A clear zone (CZ) at the cement-bone interface around the cup was evaluated 5 and 10 years postoperatively. The CZ score, which indicates the spread of the CZ, and loosening of the cup (CZ ​> ​2 ​mm on all sides or movement of the cup >4°) were also evaluated. ResultsNo patient had loosening of the cup. The mean patient age at surgery was 66.5 ​± ​9.2 years in the NIBBC group and 61.9 ​± ​7.7 years in the IBBC group (p ​= ​0.012). At 5 years postoperatively, the incidence of CZ was 36.4 ​% in the NIBBC group and 18.2 ​% in the IBBC group (p ​= ​0.056). At 10 years postoperatively, the incidence of CZ was 36.4 ​% in the NIBBC group and 20.1 ​% in the IBBC group (p ​= ​0.098). Age at surgery (p ​= ​0.045) significantly affected the incidence of CZ at 5 years but not at 10 years. The IBBC technique (p ​= ​0.042) and age at surgery (p ​= ​0.028) significantly affected the CZ score at 5 years. The IBBC technique (p ​= ​0.036) significantly affected the CZ score at 10 years. ConclusionsThe IBBC technique resulted in a significantly lower CZ score than the NIBBC technique in patients undergoing THA.

Comparison of root end sealing ability of three retrograde filling materials in teeth with root apices resected at 900 using dye penetration method under fluorescent microscope

Background: The main factor contributing to surgical endodontic dissatisfaction is an inadequate seal at the apex. The material used for retrograde filling should prevent contaminants from penetrating periradicular tissue. So the objective of this study was to evaluate and compare the ability of Mineral Trioxide Aggregate (MTA), Zirconomer and bioactive bone cement to seal the root end as retrograde filling material with apices resected at 900 angles using dye penetration method under fluorescent microscope. Methods: 36 extracted teeth samples were cut at Cementoenamel junction horizontally. Following the customary protocols of, cleaning, shaping and obturation with gutta percha and AH Plus sealer, resection of samples was done 3mm at the apical end at 90 degree angle along the long axis of the tooth with the help of diamond disc. A depth of 3mm of root end cavity was made with diamond coated ultrasonic surgical tip. The samples were randomly allocated in 3 groups: Group I: MTA ; Group II : Zirconomer; Group III: Bioactive Bone Cement . Coating of nail varnish was done with the roots except at the tip. Each material was compacted in the retrocavity using small pluggers. All the retrofilled samples were kept in acridine orange for 24 hours, following which cleaning &amp; bucco-lingual sectioning (vertical) was carried out. Confocal laser scanning fluorescent microscope was used for checking the dye penetration in these samples thereby evaluating sealing ability. Results: Group III (Bioactive Bone Cement) had the highest root end sealing ability with mean (1.4 ± 0.51) followed by Group I (MTA) (2.3 ± 0.65) and lastly Group II (Zirconomer) (4.1 ± 0.57) as root end filling material with apices resected at 900 angle using dye penetration method under fluorescent microscopy which were statistically significant. Conclusions: Bioactive Bone cement can be recommended as an acceptable retrograde filling material.

The effect of tricalcium silicate incorporation on bioactivity, injectability, and mechanical properties of calcium sulfate/bioactive glass bone cement

The conventional Polymethyl methacrylate (PMMA) bone cement is not biodegradable and not bioactive to bond with the native bone and causes tissue necrosis resulting from its high exothermic polymerization. Hence, biodegradable bioactive bone cements with suitable setting time and mechanical properties should be introduced. In this study, novel bioactive bone cements containing Calcium Sulfate Hemihydrate (CSH), Bioactive Glass (BG), and Tricalcium Silicate (TSC) were developed. Firstly, CSH and BG binary system was optimized based on preliminary setting and mechanical tests. Secondly, the composite bioactive bone cements were obtained by adding different quantities of TCS to the optimized CS-BG (1.3:1 wt % ratio) system. All groups exhibited desirable handling properties, an initial setting time of lower than 15 min, injectability of greater than 85%, and controlled degradability. Moreover, they demonstrated initial compressive strength values of higher than 12 MPa, superior to trabecular bone. After 28 days of hydration, the compressive strength of the cement containing 30% TCS reached 51.04 MPa. Furthermore, the present bone cements showed favorable bioactivity and bone-bonding ability as a result of calcium carbonate and hydroxyapatite (HA) formation. Furthermore, this novel bone cement exhibited appropriate biocompatibility and mesenchymal stem cell attachment, suggesting its potential for clinical applications.

Biological Fixation of Bioactive Bone Cement in Vertebroplasty: The First Clinical Investigation of Borosilicate Glass (BSG) Reinforced PMMA Bone Cement.

PMMA bone cement has been clinically used for decades in vertebroplasty due to its high mechanical strength and satisfactory injectability. However, the interface between bone and PMMA is fragile and more prone to refracture in situ because PMMA lacks a proper biological response from the host bone with minimal bone integration and dense fibrous tissue formation. Here, we modified PMMA by incoporating borosilicate glass (BSG) with a dual glass network of [BO3] and [SiO4], which spontaneously modulates immunity and osteogenesis. In particular, the BSG modified PMMA bone cement (abbreviated as BSG/PMMA cement) provided an alkaline microenvironment that spontaneously balanced the activities between osteoclasts and osteoblasts. Furthermore, the trace elements released from the BSGs enhanced the osteogenesis to strengthen the interface between the host bone and the implant. This study shows the first clinical case after implantation of BSG/PMMA for three months using the dual-energy CT, which found apatite nucleation around PMMA instead of fibrous tissues, indicating the biological interface was formed. Therefore, BSG/PMMA is promising as a biomaterial in vertebroplasty, overcoming the drawback of PMMA by improving the biological response from the host bone.

The Ability of Biodegradable Thermosensitive Hydrogel Composite Calcium-Silicon-Based Bioactive Bone Cement in Promoting Osteogenesis and Repairing Rabbit Distal Femoral Defects.

Osteoporotic vertebral compression fractures are a global issue affecting the elderly population. To explore a new calcium silicate bone cement, polylactic acid (PLGA)–polyethylene glycol (PEG)–PLGA hydrogel was compounded with tricalcium silicate (C3S)/dicalcium silicate (C2S)/plaster of Paris (POP) to observe the hydration products and test physical and chemical properties. The cell compatibility and osteogenic capability were tested in vitro. The rabbit femoral condylar bone defect model was used to test its safety and effectiveness in vivo. The addition of hydrogel did not result in the formation of a new hydration product and significantly improved the injectability, anti-washout properties, and in vitro degradability of the bone cement. The cholecystokinin octapeptide-8 method showed significant proliferation of osteoblasts in bone cement. The Alizarin red staining and alkaline phosphatase activity test showed that the bone cement had a superior osteogenic property in vitro. The computed tomography scan and gross anatomy at 12 weeks after surgery in the rabbit revealed that PLGA-PEG-PLGA/C3S/C2S/POP was mostly degraded, with the formation of new bone trabeculae and calli at the external orifice of the defect. Thus, PLGA-PEG-PLGA/C3S/C2S/POP composite bone cement has a positive effect on bone repair and provides a new strategy for the clinical application of bone tissue engineering materials.

An injectable pH neutral bioactive glass-based bone cement with suitable bone regeneration ability.

BackgroundAs a class of promising bone augmentation materials, bone cements have attracted particular attention. Due to various limitations, the current bone cements are still imperfect. In this study, an injectable pH neutral bioactive bone cement (PSC/CSC) was developed by mixing phosphosilicate bioactive glass (PSC) and α-calcium sulfate hemihydrate (CSH), with the goal of optimizing bone defects repairs.MethodsA range of compositions (PSC/CSC: 10P/90C, 30P/70C, 50P/50C) were developed and their physicochemical properties evaluated. Their bone regeneration ability was compared to those of two widely used bone cements as controls (calcium phosphate cement (CPC) and Genex®) in rabbit femoral condyle bone defect models for 4, 8 and 12 weeks. Based on physicochemical properties and in vivo bone regeneration ability, the PSC/CSC exhibited the best outcomes was selected. Then, in vitro, the effects of selected PSC/CSC, CPC and Genex® extracts on MC3T3-E1 cell proliferation, migration and osteogenesis as well as angiogenesis of HUVECs were examined.ResultsBased on physicochemical properties, the 30P/70C formula exhibited suitable operability and compressive strength (3.5 ± 0.3 MPa), which fulfilled the requirements for cancellous bone substitutes. In vivo, findings from micro-CT and histological analyses showed that the 30P/70C formula better promoted bone regeneration, compared to 10P/90C, 50P/50C, CPC and Genex®. Hence, 30P/70C was selected as the ideal PSC-based cement. In vitro, the 30P/70C extracts showed better promotion of cell viability, alkaline phosphatase (ALP) activity, calcium mineral deposition, mRNA and protein expression levels of osteogenesis in MC3T3-E1 cells, further supporting its superiority. Meanwhile, the 30P/70C extracts also showed better stimulation of HUVECs proliferation and angiogenesis.ConclusionThe new composite cement, 30P/70C, is a favorable bioactive glass-based bone cement with suitable operability, compressive strength and bone regeneration ability.The translational potential of this articleClinically, treatment of large bone defects is still a major challenge for orthopaedic trauma. We showed that 30P/70C has the potential to be clinically used as an injectable cement for rapid bone repairs and reconstruction of critical sized bone defects.

Highly bioactive bone cement microspheres based on α-tricalcium phosphate microparticles/mesoporous bioactive glass nanoparticles: Formulation, physico-chemical characterization and in vivo bone regeneration

Calcium phosphate cement (CPC) is a self-setting, biocompatible and osteoconductive bone cement, however its use as a bone substitute is still limited owing to its low bioactivity (i.e. its slow in vivo resorption and slow new bone formation rate) which is a challenging issue to be addressed. Herein, we report for the first time highly bioactive bone cement microspheres formulated from a cement paste containing α-tricalcium phosphate microparticles (α-TCP) and mesoporous calcium silicate bioactive glass nanoparticles (mesoporous BGn) using a water-in-oil emulsion method. Indeed, bioactive microspheres possess high potential as bone defect fillers for bone regeneration. The α-TCP microparticles were prepared by a solid state synthesis at 1400 ºC while mesoporous BGn were synthesized by template-assissted ultrasound-mediated sol-gel method. The particle size distribution of as-prepared cement microspheres was in the range of 200 – 450 µm with a sphericity index in the range of 0.92 – 0.94. The surface morphology of α-TCP microspheres revealed α-TCP micoparticles with smooth surfaces whereas α-TCP/BGn microspheres unveiled nano-roughened α-TCP microparticles. The as-prepared α-TCP/BGn cement microspheres exhibited larger specific surface area ca 18.6 m2/g, sustained release of soluble silicate (SiO44-) ions (118 ppm within a week) and high protein adsorption capacity (252 mg/g). Notably, the α-TCP/BGn cement microspheres showed excellent in vitro surface bioactivity via formation of massive amounts of bone-like hydroxyapatite spherules and aggregates on their surfaces after soaking in simulated body fluid. Importantly, the in vivo implantation of as-prepared α-TCP/BGn cement microspheres in rat calvarial critical size bone defects for 6 weeks unveiled high in vivo bioactivity in terms of substantial new bone ingrowth and significant new bone formation within the bone defect as evidenced by histological analyses, X-ray radiography and micro-computed tomography evaluations.

Influence of Monocalcium Phosphate on the Properties of Bioactive Magnesium Phosphate Bone Cement for Bone Regeneration.

Bone defects occurring for various reasons can lead to deformities and dysfunctions of the human body. Considering the need for clinical applications, it is essential for bone regeneration to exploit a scaffold with bioactive bone cement. In this study, we fabricated bioactive magnesium phosphate bone cement (BMPC) at room temperature; then, it was set at to °C and 100% humidity for 2 h. The process was as follows: Simulating a clinical environment, magnesium oxide (MgO) was formed by calcining basic magnesium carbonate (Mg2(OH)2CO3). MgO, potassium dihydrogen phosphate (KH2PO4) and carboxymethyl chitosan (C20H37N3O14, CMC) were mixed to form magnesium phosphate bone cement (MPC); then, monocalcium phosphate (Ca(H2PO4)2) was added to neutralize the alkaline product after MPC hydration to fabricate bioactive magnesium phosphate bone cement (BMPC). The influence of the doped content of Ca(H2PO4)2 on the properties of bone cement was discussed. The results showed that Ca(H2PO4)2 and CMC can adjust the setting time of bone cement to between 8 and 25 min. The compressive strength increased first and then decreased. After 48 h without additional pressure, the compressive strength reached the maximum value, which was about 38.6 MPa. Ca(H2PO4)2 and CMC can play a synergistic role in regulating the properties of BMPC. The BMPC was degradable in the simulated body fluid (SBF). The results of the cytotoxicity experiment and laser confocal microscopy experiment indicated that BMPC fabricated at room temperature had better biocompatibility and degradability, which was more consistent with clinical operation requirements. BMPC is a promising orthopedic material and is suitable for repairing bone defects.

Fabrication of elastin additive on polymethyl methacrylate and hydroxyapatite-based bioactive bone cement

In this study, nanocrystalline-Hydroxyapatite (n-HA) was composed with Polymethyl Methacrylate (PMMA) bone cement-Elastin (ELN). After the addition of different weight percentages of ELN to produce four bone cement for orthopedic application such as vertebroplasty and bone filler. Evaluation of biological property using simulated body fluid (SBF) and phosphate-buffered saline (PBS) is performed to investigate adaptability, weight loss, and examined the pH change during a specific time. The morphology of the sample was investigated using Field Emission Scanning Electron Microscopy (FE-SEM) and Energy-dispersive X-ray Spectroscopy (EDX) to examine the morphology and microchemical analysis of bone cement materials. The mechanical properties of the samples such as tensile test and Charpy impact test are measured. The observation indicates that the pH is decreased after 24 h and ultimately the pH concentration changes remained constant about 6.2–6.7. The samples had highly low water absorption and porosity by the addition of elastin polymer. The tensile test and Charpy impact test show proper mechanical performance such as elastic modulus and impact strength about 2.31 GPa and 15.71 kJ. m−2 for the sample containing 10 wt% ELN. On the other hand, this cement can be hopeful for bone application such as rhinoplasty, tooth fillers, and orthopedics.

Comparative evaluation of push-out bond strength of three retrograde filling materials in teeth with root apices resected at 90°: Mineral trioxide aggregate Angelus, Zirconomer, and Bioactive bone cement.

Surgical endodontic dissatisfaction is frequently caused by an inadequate seal at the apex. The retrograde filling material utilized should prevent any contaminants from seeping into the periradicular tissue. (1) To evaluate push-out bond strength of mineral trioxide aggregate (MTA) Angelus, Zirconomer, and Bioactive bone cement as root-end filling material, (2) To compare push-out bond strength of three different retrograde filling materials with a universal testing machine. At the cementoenamel junction, 36 removed upper anterior teeth were sliced horizontally. The samples were resected 3 mm at the apical end at a 90° angle along the long axis of the tooth, following the standard protocols. With an ultrasonic tip S12 90ND, a 3 mm root-end cavity was made. The teeth were then divided into three groups at random: Group 1: MTA Angelus, Group 2: Zirconomer, and Group 3: Bioactive bone cement. With the help of small pluggers, each material was compacted in the root-end cavity. Acrylic resin was used to embed the specimens. Each specimen's apical section was sliced into 2-mm thick slices perpendicular to the long axis. A universal testing equipment was used to apply a compressive push-out load, and the push-out bond strength was determined in megapascals. Zirconomer showed higher push-out bond strength when placed in the retrograde cavity preparation, followed by MTA Angelus and then Bioactive bone cement. Zirconomer showed superior resistance to dislodgment when compared to MTA Angelus, followed by Bioactive bone cement.

Comparison of Root End Sealing Ability of Three Retrograde Filling Materials in Teeth with Root Apices Resected at 90° using Dye Penetration Method under Fluorescent Microscope: An In-vitro Study

Background: Inadequate seal at the apex is the substantial cause for surgical endodontic dissatisfaction. The retrograde filling material which is used should prevent the egress of potential contaminants into periradicular tissue.&#x0D; Objectives: To evaluate the ability of MTA Angelus, Zirconomer and Bioactive bone cement to seal the root end as retrograde filling material; and to compare root end sealing ability of these three different retrograde filling materials with apices resected at 900 angles using dye penetration method under fluorescent microscope.&#x0D; Methodology: Thirty six extracted upper anterior teeth are to be cut horizontally at the CEJ. After following the standard protocols of, “cleaning, shaping and obturation” with gutta percha and “AH Plus sealer”, the samples will be resected 3mm at the apical end at 90 degree angle along the long axis of the tooth with the help of diamond disc. A root end cavity of depth 3mm will be made with Diamond coated ultrasonic surgical tip S12 90 ND. The teeth will be randomly categorized in 3 groups: Group 1: MTA angelus; Group 2: Zirconomer; Group 3: Bioactive Bone Cement. Following which the roots to be coated with nail varnish except the tip. Each material will be compressed in the root end cavity with the help of small pluggers. All the samples which are retrofilled will be kept in acrydine orange for a duration of 24 hours, following which cleaning &amp; bucco-lingual sectioning(vertical) will be done. Fluorescent microscope will be used for observation of sectioned root samples.&#x0D; Expected Results: Bioactive bone cement is expected to have better sealing ability of the retrograde cavity preparation with minimal or no microleakage followed by MTA Angelus and then Zirconomer.&#x0D; Conclusion: If this study proves correct, this would be helpful for the clinicians to choose better and the most efficient retrograde filling material with best sealing ability and minimal microleakage in a retrograde preparation which will aid in success of the root canal treatment further resolving the infection.

Manipulation of the degradation behavior of calcium phosphate and calcium sulfate bone cement system by the addition of micro-nano calcium phosphate

The mismatch between the degradation performance of bioactive bone cement (calcium phosphate-CPC and calcium sulfate-CSC) and the growth rate of new bone has always restricted its clinical application. In view of the weak mechanical strength and poor degradation performance of CPC and CSC, this study first prepared micro-nano calcium phosphate (MNC) with different Ca/P ratio and explored the influence of MNC on the hydration and mechanical properties of cement by adding MNC to the CPC and CSC. The results show that MNC can promote the hydration reaction of CPC and CSC and affect the growth of cement crystals. Among all groups, MNC with Ca/P ratio of 1.2 can greatly improve the mechanical properties and setting time of CPC, increase the compressive strength of CPC from 10.18 ± 1.51 to 19.23 ± 0.55 MPa, and shorten the setting time from 38.33 ± 2.89 to 18.33 ± 2.89 min. In addition, the addition of low content of MNC promoted the degradation of CPC, and also promoted the self-reinforcing effect of CPC during the degradation process, and further improved the mechanical properties of cement. MNC not only affects the morphology of CSC crystals but also produces calcium phosphate particles with smaller diameters to fill between the CSC crystals, which reduces porosity, improves mechanical properties, and delays the degradation of CSC. The as-prepared cements were supposed to match the new bone ingrowth in vivo and have the potential application in orthopedic surgery for filling non-load-bearing bone defects.

Risk factors for a radiolucent line around the acetabular component with an interface bioactive bone cement technique after primary cemented total hip arthroplasty

AimsThe main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA.MethodsA retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis.ResultsRLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7).ConclusionThis study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL.Cite this article: Bone Joint Open 2021;2(5):278–292.

Titania-Containing Bone Cement Shows Excellent Osteoconductivity in a Synovial Fluid Environment and Bone-Bonding Strength in Osteoporosis.

Titania bone cement (TBC) reportedly has excellent in vivo bioactivity, yet its osteoconductivity in synovial fluid environments and bone-bonding ability in osteoporosis have not previously been investigated. We aimed to compare the osteoconductivity of two types of cement in a synovial fluid environment and determine their bone-bonding ability in osteoporosis. We implanted TBC and commercial polymethylmethacrylate bone cement (PBC) into rabbit femoral condyles and exposed them to synovial fluid pressure. Rabbits were then euthanized at 6, 12, and 26 weeks, and affinity indices were measured to evaluate osteoconductivity. We generated a rabbit model of osteoporosis through bilateral ovariectomy (OVX) and an 8-week treatment with methylprednisolone sodium succinate (PSL). Pre-hardened TBC and PBC were implanted into the femoral diaphysis of the rabbits in the sham control and OVX + PSL groups. Affinity indices were significantly higher for TBC than for PBC at 12 weeks (40.9 ± 16.8% versus 24.5 ± 9.02%) and 26 weeks (40.2 ± 12.7% versus 21.2 ± 14.2%). The interfacial shear strength was significantly higher for TBC than for PBC at 6 weeks (3.69 ± 1.89 N/mm2 versus 1.71 ± 1.23 N/mm2) in the OVX + PSL group. These results indicate that TBC is a promising bioactive bone cement for prosthesis fixation in total knee arthroplasty, especially for osteoporosis patients.

In-vitro heat-generating and apatite-forming abilities of PMMA bone cement containing TiO2 and Fe3O4

Poly (methyl methacrylate) (PMMA) bone cement is widely used as a filler for repairing bone defects. To improve the effectiveness of the treatment for bone defects caused by metastatic bone tumours, we propose the formulation of PMMA cement containing titania (TiO2) and magnetite (Fe3O4) that offers high bone affinity, making the cement suitable for use in magnetic hyperthermia. The TiO2 and Fe3O4 contents of the PMMA cement varied from 20 to 45 mass%. The various cement samples were evaluated for their apatite-forming ability and heat-generation characteristics. The samples containing TiO2 in concentrations of 15 mass% or higher formed apatite on their surfaces within 14 days in a simulated body fluid. The heat-generation characteristics of the samples were evaluated by applying an alternating current (AC) magnetic field under the following conditions: |H| = 40 Oe and f = 600 kHz, or |H| = 100 Oe and f = 100 kHz. The surface temperatures of the samples containing 25 and 30 mass% Fe3O4 reached 42.3 and 44.8 °C, respectively, at |H| = 40 Oe and f = 600 kHz. During hyperthermia treatment, cancer cells die at temperatures higher than 42 °C, and the cement samples fabricated in this study could reach this temperature. However, since some degree of heat loss will occur in vivo, it is necessary to ensure that the temperature is higher than 42 °C by varying the AC magnetic field. Nevertheless, the fact that the samples containing Fe3O4 concentrations of 25 mass% or higher generated enough heat under the AC magnetic field makes them suitable for clinical use in hyperthermia. Thus, PMMA cement containing 15 mass% or more of TiO2 and 25 mass% or more of Fe3O4 should be investigated as a bioactive bone cement with a strong hyperthermia effect.

Minimum 5year follow-up of clinical and radiographic results of cemented acetabular components with an interface bioactive bone cement technique in primary cemented total hip arthroplasty.

A well-fixed cement-bone interface is a crucial factor for acetabular and femoral components in cemented total hip arthroplasty (THA). The aim of the present study was to evaluate the middle-term clinical and radiological results of fixing the acetabular component with an interface bioactive bone cement (IBBC) technique in primary cemented THA. We undertook a retrospective review was undertaken of 193 primary cemented THAs in 174 patients using acetabular components cemented with an IBBC technique and followed for a minimum of 5years (mean 8.3years; range 5-17years). Baseline data, clinical and radiological outcomes were evaluated. Japanese Orthopedic Association hip score and modified Harris hip scores demonstrated significant clinical improvement in all patients (p < 0.001). Radiolucent lines were detected in 15 hips (7.8%) at the first year and 24 hips (12.4%) at the final post-operative follow-up. The Kaplan-Meier survivorship with radiographic loosening as the end point was 97.8% [95% confidence interval (CI) 95.2-100]. With revision of the acetabular component for aseptic loosening as the end point, component survival was 99.0% (95% CI 97.5-100). With revision of the acetabular component for any reason as the end point, component survival was 97.0% (95% CI 93.9-100). Clinical and radiological results of the acetabular component with the IBBC technique in primary cemented THA were excellent.

Magnesium Calcium Phosphate Cement Incorporating Citrate for Vascularized Bone Regeneration.

The development of bioactive bone cement is still a challenge for vascularized bone regeneration. Citrate participated in multiple biological processes, such as energy metabolism, osteogenesis, and angiogenesis. However, it is difficult to obtain a thorough and comprehensive understanding on osteogenic effects of exogenous citrate from different experimental conditions and treatment methods. In this study, by using a magnesium calcium phosphate cement (MCPC) matrix, we investigated the dual effect of exogenous citrate on osteogenesis and angiogenesis. Our studies show that citrate elevates the osteogenic function of osteoblasts under low doses and the angiogenic function of vascular endothelial cells under a broader dose range. These findings furnish a new strategy for regulating angiogenesis and osteogenic differentiation by administration of citrate in MCPC, driving the development of bioactive bone repair materials.