Modification of Mechanical Properties, Polymerization Temperature, and Handling Time of Polymethylmethacrylate Cement for Enhancing Applicability in Vertebroplasty

Abstract

Polymethylmethacrylate (PMMA) bone cement is a popular bone void filler for vertebroplasty. However, the use of PMMA has some drawbacks, including the material's excessive stiffness, exothermic polymerization, and short handling time. This study aimed to create an ideal modified bone cement to solve the above-mentioned problems. Modified bone cements were prepared by combining PMMA with three different volume fractions of castor oil (5%, 10%, and 15%). The peak polymerization temperatures, times to achieve the peak polymerization temperature, porosities, densities, modulus and maximum compression strengths of standard (without castor oil), and modified cements were investigated following storage at ambient temperature (22°C) or under precooling conditions (3°C). Six specimens were tested in each group of the aforementioned parameters. Increasing castor oil content and precooling treatment effectively decreased the peak polymerization temperatures and increased the duration to achieve the peak polymerization temperature (P < 0.05). Furthermore, the mechanical properties of the material, including density, modulus, and maximum compression strength, decreased with increasing castor oil content. However, preparation temperature (room temperature versus precooling) had no significant effect (P > 0.05) on these mechanical properties. In conclusion, the addition of castor oil to PMMA followed by precooling created an ideal modified bone cement with a low modulus, low polymerization temperature, and long handling time, enhancing its applicability and safety for vertebroplasty.

Identifying alternative antibiotics that elute from calcium sulfate beads for treatment of orthopedic infections

“…Antibiotics rapidly elute from PMMA within the first 24 h, but elution then drastically declines in a logarithmic pattern over a matter of days, 7,8 with prolonged subtherapeutic exposure raising concern for facilitating drug‐resistant pathogens 9,10 . Furthermore, the use of antibiotics in PMMA is restricted to those agents which can retain their antimicrobial function following the thermal challenge which occurs during exothermic PMMA polymerization, which can exceed temperatures of 100°C–110°C 11,12 …”

“…9,10 Furthermore, the use of antibiotics in PMMA is restricted to those agents which can retain their antimicrobial function following the thermal challenge which occurs during exothermic PMMA polymerization, which can exceed temperatures of 100°C-110°C. 11,12 In light of the limitations associated with PMMA, commercially available biodegradable bone graft substitutes are gaining attention as alternative local antibiotic delivery vehicles. Calcium sulfate (CaSO 4 ), a commonly used bone graft substitute, can be molded intra-operatively into radiopaque beads that resorb in 30-60 days, which permits implantation without the need for a second surgery for removal.…”

Synthesis and Characterization of an Injectable and Hydrophilous Expandable Bone Cement Based on Poly(methyl methacrylate)

“…Tai et al showed that the Young's modulus and compression strength of PMMA were notably reduced with increasing porosity when modified by combining with castor oil. 23 Other porogenic agents such as sodium hyaluronate 24 and gelatin 25 have also been identified. In addition, polymers such as calcium phosphate cement 26 with relatively poor strength were utilized to manufacture the composite PMMA bone cement.…”

Precision medicine strategies for spinal degenerative diseases: Injectable biomaterials with in situ repair and regeneration

“…Given the short-term high temperature rise of PMMA, Tai et al. used castor oil as an additive [ 80 ], and Boger et al. selected N-Methyl-pyrrolidone (NMP), an organic monomer that can be embedded in PMMA segments, to partially replace MMA [ 81 ], which can effectively alleviate the thermal effect of bone cement.…”