A Novel Composite PMMA-based Bone Cement with Reduced Potential for Thermal Necrosis

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Polymer Chemistry

Background:

• Percutaneous vertebroplasty (VP) and balloon kyphoplasty (BKP) are common treatments for painful vertebral compression fractures.
• Poly(methyl methacrylate) (PMMA) bone cement is widely used in VP and BKP but generates high exothermic temperatures.
• The high exothermic temperature of PMMA cement may cause thermal necrosis in surrounding tissues.

Purpose of the Study:

• To develop a novel composite PMMA bone cement incorporating phase change material microcapsules (PCMc) to mitigate heat generation.
• To evaluate the thermal and mechanical properties of the composite PMMA bone cement.
• To assess the potential of the modified cement to reduce thermal necrosis in vertebral augmentation procedures.

Main Methods:

• Composite PMMA bone cement was prepared by mixing PCMc (paraffin-containing microcapsules) with PMMA powder.
• The thermal properties (exothermic temperature, setting time) and mechanical properties (compressive strength, compressive modulus) of the composite cement were measured.
• Biocompatibility and the extent of thermal necrosis were compared to a control PMMA cement.

Main Results:

• Composite PMMA bone cement exhibited significantly lower maximum exothermic temperatures compared to control cement.
• The composite cement demonstrated increased setting time, comparable biocompatibility, and a significantly smaller thermal necrosis zone.
• Compressive strength and compressive modulus were significantly lower in the composite cement.

Conclusions:

• Incorporating PCMc into PMMA bone cement effectively reduces the exothermic temperature during setting.
• Composite PMMA bone cement with 20% PCMc shows promise for reducing thermal necrosis in VP and BKP.
• Further evaluation of this novel composite cement is warranted for clinical application in vertebral augmentation.