Fracture Callus Mineral Density and Content Evaluation by Quantitative Computerized Tomography

Abstract

Purpose: To evaluate the mineral density and the atomic value of the fracture callus by quantitative computer tomography (QCT) and define a relation between mineralization, atomic content and the stability of the fracture that cannot be assessed by conventional radiography. Materials and
Methods: A fracture is created at the right tibia of 24 local albino male rabbits. The mineral density and the atomic number is measured on day 15, 28, 42 and 90. Conventional radiographs and histological sections are obtained on the same days. The non-fractured contra-lateral tibia was the control.
Results: A significant decrease in density was observed on day 28 and 42. The atomic number remained almost constant throughout the experiment. Radiology revealed periosteal callus formation on day 28. Histological findings were in accordance with the QCT and conventional radiographic findings. The density of the fracture callus on day 15 was 1.385 ± 0.115 g/cm2.
Discussion: Callus mineralization alone cannot predict the mechanical outcome of the fractured bone. The cellular mechanism of fracture healing should, therefore, be further evaluated by light and electron microscopy, in order to asses the mechanism that maintains the atomic content and decreases the mineral density.