Microwave assisted wet precipitation method was used to synthesize calcium deficient strontium doped β-tricalcium phosphate (Sr-βTCP) with a chemical formula of Ca2.96-xSrx(PO4)2. Sr-βTCP was reacted with monocalcium phosphate monohydrate [Ca(H2PO4)2.H2O, MCPM] in presence of water to furnish corresponding Sr containing brushite cement (Sr-Brc). The samples were characterized by using X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). Strontium content in the prepared samples was determined by using inductively coupled plasma optical emission spectrometry (ICP-OES). The effect of Sr2+ions on the structural, mechanical, setting properties and drug release of the cement is reported. Incorporation of Sr2+ions improved the injectability, setting time and mechanical properties of the Brc. The release profiles of antibiotics incorporated in Brc and Sr-Brc confirmed that the Sr incorporation into the Brc results in the efficient release of the antibiotics from the cement.
Revision arthroplasty of the hip is often complicated by infection, bone loss, and perioperative fracture of the femur. A simple, inexpensive spacer that keeps tissue planes intact and prevents soft tissue contracture during the interoperative period of a 2-stage revision is described. This can provide intramedullary support to a fractured or weak femur and enable local antibiotic delivery, as well as permit limited mobilization of the patient. It can be easily fabricated during surgery using universally available materials and can be tailored for specific requirements. Such a spacer was used in 5 cases. The experience is presented, and the technique and pitfalls are discussed.
Glenoid conformity is one of the important aspects that could contribute to implant stability. However, the optimal conformity is still being debated among the researchers. Therefore, this study aims to analyze the stress distribution of the implant and cement in three types of conformity (conform, non-conform, and hybrid) in three load conditions (central, anterior, and posterior). Glenoid implant and cement were reconstructed using Solidwork software and a 3D model of scapula bone was done using MIMICS software. Constant load, 750 N, was applied at the central, anterior, and posterior region of the glenoid implant which represents average load for daily living activities for elder people, including, walking with a stick and standing up from a chair. The results showed that, during center load, an implant with dual conformity (hybrid) showed the best (Max Stress-3.93 MPa) and well-distributed stress as compared to other conformity (Non-conform-7.21 MPa, Conform-9.38 MPa). While, during eccentric load (anterior and posterior), high stress was located at the anterior and posterior region with respect to the load applied. Cement stress for non-conform and hybrid implant recorded less than 5 MPa, which indicates it had a very low risk to have cement microcracks, whilst, conform implant was exposed to microcrack of the cement. In conclusion, hybrid conformity showed a promising result that could compromise between conform and non-conform implant. However, further enhancement is required for hybrid implants when dealing with eccentric load (anterior and posterior).
The present concepts in Total Hip Arthroplasty advocate mechanical cement interlock
with trabecular bone utilising the third-generation cementing technique. However, the
force generated can easily reach peak pressure of 122 kPa to 1500 kPa, leading to
extrusion of cement through nutrient foramina into femoral cortex into nutrient vessels,
henceforth the retrograde arteriovenogram. (Copied from article).
This study investigated the impact of calcium silicate (CS) content on composition, compressive mechanical properties, and hardness of CS cermets with Ti-55Ni and Ti-6Al-4V alloys sintered at 1200°C. The powder metallurgy route was exploited to prepare the cermets. New phases of materials of Ni16Ti6Si7, CaTiO3, and Ni31Si12 appeared in cermet of Ti-55Ni with CS and in cermet of Ti-6Al-4V with CS, the new phases Ti5Si3, Ti2O, and CaTiO3, which were emerged during sintering at different CS content (wt%). The minimum shrinkage and density were observed in both groups of cermets for the 50 and 100 wt% CS content, respectively. The cermets with 40 wt% of CS had minimum compressive Young's modulus. The minimum of compressive strength and strain percentage at maximum load were revealed in cermets with 50 and 40 wt% of CS with Ti-55Ni and Ti-6Al-4V cermets, respectively. The cermets with 80 and 90 wt% of CS showed more plasticity than the pure CS. It concluded that the composition and mechanical properties of sintered cermets of Ti-55Ni and Ti-6Al-4V with CS significantly depend on the CS content in raw cermet materials. Thus, the different mechanical properties of the cermets can be used as potential materials for different hard tissues replacements.
Percutaneous vertebroplasty (PV) involves injection of polymethylmethacrylate bone cement into vertebral body for relief of pain and strengthening of bone in symptomatic vertebral compression fractures.Passage of bone cement into vertebral venous plexus and then into the lungs is a rare and serious complication of PV. The reported incidence up to 26%.We present an incidental finding of pulmonary cement embolism (PCE) after PV. A 68-year-old woman with history of PV 3 years previously for T11 osteoporotic fracture presented to us with cough for 3 weeks following choking on a fish bone.Chest X-ray showed left lower zone consolidation and a high-density opacity in a tubular branching pattern, corresponding to pulmonary arterial distribution. Contrasted computed tomography of the thorax showed segmental pulmonary cement embolism of both lungs and left lower lobe consolidation.She underwent bronchoscopy with findings of a purulent secretion from the left lower lobe. Her symptoms resolved after 2 weeks of antibiotics. She was managed conservatively for the PCE as she remained asymptomatic.This case highlights the need for a standard post-PV chest X-ray, as patients with cement embolisms can be completely asymptomatic. Measures to minimise the risk of pulmonary cement embolisms during PV need to be taken.
The demand for durable, resistant, and high-strength structural material has led to the use of fibers as reinforcing elements. This paper presents an investigation into the inclusion of chopped steel wool fibers (CSWFs) in cement to form a high-flexural strength cementitious composite matrix (CCM). CSWFs were used as the primary reinforcement in CCM at increments of 0.5 wt%, from 0.5-6 wt%, with ratios of cement to sand of 1:1.5 and water to cement of 0.45. The inclusion of CSWFs resulted in an excellent optimization of the physicomechanical properties of the CCM, such as its density (2.302 g/cm3), compressive strength (61.452 MPa), and maximum flexural strength (10.64 MPa), all of which exceeded the performances of other reinforcement elements reported in the literature.
Infection after joint replacement surgery is problematic and difficult to treat. The utility of antibiotic laden bone cement for reduction of risk of infection in primary and revision joint replacement surgery has already been established in many studies. In this study, we examined the efficacy of bone cement containing cefuroxime, employing a modified in vitro Kirby-Bauer susceptibility model for investigation of 13 strains of organisms that are found in orthopaedic infections. Organisms investigated were broad spectrum and effective for Gram-positive, Gram-negative, aerobic organisms and anaerobes. Simplex P with added cefuroxime was effective against 8 out of 13 strains. Cefuroxime is stable during exothermic polymerisation of the cement, and is released from the cement at concentrations high enough to inhibit the growth of most organisms encountered after joint arthroplasty.
We evaluated the efficacy of a cement gun to improve the depth of cement penetration in total knee arthroplasty. Ninety-one consecutive patients from two hospitals were recruited for this study. For Group I cement was applied to the tibial baseplate and the proximal tibia with fingers. Group 2 had similar application of cement to the tibial baseplate but cement was pressurized into the proximal tibia using a cement gun.. The knee was kept extended until the cement hardened. Standard post-operative x-rays were reviewed to assess cement penetration into the proximal tibia. The mean cement penetration was 2.1 mm in Group 1 and 3.1 mm in Group 2 and the difference was statistically significant. The use of the cement gun improves cement penetration into the proximal tibia and facilitates early stability of the implant fixation to the bone.
A novel injectable calcium phosphate bone cement (osteopaste) has been
developed. Its potential application in orthopaedics as a filler of bone defects has been
studied. The biomaterial was composed of tetra-calcium phosphate (TTCP) and tricalcium
phosphate (TCP) powder. The aim of the present study was to evaluate the
healing process of osteopaste in rabbit tibia.(Copied from article).
In selecting the binder composition for oil well application, its stability is an important design parameter. This paper presents the results of an experimental study conducted for comparing the linear expansion characteristics of geopolymer cement with the traditionally used ASTM Class G cement system. The expansion test was done in a water bath at 60 °C subjected to different curing intervals. The linear expansion of a cement system defines as the dimensional changes occur in the system, which is sometimes required to avoid the cement shrinkage during the hydration phase. In the case when the desired level of expansion is not achieved in the system, then the commercially available expandable materials are added in the class G cement system that enables the system to expand to the desired level. Shrinkage in the cementing system causes the formation of a microannulus or induces a gap that may allow the migration of fluid, hence the integrity of the system could be lost. This experimental study has revealed that the geopolymer cement tends to expand 0.15%-0.2% without the addition of any admixture, whereas the ASTM Class G cement has shown a lower value of linear expansion, which was obtained less than 0.1% after 18 days of curing. In the case of Class G cement, the addition of expandable material helped to increase the expansion; in the case of a geopolymer system, the additive has further accelerated the expansion.
A major weakness of current orthopedic implant materials, for instance sintered hydroxyapatite (HA), is that they exist as a hardened form, requiring the surgeon to fit the surgical site around an implant to the desired shape. This can cause an increase in bone loss, trauma to the surrounding tissue, and longer surgical time. A convenient alternative to harden bone filling materials are injectable bone substitutes (IBS). In this article, recent progress in the development and application of calcium phosphate (CP)-based composites use as IBS is reviewed. CP materials have been used widely for bone replacement because of their similarity to the mineral component of bone. The main limitation of bulk CP materials is their brittle nature and poor mechanical properties. There is significant effort to reinforce or improve the mechanical properties and injectability of calcium phosphate cement (CPC) and this review resumes different alternatives presented in this specialized literature.
Matched MeSH terms: Bone Cements/metabolism; Bone Cements/chemistry
Image analysis techniques are gaining popularity in the studies of civil engineering materials. However, the current established image analysis methods often require advanced machinery and strict image acquisition procedures which may be challenging in actual construction practices. In this study, we develop a simplified image analysis technique that uses images with only a digital camera and does not have a strict image acquisition regime. Mortar with 10%, 20%, 30%, and 40% pozzolanic material as cement replacement are prepared for the study. The properties of mortar are evaluated with flow table test, compressive strength test, water absorption test, and surface porosity based on the proposed image analysis technique. The experimental results show that mortar specimens with 20% processed spent bleaching earth (PSBE) achieve the highest 28-day compressive strength and lowest water absorption. The quantified image analysis results show accurate representation of mortar quality with 20% PSBE mortar having the lowest porosity. The regression analysis found strong correlations between all experimental data and the compressive strength. Hence, the developed technique is verified to be feasible as supplementary mortar properties for the study of mortar with pozzolanic material.
Nowadays, Kenaf fiber is sustainably useful in marine structures and has become one of the materials that may be high in demand as it is light, biodegradable and environmental friendly. This study investigates the effect of fiber percentage on compressive strength of fiber reinforced concrete (FRC) and the relationship between compressive strength and time of FRC immersion in seawater. FRC concrete cubes were prepared using four different percentage of fiber (0%, 1.5%, 3.0% and 4.5%). These FRC were immersed in seawater for 7, 14 and 21 days for three consecutive weeks. Based on the experiment, it was found that there was improvement in compressive strength of FRC when compared to plain cement concrete. The results showedthat 3.0% of KF to cement matrix concrete determined the highest compressive strength of 205.43 Pa while 0% of KF fiber to cement concrete matrix (control specimen) showed the lowest compressive strength of 158.28 Pa. Also the addition of Kenaf fiber to cement concrete decreased the seawater absorption more than concrete with absolutely 0% of KF fiber to cement concrete (control specimen). In conclusion, the results did show significant improvement and a consistent trend on strength with the addition of FRC. This study also revealed that the percentage of water absorption was on the increase for 0, 7 and 14 days and become constant after day 21. This is due to manufacturing defects that occurred which block the water from entering the material and making the material absorb less water.
Polymethyl methacrylate (PMMA) bone cements (BCs) have some drawbacks, including limited bioactivity and bone formation, as well as inferior mechanical properties, which may result in failure of the BC. To deal with the mentioned issues, novel bioactive polymethyl methacrylate-hardystonite (PMMA-HT) bone cement (BC) reinforced with 0.25 and 0.5 wt% of carbon nanotube (CNT) and reduced graphene oxide (rGO) was synthesized. In this context, the obtained bone cements were evaluated in terms of their mechanical and biological characteristics. The rGO reinforced bone cement exhibited better mechanical properties to the extent that the addition of 0.5 wt% of rGO where its compressive and tensile strength of bioactive PMMA-HT/rGO cement escalated from 92.07 ± 0.72 MPa, and 40.02 ± 0.71 MPa to 187.48 ± 5.79 MPa and 64.92 ± 0.75 MPa, respectively. Besides, the mechanisms of toughening, apatite formation, and cell interaction in CNT and rGO encapsulated PMMA have been studied. Results showed that the existence of CNT and rGO in BCs led to increase of MG63 osteoblast viability, and proliferation. However, rGO reinforced bone cement was more successful in supporting MG63 cell attachment compared to the CNT counterpart due to its wrinkled surface, which made a suitable substrate for cell adhesion. Based on the results, PMMA-HT/rGO can be a proper bone cement for the fixation of load-bearing implants.
Background and Objectives: Hip fractures constitute the most debilitating complication of osteoporosis with steadily increasing incidences in the aging population. Their intramedullary nailing can be challenging because of poor anchorage in the osteoporotic femoral head. Cement augmentation of Proximal Femoral Nail Antirotation (PFNA) blades demonstrated promising results by enhancing cut-out resistance in proximal femoral fractures. The aim of this study was to assess the impact of augmentation on the fixation strength of TFN-ADVANCEDTM Proximal Femoral Nailing System (TFNA) blades and screws within the femoral head and compare its effect when they are implanted in centre or anteroposterior off-centre position. Materials and Methods: Eight groups were formed out of 96 polyurethane low-density foam specimens simulating isolated femoral heads with poor bone quality. The specimens in each group were implanted with either non-augmented or cement-augmented TFNA blades or screws in centre or anteroposterior off-centre positions, 7 mm anterior or posterior. Mechanical testing was performed under progressively increasing cyclic loading until failure, in setup simulating an unstable pertrochanteric fracture with a lack of posteromedial support and load sharing at the fracture gap. Varus-valgus and head rotation angles were monitored. A varus collapse of 5° or 10° head rotation was defined as a clinically relevant failure. Results: Failure load (N) for specimens with augmented TFNA head elements (screw/blade centre: 3799 ± 326/3228 ± 478; screw/blade off-centre: 2680 ± 182/2591 ± 244) was significantly higher compared with respective non-augmented specimens (screw/blade centre: 1593 ± 120/1489 ± 41; screw/blade off-centre: 515 ± 73/1018 ± 48), p < 0.001. For both non-augmented and augmented specimens failure load in the centre position was significantly higher compared with the respective off-centre positions, regardless of the head element type, p < 0.001. Augmented off-centre TFNA head elements had significantly higher failure load compared with non-augmented centrally placed implants, p < 0.001. Conclusions: Cement augmentation clearly enhances the fixation stability of TFNA blades and screws. Non-augmented blades outperformed screws in the anteroposterior off-centre position. Positioning of TFNA blades in the femoral head is more forgiving than TFNA screws in terms of failure load.
Gentamicin, whether administered either intravenously, incorporated into bone cement or for local intra-operative irrigation, is a commonly used antibiotic in orthopaedic practice. The former two have been well studied, however the literature on the therapeutic efficacy and safety of gentamicin irrigation is sparse. The objective of this study was to assess systemic absorption of gentamicin irrigation in joint replacement surgery. This was a non-randomised, prospective study. Ninety-eight patients (group A) who underwent total joint replacement and 40 patients (group B) who underwent hemi-arthroplasty were treated traoperatively with gentamicin irrigation. Serum gentamicin levels were assayed at 4 hours and 24 hours post-surgery. Sixteen of 98 patients in group A (16%) and 12 out of 40 patients in group B (30%) were found to have serum gentamicin level above 2mcg/ml at 4 hours post-surgery. We conclude that intra-articular gentamicin irrigation is systemically absorbed at substantial levels.
Infection of the hip after implant fixation is an uncommon yet devastating complication that results in poor long-term outcome. The gold standard treatment for chronic infection after hip arthroplasty is a two-stage protocol: eradication of infection, follow by re-implantation arthroplasty. The use of interim antibiotic-laden cement spacer has become a popular procedure to maintain hip joint function and provide antibiotic elution simultaneously before re-implantation. However, antibiotic cement spacer is mechanically weak and breaks if overloaded. Therefore, we designed a cement mould with metallic endoskeleton with the aim of creating a stronger, inexpensive, antibiotic-impregnated spacer resembling a unipolar arthroplasty. We report two cases of severe hip joint infection after implant fixation (bipolar hemiarthroplasty, screw fixation neck of femur). Both patients had undergone first stage surgery of debridement and articulating antibiotic cement insertion using our design. Although the second stage surgery was planned for these patients, both patients delayed the operation in view of good functional status after a year walking with the antibiotic cement spacer. These cases showed that the mechanical property of the new antibiotic cement spacer was promising but further mechanical studies upon this new endoskeleton design are required.
Bone regeneration is a rapidly growing field that seeks to develop new biomaterials to regenerate bone defects. Conventional bone graft materials have limitations, such as limited availability, complication, and rejection. Glass ionomer cement (GIC) is a biomaterial with the potential for bone regeneration due to its bone-contact biocompatibility, ease of use, and cost-effectiveness. GIC is a two-component material that adheres to the bone and releases ions that promote bone growth and mineralization. A systematic literature search was conducted using PubMed-MEDLINE, Scopus, and Web of Science databases and registered in the PROSPERO database to determine the evidence regarding the efficacy and bone-contact biocompatibility of GIC as bone cement. Out of 3715 initial results, thirteen studies were included in the qualitative synthesis. Two tools were employed in evaluating the Risk of Bias (RoB): the QUIN tool for assessing in vitro studies and SYRCLE for in vivo. The results indicate that GIC has demonstrated the ability to adhere to bone and promote bone growth. Establishing a chemical bond occurs at the interface between the GIC and the mineral phase of bone. This interaction allows the GIC to exhibit osteoconductive properties and promote the growth of bone tissue. GIC's bone-contact biocompatibility, ease of preparation, and cost-effectiveness make it a promising alternative to conventional bone grafts. However, further research is required to fully evaluate the potential application of GIC in bone regeneration. The findings hold implications for advancing material development in identifying the optimal composition and fabrication of GIC as a bone repair material.
This study is focused on finite element analysis of a model comprising femur into which a femoral component of a total hip replacement was implanted. The considered prosthesis is fabricated from a functionally graded material (FGM) comprising a layer of a titanium alloy bonded to a layer of hydroxyapatite. The elastic modulus of the FGM was adjusted in the radial, longitudinal, and longitudinal-radial directions by altering the volume fraction gradient exponent. Four cases were studied, involving two different methods of anchoring the prosthesis to the spongy bone and two cases of applied loading. The results revealed that the FG prostheses provoked more SED to the bone. The FG prostheses carried less stress, while more stress was induced to the bone and cement. Meanwhile, less shear interface stress was stimulated to the prosthesis-bone interface in the noncemented FG prostheses. The cement-bone interface carried more stress compared to the prosthesis-cement interface. Stair climbing induced more harmful effects to the implanted femur components compared to the normal walking by causing more stress. Therefore, stress shielding, developed stresses, and interface stresses in the THR components could be adjusted through the controlling stiffness of the FG prosthesis by managing volume fraction gradient exponent.