Abstract

Polymethylmethacrylate PMMA is an acrylic that has been already proposed as a composite to adhere together the fractured bone structures. Subsequently, augmentation bone cements have incorporated Calcium Biophosphonates as vital part of its components to increase the biocompatibility with osseous tissues. Minimally invasive percutaneous techniques such as Vertebroplasty and Kyphoplasty have been developed to reduce surgical impact on patients, but in turn have been reported undesirable effects as extravasations of the cement outside of the planning target volume due to the compression of the internal bone fluids or other tissues. An in situ variable that helps favoring of the PMMA polymerization process is the temperature; however, it may bring deleterious effects. On the methodology, an assay was addressed varying the Hydroxyapatite HAp concentration. Also the cement processing was modified by setting water as a vehicle for particle dispersion. The ratios of HAp/PMMA concentrations were: 0.00000, 0.02167, 0.09062, 0.16619 and 0.50000 mixed in PMMA and liquid catalyst and monomer. The thermal profiles were measured during polymerization and analyzed. Nuclear magnetic resonance NMR analysis was carried out on the polymerization process in an aqueous state to monitor the H-H2O proton signal. As results, an increasing in the cement hardness time was found in the proportion of the HAp concentration. The highest τ polymerization time was found for the x5 concentration and the signal from the water trapped in the HAp amorfous lattice was determined around ~5 ppm in the 1H NMR spectra.