Polymethylmethacrylate Bone Cement Research Articles

PMMA Bone Cement: Antibiotic Elution and Mechanical Properties in the Context of Clinical Use.

This literature review discusses the use of antibiotic loaded polymethylmethacrylate bone cements in arthroplasty. The clinically relevant differences that have to be considered when antibiotic loaded bone cements (ALBC) are used either for long-term implant fixation or as spacers for the treatment of periprosthetic joint infections are outlined. In this context, in vitro findings for antibiotic elution and material properties are summarized and transferred to clinical use.

The Effects of Bone Cement Volume in Percutaneous Vertebroplasty for Thoracolumbar Junction Vertebral Compression Fractures: A Clinical Comparative Study.

We compared the outcomes of patients treated with different volumes of polymethyl methacrylate bone cement during percutaneous vertebroplasty (PVP) for thoracolumbar vertebral compression fractures. We performed a comparative, retrospective study of 316 patients who underwent PVP for a single-level thoracolumbar vertebral compression fracture. Patients were divided into two groups: group A (≤5 mL; n = 146) and group B (>5 mL; n = 170). The visual analogue scale (VAS) for pain and the Roland-Morris Disability Questionnaire (RDQ) scores were compared between the two groups at 1 week and at 1, 6, 12, and 24 months after PVP. The incidence of cement leakage into the intervertebral discs was evaluated by a postoperative lateral radiograph assessment. Patients were evaluated for new fractures 1 and 2 years after PVP or when new fractures were suspected. Among the 316 patients enrolled, 245 completed the clinical research. No difference between groups A and B in terms of the VAS, RDQ, and rate of complications at all time points after surgery was observed. The presence of intervertebral disc leakage was a relative risk (RR) for subsequent total vertebral fracture (RR, 6.42; 95% confidence interval (CI), 2.72-14.19; P < 0.0001) and adjacent vertebral fracture (RR, 8.03; 95% CI, 2.74-23.54; P = 0.0001). A high volume of bone cement may increase the rate of subsequent total and adjacent vertebral fractures. However, the occurrence of intervertebral disc leakage is the principal risk factor for these negative outcomes of PVP.

Characterization and Biomechanical Study of a Novel Magnesium Potassium Phosphate Cement.

Magnesium potassium phosphate cement (MKPC) has attracted considerable attention as a bone regeneration material. However, there are only a few reports on its biomechanical properties. To evaluate the biomechanical properties of MKPC, we compared the mechanical parameters of pedicle screws enhanced with either MKPC or polymethyl methacrylate (PMMA) bone cement. The results show that the maximum pull-out force of the pedicle screws was 417.86 ± 55.57 and 444.43 ± 19.89 N after MKPC cement setting for 30 min and 12 h, respectively, which was better than that of the PMMA cement. In fatigue tests, the maximum pull-out force of the MKPC cement group was 435.20 ± 7.96 N, whereas that of the PMMA cement in the control group was 346.80 ± 7.66 N. Furthermore, the structural characterization analysis of the MKPC cement revealed that its microstructure after solidification was an irregular tightly packed crystal, which improved the mechanical strength of the cement. The maximum exothermic temperature of the MKPC reaction was 45.55 ± 1.35 °C, the coagulation time was 7.89 ± 0.37 min, and the compressive strength was 48.29 ± 4.76 MPa, all of which meet the requirements of clinical application. In addition, the MKPC cement did not significantly inhibit cell proliferation or increase apoptosis, thus indicating good biocompatibility. In summary, MKPC exhibited good biomechanical properties, high initial strength, good biocompatibility, and low exothermic reaction temperature, demonstrating an excellent application potential in the field of orthopedics.

Preparation, Characterization and Evaluation of a Poly Methyl Methacrylate Bone Cement Modified by Montmorillonite Loaded with Silver Nano Particles

Preparation, Characterization and Evaluation of a Poly Methyl Methacrylate Bone Cement Modified by Montmorillonite Loaded with Silver Nano Particles

A Preliminary Review of Modified Polymethyl Methacrylate and Calcium-Based Bone Cement for Improving Properties in Osteoporotic Vertebral Compression Fractures

The incidence of osteoporotic vertebral compression fractures (OVCFs) increases gradually with age, resulting in different degrees of pain for patients, even possible neurological damage and deformity, which can seriously affect their quality of life. Vertebral augmentation plays an important role in the surgical treatment of OVCFs. As the most widely used bone cement material, polymethyl methacrylate (PMMA) offers inherent advantages, such as injectability, ease of handling, and cost-effectiveness. However, with its application in the clinic, some disadvantages have been found, including cytotoxicity, high polymerization temperature, high elastic modulus, and high compressive strength. To improve the mechanical properties and the biological performance of conventional PMMA bone cement, several studies have modified it by adding bioceramics, bioglass, polymer materials, nanomaterials, and other materials, which have exhibited some advantages. In addition, other alternative materials, such as calcium phosphate, calcium sulfate, and calcium silicate cements—including their modifications—have also been explored. In this review, we examined the existing research on the side-effects of conventional PMMA bone cement, modified PMMA bone cement, and other alternative materials designed to improve properties in OVCFs. An overview of various modified bone cements can help further scientific research and clinical applications.

The mechanism by which enoxaparin sodium–high-viscosity bone cement reduces thrombosis by regulating CD40 expression in endothelial cells

ObjectivePMMA bone cement leads to the development of local thrombi. Our study found that ES-PMMA bone cement, a novel material, can reduce local thrombosis. We used a simple and reproducible animal model to confirm the reduction in local thrombosis and preliminarily explored the associated molecular mechanism.MethodsNew Zealand rabbits, which were used to model thrombosis using extracorporeal carotid artery shunts, were divided into the following three groups, with 10 rabbits in each group: the sham group, PMMA group and ES-PMMA group. Four hours after modelling, experimental samples were collected, and the degree of thrombosis was compared between the groups. The expression of thrombomodulin in endothelial cells was quantified in vascular tissues samples.ResultsThrombosis was observed in the PMMA group and ES-PMMA group but not in the sham group. The thrombosis weight was 0.00732 ± 0.00089 g/cm in the PMMA group and 0.00554 ± 0.00077 g/cm in the ES-PMMA group (P < 0.001). Quantitative real-time polymerase chain reaction (RT–qPCR) and Western blotting revealed that the expression of CD40, which can regulate thrombosis in vascular endothelial cells, was significantly lower in the ES-PMMA group than in the PMMA group.ConclusionCompared with PMMA bone cement, ES-PMMA bone cement can reduce local thrombosis by decreasing the expression of the thrombus-associated regulatory protein CD40 in vascular endothelial cells.

Study of polymethylmethacrylate/tricalcium silicate composite cement for orthopedic application

BackgroundAmong orthopedic surgery materials, poly (methyl methacrylate) (PMMA) is most commonly used for its excellent mechanical properties and rapid self-setting time. However, PMMA bone cement has been reported to cause thermal necrosis and to have poor bioactivity, which must be improved. In contrast, tricalcium silicate (TCS), the most significant component of Portland Cement and the most effective bone cement material, might not always meet the needs of the cement due to its poor mechanical properties and elevated pH levels during hydration. We hypothesize that the benefits of both PMMA and TCS can be harnessed by mixing them together in different proportions. This would represent a better solution for the issues faced when using them alone. MethodsWe, therefore, prepared a novel organic-inorganic PMMA/TCS composite bone cement mixing PMMA and different amounts of TCS and tested its effect on the biophysical properties. ResultsThe addition of 30% TCS reduced the exothermic temperature and pH variation during cement setting and hydration processes. However, the mechanical and handling properties of the bioactive PMMA/TCS composite were not affected. The in vitro study also revealed that the composite materials had higher cell viability than pure PMMA and TCS. Also, the in vivo study on animals indicated that the composite materials were more capable of forming bone, which further reinforced the biocompatibility of the proposed PMMA/TCS bone cement. ConclusionBy combining the advantages of each component, it could be possible to construct a more effective composite bone cement material. This would meet the needs of implantation material for orthopedic surgeries or a possible bone filler.

Antimicrobial peptide in polymethylmethacrylate bone cement as a prophylaxis of infectious complications in orthopedics-an experiment in a murine model.

Polymethylmethacrylate (PMMA) bone cement mixed with antibiotics is used in orthopedic surgery to cope with implant-related infections which are typically associated with the formation of bacterial biofilms. Taking into account the growing bacterial resistance to current antibiotics, we examined here the efficacy of a selected antimicrobial peptide (AMP) mixed into the bone cement to inhibit bacterial adhesion and the consequent biofilm formation on its surface. In particular, we followed the formation of bacterial biofilms of methicillin-resistant Staphylococcus aureus (MRSA) on implants made from PMMA bone cement loaded with AMP composed of 12 amino acid residues. This was evaluated by CFU counting of bacteria released by sonication from the biofilms formed on their surfaces after these implants were retrieved from the infected murine femoral canals. The AMP loaded in these model implants prevented adhesion of MRSA and the subsequent formation of MRSA biofilm on the surfaces of more than 80% of these implants, whereas biofilms did form on control implants made from the plain cement. The results of our experiments performed in the murine femoral canal indicate the potential for this murine osteomyelitis model to mimic actual operations in orthopedics.

Research progress on health hazards and occupational protection of prolymethylmethacrylate bone cement in the operating room

There are many occupational risk factors in operating room work. Polymethyl methacrylate (PMMA) , as a kind of common bone filling and repairing material, is widely used in the fixation of artificial joints, oral braces and orthopedic prosthesis. However, PMMA will release methyl methacrylate (MMA) monomer when it is implanted into human tissues and polymerized to harden, which is toxic to the body. This paper analyzes harmful factors in using PMMA bone cement, and then explores corresponding occupational protection knowledge, in order to reduce the occurrence of occupational hazards related to PMMA bone cement and enhance the self-protection ability of the operation room medical staff.

Risk factors of fracture following curettage for bone giant cell tumors of the extremities

BackgroundFollowing curettage of giant cell tumor of bone (GCTB), it is common to fill the cavity with polymethylmethacrylate (PMMA) bone cement, bone allograft, or artificial bone to maintain bone strength; however, there is a 2–14% risk of postoperative fractures. We conducted this retrospective study to clarify the risk factors for fractures after curettage for GCTB of the extremities.MethodsThis study included 284 patients with GCTBs of the extremities who underwent curettage at our institutions between 1980 and 2018 after excluding patients whose cavities were not filled with anything or who had additional plate fixation. The tumor cavity was filled with PMMA bone cement alone (n = 124), PMMA bone cement and bone allograft (n = 81), bone allograft alone (n = 63), or hydroxyapatite graft alone (n = 16).ResultsFractures after curettage occurred in 10 (3.5%) patients, and the median time from the curettage to fracture was 3.5 months (interquartile range [IQR], 1.8–8.3 months). The median postoperative follow-up period was 86.5 months (IQR, 50.3–118.8 months). On univariate analysis, patients who had GCTB of the proximal or distal femur (1-year fracture-free survival, 92.5%; 95% confidence interval [CI]: 85.8–96.2) presented a higher risk for postoperative fracture than those who had GCTB at another site (100%; p = 0.0005). Patients with a pathological fracture at presentation (1-year fracture-free survival, 88.2%; 95% CI: 63.2–97.0) presented a higher risk for postoperative fracture than those without a pathological fracture at presentation (97.8%; 95% CI: 95.1–99.0; p = 0.048). Patients who received bone grafting (1-year fracture-free survival, 99.4%; 95% CI: 95.7–99.9) had a lower risk of postoperative fracture than those who did not receive bone grafting (94.4%; 95% CI: 88.7–97.3; p = 0.003).ConclusionsFor GCTBs of the femur, especially those with pathological fracture at presentation, bone grafting after curettage is recommended to reduce the risk of postoperative fracture. Additional plate fixation should be considered when curettage and cement filling without bone grafting are performed in patients with GCTB of the femur. This should be specially performed for those patients with a pathological fracture at presentation.

Digital Mapping of a Massive Skull-Base Ameloblastoma with Intracranial Extension, Resection, and Reconstruction Using 3D Templates and Molds: Descriptive Case Report and Review

Radical surgery is the mainstay for the treatment of recurrent ameloblastomas; however, it leads to large, complex defects. In this case report, we present an innovative technique of digitally aided resection and reconstruction. A massive histologically confirmed acanthomatous ameloblastoma of the skull-base was digitally mapped with the help of three-dimensional (3D) computed tomography and a custom resection template was fabricated. Digital resection of the skull-base tumor with intracranial extension was done virtually and the resultant defect was reconstructed to create an anatomical replica of the contralateral unaffected side. The tumor was successfully resected with adequate margins guided by the resection template to avoid injury to adjacent vital structures. Subsequent reconstruction was performed by first adapting polymethyl methacrylate bone cement into a series of custom-made 3D molds. Once set, this bone cement served as a reconstructive implant to bridge the ablative defect. The implant offered a precise fit and was secured to healthy adjacent bone using titanium microplates. We present a 6-month follow-up of the case with satisfactory aesthetic results. 3D printing technology has the potential to revolutionize the arena of craniofacial resection with excellent cosmesis and no donor site morbidity if applied appropriately as described here.

Application of Antibiotic-Impregnated Polymethyl-Methacrylate Bone Cement for the Treatment of Infected Cranioplasties: Initial Experience.

Management of infected cranioplasty implants remains a surgical challenge. Surgical debridement, removal of the infected implant, and prolonged antibiotic therapy are part of the acute management. In addition, cranioplasty removal poses the risk of dural tear. Reconstruction of the cranial defect is usually delayed for several months to years, increasing the difficulty due to soft tissue contraction and scarring. The aim of the study was to propose an alternative to delayed reconstruction in the face of infection with a dual purpose: treat the infection with a material which delivers antibiotic to the area (polymethyl-methacrylate antibiotic) and which functions as a temporary or permanent cranioplasty. We reviewed the records of 3 consecutive patients who underwent single-stage polymethyl-methacrylate antibiotic salvage cranioplasty. All patients underwent debridement of infected tissue. Titanium mesh was placed over the bony defect. Polymethyl methacrylate impregnated with vancomycin and tobramycin was then spread over the plate and defect before closure. Patients also received extended treatment with systemic antimicrobials. Early outcomes have been encouraging for both cosmesis and treatment of infection. Benefits of this treatment strategy include immediate reconstruction rather than staged procedures and delivery of high concentrations of antibiotics directly to the affected area in addition to systemic antibiotics.

Antimicrobial PMMA Bone Cement Containing Long Releasing Multi-Walled Carbon Nanotubes.

Prosthetic joint infections (PJIs) ensued from total joint replacement (TJR) pose a severe threat to patients that involve poor health outcomes, severe pain, death (in severe cases), and negative influence patients’ quality of life. Antibiotic-loaded bone cement (ALBC) is frequently used for the prevention and treatment of PJI. This work aims to study gentamicin release from carbon nanotubes (CNTs) incorporated in polymethyl methacrylate (PMMA) bone cement to prolong release over several weeks to provide prophylaxis from PJIs after surgery. Different CNT concentrations were tested with the presence of gentamicin as a powder or preloaded onto carboxyl functionalized CNTs. The different types of bone cement were tested for drug release, mechanical properties, water uptake, antimicrobial properties, and cytocompatibility with human osteoblast cells (MTT, LDH, alizarin red, and morphology). Results showed prolonged release of gentamicin from CNT-loaded bone cements over several weeks compared to gentamicin-containing bone cement. Additionally, the presence of CNT enhanced the percentage of gentamicin released without adversely affecting the nanocomposite mechanical and antimicrobial properties needed for performance. Cytotoxicity testing showed non-inferior performance of the CNT-containing bone cement to the equivalent powder containing cement. Therefore, the developed nanocomposites may serve as a novel PMMA bone cement to prevent PJIs.

Antibiotic-free antimicrobial poly (methyl methacrylate) bone cements: A state-of-the-art review.

Prosthetic joint infection (PJI) is the most serious complication following total joint arthroplasty, this being because it is associated with, among other things, high morbidity and low quality of life, is difficult to prevent, and is very challenging to treat/manage. The many shortcomings of antibiotic-loaded poly (methyl methacrylate) (PMMA) bone cement (ALBC) as an agent for preventing and treating/managing PJI are well-known. One is that microorganisms responsible for most PJI cases, such as methicillin-resistant S. aureus, have developed or are developing resistance to gentamicin sulfate, which is the antibiotic in the vast majority of approved ALBC brands. This has led to many research efforts to develop cements that do not contain gentamicin (or, for that matter, any antibiotic) but demonstrate excellent antimicrobial efficacy. There is a sizeable body of literature on these so-called “antibiotic-free antimicrobial” PMMA bone cements (AFAMBCs). The present work is a comprehensive and critical review of this body. In addition to summaries of key trends in results of characterization studies of AFAMBCs, the attractive features and shortcomings of the literature are highlighted. Shortcomings provide motivation for future work, with some ideas being formulation of a new generation of AFAMBCs by, example, adding a nanostructured material and/or an extract from a natural product to the powder and/or liquid of the basis cement, respectively.

Incorporation of graphene nanoplatelets/hydroxyapatite in PMMA bone cement for characterization and enhanced mechanical properties of biopolymer composites

Polymethylmethacrylate (PMMA) in powder form is broadly used as bone cement in orthopedic applications due to its expanded mechanical, physical, and chemical properties. In this study, a hybrid PMMA biopolymer nanocomposite is developed by the supplement of graphene nanoplatelets (GnP) and hydroxyapatite (HA) powders of nano-size with combined loadings ranging from 0.5 to 2.5 weight %. Both materials were applied uniformly to reinforce commercial bone cement made of polymethylmethacrylate. The findings showed that adding 1.5 wt.% of combined HA and GnP nanoparticles to the powder of PMMA bone cement resulted in the expansion of flexural strength by 49.28%, the flexural modulus by 30.80%, the compression strength by 31.7%, and the compression modulus by 57.41%. The nanocomposite was characterized using Energy Dispersive X-Ray Analysis (EDS), Fourier transforms infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) to study the distribution of reinforced nanoparticles. Scanning Electron Microscopy (SEM) analysis of the prepared samples and fractured surface shows the proper dispersion of nanofillers into the matrix phase and possible reasons behind fracture. The inclusion of GnP and HA in the PMMA enhances the mechanical performances required for biomedical components. Also, the SEM findings of the mechanically tested broken surface of the polymer nanocomposite samples demonstrated the feasibility of the proposed material for joint replacement surgical procedures and orthopedic implants.

A digital twin for simulating the vertebroplasty procedure and its impact on mechanical stability of vertebra in cancer patients.

We present the application of ReconGAN, introduced in a previous study, for simulating the vertebroplasty (VP) operation and its impact on the fracture response of a vertebral body. ReconGAN consists of a Deep Convolutional Generative Adversarial Network (DCGAN) and a finite element based shape optimization algorithm to virtually reconstruct the trabecular bone microstructure. The VP procedure involves injecting shear‐thinning liquid bone cement through a needle in the trabecular region to reinforce a diseased or fractured vertebra. To simulate this treatment modality, computational fluid dynamics (CFD) is employed to predict the morphology of the injected cement within the bone microstructure. A power‐law equation is utilized to characterize the non‐Newtonian shear‐thinning behavior of the polymethyl methacrylate (PMMA) bone cement during injection simulations. The CFD model is coupled with the level‐set method to simulate the motion of the interface separating bone cement and bone marrow. After predicting the cement morphology, a data co‐registration algorithm is employed to transform the CFD model to a high‐fidelity continuum damage mechanics (CDM) finite element model of the augmented vertebra for predicting the fracture response. A feasibility study is presented to demonstrate the ability of this CFD‐CDM framework to investigate the effect of VP on the mechanical integrity of the vertebral body in a cancer patient with a lytic metastatic tumor.

Confocal laser scanning microscopic evaluation of sealing ability of bone cement, mineral trioxide aggregate and biodentine as root-end filling materials

Aim: To compare the sealing ability of polymethylmethacrylate (PMMA) bone cement, mineral trioxide aggregate (MTA), and Biodentine as root-end filling materials by assessing the degree of microleakage through confocal laser scanning microscopy. Materials and Methods: Thirty extracted maxillary incisors were root canal treated using the rotary ProTaper system. Apical root resections followed by retrograde cavity preparation were done. The teeth were divided into three groups and filled with the 3 tested materials (PMMA bone cement, MTA, and Biodentine). Samples were coated with nail varnish, immersed in 0.5% aqueous solution of rhodamine B dye for 24 h, and rinsed with water to remove excess dye. Samples were horizontally sectioned at 1 mm intervals into three using a diamond disk and were labeled A, B, and C and considered first, second, and third, respectively, based on their distance from the apex. Each slice was divided into four equal parts and evaluated using a confocal laser scanning microscope. Dye penetration was scored based on the amount of microleakage. The data were analyzed using one-way analysis of variance. Results: Intergroup comparison of the mean scores of dye penetration among the three materials showed that there is a statistical difference between PMMA bone cement, MTA, and Biodentine, in sections B and C (P ≤ 0.05). The three groups showed no statistical difference in dye penetration scores in section A. Conclusion: The microleakage is least with PMMA bone cement followed by Biodentine and MTA. Microleakage was least in section C followed by sections B and A.

Comparison of Methodologies for Selection of Bone Cements for Orthopaedic Surgical Procedures

Background: Poly (methyl methacrylate) (PMMA) bone cement is widely used in ortho-paedic procedures of vertebroplasty (VP) balloon kyphoplasty (BKP) and cemented total joint arthro-plasty (TJA). While only very few PMMA bone cement brands are approved (by the appropriate regulatory authority) for VP and BKP, many are approved for cemented TJA. Selection of cement for these applications must be done considering a very large number of clinically relevant properties, such as injectability, setting time, maximum polymerization temperature, polymerization rate, com-pressive strength, fracture toughness, fatigue life, and cytocompatibility. In the literature, there is a shortage of studies on methodologies for the selection of PMMA bone cement. Purpose: The present work addresses the aforementioned shortcoming of the literature. Methods: Three material selection methodologies (Desirability, Utility, and Weighted Property Index Methods) were applied to two study sets. Study Set 1 comprised three experimental types of bone cement for VP or BKP and five in vitro values of clinically-relevant cement properties and Set 2 comprised six approved antibiotic-loaded bone cement (ALBC) brands for cemented TJA and in vitro values of four clinically-relevant cement properties. Results: For each of the study sets, slight differences in the ranks of the materials were found de-pending on the selection methodology used, but when all the selection methodologies were consid-ered, there was clear differentiation in ranks. The relative attractions and challenges of the three se-lection methodologies used are highlighted. Conclusion: Decision makers in orthopaedic hospitals and clinics as well as orthopaedic surgeons, should find the results of the present study useful.

A PMMA bone cement with improved antibacterial function and flexural strength

A novel non-leaching antibacterial bone cement has been developed and evaluated. An antibacterial furanone derivative was synthesized and covalently coated onto the surface of alumina filler particles, followed by mixing into a conventional poly(methyl methacrylate) bone cement. Flexural strength and bacterial viability were used to evaluate the modified cements. Effects of coated antibacterial moiety content, coated alumina filler particle size and loading were investigated. Results showed that almost all the modified cements showed higher flexural strength (up to 10%), flexural modulus (up to 18%), and antibacterial activity (up to 67% to S. aureus and up to 84% to E. coli), as compared to original poly(methyl methacrylate) cement. Increasing antibacterial moiety and filler loading significantly enhanced antibacterial activity. On the other hand, increasing coated filler particle size decreased antibacterial activity. Increasing antibacterial moiety content and particle size did not significantly affect flexural strength and modulus. Increasing filler loading did not significantly affect flexural modulus but reduced flexural strength. Antibacterial agent leaching tests showed that it seems no leachable antibacterial component from the modified experimental cement to the surrounding environment. Within the limitations of this study, the modified poly(methyl methacrylate) bone cement may potentially be developed into a clinically useful bone cement for reducing in-surgical and post-surgical infection.

Evaluation of the Effect of Selected Physiological Fluid Contaminants on the Mechanical Properties of Selected Medium-Viscosity PMMA Bone Cements.

Revision surgeries several years after the implantation of the prosthesis are unfavorable from the patient’s point of view as they expose him to additional discomfort, to risk of complications and are expensive. One of the factors responsible for the aseptic loosening of the prosthesis is the gradual degradation of the cement material as a result of working under considerable loads, in an aggressive environment of the human body. Contaminants present in the surgical field may significantly affect the durability of the bone cement and, consequently, of the entire bone-cement-prosthesis system. The paper presents the results of an analysis of selected mechanical properties of two medium-viscosity bone cements DePuy CMW3 Gentamicin and Heraeus Palamed, for the samples contaminated with saline and blood in the range of 1–10%. The results obtained for compressive strength and modulus of elasticity were subjected to statistical analysis, which estimated the nature of changes in these parameters depending on the amount and type of contamination and their statistical significance.