Variability of mineral density in coralline hydroxyapatite spheres: study by quantitative computed tomography

Area of Science:

• Biomaterials Science
• Medical Imaging
• Orthopedic Research

Background:

• Coralline hydroxyapatite spheres are used for reconstruction after enucleation.
• The long-term integration and fate of these implants are not well understood.
• Fibrovascular ingrowth is crucial for implant integration.

Purpose of the Study:

• To determine the mineral density (MD) of coralline hydroxyapatite spheres prior to implantation using quantitative computed tomography (qCT).
• To assess the variability of MD within and between hydroxyapatite implants.
• To evaluate the potential of qCT for monitoring implant integration.

Main Methods:

• Quantitative computed tomography (qCT) was used to measure the mineral density (MD) of hydroxyapatite spheres before implantation.
• Intersphere and intrasphere MD variations were analyzed.
• The density of hydroxyapatite spheres was compared to newly formed endochondral bone.

Main Results:

• Significant intersphere variability in MD was observed, with variations up to 200% and a near Gaussian distribution.
• Intrasphere MD showed no significant variation between central and peripheral sites.
• The density of coralline hydroxyapatite spheres was approximately 400% greater than that of newly formed endochondral bone.

Conclusions:

• Quantitative computed tomography (qCT) is a valuable tool for determining mineral density (MD) in hydroxyapatite implants.
• Marked variability exists in the MD of coralline hydroxyapatite spheres, necessitating monitoring.
• Understanding MD variations is important for assessing the long-term fate and integration of these bone reconstruction implants.