Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bone Cements”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2004

Effects of the initial temperature of acrylic bone cement liquid monomer on the properties of the stem-cement interface and cement polymerization.

It has been shown that preheating the femoral stem prior to insertion minimizes interfacial porosity at the stem-cement interface. In this study, the effects of methylmethacrylate monomer temperature prior to mixing on the properties of stem-cement interface and cement polymerization were evaluated for 4 degrees C, room temperature, and 37 degrees C using a test model and cementing techniques that simulated a clinical situation. The nature and extent of interfacial porosity of stem-cement interface was quantified, the static shear strength of the stem-cement interface determined, and the time and temperature of polymerization at the cement-bone interface were measured. Compared to RT monomer, preheating monomer to 37 degrees C produced higher polymerization temperatures and greater initial interfacial shear strength with an unchanged amount of interfacial porosity. Precooling monomer to 4 degrees C produced lower polymerization temperatures and decreased initial interfacial shear strength, with the amount of interfacial porosity unchanged compared to the RT group. Although clinical techniques of preheating or precooling bone cement have some effects on the properties of the stem-cement interface and cement polymerization, they do not appear to enhance implant fixation.

Chromium↗
PubMed1986

Influence of mixing technique on some properties of PMMA bone cement.

PMMA bone cements (Refobacin-Palacos R, Sulfix 6, AKZ, and CMW bone cement, types I and II), from six different clinics, were investigated in three stages. In the first stage, studies of density, hardness, flexural strength, and compressive strength were made, as well as molecular weight measurements and microscopic investigations. These studies reflected the current state of techniques of application used in operating theaters. They revealed wide variations in the properties of the materials studied. Secondly, a comprehensive study of the process-technology in the laboratory was performed. The following variables were investigated or discussed: mixing vessel, order of the individual components, mixing time, rate of mixing, pressure application on the mixed bone cement, kneading, cement thickness, pouring into the syringe, contact force during polymerization, and preparation quantity. The third stage involved the development and clinical testing of an improved mixing technique. Using this improved mixing technique, all three selected clinics achieved far better results with reduced variability. A comparison between a centrifuging technique after mixing and our improved, but conventional, mixing technique, displays advantages for the latter. The question regarding a correlation between cement specimens of high porosity and early implant loosening could not be answered on the basis of the 43 PMMA bone cement explants investigated (implanted 6 months to 15 years). In some cases, the studies revealed that the bone cement manufacturers should be required to revise and quantify existing instructions for use. The users, on the other hand, should give more consideration to the mixing technique and its consequences.

Bone Cements↗
PubMed1982

Strength of the cement-bone interface.

The fixation of total joint components to bone using acrylic bone cement is by the penetration of the cement into the microstructure of cancellous bone to achieve a mechanical interlock. It has been shown that the method of cement application and the preparation of the cancellous surface significantly affects both the tensile and shear strengths of the cement-bone interface. Doughy cement finger-packed on an uncleaned surface resulted in a very low interface strength compared to a low-viscosity cement made to penetrate a cleaned bone surface. Maximum strengths were achieved for cancellous bone cleaned by using either a high-intensity water lavage or a polyethylene brush and by facilitating penetration of the cement for distances of 5 to 10 mm into the bone.

Biomechanical Phenomena↗
PubMed1989

Adhesive bone cement both to bone and metals: 4-META in MMA initiated with tri-n-butyl borane.

In order to develop a new bone cement which is expected to prevent loosening of a prosthesis by better adhesion, the cement composed of 4-methacryloyloxyethyl trimellitate anhydride (4-META) and methyl methacrylate (MMA) as monomers and tri-n-butyl borane (TBB) as an initiator was evaluated. The tensile bond strength between bone and metals adhered with 4-META/MMA-TBB cement was above 7 MPa. The values were higher than that with conventional bone cement (1 MPa) or MMA-TBB cement (2 MPa). Therefore, 4-META was effective for improving adhesion. When cohesive failure of the bone was observed with the scanning electron micrography after the tensile test, fracture occurred on the bone side below the interface between the bone and the 4-META/MMA-TBB cement. This result showed that the cement adhered tightly to both the bone and metals. Thus, it is concluded that the 4-META/MMA-TBB cement is useful as an adhesive bone cement.

Adhesiveness↗
PubMed1993

Penetration and shear strength of cement-bone interfaces in vivo.

Using sham replacement of the proximal femur in adult mongrel dogs, shear strength at the interface between polymethylmethacrylate bone cement and cancellous bone has been found to be linearly dependent on the depth of penetration of the cement into the bone. Shear strength at the interface was increased by 82% and penetration by 74% when distal bone plugging, pressure lavage, and pressurized insertion of cement were employed. Use of a lower-viscosity cement gave a further 18% increase in penetration and shear strength. There was no film of blood at the cement-bone interface with pressurized insertion of Simplex P and Palacos R cements.

Acrylic Resins↗
PubMed2003

Material changes in osteoporotic human cancellous bone following infiltration with acrylic bone cement for a vertebral cement augmentation.

Bone cement infiltration can be effective at mechanically augmenting osteoporotic vertebrae. While most published literature describes the gain in mechanical strength of augmented vertebrae, we report the first measurements of viscoelastic material changes of cancellous bone due to cement infiltration. We infiltrated cancellous core specimen harvested from osteoporotic cadaveric spines with acrylic bone cement. Bone specimen before and after cement infiltration were subjected to identical quasi-static and relaxation loading in confined and free compression. Testing data were fitted to a linear viscoelastic model of compressible material and the model parameters for cement, native cancellous bone, and cancellous bone infiltrated (composite) with cement were identified. The fitting demonstrated that the linear viscoelastic model presented in this paper accurately describes the mechanical behaviour of cement and bone, before and after infiltration. Although the composite specimen did not completely adopt the properties of bulk bone cement, the stiffening of cancellous bone due to cement infiltration is considerable. The composite was, for example, 8.5 times stiffer than native bone. The local stiffening of cancellous bone in patients may alter the load transfer of the augmented motion segment and may be the cause of subsequent fractures in the vertebrae adjacent to the ones infiltrated with cement. The material model and parameters in this paper, together with an adequate finite-element model, can be helpful to investigate the load shift, the mechanism for subsequent fractures, and filling patterns for ideal cement infiltration.

Bone Density↗
PubMed1990

About radioactivity in some PMMA bone cements.

Various bone cements containing zirconium oxide (ZrO2) as X-ray contrast medium were tested for radioactivity by means of a gamma spectrometer. All measured bone cements (PALACOS, IMPLAST, SULFIX-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. As these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be substituted by high purity radiation-free zirconium oxide or barium sulfate.

Bone Cements↗
PubMed1997

Tensile strength of the cement-bone interface depends on the amount of bone interdigitated with PMMA cement.

An experimental investigation was performed to (1) determine the general mechanical behavior and in particular, the post-yield behavior of the cement-bone interface under tensile loading, (2) determine where interface failure occurs, and (3) determine if the mechanical properties of the interface could be related to the density of bone at the interface and/or the amount of cement-bone interdigitation. Seventy-one cement-bone test specimens were machined from human proximal femurs that had been broached and cemented using contemporary cementing techniques. The amount of cement-bone interdigitation was documented and the quantitative computed tomography equivalent mineral density (QCT density) of the bone with cement was measured. Specimens were loaded to failure in tension under displacement control and exhibited linear elastic behavior with some reduction in stiffness until the peak tensile stress was reached (1.28 +/- 0.79 MPa). A substantial amount of strain softening (negative tangent stiffness) with an exponential-type decay was found after the peak stress and continued until there was complete debonding of the specimens (at 0.93 +/- 0.44 mm displacement). Interfacial failure most often occurred at the extent of cement penetration into the bone (56% of specimens) or with small spicules of cement left in the bone (38% of specimens). The results showed that the post-yield tensile behavior contributes substantially to the energy required to cause failure of the cement-bone interface, but the post-yield behavior was not well correlated with the amount of interdigitation or density of bone. Linear regression analysis revealed a moderate (r2 = 0.499, p < 0.0001) positive relationship between the tensile strength of the cement-bone interface and the quantity of bone interdigitated with the cement.

Adult↗
PubMed1979

Biomechanics of the femoral component of total hip prostheses with particular reference to the stress in the bone-cement.

Two-dimensional finite element analyses were used to determine the normal and shear stress distributions at the prostheses-cement and cement-bone interfaces in the femoral component of a total hip replacement. Various combinations of stem, cement and bone stiffnesses were investigated. In particular the influences of stem taper, cement stiffness, prosthesis stiffness and the effect of a plateau, on the cement stresses were examined and compared. It was particulary noticeable that the normal direct stress across the cement in the proximal region of the stem, both literally and medially, as generally compressive. It was found that the more flexible the cement the more uniform were the stress distributions. Furthermore, these stresses increase as the stiffness of the stem decreases.

Biomechanical Phenomena↗
PubMed1990

Use of high-energy shock waves for bone cement removal.

The revision rate of total hip arthroplasty has increased dramatically over recent years, leading to different methods of extraction of the femoral cement mantle to reduce operative time and surgical risks. The use of high-energy shock waves produced by the Dornier HM.3 Lithotripter to interrupt the cement-bone interface and to reduce the material properties of the cement is investigated. Tests were conducted to measure the pull-out strength of cemented treated rods versus untreated rods, from the medullary canal of canine femurs. The treated femurs showed an average reduction in pull-out strength of 43%. An investigation involving the material properties of acrylic bone cement was also conducted. The properties tested were the compressive modulus of elasticity, the ultimate compressive strength, the ultimate tensile strength, and fracture toughness. The scanning electron microscope aided in determining whether microfractures in the cement resulted from the shock wave treatment. A theoretical study utilizing the finite element method was used to investigate areas of select shock wave treatment about the femoral prosthesis. Analysis of the results showed that the lithotripter treatment had no significant effect on the compressive properties but reduced the tensile properties and fracture toughness significantly. Scanning electron microscopy uncovered definite areas of induced microfractures not present in the control specimens. This study supports the concept of clinically noninvasive, preoperative shock wave treatment prior to total hip revision.

Animals↗
PubMed1982

The influence of femoral stem thickness and implantation technique on the strength of the bone cement bond.

The influence of stem thickness, stem orientation, and insertion pressure on the strength of a prosthesis-cement-bone system was studied in vitro. Three types of prostheses were used with thick and thin stems, allowing for thick or thin cement envelopes. They were implanted with different stem orientations, and with and without a distal femoral cement plug. They were then loaded in a testing machine until a discontinuity of the load deflection curve occurred. The main factor determining the failure load was the presence of the distal plug. In specimens with plugs the main load at failure was 6.5 N, in specimens without a plug it was 4.8 N (P greater than 0.05). The most stable combination was the thick stem with a thin cement envelope placed in valgus or neutral orientation, and implanted with a distal cement plug. It was concluded that when no plug was present failure occurred at the bone-cement interface; when a plug was present it occurred at the prosthesis-cement interface.

Adult↗
PubMed2006

The in vitro bioactivity of two novel hydrophilic, partially degradable bone cements.

Composite bone cements were prepared with bioactive glasses (MgO-SiO(2)-3CaO.P(2)O(5)) of different reactivities. The matrix of these so-called hydrophilic, partially degradable and bioactive cements was composed of a starch/cellulose acetate blend and poly(2-hydroxyethyl methacrylate). The addition of 30 wt.% of glasses to this system made them bioactive in acellular medium: a dense apatite layer formed on the surface after 7 days of immersion in simulated body fluid. This was demonstrated both by microscopic and infrared spectroscopic techniques. The composition of the glass and, consequently, its structure was found to have important effects on the rate of the apatite formation. The combination of reactivity obtained by one formulation with the hydrophilic and degradable character of these cements makes them a very promising alternative to conventional acrylic bone cements, by allowing a better stabilization of the implant and a stronger adhesion to the bone.

Apatites↗
PubMed2001

Characterization of powder components of commercial bone cements.

Acrylic bone cements have been used in orthopedic surgery without detailed information on their basic characteristics, especially on their powder components. In this study, the powder components of seven bone cements available on the market in Japan were characterized for morphology, polymer structure and molecular weight, content of residual monomer and benzoyl peroxide (BPO), and thermal properties using scanning electron microscopy, nuclear magnetic resonance spectroscopy, size exclusion chromatography, high performance liquid chromatography, and differential scanning calorimetry, respectively. Considerable differences between the seven bone cements were found in polymer structure and molecular weight, and especially in BPO content and in the morphology of the polymer particles such as shape, size and distribution. It was found that the BPO content was not always in agreement with the value given by the manufacturers on the package.

Acrylic Resins↗
PubMed2001

The effects of particulate bone cements at the bone-implant interface.

We used a rat model in vivo to study the effects of particulate bone cements at the bone-implant interface. A ceramic pin was implanted into the tibiae of 48 rats. Three types of particle of clinically relevant size were produced from one bone-cement base without radio-opacifier, with zirconium dioxide (ZrO2) and with barium sulphate (BaSO4). The rats were randomly assigned to four groups to receive one of the three bone cements or normal saline with 2% v/v Sprague-Dawley serum as the control. A total of 10(9) particles was injected into the knee at 8, 10 and 12 weeks after the original surgery. The animals were killed at 14 weeks and the tibiae processed for histomorphometry. The area of fibrous tissue and the gap between the implant and bone were measured using image analysis. All three types of particle were associated with a larger area of bone resorption than the control. Only in the case of the BaSO4-containing cement did this reach statistical significance (p = 0.01). Particles of bone cement appear to promote osteolysis at the bone-implant interface and this effect is most marked when BaSO4 is used as the radiopaque agent.

Animals↗
PubMed2005

VersaBond bone cement prospective randomized study of the clinical properties of a new bone cement in total knee replacement.

VersaBond is a newly developed bone cement. To investigate its clinical performance, VersaBond was compared to Palacos R in a prospective randomized study in total knee replacement. Fifty-nine patients (61 knees) undergoing total knee replacement were randomized to either VersaBond or Palacos R bone cement and followed for 24 months using radiostereometric analysis (RSA). Up to 2 years there were no significant differences in clinical performance between the two cements. The mean/median values for implant migration were very similar for the two bone cements, as were the dispersion, and distribution of outliers. Also the proportion "stable" and "continuously migrating" implants was similar between the two cements. The result of this study indicates that VersaBond bone cement will perform at least equally as well as Palacos R in total knee replacement as regards as aseptic loosening.

Aged↗
PubMed1997

Neurotoxicity testing of a new bioactive bone cement.

Bioactive bone cement (BABC) is a novel artificial bone cement. It has some noteworthy characteristics that are applicable to neurological surgery. The toxicity of BABC to the nervous system was tested by implanting BABC and polymethylmethacrylate (PMMA) cement as a control at the parietal and the suboccipital regions of the skull in beagles. The auditory brainstem response (ABR) was tested before and after implantation. Sections of the cerebral cortex and the acoustic nerve were examined at 3 and 6 months after implantation. No abnormal ABR was found in any animals. Histological examination of the cerebral cortex and acoustic nerve demonstrated slight gliosis in both the BABC and PMMA cement groups, but no other abnormalities.

Animals↗
PubMedDate not supplied

Effect of posterior cruciate sacrificing on durability of the cement-bone interface: a nine-year survivorship study of 100 total condylar knee arthroplasties.

This paper presents a survivorship analysis of the second group of 100 consecutive primary total-condylar knee arthroplasties carried out in 75 patients between 1979-80 with a maximum follow-up of 9 years. With this type of knee arthroplasty the posterior cruciate ligament is routinely sacrificed. Survivorship results revealed that 98.9% of the knees had a good outcome at 9 years of follow-up, using revision surgery for aseptic and septic loosening, and radiographic evidence of global radiolucency or shift of the component as the end point. Radiographic survivorship analysis showed well-fixed components in 87% of implants using endpoint criteria of appearance and progression of radiolucency under the tibial component. Sacrificing the posterior cruciate ligament does not adversely affect the durability of fixation of total-condylar knee arthroplasty. Bone cement provides an excellent fixation of the total knee implant.

Adult↗
PubMed1982

Transient and residual stresses and displacements in self-curing bone cement - Part I: characterization of relevant volumetric behavior of bone cement.

In this first part of a two-part report, some aspects of the volumetric behavior of bone cement during its curing process are examined as a prelude to an analysis for the transient and residual stresses and displacements in stem fixation systems. Experiments show that stress generation in the cement is associated with its temperature while curing and that during the cooling phase, the stresses are mainly due to thermal as opposed to bulk shrinkage. The appropriate coefficient of thermal expansion of bone cement has been evaluated from measurements in a simulated fixation system in conjuction with a thermoelastic analysis.

Acrylates↗