Water uptake and release from iodine-containing bone cement

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Imaging

Background:

• Polymethyl methacrylate (PMMA) bone cement is widely used in orthopedic surgery.
• Water-soluble contrast media are incorporated into bone cement for intraoperative imaging.
• Understanding the interaction between contrast media and PMMA cement is crucial for predicting cement behavior and patient outcomes.

Purpose of the Study:

• To investigate the water uptake and release characteristics of PMMA cement containing iohexol and iodixanol.
• To determine the diffusion coefficients of water in the cement formulations.
• To assess the long-term release profiles of the contrast media from the bone cement.

Main Methods:

• Water uptake and release studies were conducted on PMMA cement formulations.
• Diffusion coefficients were calculated based on water uptake curves following classic diffusion theory.
• Micro-computed tomography (microCT) was used to evaluate the cement integrity and radiolucent zones.

Main Results:

• Iohexol demonstrated the highest water uptake (3.7%), followed by iodixanol (2.3%) and Palacos R (1.9%).
• Iohexol exhibited the lowest diffusion coefficient, while Palacos R had the highest.
• Long-term release of iohexol from the bone cement exceeded 25 microg/mL, compared to over 10 microg/mL for iodixanol.

Conclusions:

• The water uptake and release of iohexol and iodixanol in PMMA cement follow diffusion principles.
• Iohexol shows significantly higher water uptake and release compared to iodixanol.
• The risk of developing an observable radiolucent zone around the cement is negligible, irrespective of the contrast agent used.