Radiopacity of tantalum-loaded acrylic bone cement

A Review of PMMA Bone Cement and Intra-Cardiac Embolism

Percutaneous vertebroplasty procedure is of major importance, given the significantly increasing aging population and the higher number of orthopedic procedures related to vertebral compression fractures. Vertebroplasty is a complex technique involving the injection of polymethylmethacrylate (PMMA) into the compressed vertebral body for mechanical stabilization of the fracture. Our understanding and ability to modify these mechanisms through alterations in cement material is rapidly evolving. However, the rate of cardiac complications secondary to PMMA injection and subsequent cement leakage has increased with time. The following review considers the main effects of PMMA bone cement on the heart, and the extent of influence of the materials on cardiac embolism. Clinically, cement leakage results in life-threatening cardiac injury. The convolution of this outcome through an appropriate balance of complex material properties is highlighted via clinical case reports.

Calcium phosphate cements with strontium halides as radiopacifiers

High radiopacity is required to monitor the delivery and positioning of injectable implants. Inorganic nonsoluble radiopacifiers are typically used in nondegradable bone cements; however, their usefulness in resorbable cements is limited due to their low solubility. Strontium halides, except strontium fluoride, are ionic water-soluble compounds that possess potential as radiopacifiers. In this study, we compare the radiopacity, mechanical properties, composition, and cytotoxicity of radiopaque brushite cements prepared with strontium fluoride (SrF2 ), strontium chloride (SrCl2 ·6H2 O), strontium bromide (SrBr2 ), or strontium iodide (SrI2 ). Brushite cements containing 10 wt % SrCl2 ·6H2 O, SrBr2 , or SrI2 exhibited equal to or higher radiopacity than commercial radiopaque cements. Furthermore, the brushite crystal lattice in cements that contained the ionic radiopacifiers was larger than in unmodified cements and in cements that contained SrF2 , indicating strontium substitution. Despite the fact that the strontium halides increased the solubility of the cements and affected their mechanical properties, calcium phosphate cements containing SrCl2 ·6H2 O, SrBr2 , and SrI2 showed no significant differences in Saos-2 cell viability and proliferation with respect to the control. Strontium halides: SrCl2 ·6H2 O, SrBr2 , and SrI2 may be potential candidates as radiopacifiers in resorbable biomaterials although their in vivo biocompatibility, when incorporated into injectable implants, is yet to be assessed.

Bone cements and their potential use in a mandibular endoprosthesis

Bone cement was first used in the 1950s. Since then many modifications have been made and alternatives developed to the original polymethylmethacrylate (PMMA) cement. In view of the use of bone cement in a novel mandibular endoprosthetic system, we performed a review of the current literature on this material. Different cements are described and their potential use in a mandibular endoprosthetic system discussed. The PMMA-based cements are currently the most suitable choice. Plain PMMA has the longest track record and is the default choice for the initial development phase of this system. If there is a significant risk of infection, then an antibiotic-loaded PMMA cement can be selected. However, modified PMMA cements, composite resin cements, osteoinductive calcium phosphate compounds, and cementless fixation are options that offer advantages over PMMA cements, and further research should be conducted to study their suitability.

Cement leakage in a symptomatic vertebral hemangioma: a case report and review of the literature

We present the case of a 50-year-old male with consistent back pain, not resolving with conservative treatment. Plain radiograms demonstrated a lytic lesion at the level of the 8^th thoracic vertebra. Thorough examination with computerized tomography and magnetic resonance imaging revealed a hemangioma extending to the posterior third of the vertebral body, compressing the spinal cord at the level of 8^th thoracic vertebra. A percutaneous vertebroplasty was performed. The post-operative computerized tomography scan demonstrated cement leakage. After thorough cement removal combined with extensive decompression and posterior stabilization, the patient reported gradual improvement of his symptoms and was able to return successfully to his work a few months later.

Alternative acrylic bone cement formulations for cemented arthroplasties: present status, key issues, and future prospects

All the commercially available plain acrylic bone cement brands that are used in cemented arthroplasties are based on poly (methyl methacrylate) and, with a few exceptions, have the same constituents. It is well known that these brands are beset with many drawbacks, such as high maximum exotherm temperature, lack of bioactivity, and volumetric shrinkage upon curing. Furthermore, concerns have been raised about a number of the constituents, such as toxicity of the activator (N,N,dimethyl-p-toluidine) and possible involvement of the radiopacifier (BaSO(4) or ZrO(2) particles) in third-body wear. Thus, over the years, many research efforts have been expended to address these drawbacks, culminating in a large number of alternative formulations, which may be grouped into 16 categories. Although there are a number of reviews of the large literature that now exists on these formulations, each covers only some of the categories and none contains a detailed discussion of the germane issues. The objective of the present work, therefore, was to present a comprehensive and critical review of the whole field. In addition to succinct descriptions of the cements in each category, there are explicative summaries of literature reports, a detailed discussion of several key issues surrounding the potential for use of these cements in cemented arthroplasties, and a presentation of numerous ideas for future studies.